[Illustration]

PATHFINDER PHYSIOLOGY No. 3

HYGIENIC PHYSIOLOGY

WITH SPECIAL REFERENCE TO THE USE OF

ALCOHOLIC DRINKS AND NARCOTICS

BEING A REVISED EDITION OF THE

FOURTEEN WEEKS IN HUMAN PHYSIOLOGY

BY JOEL DORMAN STEELE, PH. D. 

ENLARGED EDITION WITH SELECTED READINGS

_Edited for the use of Schools, in accordance with the recentLegislation upon Temperance Instruction_

INDORSEMENT. 

BOSTON, _June_ 20, 1889. 

The Pathfinder Series of Text-books on Anatomy, Physiology, and Hygieneconsists of the following volumes:

I. Child's Health Primer (for Primary Grades). 

II. Hygiene for Young People or, Young People's Physiology. (forIntermediate Classes)

III. Hygienic Physiology (for Advanced Pupils). 

The above are the series originally prepared (as their general titleindicates) to supply the demand created by the laws for temperanceinstruction in public schools in the United States. They were written byexperts under the supervision of the Scientific Department of the NationalWoman's Christian Temperance Union, published by the instigation of thesame, and have been carefully revised from time to time, under the samesupervision, to keep them abreast with the latest teachings of science. 

Being both teachable and well adapted to grade, their educational value, as proven by schoolroom tests, is of the highest order. We thereforecordially indorse and highly recommend the Pathfinder Series for use inschools. 

MARY H. HUNT, _National and International Superintendent of the Scientific Dep't ofthe Woman's Christian Temperance Union; Life Director of the NationalEducational Association. _

ADVISORY BOARD:

JOSEPH COOK, WILLIAM E. SHELDON, ALBERT H. PLUMB, D. D. , DANIEL DORCHESTER, D. D. 

PREFACE

The term Physiology, or the science of the functions of the body, has cometo include Anatomy, or the science of its structure, and Hygiene, or thelaws of health; the one being essential to the proper understanding ofphysiology, and the other being its practical application to life. Thethree are intimately blended, and in treating of the different subjectsthe author has drawn no line of distinction where nature has made none. This work is not prepared for the use of medical students, but for theinstruction of youth in the principles which underlie the preservation ofhealth and the formation of correct physical habits. All else is madesubservient to this practical knowledge. A simple scientific dress is usedwhich, while conducing to clearness, also gratifies that general desire ofchildren to know something of the nomenclature of any study they pursue. 

To the description of each organ is appended an account of its most commondiseases, accidents, etc. , and, when practicable, their mode of treatment. A pupil may thus learn, for example, the cause and cure of "a cold, " themanagement of a wound, or the nature of an inflammation. 

The Practical Questions, which have been a prominent feature in otherbooks of the series, will be found, it is hoped, equally useful in thiswork. Directions for preparing simple microscopic objects, andillustrations of the different organs, are given under each subject. 

The Readings, which represent the ideas but not always the exactphraseology of the author quoted, have, in general, been selected withdirect reference to Practical Hygiene, a subject which now largelyoccupies the public mind. The dangers that lurk in foul air andcontaminated water, in bad drainage, leaky gas pipes, and defectiveplumbing, in reckless appetites, and in careless dissemination ofcontagious diseases, are here portrayed in such a manner as, it istrusted, will assist the pupil to avoid these treacherous quicksands, andto provide for himself a solid path of health. 

Under the heading of Health and Disease will be found Hints about the sickroom, Directions for the use of Disinfectants, Suggestions as to what todo "Till the Doctor comes, " and a list of antidotes for Poisons. Questionsfor Class Use, a full Glossary, and an ample Index complete the book. 

Believing in a Divine Architect of the human form, the author can notrefrain from occasionally pointing out His inimitable workmanship, andimpressing the lesson of a Great Final Cause. 

The author has gleaned from every field, at home and abroad, to securethat which would interest and profit his pupils. In general, Flint's greatwork on the "Physiology of Man, " an undisputed authority on both sides ofthe Atlantic, has been adopted as the standard in digestion, respiration, circulation, and the nervous system. Leidy's "Human Anatomy, " and Sappey's"Traité d'Anatomie" have been followed on all anatomical questions, andhave furnished many beautiful drawings. Huxley's "Physiology" has affordedexceedingly valuable aid. Foster's "Text-Book of Physiology, " Hinton's"Health and its Conditions, " Black's "Ten Laws of Health, " Williams'spractical essay on "Our Eyes and How to Use them, " Le Pileur's charmingtreatise on "The Wonders of the Human Body, " and that quaint volume, "OddHours of a Physician, " have aided the author with facts and fancies. Thewritings of Draper, Dalton, Carpenter, Yalentin, Mapother, Watson, Lankester, Letheby, Hall, Hamilton, Bell, Wilson, Bower, Cutter, Hutchison, Wood, Bigelow, Stille, Holmes, Beigel, and others have beenfreely consulted. 

PUBLISHERS' NOTE. 

An ABRIDGED EDITION of this work is published, to afford a cheaper manual--adapted to Junior Classes and Common Schools. The abridgment containsthe essence of this text, nearly all its illustrations, and the whole ofthe Temperance matter as here presented. 

ORDER "HYGIENIC PHYSIOLOGY, ABRIDGED. "

READING REFERENCES. 

Foster's "Text-Book of Physiology"; Leidy's "Human Anatomy"; Draper's"Human Physiology"; Dalton's "Physiology and Hygiene"; Cutter's"Physiology"; Johnston and Church's "Chemistry of Common Life"; Letheby's"Food"; Tyndall "On Light, " and "On Sound"; Mint's "Physiology of Man ";Rosenthal's "Physiology of the Muscles and Nerves"; Bernstein's "FiveSenses of Man"; Huxley and Youmans's "Physiology and Hygiene"; Sappey's"Traité d'Anatomie "; Luys's "Brain and its Functions"; Smith's "Foods";Bain's "Mind and Body"; Pettigrew's "Animal Locomotion"; Carpenter's"Human Physiology, " and "Mental Physiology"; Wilder and Gage's "Anatomy";Jarvis's "Physiology and Laws of Health. "

Hargreaves's "Alcohol and Science"; Richardson's "Ten Lectures onAlcohol, " and "Diseases of Modern Life"; Brown's "Alcohol"; Davis's"Intemperance and Crime"; Pitman's "Alcohol and the State"; "Anti-Tobacco"; Howie's "Stimulants and Narcotics"; Hunt's "Alcohol as Food orMedicine"; Schützenberger's "Fermentation"; Hubbard's "Opium Habit andAlcoholism"; Trouessart's "Microbes, Ferments, and Molds. "

CONTENTS

INTRODUCTION

I. --THE SKELETON

THE HEAD

THE TRUNK

THE LIMBS

II. --THE MUSCLES

III. --THE SKIN

THE HAIR AND THE NAILS

THE TEETH

IV. --RESPIRATION AND THE VOICE

V. --THE CIRCULATION

THE BLOOD

THE HEART

THE ARTERIES

THE VEINS

VI. --DIGESTION AND FOOD

VII. --THE NERVOUS SYSTEM

THE BRAIN

THE SPINAL CORD AND THE NERVES

THE SYMPATHETIC SYSTEM

VIII. --THE SPECIAL SENSES

TOUCH

TASTE

SMELL

HEARING

SIGHT

IX. --HEALTH AND DISEASE. --DEATH AND DECAY

1. HINTS ABOUT THE SICK ROOM

2. DISINFECTANTS

3. WHAT TO DO "TILL THE DOCTOR COMES"

4. ANTIDOTES TO POISONS

X. --SELECTED READINGS

XI. --APPENDIX

QUESTIONS FOR CLASS USE

GLOSSARY

INDEX

SUGGESTIONS To Teachers

Seeing is believing--more than that, it is often knowing and remembering. The mere reading of a statement is of little value compared with theobservation of a fact. Every opportunity should therefore be taken ofexhibiting to the pupil the phenomena described, and thus making themreal. A microscope is so essential to the understanding of many subjects, that it is indispensable to the proper teaching of Physiology. A suitableinstrument and carefully prepared specimens, showing the structure of thebones, the skin, and the blood of various animals, the pigment cells ofthe eye, etc. , may be obtained at a small cost from any good optician. 

On naming the subject of a paragraph, the pupil should be prepared to tellall he knows about it. No failure should discourage the teacher inestablishing this mode of study and recitation. A little practice willproduce the most satisfactory results. The unexpected question and the aptreply develop a certain sharpness and readiness which are worthy ofcultivation. The questions for review, or any others that the wit of theteacher may suggest, can be effectively used to break the monotony of atopical recitation, thereby securing the benefits of both systems. 

The pupil should expect to be questioned each day upon any subject passedover during the term, and thus the entire knowledge gained will be withinhis grasp for instant use. While some are reciting to the teacher, letothers write on slates or on the blackboard. At the close of therecitation, let all criticise the ideas, the spelling, the use ofcapitals, the pronunciation, the grammar, and the mode of expression. Greater accuracy and much collateral drill may thus be secured at littleexpense of valuable school time. 

The Introduction is designed merely to furnish suggestive material for thefirst lesson, preparatory to beginning the study. Other subjects forconsideration may be found in the section on Health and Disease, in theSelected Readings, and among the questions given in the Appendix. Wheretime will allow, the Selected Readings may profitably be used inconnection with the topics to which they relate. Questions upon them areso incorporated with those upon the text proper that they may be employedor not, according to the judgment of the teacher. 

NOTE. --Interest in the study of Physiology will be much increased by theuse of the microscope and prepared slides. These may be obtained from anygood optician. 

INTRODUCTION. 

Physiological study in youth is of inestimable value. Precious lives arefrequently lost through ignorance. Thousands squander in early years thestrength which should have been kept for the work of real life. Habits areoften formed in youth which entail weakness and poverty upon manhood, andare a cause of lifelong regret. The use of a strained limb may permanentlydamage it. Some silly feat of strength may produce an irreparable injury. A thoughtless hour of reading by twilight may impair the sight for life. Aterrible accident may happen, and a dear friend perish before our eyes, while we stand by powerless to render the assistance we could so easilygive did we "only know what to do. " The thousand little hints which maysave or lengthen life, may repel or abate disease, and the simple lawswhich regulate our bodily vigor, should be so familiar that we may bequick to apply them in an emergency. The preservation of health is easierthan the cure of disease. Childhood can not afford to wait for the lessonof experience which is learned only when the penalty of violated law hasbeen already incurred, and health irrevocably lost. 

NATURE'S LAWS INVIOLABLE. --In infancy, we learn how terribly Naturepunishes a violation of certain laws, and how promptly she applies thepenalty. We soon find out the peril of fire, falls, edged tools, and thelike. We fail, however, to notice the equally sharp and certainpunishments which bad habits entail. We are quick to feel the need offood, but not so ready to perceive the danger of an excess. A lack of airdrives us at once to secure a supply; foul air is as fatal, but it givesus no warning. 

Nature provides a little training for us at the outset of life, but leavesthe most for us to learn by bitter experience. So in youth we throw awayour strength as if it were a burden of which we desire to be rid. We eatanything, and at any time; do anything we please, and sit up any number ofnights with little or no sleep. Because we feel only a momentarydiscomfort from these physical sins, we fondly imagine when that is gonewe are all right again. Our drafts upon our constitution are promptlypaid, and we expect this will always be the case; but some day they willcome back to us, protested; Nature will refuse to meet our demands, and weshall find ourselves physical bankrupts. 

We are furnished in the beginning with a certain vital force upon which wemay draw. We can be spendthrifts and waste it in youth, or be wise and sohusband it till manhood. Our shortcomings are all charged against thisstock. Nature's memory never fails; she keeps her account with perfectexactness. Every physical sin subtracts from the sum and strength of ouryears. We may cure a disease, but it never leaves us as it found us. Wemay heal a wound, but the scar still shows. We reap as we sow, and we mayeither gather in the thorns, one by one, to torment and destroy, or we mayrejoice in the happy harvest of a hale old age. 

I. 

THE SKELETON. 

"Not in the World of Light alone, Where God has built His blazing throne, Nor yet alone on earth below, With belted seas that come and go, And endless isles of sunlit greenIs all thy Maker's glory seen--Look in upon thy wondrous frame, Eternal wisdom still the same!"

HOLMES. 

ANALYSIS OF THE SKELETON. 

NOTE. --The following Table of 206 bones is exclusive of the 8 sesamoidbones which occur in pairs at the roots of the thumb and great toe, making214 as given by Leidy and Draper. Gray omits the bones of the ear, andnames 200 as the total number. 

THE SKELETON. _| I. THE HEAD (_28 bones. _)| _| | Frontal Bone (forehead). | _ | Two Parietal Bones. | | 1. CRANIUM. . . . . . . . . . . . . . | Two Temporal (temple) Bones. | | (_8 bones. _) | Sphenoid Bone. | | | Ethmoid (sieve-like bone at root of nose). | | |_Occipital Bone (back and base of skull). | | _| | | Two Superior Maxillary (upper jaw) Bones. | | | Inferior Maxillary (lower jaw) Bone. | | | Two Malar (cheek) Bones. | | 2. FACE. . . . . . . . . . . . . . . . . | Two Lachrymal Bones. | | (_14 bones. _) | Two Turbinated (scroll like) Bones, each| | | side of nose. | | | Two Nasal Bones (Bridge of nose). | | | Vomer (the bone between the nostrils). | | |_Two Palate Bones. | | _| | | Hammer. | | 3. EARS. . . . . . . . . . . . . . . . . | Anvil. | |_ (_6 bones. _) |_Stirrup. || II. THE TRUNK (_54 bones. _)| _| | Cervical Vertebræ (seven vertebræ of the| _ | neck). | | 1. SPINAL COLUMN. . . . . . . . | Dorsal Vertebræ (twelve vertebræ of the| | | back). | | | Lumbar Vertebræ (five vertebræ of the| | |_ loins). | | _| | | True Ribs. | | 2. RIBS. . . . . . . . . . . . . . . . . |_False Ribs. | || | 3. STERNUM (breastbone). | || | 4. OS HYOIDES (bone at the root of tongue). | | _| | | Two Innominata. | |_5. PELVIS. . . . . . . . . . . . . . . | Sacrum. | |_Coccyx. || III. THE LIMBS (_124 bones. _)| _| _ | _Clavicle. _| | Shoulder. . . |__Scapula. _| _ | _| | 1. UPPER LIMBS. . . . . . . . . . | | _Humerus. _| | (_64 bones. _) | Arm. . . . . . . . |__Ulna and Radius. _| | | _| | | | _Eight Wrist or Carpal| | | | Bones. _| | |_Hand. . . . . . . | _Five Metacarpal Bones. _| | |__Phalanges (14 bones). _| | _| | _ | _Femur. _| | | Leg. . . . . . . . | _Patella. _| | | |__Tibia and Fibula. _| | 2. LOWER LIMBS. . . . . . . . . . | _| |_ (_60 bones. _) | | _Seven Tarsal Bones. _|_ | Foot. . . . . . . | _Five Metatarsal Bones. _|_ |__Phalanges (14 bones). _

_| 1. Uses. _ | 2. Composition. | 1. FORM, STRUCTURE, | 3. Structure. | ETC. , OF THE BONES | 4. Growth. | | 5. Repair. THE SKELETON | |_6. The Joints. | _| 2. CLASSIFICATION OF | 1. The Head. |_ THE BONES. | 2. The Trunk. |_3. The Limbs. THE SKELETON. 

I. FORM, STRUCTURE, ETC. , OF THE BONES. 

(_See page 269_. )

THE SKELETON, or framework of the "House we live in, " is composed of about200 bones. [Footnote: The precise number varies in different periods oflife. Several which are separated in youth become united in old age. Thusfive of the "false vertebræ" at the base of the spine early join in onegreat bone--the sacrum; while four tiny ones below it often run into abony mass--the coccyx (Fig. 6); in the child, the sternum is composed ofeight pieces, while in the adult it consists of only three. While, however, the number of the bones is uncertain, their relative length is soexact that the length of the entire skeleton, and thence the height of theman, can be obtained by measuring a single one of the principal bones. Fossil bones and those found at Pompeii have the same proportion as ourown. ]

USES AND FORMS OF THE BONES. --They have three principal uses: 1. Toprotect the delicate organs; [Footnote: An organ is a portion of the bodydesigned for a particular use, called its _function_. Thus the heartcirculates the blood; the liver produces the bile. ] 2. To serve as leverson which the muscles may act to produce motion; and 3. To preserve theshape of the body. 

Bones differ in form according to the uses they subserve. For conveniencein walking, some are long; for strength and compactness, some are shortand thick; for covering a cavity, some are flat; and for special purposes, some are irregular. The general form is such as to combine strength andlightness. For example, all the long bones of the limbs are round andhollow, thus giving with the same weight a greater strength, [Footnote:Cut a sheet of foolscap in two pieces. Roll one half into a compactcylinder, and fold the other into a close, flat strip; support the ends ofeach and hang weights in the middle until they bend. The superior strengthof the roll will astonish one unfamiliar with this mechanical principle. In a rod, the particles break in succession, first those on the outside, and later those in the center. In a tube, the particles are all arrangedwhere they resist the first strain. Iron pillars are therefore casthollow. Stalks of grass and grain are so light as to bend before a breathof wind, yet are stiff enough to sustain their load of seed. Bone has beenfound by experiment to possess twice the resisting property of solid oak. ]and also a larger surface for the attachment of the muscles. 

The Composition of the Bones at maturity is about one part animal to twoparts mineral matter. The proportion varies with the age. In youth it isnearly half and half, while in old age the mineral is greatly in excess. By soaking a bone in weak muriatic acid, and thus dissolving the mineralmatter, its shape will not change, but its stiffness will disappear, leaving a tough, gristly substance [Footnote: Mix a wineglass of muriaticacid with a pint of water, and place in it a sheep's rib. In a day or two, the bone will become so soft that it can be tied into a knot. In the sameway, an egg may be made so pliable that it can be crowded into a narrow-necked bottle, within which it will expand, and become an object of greatcuriosity to the uninitiated. By boiling bones at a high temperature, theanimal matter separates in the form of gelatine. Dogs and cats extract theanimal matter from the bones they eat. Fossil bones deposited in theground during the Geologic period, were found by Cuvier to containconsiderable animal matter. Gelatine was actually extracted from theCambridge mastodon, and made into glue. A tolerably nutritious food mightthus be manufactured from bones older than man himself. ] (cartilage) whichcan be bent like rubber. 

If the bone be burned in the fire, thus consuming the animal matter, theshape will still be the same, but it will have lost its tenacity, and thebeautiful, pure-white residue [Footnote: From bones thus calcined, thephosphorus of the chemist is made. See Steele's "Popular Chemistry, " page114. If the animal matter be not consumed, but only charred, the bone willbe black and brittle. In this way, the "boneblack" of commerce ismanufactured. ] may be crumbled into powder with the fingers. 

FIG. 2. 

[Illustration: _The Thigh Bone, or Femur, sawed lengthwise. _]

We thus see that a bone receives hardness and rigidity from its mineral, and tenacity and elasticity from its animal matter. 

The entire bone is at first composed of cartilage, which gradually_ossifies_ or turns to bone. [Footnote: The ossification of the boneson the sides and upper part of the skull, for example, begins by a roundedspot in the middle of each one. From this spot the ossification extendsoutward in every direction, thus gradually approaching the edges of thebone. When two adjacent bones meet, there will be a line where their edgesare in contact with each other, but have not yet united; but when morethan two bones meet in this way, there will be an empty space between themat their point of junction. Thus, if you lay down three coins upon thetable with their edges touching one another, there will be a three-sidedspace in the middle between them; if you lay down four coins in the samemanner, the space between them will be four-sided. Now at the back part ofthe head there is a spot where three bones come together in this way, leaving a small, three-sided opening between them: this is called the"posterior fontanelle. " On the top of the head, four bones come together, leaving between them a large, four-sided opening: this is called the"anterior fontanelle. " These openings are termed the _fontanelles_, because we can feel the pulsations of the brain through them, like thebubbling of water in a fountain. They gradually diminish in size, owing tothe growth of the bony parts around them, and are completely closed at theage of four years after birth. --DALTON. ] Certain portions near the jointsare long delayed in this process, and by their elasticity assist inbreaking the shock of a fall. [Footnote: Frogs and toads, which move byjumping, and consequently receive so many jars, retain these unossifiedportions (epiphyses) nearly through, life, while alligators and turtleswhose position is sprawling, and whose motions are measured do not havethem at all--LEIDY] Hence the bones of children are tough, are not readilyfractured, and when broken easily heal again; [Footnote: This is only oneof the many illustrations of the Infinite care that watches over helplessinfancy, until knowledge and ability are acquired to meet the perils oflife. ] while those of elderly people are liable to fracture, and do notquickly unite. 

FIG. 3. 

[Illustration: _A thin slice of Bone, highly magnified showing thelacunæ, the tiny tubes (canaliculi) radiating from them, and fourHaversian canals, three seen crosswise and one lengthwise. _]

THE STRUCTURE OF THE BONES--When a bone is sawed lengthwise, it is foundto be a compact shell filled with a spongy substance This fillingincreases in quantity, and becomes more porous at the ends of the bone, thus giving greater size to form a strong joint, while the solid portionincreases near the middle, where strength alone is needed. Each fiber ofthis bulky material diminishes the shock of a sudden blow, and also actsas a beam to brace the exterior wall. The recumbent position of thealligator protects him from falls, and therefore his bones contain verylittle spongy substance. 

In the body, bones are not the dry, dead, blanched things they commonlyseem to be, but are moist, living, pinkish structures, covered with atough membrane, called the per-i-os'-te-um [Footnote: The relations of theperiosteum to the bone are very interesting. Instances are on record wherethe bone has been removed, leaving the periosteum, from which the entirebone was afterward renewed. ] (_peri_, around, and _osteon_, abone), while the hollow is filled with marrow, rich in fat, and full ofblood vessels. If we examine a thin slice with the microscope, we shallsee black spots with lines running in all directions, and looking verylike minute insects. These are really little cavities, called la-cu'-næ[Footnote: When the bone is dry, the lacunæ are filled with air, whichrefracts the light, so that none of it reaches the eye, and hence thecavities appear black. ] from which radiate tiny tubes. The lacunæ arearranged in circles around larger tubes, termed from their discoverer, _Haversian canals_, which serve as passages for the blood vesselsthat nourish the bone. 

GROWTH OF THE BONES. --By means of this system of canals, the bloodcirculates as freely through the bones as through any part of the body, The whole structure is constantly but slowly changing, [Footnote: Bone issometimes produced with surprising rapidity. The great Irish Elk iscalculated by Prof. Owen to have cast off and renewed, annually in itsantlers eighty pounds of bone. ] old material being taken out and new putin. A curious illustration is seen in the fact that if madder be mixedwith the food of pigs, it will tinge their bones red. 

REPAIR OF THE BONES. --When a bone is broken, the blood at once oozes outof the fractured ends. This soon gives place to a watery fluid, which in afortnight thickens to a gristly substance, strong enough to hold them inplace. Bone matter is then slowly deposited, which in five or six weekswill unite the broken parts. Nature, at first, apparently endeavors toremedy the weakness of the material by excess in the quantity, and so thenew portion is larger than the old. But the extra matter will be graduallyabsorbed, sometimes so perfectly as to leave no trace of the injury. (Seep. 271. )

A broken limb should be held in place by splints, or a plaster cast, toenable this process to go on uninterruptedly, and also lest a sudden jarmight rupture the partially mended break. For a long time, the new portionconsists largely of animal matter, and so is tender and pliable. Theutmost care is therefore necessary to prevent a malformation. 

THE JOINTS are packed with a soft, smooth cartilage, or gristle, whichfits so perfectly as to be airtight. Upon convex surfaces, it is thickestat the middle, and upon concave surfaces, it is thickest at the edge, orwhere the wear is greatest. In addition, the ends of the bones are coveredwith a thin membrane, the _synovial_ (_sun_, with; _ovum_, an egg), which secretes a viscid fluid, not unlike the white of an egg. This lubricates the joints, and prevents the noise and wear of friction. The body is the only machine that oils itself. 

The bones which form the joint are tied with stout ligaments (_ligo_, I bind), or bands, of a smooth, silvery white tissue, [Footnote: Thegeneral term _tissue_ is applied to the various textures of which theorgans are composed. For example, the osseous tissue forms the bones; thefibrous tissue, the skin, tendons, and ligaments. ] so strong that thebones are sometimes broken without injuring the fastenings. 

II. CLASSIFICATION OF THE BONES. 

For convenience, the bones of the skeleton are considered in threedivisions: the _head_, the _trunk_, and the _limbs_. 

1. THE HEAD. 

THE BONES OF THE SKULL AND THE FACE form a cavity for the protection ofthe brain and the four organs of sense, viz. : sight, smell, taste, andhearing. All these bones are immovable except the lower jaw, which ishinged [Footnote: A ring of cartilage is inserted in its joints, somethingafter the manner of a washer in machinery. This follows the movements ofthe jaw, and admits of freer motion, while it guards against dislocation. ]at the back so as to allow for the opening and shutting of the mouth. 

THE SKULL is composed, in general, of two compact plates, with a spongylayer between. These are in several pieces, the outer ones being joined bynotched edges, sutures (su'tyurs, ), in the way carpenters termdovetailing. (See Fig. 4. )

FIG. 4. 

[Illustration: _The Skull. _--1. _frontal bone;_ 2, _parietal bone;_3, _temporal bone;_ 4, _the sphenoid bone;_ 5, _ethmoid bone;_ 6, _superior maxillary (upper jaw) bone;_ 7, _malar bone;_ 8, _lachrymalbone;_ 9, _nasal bone;_ 10, _inferior maxillary (lower jaw) bone. _]

The peculiar structure and form of the skull afford a perfect shelter forthe brain--an organ so delicate that, if unprotected, an ordinary blowwould destroy it. Its oval or egg shape adapts it to resist pressure. Thesmaller and stronger end is in front, where the danger is greatest. Projections before and behind shield the less protected parts. The hardplates are not easy to penetrate. [Footnote: Instances have been knownwhere bullets, striking against the skull, have glanced off, beenflattened, or even split into halves. In the Peninsular Campaign, theauthor saw a man who had been struck in the forehead by a bullet which, instead of penetrating the brain, had followed the skull around to theback of the head, and there passed out. ] The spongy packing deadens everyblow. [Footnote: An experiment resembling the familiar one of the balls inNatural Philosophy ("Steele's Popular Physics, " Fig. 6, p. 26), beautifully illustrates this point. Several balls of ivory are suspendedby cords, as in Fig. 5. If A be raised and then let fall, it will transmitthe force to B, and that to C, and so on until F is reached, which willfly off with the impulse. If now a ball of spongy bone be substituted foran ivory one anywhere in the line, the force will be checked, and the lastball will not stir. ] The separate pieces with their curious joiningsdisperse any jar which one may receive, and also prevent fractures fromspreading. 

FIG. 5. 

[Illustration]

The frequent openings in this strong bone box afford safe avenues for thepassage of numerous nerves and vessels which communicate between the brainand the rest of the body. 

FIG. 6. 

[Illustration: _The Spine; the seven vertebræ of the neck, cervical; thetwelve of the back, dorsal; the five of the loins, lumbar;_ a, _thesacrum, and_ b, _the coccyx, coming the nine "false vertebræ. "_(p. 3). ]

2 THE TRUNK. 

THE TRUNK has two important cavities. The upper part, or _chest_, contains the heart and the lungs, and the lower part, or _abdomen_, holds the stomach, liver, kidneys, and other organs (Fig. 31). Theprincipal bones are those of the _spine_, the _ribs_, and the_hips_. 

THE SPINE consists of twenty-four bones, between which are placed pads ofcartilage. [Footnote: These pads vary in thickness from one fourth to onehalf an inch. They become condensed by the weight they bear during theday, so that we are somewhat shorter at evening than in the morning. Their elasticity causes them to resume their usual size during the night, or when we lie down for a time. ] A canal is hollowed out of the columnfor the safe passage of the spinal cord. (See Fig. 50. ) Projections(processes) at the back and on either side are abundant for the attachmentof the muscles. The packing acts as a cushion to prevent any jar fromreaching the brain when we jump or run, while the double curve of thespine also tends to disperse the force of a fall. Thus on every side theutmost caution is taken to guard that precious gem in its casket. 

THE PERFECTION OF THE SPINE surpasses all human contrivances. Its varioususes seem a bundle of contradictions. A chain of twenty-four bones is madeso stiff that it will bear a heavy burden, and so flexible that it willbend like rubber; yet, all the while, it transmits no shock, and evenhides a delicate nerve within that would thrill with the slightest touch. Resting upon it, the brain is borne without a tremor; and, clinging to it, the vital organs are carried without fear of harm. 

FIG. 7. 

[Illustration: B, _the first cervical vertebra, the atlas;_ A, _theatlas, and the second cervical vertebra, the axis;_ e, _the odontoidprocess;_ c, _the foramen. _]

THE SKULL ARTICULATES with (is jointed to) the spine in a peculiar manner. On the top of the upper vertebra (atlas [Footnote: Thus called because, as, in ancient fable, the god Atlas supported the world on his shoulders, so in the body this bone bears the head. ]) are two little hollows(_a_, _b_, Fig. 7), nicely packed and lined with the synovialmembrane, into which fit the corresponding projections on the lower partof the skull, and thus the head can rock to and fro. The second vertebra(axis) has a peg, _e_, which projects through a hole, _c_, inthe first. 

FIG. 8. 

[Illustration: _The Thorax or Chest. _ a, _the sternum;_ b _to_ c, _thetrue ribs;_ d _to_ h, _the false ribs;_ g, h, _the floating ribs;_ i, k, _the dorsal vertebræ. _]

The surfaces of both vertebræ are so smooth that they easily glide on eachother, and thus, when we move the head side wise, the atlas turns aroundthe peg, _e_, of the axis. 

THE RIBS, also twenty-four in number, are arranged in pairs on each sideof the chest. At the back, they are all attached to the spine. In front, the upper seven pairs are tied by cartilages to the breastbone (sternum);three are fastened to each other and to the cartilage above, and two, thefloating ribs, are loose. 

The natural form of the chest is that of a cone diminishing upward. But, owing to the tightness of the clothing commonly worn, the reverse is oftenthe case. The long, slender ribs give lightness, [Footnote: If the chestwall were in one bone thick enough to resist a blow, it would be unwieldyand heavy As it is, the separate bones bound by cartilages yieldgradually, and diffuse the force among them all, and so are rarelybroken. ] the arched form confers strength, and the cartilages impartelasticity, --properties essential to the protection of the delicate organswithin, and to freedom of motion in respiration. (See note, p. 80. )

FIG. 9. 

[Illustration: _The Pelvis. _ a, _the sacrum;_ b, b, _the rightand the left innominatum. _]

THE HIP BONES, called by anatomists the innominata, or nameless bones, form an irregular basin styled the _pelvis_ (_pelvis_, a basin). In the upper part, is the foot of the spinal column--a wedge-shaped bonetermed the _sacrum_ [Footnote: So called because it was ancientlyoffered in sacrifice. ] (sacred), firmly planted here between thewidespreading and solid bones of the pelvis, like the keystone to an arch, and giving a steady support to the heavy burden above. 

3. THE LIMBS. 

TWO SETS OF LIMBS branch from the trunk, viz. : the upper, and the lower. They closely resemble each other. The arm corresponds to the thigh; theforearm, to the leg; the wrist, to the ankle; the fingers, to the toes. The fingers and the toes are so much alike that they receive the samename, _digits_, while the several bones of both have also the commonappellation, _phalanges_. The differences which exist grow out oftheir varying uses. The foot is characterized by strength; the hand, bymobility. 

FIG. 10. 

[Illustration: _The Shoulder Joint. _ a, _the clavicle;_ b, _the scapula. _]

1. THE UPPER LIMBS. --THE SHOULDER. --The bones of the shoulder are thecollar bone (clavicle), and the shoulder blade (scapula). The_clavicle_ (_clavis_, a key) is a long, slender bone, shapedlike the Italic _f_. It is fastened at one end to the breastbone andthe first rib, and, at the other, to the shoulder blade. (See Fig. 1. ) Itthus holds the shoulder joint out from the chest, and gives the armgreater play. If it be removed or broken, the head of the arm bone willfall, and the motions of the arm be greatly restricted. [Footnote: Animalswhich use the forelegs only for support (as the horse, ox, etc. ), do notpossess this bone. "It is found in those that dig, fly, climb and seize. "]

THE SHOULDER BLADE is a thin, flat, triangular bone, fitted to the top andback of the chest, and designed to give a foundation for the muscles ofthe shoulder. 

THE SHOULDER JOINT. --The arm bone, or _humerus_, articulates with theshoulder blade by a ball-and-socket joint. This consists of a cup-likecavity in the latter bone, and a rounded head in the former, to fit it, --thus affording a free rotary motion. The shallowness of the socketaccounts for the frequent dislocation of this joint, but a deeper onewould diminish the easy swing of the arm. 

FIG. 11. 

[Illustration: _Bones of the right Forearm. _ H, _the humerus;_R, _the radius; and_ U, _the ulna. _]

THE ELBOW. --At the elbow, the humerus articulates with the _ulna_--aslender bone on the inner side of the forearm--by a hinge joint whichadmits of motion in only two directions, _i. E. _, backward andforward. The ulna is small at its lower end; the _radius_, or largebone of the forearm, on the contrary, is small at its upper end, while itis large at its lower end, where it forms the wrist joint. At the elbow, the head of the radius is convex and fits into a shallow cavity in theulna, while at the wrist the ulna plays in a similar socket in the radius. Thus the radius may roll over and even cross the ulna. 

THE WRIST, or _carpus_, consists of two rows of very irregular bones, one of which articulates with the forearm; the other, with the hand. Theyare placed side to side, and so firmly fastened as to admit of only agliding motion. This gives little play, but great strength, elasticity, and power of resisting shocks. 

THE HAND. --The _metacarpal_ (_meta_, beyond; _karpos_, wrist), or bones of the palm, support each a thumb or a finger. Eachfinger has three bones, while the thumb has only two. The first bone ofthe thumb, standing apart from the rest, enjoys a special freedom ofmotion, and adds greatly to the usefulness of the hand. 

FIG. 12. 

[Illustration: _Bones of the Hand and the Wrist. _]

The first bone (Figs. 11, 12) of each finger is so attached to thecorresponding metacarpal bone as to move in several directions upon it, but the other phalanges form hinge joints. 

The fingers are named in order: the thumb, the index, the middle, thering, and the little finger. Their different lengths cause them to fit thehollow of the hand when it is closed, and probably enable us more easilyto grasp objects of varying size. If the hand clasps a ball, the tips ofthe fingers will be in a straight line. 

The hand in its perfection belongs only to man. Its elegance of outline, delicacy of mold, and beauty of color have made it the study of artists;while its exquisite mobility and adaptation as a perfect instrument haveled many philosophers to attribute man's superiority even more to the handthan to the mind. [Footnote: How constantly the hand aids us in explainingor enforcing a thought! We affirm a fact by placing the hand as if wewould rest it firmly on a body; we deny by a gesture putting the false orerroneous proposition away from us; we express doubt by holding the handsuspended, as if hesitating whether to take or reject. When we part fromdear friends, or greet them again after long absence, the hand extendstoward them as if to retain, or to bring them sooner to us. If a recitalor a proposition is revolting, we reject it energetically in gesture as inthought. In a friendly adieu we wave our good wishes to him who is theirobject; but when it expresses enmity, by a brusque movement we sever everytie. The open hand is carried backward to express fear or horror, as wellas to avoid contact; it goes forward to meet the hand of friendship; it israised suppliantly in prayer toward Him from whom we hope for help; itcaresses lovingly the downy cheek of the infant, and rests on its headinvoking the blessing of Heaven, --_Wonders of the Human Body_. ]

FIG. 13. 

[Illustration: _The Mechanism of the Hip Joint. _]

2. THE LOWER LIMBS. --THE HIP--The thigh bone, or _femur_, is thelargest and necessarily the strongest in the skeleton, since at every stepit has to bear the weight of the whole body. It articulates with the hipbone by a ball-and-socket joint. Unlike the shoulder joint, the cup hereis deep, thus affording less play, but greater strength. It fits sotightly that the pressure of the air largely aids in keeping the bones inplace. [Footnote: In order to test this, a hole was bored through a hipbone, so as to admit air into the socket, the thigh bone at once fell outas far as the ligaments would permit. An experiment was also devisedwhereby a suitably prepared hip joint was placed under the receiver of anair pump. On exhausting the air, the weight of the femur caused it to dropout of the socket, while the readmission of the air raised it to itsplace. Without this arrangement, the adjacent muscles would have beencompelled to bear the additional weight of the thighbone every time it wasraised. Now the pressure of the air rids them of this unnecessary burden, and hence they are less easily fatigued--WEBER] Indeed, when the musclesare cut away, great force is required to detach the limbs. 

THE KNEE is strengthened by the patella_, or kneepan (_patella_, little dish), a chestnut-shaped bone firmly fastened over the joint. 

The shin bone, or _tibia_, the large, triangular bone on the innerside of the leg, articulates both with the femur and the foot by hingejoints. The kneejoint is so made, however, as to admit of a slight rotarymotion when the limb is not extended. 

The _fibula_ (_fibula_, a clasp), the small, outside bone of theleg, is firmly bound at each end to the tibia. (See Fig. 1. ) It isimmovable, and, as the tibia bears the principal weight of the body, thechief use of this second bone seems to be to give more surface to whichthe muscles may be attached. [Footnote: A young man in the hospital atLimoges had lost the middle part of his tibia. The lost bone was notreproduced, but the fibula, the naturally weak and slender part of theleg, became thick and strong enough to support the whole body. --STANLEY'S_Lectures_. ]

THE FOOT. --The general arrangement of the foot is strikingly like that ofthe hand (Fig. 1). The several parts are the _tarsus_, the_metatarsus_, and the _phalanges_. The graceful arch of thefoot, and the numerous bones joined by cartilages, give an elasticity tothe step that could never be attained by a single, flat bone. [Footnote:The foot consists of an arch, the base of which is more extended in frontthan behind, and the whole weight of the body is made to fall on this archby means of a variety of joints. These joints further enable the foot tobe applied, without inconvenience, to rough and uneven surfaces. --HINTON. ]The toes naturally lie straight forward in the line of the foot. Fewpersons in civilized nations, however, have naturally formed feet. The bigtoe is crowded upon the others, while crossed toes, nails grown-in, enormous joints, corns, and bunions abound. 

THE CAUSE OF THESE DEFORMITIES is found in the shape and size offashionable boots and shoes. The sole ought to be large enough for fullplay of motion, the uppers should not crowd the toes, and the heels shouldbe low, flat, and broad. As it is, there is a constant warfare betweenNature and our shoemakers, [Footnote: When we are measured for boots orshoes, we should stand on a sheet of paper, and have the shoemaker markwith a pencil the exact outline of our feet as they bear our whole weight. When the shoe is made, the sole should exactly cover this outline. ] and weare the victims. The narrow point in front pinches our toes, and compelsthem to override one another; the narrow sole compresses the arch; whilethe high heel, by throwing all the weight forward on the toes, strains theankle, and, by sending the pressure where Nature did not design it tofall, causes that joint to become enlarged. The body bends forward to meetthe demand of this new motion, and thus loses its uprightness and beauty, making our gait stiff and ungraceful. (See p. 271. )

DISEASES, ETC. --l. _Rickets_, a disease of early life, is caused by alack of mineral matter in the bones, rendering them soft and pliable, sothat they bend under the weight of the body. They thus become permanentlydistorted, and of course are weaker than if they were straight, [Footnote:Just here appears an exceedingly beautiful provision. As soon as thedisproportion of animal matter ceases, a larger supply of mineral is sentto the weak points, and the bones actually become thicker, denser, harder, and consequently stronger at the very concave part where the stress ofpressure is greatest. --WATSON'S _Lectures_. We shall often haveoccasion to refer to similar wise and providential arrangements wherebythe body is enabled to remedy defects, and to prepare for accidents. ]Rickets is most common among children who have inherited a feebleconstitution and who are ill fed, or who live in damp, ill-ventilatedhouses. "Rickety" children should have plenty of fresh air and sunlight, nourishing food, comfortable clothing, and, in short, the best of hygieniccare. 

2. _A Felon_ is a swelling of the finger or thumb, usually of thelast joint. It is marked by an accumulation beneath the periosteum andnext the bone. The physician will merely cut through the periosteum, andlet out the effete matter. 

3. _Bowlegs_ are caused by children standing on their feet before thebones of the lower limbs are strong enough to bear their weight. Thecustom of encouraging young children to stand by means of a chair or thesupport of the hand, while the bones are yet soft and pliable, is a cruelone, and liable to produce permanent deformity. Nature will set the childon its feet when the proper time comes. 

4. _Curvature of the Spine_. --When the spine is bent, the packingbetween the vertebræ becomes compressed on one side into a wedge-likeshape. After a time, it will lose its elasticity, and the spine willbecome distorted. This often occurs in the case of students who bendforward to bring their eyes nearer their books, instead of lifting theirbooks nearer their eyes, or who raise their right shoulder above theirleft when writing at a desk which is too high. Round shoulders, small, weak lungs, and, frequently, diseases of the spine are the consequences. An erect posture in reading or writing conduces not alone to beauty ofform, but also to health of body. We shall learn hereafter that the actionof the muscles bears an important part in preserving the symmetry of thespine. Muscular strength comes from bodily activity; hence, one of thebest preventives of spinal curvature is daily exercise in the open air. 

5. _Sprains_ are produced when the ligaments which bind the bones ofa joint are strained, twisted, or torn from their attachments. They arequite as serious as a broken bone, and require careful attention lest theylead to a crippling for life. By premature use a sprained limb may bepermanently impaired. Hence, the joint should be kept quiet, even afterthe immediate pain is gone. 

6. _A Dislocation_ is the forcible displacement of a bone from itssocket. It is, generally, the result of a fall or a violent blow. Thetissues of the joint are often ruptured, while the contraction of themuscles prevents the easy return of the bone to its place. A dislocationshould be reduced as soon as possible after the injury, beforeinflammation supervenes. 

PRACTICAL QUESTIONS. 

1. Why does not a fall hurt a child as much as it does a grown person?

2. Should a young child ever be urged to stand or walk?

3. What is meant by "breaking one's neck"?

4. Should chairs or benches have straight backs?

5. Should a child's feet be allowed to dangle from a high seat?

6. Why can we tell whether a fowl is young by pressing on the point of thebreastbone?

7. What is the use of the marrow in the bones?

8. Why is the shoulder so often put out of joint?

9. How can you tie a knot in a bone?

10. Why are high pillows injurious?

11. Is a stooping posture a healthful position?

12. Should a boot have a heel piece?

13. Why should one always sit and walk erect?

14. Why does a young child creep rather than walk?

15. What is the natural direction of the big toe?

16. What is the difference between a sprain and a fracture? A dislocation?

17. Does the general health of the system affect the strength of thebones?

18. Is living bone sensitive? _Ans_. --Scrape a bone, and its vesselsbleed; cut or bore a bone, and its granulations sprout up; break a bone, and it will heal; cut a piece away, and more bone will readily beproduced; hurt it in any way, and it inflames; burn it, and it dies. Takeany proof of sensibility but the mere feeling of pain, and it will answerto the proof. --BELL'S _Anatomy_. Animal sensibility would beinconvenient; it is therefore not to be found except in diseased bone, where it sometimes exhibits itself too acutely. --TODD'S _Cyclopedia ofAnatomy_. 

19. Is the constitution of bone the same in animals as in man?_Ans_. --The bones of quadrupeds do not differ much from those of man. In general they are of a coarser texture, and in some, as in those of theelephant's head, we find extensive air cells. --TODD'S _Anatomy_. 

II. 

THE MUSCLES. 

"Behold the outward moving frame, Its living marbles jointed strongWith glistening band and silvery thong, And link'd to reason's guiding reinsBy myriad rings in trembling chains, Each graven with the threaded zoneWhich claims it as the Master's own. "

HOLMES. 

ANALYSIS OF THE MUSCLES. 

_| 1. The Use of the Muscles. | 2. Contractility of the Muscles. _ | 3. Arrangement of the Muscles. | 1. THE USE, STRUCTURE | 4. The two Kinds of Muscles. | AND ACTION OF THE | 5. The Structure of the Muscles. | MUSCLES. | 6. The Tendons for Fastening Muscles. | | 7. The Muscles and Bones as Levers. | | 8. The Effect of Big Joints. | | 9. Action of the Muscles in Walking. | |_10. Action of the Muscles in Walking. || 2. THE MUSCULAR SENSE. | _| 3. HYGIENE OF THE | 1. Necessity of Exercise. | MUSCLES. | 2. Time for Exercise. | |_ 3. Kinds of Exercise. || 4. WONDERS OF THE MUSCLES. | _| | 1. St. Vitus's Dance. | | 2. Convulstions. | | 3. Locked-jaw. |_5. DISEASES. | 4. Gout. | 5. Rheumatism. | 6. Lumbago. |_ 7. A Ganglion. 

FIG. 14. 

[Illustration]

THE MUSCLES. 

THE USE OF THE MUSCLES. --The skeleton is the image of death. Its unsightlyappearance instinctively repels us. We have seen, however, what uses itsubserves in the body, and how the ugly-looking bones abound in nicecontrivances and ingenious workmanship. In life, the framework is hiddenby the flesh. This covering is a mass of muscles, which by theirarrangement and their properties not only give form and symmetry to thebody, but also produce its varied movements. 

In Fig. 14, we see the large exterior muscles. Beneath these are manyothers; while deeply hidden within are tiny, delicate ones, too small tobe seen with the naked eye. There are, in all, about five hundred, eachhaving its special use, and all working in exquisite harmony andperfection. 

CONTRACTILITY. --The peculiar property of the muscles is their power ofcontraction, whereby they decrease in length and increase in thickness. [Footnote: The maximum force of this contraction has been estimated ashigh as from eighty-five to one hundred and fourteen pounds per squareinch. ] This may be caused by an effort of the will, by cold, by a sharpblow, etc. It does not cease at death, but, in certain cold-bloodedanimals, a contraction of the muscles is often noticed long after the headhas been cut off. 

ARRANGEMENT OF THE MUSCLES. [Footnote: "Could we behold properly themuscular fibers in operation, nothing, as a mere mechanical exhibition, can be conceived more superb than the intricate and combined actions thatmust take place during our most common movements. Look at a person runningor leaping, or watch the motions of the eye. How rapid, how delicate, howcomplicated, and yet how accurate, are the motions required! Think of theendurance of such a muscle as the heart, that can contract, with a forceequal to sixty pounds, seventy-five times every minute, for eighty yearstogether, without being weary. "]--The muscles are nearly all arranged inpairs, each with its antagonist, so that, as they contract and expandalternately, the bone to which they are attached is moved to and fro. (Seep. 275. )

If you grasp the arm tightly with your hand just above the elbow joint, and bend the forearm, you will feel the muscle on the inside (biceps, _a_, Fig. 14) swell, and become hard and prominent, while the outsidemuscle (triceps, _f_) will be relaxed. Now straighten the arm, andthe swelling and hardness of the inside muscle will vanish, while theoutside one will, in turn, become rigid. So, also, if you clasp the armjust below the elbow, and then open and shut the fingers, you can feel thealternate expanding and relaxing of the muscles on opposite sides of thearms. 

If the muscles on one side of the face become palsied, those on the otherside will draw the mouth that way. Squinting is caused by one of thestraight muscles of the eye (Fig. 17) contracting more strongly than itsantagonist. 

KINDS OF MUSCLES. --There are two kinds of muscles, the _voluntary_, which are under the control of our will, and the _involuntary_, which are not. Thus our limbs stiffen or relax as we please, but theheart beats on by day and by night. The eyelid, however, is bothvoluntary and involuntary, so that while we wink constantly withouteffort, we can, to a certain extent, restrain or control the motion. 

STRUCTURE OF THE MUSCLES. --If we take a piece of lean beef and wash outthe red color, we can easily detect the fine fibers of which the meat iscomposed. In boiling corned beef for the table, the fibers often separate, owing to the dissolving of the delicate tissue which bound them together. By means of the microscope, we find that these fibers are made up ofminute filaments (_fibrils_), and that each fibril is composed of arow of small cells arranged like a string of beads. This gives the musclesa peculiar striped (striated) appearance. [Footnote: The involuntarymuscles consist generally of smooth, fibrous tissue, and form sheets ormembranes in the walls of hollow organs. By their contraction they changethe size of cavities which they inclose. Some functions, however, like theaction of the heart, or the movements of deglutition (swallowing), requirethe rapid, vigorous contraction, characteristic of the voluntary musculartissue--FLINT. ] (See p. 276. ) The cells are filled with a fluid orsemifluid mass of living (protoplasmic) matter. 

FIG. 15. 

[Illustration: _Microscopic view of a Muscle, showing, at one end, thefibrillæ; and, at the other, the disks, or cells, of the fiber. _]

The binding of so many threads into one bundle [Footnote: We shall learnhereafter how these fibers are firmly tied together by a mesh of fineconnective tissue which dissolves in boiling, as just described] confersgreat strength, according to a mechanical principle that we seeexemplified in suspension bridges, where the weight is sustained, not bybars of iron, but by small wires twisted into massive ropes. 

FIG. 16. 

[Illustration: _Tendons of the Hand. _]

THE TENDONS. --The ends of the muscles are generally attached to the boneby strong, flexible, but inelastic tendons. [Footnote: The tendons may beeasily seen in the leg of a turkey as it comes on our table; so we maystudy Physiology while we pick the bones. ] The muscular fibers spring fromthe sides of the tendon, so that more of them can act upon the bone thanif they went directly to it. Besides, the small, insensible tendon canbetter bear the exposure of passing over a joint, and be more easilylodged in some protecting groove, than the broad, sensitive muscle. Thismode of attachment gives to the limbs strength, and elegance of form. Thus, for example, if the large muscles of the arm extended to the hand, they would make it bulky and clumsy. The tendons, however, reach only tothe wrist, whence fine cords pass to the fingers (Fig. 16). 

Here we notice two other admirable arrangements. 1. If the long tendons atthe wrist on contracting should rise, projections would be made and thusthe beauty of the slender joint be marred. To prevent this, a stout bandor bracelet of ligament holds them down to their place. 2. In order toallow the tendon which moves the last joint of the finger to pass through, the tendon which moves the second joint divides at its attachment to thebone (Fig. 16). This is the most economical mode of packing the muscles, as any other practicable arrangement would increase the bulk of theslender finger. 

FIG. 17. 

[Illustration: _Muscles of the Right Eye:_ A, _superiorstraight, _ B, _superior oblique passing through a pulley, _ D; G, _inferior oblique, _ H, _external straight, and, back of it, theinternal straight muscle. _]

Since the tendon can not always pull in the direction of the desiredmotion, some contrivance is necessary to meet the want. The tendon (B)belonging to one of the muscles of the eye, for example, passes through aring of cartilage, and thus a rotary motion is secured. 

FIG. 18. 

[Illustration: _The three classes of Levers, and also the foot as aLever. _]

THE LEVERS OF THE BODY. [Footnote: A _lever_ is a stiff bar restingon a point of support, called the _fulcrum_ (_F_), and having connectedwith it a _weight_ (_W_) to be lifted, and a _power_ (_P_) to move it. There are three classes of levers according to the arrangement of thepower, weight, and fulcrum. In the first class, the _F_ is between the_P_ and _W_; in the second, the _W_ is between the _P_ and _F_; and inthe third, the _P_ is between the _W_ and _F_ (Fig. 18). A pump handleis an example of the first; a lemon squeezer, of the second; and apair of fire tongs, of the third. See "Popular Physics, " pp. 81-83, for afull description of this subject, and for many illustrations. ]--Inproducing the motions of the body, the muscles use the bones as levers. Wesee an illustration of the _first class_ of levers in the movementsof the head. The back or front of the head is the weight to be lifted, thebackbone is the fulcrum on which the lever turns, and the muscles at theback or front of the neck exert the power by which we toss or bow thehead. 

FIG. 19. 

[Illustration: _The hand as a Lever of the third class. _]

When we raise the body on tiptoe, we have an instance of the _secondclass_. Here, our toes resting on the ground form the fulcrum themuscles of the calf (gas-troc-ne'-mi-us, _j_ and so-le'-us, Fig. 14), acting through the tendon of the heel, [Footnote: This is called theTendon of Achilles (_k_, Fig. 14) and is so named because, as thefable runs, when Achilles was an infant his mother held him by the heelwhile she dipped him in the River Styx, whose water had the power ofrendering one invulnerable to any weapon. His heel, not being wet, was hisweak point, to which Paris directed the fatal arrow--"This tendon, " saysMapother, "will bear one thousand pounds weight before it will break. " Thehorse is said to be "hamstrung, " and is rendered useless, when the Tendonof Achilles is cut. (see p. 284. )] are the power and the weight is borneby the ankle joint. 

An illustration of the _third class_ is found in lifting the handfrom the elbow. The hand is the weight, the elbow the fulcrum, and thepower is applied by the biceps muscle at its attachment to the radius (A, Fig. 19. ) In this form of the lever there is great loss of force, becauseit is applied at such a distance from the weight, but there is a gain ofvelocity, since the hand moves so far by such a slight contraction of themuscle. The hand is required to perform quick motions, and therefore thismode of attachment is desirable. 

The nearer the power is applied to the resistance, the more easily thework is done. In the lower jaw, for example, the jaw is the weight, thefulcrum is the hinge joint at the back, and the muscles (temporal, _d_, and the mas'-se'ter, _e_, Fig. 14) on each side are thepower. [Footnote: We may feel the contraction of the masseter by placingour hand on the face when we work the jaw, while the temporal can bereadily detected by putting the fingers on the temple while we arechewing. The tendon of the muscle (digastric)--one of those which open thejaw--passes through a pulley (_c_, Fig. 14) somewhat like the one inthe eye. ] They act much closer to the resistance than those in the hand, since here we desire force, and there, speed. 

FIG. 20. 

[Illustration: _The Kneejoint;_ k, _the patella;_ f, _thetendon. _]

THE ENLARGEMENT OF THE BONES AT THE JOINTS not only affords greatersurface for the attachment of the muscles, as we have seen, but alsoenables them to work to better advantage. Thus, in Fig. 20 it is evidentthat a muscle acting in the line _f b_ would not bend the lower limbso easily as if it were acting in the line _f k_, since in the formercase its force would be about all spent in drawing the bones more closelytogether, while in the latter it would pull more nearly at a right angle. Thus the tendon _f_, by passing over the patella, which is itselfpushed out by the protuberance _b_ of the thigh bone, pulls at alarger angle, [Footnote: The chief use of the processes of the spine (Fig. 6) and other bones is, in the same way, to throw out the point on whichthe power acts as far from the fulcrum as possible. The projections of theulna ("funny bone") behind the elbow, and that of the heel bone to whichthe Tendon of Achilles is attached, are excellent illustrations (Fig. 1). ]and so the leg is thrown forward with ease in walking and with great forcein kicking. 

HOW WE STAND ERECT. --The joints play so easily, and the center of gravityin the body is so far above the foot, that the skeleton can not of itselfhold our bodies upright. Thus it requires the action of many muscles tomaintain this position. The head so rests upon the spine as to tend tofall in front, but the muscles of the neck steady it in its place. [Footnote: In animals the jaws are so heavy, and the place where the headand spine join is so far back, that there can be no balance as there is inman. There are therefore large muscles in their necks. We readily findthat we have none if we get on "all fours" and try to hold up the head. Onthe other hand, gorillas and apes can not stand erect like man, for thereason that their head, trunk, legs, etc. , are not balanced by muscles, soas to be in line with one another. ] The hips incline forward, but are helderect by the strong muscles of the back. The trunk is nicely balanced onthe head of the thigh bones. The great muscles of the thigh acting overthe kneepan tend to bend the body forward, but the muscles of the calfneutralize this action. The ankle, the knee, and the hip lie in nearly thesame line, and thus the weight of the body rests directly on the keystoneof the arch of the foot. So perfectly do these muscles act that we neverthink of them until science calls our attention to the subject, and yet toacquire the necessary skill to use them in our infancy needed patientlessons, much time, and many hard knocks. 

FIG. 21. 

[Illustration: _Action of the Muscles which keep the body erect. _]

HOW WE WALK. --Walking is as complex an act as standing. It is really aperilous performance, which has become safe only because of constantpractice. We see how violent it is when we run against a post in the dark, and find with what headlong force we were hurling ourselves forward. Holmes has well defined walking as a perpetual falling with a constantself-recovery. Standing on one foot, we let the body fall forward, whilewe swing the other leg ahead like a pendulum. Planting that foot on theground, to save the body from falling farther, we then swing the firstfoot forward again to repeat the same operation. [Footnote: It is acurious fact that one side of the body tends to outwalk the other; and so, when a man is lost in the woods, he often goes in a circle, and at lastcomes round to the spot whence he started. ]

The shorter the pendulum, the more rapidly it vibrates; and so short-legged people take quicker and shorter steps than long-legged ones. [Footnote: In this respect, Tom Thumb was to Magrath, whose skeleton, eight and one half feet high, is now in the Dublin Museum, what a littlefast-ticking, French mantel clock is to a big, old-fashioned, upright, corner timepiece. ] We are shorter when walking than when standing still, because of this falling forward to take a step in advance. [Footnote:Women find that a gown that will swing clear of the ground when they arestanding still, will drag the street when they are walking. The length ofthe step may be increased by muscular effort, as when a line of soldierskeep step in spite of their having legs of different lengths. Such a modeof walking is necessarily fatiguing. (See p. 280. )]

In running, we incline the body more, and so, as it were, fall faster. When we walk, one foot is on the ground all the time, and there is aninstant when both feet are planted upon it; but in running there is aninterval of time in each step when both feet are off the ground, and thebody is wholly unsupported. As we step alternately with the feet, we areinclined to turn the body first to one side and then to the other. Thismovement is sometimes counterbalanced by swinging the hand on the oppositeside. [Footnote: In ordinary walking the speed is nearly four miles anhour, and can be kept up for a long period. But exercise and a specialaptitude for it enable some men to walk great distances in a relativelyshort space of time. Trained walkers have gone seventy-five miles intwenty hours, and walked the distance of thirty-seven miles at the rate offive miles an hour. The mountaineers of the Alps are generally goodwalkers, and some of them are not less remarkable for endurance than forspeed. Jacques Balmat, who was the first to reach the summit of MontBlanc, at sixteen years of age could walk from the hamlet of the Pélerinsto the mountain of La Côte in two hours, --a distance which the best-trained travelers required from five to six hours to get over. At the timeof his last attempt to reach the top of Mont Blanc, this same guide, thentwenty years old, passed six days and four nights without sleeping orreposing a single moment. One of his sons, Édouard Balmat, left Paris tojoin his regiment at Genoa; he reached Chamouni the fifth day at evening, having walked three hundred and forty miles. After resting two days, heset off again for Genoa, where he arrived in two days. Several yearsafterward, this same man left the baths at Louèche at two o'clock in themorning, and reached Chamouni at nine in the evening, having walked adistance equal to about seventy-five miles in nineteen hours. In 1844, anold guide of De Saussure, eighty years old, left the hamlet of Prats, inthe valley of Chamouni, in the afternoon, and reached the Grand-Mulets atten in the evening; then, after resting some hours, he climbed the glacierto the vicinity of the Grand Plateau, which has an altitude of aboutthirteen thousand feet, and then returned to his village withoutstopping. --_Wonders of the Body_. ]

THE MUSCULAR SENSE. --When we lift an object, we feel a sensation ofweight, which we can compare with that experienced in lifting anotherbody. [Footnote: If a small ivory ball be allowed to roll down the cheektoward the lips, it will appear to increase in weight. In general, themore sensitive parts of the body recognize smaller differences in weight, and the right hand is more accurate than the left. We are very apt, however, to judge of the weight of a body from previous conceptions. Thus, shortly after Sir Humphrey Davy discovered the metal potassium, he placeda piece of it in the hand of Dr. Pierson, who exclaimed: "Bless me! Howheavy it is!" Really, however, potassium is so light that it will float onwater like cork. ] By balancing it in the hand. The muscular sense isuseful to us in many ways. It guides us in standing or moving. We gratifyit when we walk erect and with an elastic step, and by dancing, jumping, skating, and gymnastic exercises. 

NECESSITY OF EXERCISE. --The effect of exercise upon a muscle is verymarked. [Footnote: The greater size of the breast (pectoral muscle) of apigeon, as compared with that of a duck, shows how muscle increases withuse. The breast of a chicken is white because it is not used for flight, and therefore gets little blood. ] By use it grows larger, and becomeshard, compact, and darker-colored; by disuse it decreases in size, andbecomes soft, flabby, and pale. 

Violent exercise, however, is injurious, since we then tear down fasterthan nature can build up. Feats of strength are not only hurtful, butdangerous. Often the muscles are strained or ruptured, and blood vesselsburst in the effort to outdo one's companions. [Footnote: Instances havebeen known of children falling dead from having carried to excess sopleasant and healthful an amusement as jumping the rope, and of personsrupturing the Tendon of Achilles in dancing. The competitive lifting ofheavy weights is unwise, sometimes fatal. ] (See p. 278. )

Two thousand years ago, Isocrates, the Greek rhetorician, said: "Exercisefor health, not for strength. " The cultivation of muscle for its own sakeis a return to barbarism, while it enfeebles the mind, and ultimately thebody. The ancient gymnasts are said to have become prematurely old, andthe trained performers of our own day soon suffer from the strain they putupon their muscular system. Few men have sufficient vigor to become bothathletes and scholars. Exercise should, therefore, merely supplement thedeficiency of our usual employment. _A sedentary life needs daily, moderate exercise, which always stops short of fatigue_. This is a lawof health. (See p. 280. )

No education is complete which fails to provide for the development of themuscles. Recesses should be as strictly devoted to play as study hours areto work. Were gymnastics or calisthenics as regular an exercise as grammaror arithmetic, fewer pupils would be compelled to leave school on accountof ill health; while spinal curvatures, weak backs, and ungraceful gaitswould no longer characterize so many of our best institutions. 

TIME FOR EXERCISE. --We should not exercise after long abstinence fromfood, nor immediately after a meal, unless the meal or the exercise bevery light. There is an old-fashioned prejudice in favor of exercisebefore breakfast--an hour suited to the strong and healthy, but entirelyunfitted to the weak and delicate. On first rising in the morning, thepulse is low, the skin relaxed, and the system susceptible to cold. Feeblepersons, therefore, need to be braced with food before they brave theoutdoor air. 

WHAT KIND OF EXCERCISE TO TAKE. --For children, games are unequaled. Walking, the universal exercise, [Footnote: The custom of walking, soprevalent in England, has doubtless much to do with the superior physiqueof its people. It is considered nothing for a woman to take a walk ofeight or ten miles, and long pedestrian excursions are made to all partsof the country. The benefits which accrue from such an open-air life aresadly needed by the women of our own land. A walk of half a dozen milesshould be a pleasant recreation for any healthy person. ] is beneficial, asit takes one into the open air and sunlight. Running is better, since itemploys more muscles, but it must not be pushed to excess, as it taxes theheart, and may lead to disease of that organ. Rowing is more effectual inits general development of the system. Swimming employs the muscles of thewhole body, and is a valuable acquirement, as it may be the means ofsaving life. Horseback riding is a fine accomplishment, and refreshes bothmind and body. Gymnastic or calisthenic exercises bring into play all themuscles of the body, and when carefully selected, and not immoderatelyemployed, are preferable to any other mode of indoor exercise. [Footnote:The employment of the muscles in exercise not only benefits their especialstructure, but it acts on the whole system. When the muscles are put inaction, the capillary blood vessels with which they are supplied becomemore rapidly charged with blood, and active changes take place, not onlyin the muscles, but in all the surrounding tissues. The heart is requiredto supply more blood, and accordingly beats more rapidly in order to meetthe demand. A larger quantity of blood is sent through the lungs, andlarger supplies of oxygen are taken in and carried to the various tissues. The oxygen, by combining with the carbon of the blood and the tissues, engenders a larger quantity of heat, which produces an action on the skin, in order that the superfluous warmth may be disposed of. The skin is thusexercised, as it were, and the sudoriparous and sebaceous glands are setat work. The lungs and skin are brought into operation, and the lungsthrow off large quantities of carbonic acid, and the skin large quantitiesof water, containing in solution matters which, if retained, would producedisease in the body. Wherever the blood is sent, changes of a healthfulcharacter occur. The brain and the rest of the nervous system areinvigorated, the stomach has its powers of digestion improved, and theliver, pancreas, and other organs perform their functions with more vigor. By want of exercise, the constituents of the food which pass into theblood are not oxidized, and products which produce disease are engendered. The introduction of fresh supplies of oxygen induced by exercise oxidizesthese products, and renders them harmless. As a rule, those who exercisemost in the open air will live the longest. --LANKESTER. ] (See p. 280. )

THE WONDERS OF THE MUSCLES. --The grace, ease, and rapidity with which themuscles contract are astonishing. By practice, they acquire a facilitywhich we call mechanical. The voice may utter one thousand five hundredletters in a minute, yet each requires a distinct position of the vocalorgans. We train the muscles of the fingers till they glide over the keysof the piano, executing the most exquisite and difficult harmony. Inwriting, each letter is formed by its peculiar motions, yet we make themso unconsciously that a skillful penman will describe beautiful curveswhile thinking only of the idea that the sentence is to express. The mindof the violinist is upon the music which his right hand is executing, while his left determines the length of the string and the character ofeach note so carefully that not a false sound is heard, although thevariation of a hair's breadth would cause a discord. In the arm of ablacksmith, the biceps muscle may grow into the solidity almost of a club;the hand of a prize fighter will strike a blow like a sledge hammer; whilethe engraver traces lines invisible to the naked eye, and the fingers ofthe blind acquire a delicacy that almost supplies the place of the missingsense. 

DISEASES, ETC. --l. _St. Vitus's Dance_ is a disease of the voluntarymuscles, whereby they are in frequent, irregular, and spasmodic motionbeyond the control of the will. All causes of excitement, and especiallyof fear, should be avoided, and the general health of the patientinvigorated, as this disease is closely connected with a derangement ofthe nervous system. 

2. _Convulsions_ are an involuntary contraction of the muscles. Consciousness is wanting, while the limbs may be stiff or in spasmodicaction. (See p. 261. )

3. _Locked-jaw_ is a disease in which there are spasms and acontraction of the muscles, usually beginning in the lower jaw. It isserious, often fatal, yet it sometimes follows as trivial an injury as thestroke of a whip lash, the lodgment of a bone in the throat, a fishhook inthe finger, or a tack in the sole of the foot. 

4. _Gout_ is characterized by an acute pain located chiefly in thesmall joints of the foot, especially those of the great toe, which becomeswollen and extremely sensitive. It is generally accompanied by an excessof uric acid in the blood, and a deposit of urate of soda about theaffected joint. Gout is often the result of high living, and of too muchanimal food. It is frequently inherited. 

5. _Rheumatism_ affects mainly the connective, white, fibrous tissueof the larger joints. While gout is the punishment of the rich who liveluxuriously, rheumatism afflicts alike the poor and the rich. There aretwo common forms of rheumatism--the inflammatory or acute, and thechronic. The latter is of long continuance; the former terminates morespeedily. The acute form is probably a disease of the blood, which carrieswith it some poisonous matter that is deposited where the fibrous tissueis most abundant. The disease flies capriciously from one joint toanother, and the pain caused by even the slightest motion deprives thesufferer of the use of the disabled part and its muscles. Its chief dangerlies in the possibility of its affecting the vital organs. Chronicrheumatism--the result of repeated attacks of the acute--leads to greatsuffering, and oftentimes to disorganization of the joints and aninterference with the movements of the heart. 

6. _Lumbago_ is an inflammation of the lumbar muscles and fascia. [Footnote: Lumbago is really a form of myalgia, a disease which, has itsseat in the muscles, and may thus affect any part of the body. Doubtlessmuch of what is commonly called "liver" or "kidney complaint" is only, inone case, myalgia of the chest or abdominal walls near the liver, or, inthe other, of the back and loins near the kidneys. Chronic liver diseaseis comparatively rare in the Northern States, and pain in the side is nota prominent symptom; while certain diseases of the kidneys, which are assurely fatal as pulmonary consumption, are not attended by pain in theback opposite these organs. --WEY. ] It may be so moderate as to produceonly a "lame back, " or so severe as to disable, as in the case of what ispopularly termed a "crick in the back. " Strong swimmers who sometimesdrown without apparent cause are supposed to be seized in this way. 

7. _A Ganglion_, or what is vulgarly called a "weak" or "weeping"sinew, is the swelling of a bursa. [Footnote: A bursa is a small sackcontaining a lubricating fluid to prevent friction where tendons play overhard surfaces. There is one shaped like an hourglass on the wrist, just atthe edge of the palm. By pressing back the liquid it contains, this bursamay be clearly seen. ] It sometimes becomes so distended by fluid as to bemistaken for bone. If on binding something hard upon it for a few days itdoes not disappear, a physician will remove the liquid by means of ahypodermic syringe, or perhaps cause it to be absorbed by an externalapplication of iodine. 

PRACTICAL QUESTIONS. 

1. What class of lever is the foot when we lift a weight on the toes?

2. Explain the movement of the body backward and forward, when restingupon the thigh bone as a fulcrum. 

3. What class of lever do we use when we lift the foot while sitting down?

4. Explain the swing of the arm from the shoulder. 

5. What class of lever is used in bending our fingers?

6. What class of lever is our foot when we tap the ground with our toes?

7. What class of lever do we use when we raise ourselves from a stoopingposition?

8. What class of lever is the foot when we walk?

9. Why can we raise a heavier weight with our hand when lifting from theelbow than from the shoulder?

10. What class of lever do we employ when we are hopping, the thigh bonebeing bent up toward the body and not used?

11. Describe the motions of the bones when we are using a gimlet. 

12. Why do we tire when we stand erect?

13. Why does it rest us to change our work?

14. Why and when is dancing a beneficial exercise?

15. Why can we exert greater force with the back teeth than with the frontones?

16. Why do we lean forward when we wish to rise from a chair?

17. Why does the projection of the heel bone make walking easier?

18. Does a horse travel with less fatigue over a flat than a hillycountry?

19. Can you move your upper jaw?

20. Are people naturally right or left-handed?

21. Why can so few persons move their ears by the muscles?

22. Is the blacksmith's right arm healthier than the left?

23. Boys often, though foolishly, thrust a pin into the flesh just abovethe knee. Why is it not painful?

24. Will ten minutes' practice in a gymnasium answer for a day's exercise?

25. Why would an elastic tendon be unfitted to transmit the motion of amuscle?

26. When one is struck violently on the head, why does he instantly fall?

27. What is the cause of the difference between light and dark meat in afowl?

III. 

THE SKIN. 

A protection from the outer world, it is our only means of communicatingwith it. Insensible itself, it is the organ of touch. It feels thepressure of a hair, yet bears the weight of the body. It yields to everymotion of that which it wraps and holds in place. It hides from view thedelicate organs within, yet the faintest tint of a thought shines through, while the soul paints upon it, as on a canvas, the richest and rarest ofcolors. 

ANALYSIS OF THE SKIN. 

__ | 1. The Cutis; its Composition and Character. | 1. THE STRUCTURE | 2. The Cuticle; its Composition and Character. | OF THE SKIN. | 3. The Value of the Cuticle. | |_4. The Complexion. | _| | a. _Description. _| _ | b. _Method of Growth. _| | 1. The Hair. . . . . | c. _As an Instrument of| | | Feeling. _| 2. THE HAIR AND | | d. _Indestructibility of| THE NAILS. | |_ the Hair. _| | _| |_2. The Nails. . . . | a. _Uses. _| |_b. _Method of Growth. _| _ | 3. THE MUCOUS | 1. The Structure. | MEMBRANE | 2. Connective Tissue. | |_3. Fat. | _| | 1. Number and Kinds of Teeth. | | _| | 1. The Two Sets. | 1. _The Milk Teeth. _| | |_2. _The Permanent Teeth. _| || 4. THE TEETH. | 2. Structure of the Teeth. | | 3. The Setting of the Tooth in the Jaw. | | 4. The Decay of the Teeth. | |_5. The Preservation of the Teeth. | _ _| | 1. The Two Kinds. | 1. _Oil Glands. _| | |_2. _Perpiratory Glands. _| || 5. THE GLANDS | 2. The Perspiration. | | 3. The Absorbing Power of the Skin. (See| |_ Lymphatics. )| _| | 1. About Washing and Bathing. | | 2. The Reaction. | | 3. Sea Bathing. _| 6. HYGIENE | | a. _General Principles. _| | | b. _Linen. _| | | c. _Cotton. _| |_4. Clothing. . . . . . . | d. _Woolen. _| | e. _Flannel. _| | f. _Color of Clothing. _| | g. _Structure of| | Clothing. _| | h. _Insufficient| _ |_ Clothing. _| | 1. Erysipelas. | | 2. Salt Rheum. |_7. DISEASES. | 3. Corns. | 4. Ingrowing Nails. | 5. Warts. |_6. Chilblains. 

THE SKIN. 

THE SKIN is a tough, thin, close-fitting garment for the protection of thetender flesh. Its perfect elasticity beautifully adapts it to every motionof the body. We shall learn hereafter that it is more than a merecovering, being an active organ, which does its part in the work ofkeeping in order the house in which we live. It oils itself to preserveits smoothness and delicacy, replaces itself as fast as it wears out, andis at once the perfection of use and beauty. 

1. STRUCTURE OF THE SKIN. 

CUTIS AND CUTICLE. --What we commonly call the skin--viz. , the part raisedby a blister--is only the cuticle [Footnote: _Cuticula_, little skin. It is often styled the scarfskin, and also the epidermis (_epi_, upon; and _derma_, skin). ] or covering of the cutis or true skin. Thelatter is full of nerves and blood vessels, while the former neitherbleeds [Footnote: We notice this in shaving; for if a razor goes below thecuticle, it is followed by pain and blood. So insensible is this outerlayer that we can run a pin through the thick mass at the roots of thenails without discomfort. ] nor gives rise to pain, neither suffers fromheat nor feels the cold. 

The cuticle is composed of small, flat cells or scales. These areconstantly shed from the surface in the form of scurf, dandruff, etc. , butare as constantly renewed from the cutis [Footnote: We see how rapidlythis change goes on by noticing how soon a stain of any kind disappearsfrom the skin. A snake throws off its cuticle entire, and at regularintervals. ] below. 

Under the microscope, we can see the round cells of the cuticle, and howthey are flattened and hardened as they are forced to the surface. Theimmense number of these cells surpasses comprehension. In one square inchof the cuticle, counting only those in a single layer, there are over abillion horny scales, each complete in itself. --HARTING. 

FIG. 22. 

[Illustration: A _represents a vertical section of the Cuticle. _ B, _lateral view of the cells. _ C, _flat side of scales like_ d, _magnified 250 diameters, showing the nucleated cells transformed intobroad scales. _]

VALUE OF THE CUTICLE. --In the palm of the hand, the sole of the foot, andother parts especially liable to injury, the cuticle is very thick. Thisis a most admirable provision for their protection. [Footnote: We can holdthe hand in strong brine with impunity, but the smart will quickly tell uswhen there is even a scratch in the skin. Vaccine matter must be insertedbeneath the cuticle to take effect. This membrane doubtless prevents manypoisonous substances from entering the system. ] By use, it becomes callousand horny. The boy who goes out barefoot for the first time, "treading asif on eggs, " can soon run where he pleases among thistles and over stones. The blacksmith handles hot iron without pain, while the mason lays stonesand works in lime, without scratching or corroding his flesh. 

THE COMPLEXION. --In the freshly made cells on the lower side of thecuticle, is a pigment composed of tiny grains. [Footnote: These grains areabout 1/2000 of an inch in diameter, and, curiously enough, do not appearopaque, but transparent and nearly colorless. --MARSHALL. ] In the varyingtint of this coloring matter, lies the difference of hue between theblonde and the brunette, the European and the African. In the purestcomplexion, there is some of this pigment, which, however, disappears asthe fresh, round, soft cells next the cutis change into the old, flat, horny scales at the surface. 

Scars are white, because this part of the cuticle is not restored. The sunhas a powerful effect upon the coloring matter, and so we readily "tan" onexposure to its rays. If the color gathers in spots, it forms freckles. [Footnote: This action of the sun on the pigment of the skin is verymarked. Even among the Africans, the skin is observed to lose its intenseblack color in those who live for many months in the shades of the forest. It is said that Asiatic and African women confined within the walls of theharem, and thus secluded from the sun, are as fair as Europeans. Among theJews who have settled in Northern Europe, are many of light complexion, while those who live in India are as dark as the Hindoos. Intense heatalso increases this coloring matter, and thus a furnace-man's skin, evenwhere protected by clothing, becomes completely bronzed. The black pigmenthas been known to disappear during severe illness, and a lighter color tobe developed in its place. Among the negroes, are sometimes found peoplewho have no complexion, _i. E. _, there is no coloring matter in theirskin, hair, or the iris of their eyes. These persons are called Albinos. ]

II. HAIR AND NAILS. 

The Hair and the Nails are modified forms of the cuticle. 

FIG. 23. 

[Illustration: A _Hair, magnified 600 diameters. _ S, _the sac(follicle);_ P, _the papilla, showing the cells and the bloodvessels:_ V. ]

THE HAIR is a protection from heat and cold, and shields the head fromblows. It is found on nearly all parts of the body, except the palms ofthe hands and the soles of the feet. The outside of a hair is hard andcompact, and consists of a layer of colorless scales, which overlie oneanother like the shingles of a house; the interior is porous, [Footnote:In order to examine a hair, it should be put on the slide of themicroscope, and covered with a thin glass, while a few drops of alcoholare allowed to flow between the cover and the slide. This causes the air, which fills the hair and prevents our seeing its structure, to escape. ]and probably conveys the liquids by which it is nourished. 

Each hair grows from a tiny bulb (papilla), which is an elevation of thecutis at the bottom of a little hollow in the skin. From the surface ofthis bulb, the hair is produced, like the cuticle, by the constantformation of new cells at the bottom. When the hair is pulled out, thisbulb, if uninjured, will produce a new one; but, when once destroyed, itwill never grow again. [Footnote: Hair grows at the rate of about five toseven inches in a year. It is said to grow after death. This appearance isdue to the fact that by the shrinking of the skin the part below thesurface is caused to project, which is especially noticeable in thebeard. ] The hair has been known to whiten in a single night by fear, fright, or nervous excitement. When the color has once changed, it can notbe restored. [Footnote: Hair dyes, or so-called "hair restorers, " arealmost invariably deleterious substances, depending for their coloringproperties upon the action of lead or lunar caustic. Frequent instances ofhair poisoning have occurred, owing to the common use of such dangerousarticles. If the growth of the hair be impaired, the general constitutionor the skin needs treatment. This is the work of a skillful physician, andnot of a patent remedy. Dame Fashion has her repentant freaks as well asher ruinous follies, and it is a healthful sign that the era of universalhair dyeing has been blotted out from her present calendar, and the grayhairs of age are now honored with the highest place in "style" as well asin good sense and cleanliness. ] (See p. 285. )

Wherever hair exists, tiny muscles are found, interlaced among the fibersof the skin. These, when contracting under the influence of cold orelectricity, pucker up the skin, and cause the hair to stand on end. [Footnote: In horses and other animals which are able to shake the wholeskin, this muscular tissue is much more fully developed than in man. ] Thehairs themselves are destitute of feeling. Nerves, however, are found inthe hollows in which the hair is rooted, and so one feels pain when it ispulled. [Footnote: These nerves are especially abundant in the whiskers ofthe cat, which are used as feelers. ] Thus the insensible hairs becomewonderfully delicate instruments to convey an impression of even theslightest touch. 

FIG. 24. 

[Illustration: A, _a perspiratory tube with its gland;_ B, _a hairwith a muscle and two oil glands;_ C, _cuticle;_ D, _thepapillæ;_ and E, _fat cells. _]

Next to the teeth and bones, the hair is the least destructible part ofthe body, and its color is often preserved for many years after the otherportions have gone to decay. [Footnote: Fine downy hairs, such as aregeneral upon the body, have been detected in the little fragments of skinfound beneath the heads of the nails by which, centuries ago, certainrobbers were fastened to the church doors, as a punishment for theirsacrilege. ]

THE NAILS protect the ends of the tender finger, and toe, and give uspower more firmly to grasp and easily to pick up any object we may desire. They enable us to perform a hundred little, mechanical acts which elsewere impossible. At the same time, their delicate color and beautifuloutline give a finish of ornament to that exquisite instrument, the hand. The nail is firmly set in a groove (matrix) in the cuticle, from which itgrows at the root in length [Footnote: By making a little mark on the nailnear the root we can see, week by week, how rapidly this process goes on, and so form some idea of what a multitude of cells must be transformedinto the horny matter of the nail. ] and from beneath in thickness. So longas the matrix at the root is uninjured, the nail will be replaced afterany accident. (See p. 288. )

III. THE MUCOUS MEMBRANE. 

STRUCTURE. --At the edges of the openings into the body, the skin seems tostop and give place to a tissue which is redder, more sensitive, moreliable to bleed, and is moistened by a fluid, or mucus, as it is called. Really, however, the skin does not cease, but passes into a more delicatecovering of the same general structure, viz. , an outer, hard, bloodless, insensible layer, and an inner, soft, sanguine, nervous one. [Footnote:With a dull knife, we can scrape from the mucous membrane which lines themouth some of the cuticle for examination under the microscope. In asimilar way, we can obtain cuticle from the surface of the body for studyand comparison. ] Thus every part of the body is wrapped in a kind ofdouble bag, made of tough skin on the outside, and tender mucous membraneon the inside. 

CONNECTIVE TISSUE. --The cutis and the corresponding layer of the mucousmembrane consist chiefly of a fibrous substance interlaced, like felt. Itis called connective tissue, because it connects all the different partsof the body. It spreads from the cutis, invests muscles, bones, andcartilages, and thence passes into the mucous membrane. So thoroughly doesit permeate the body, that, if the other tissues were destroyed, it wouldgive a perfect model of every organ. [Footnote: It is curious to noticehow our body is wrapped in membrane. On the outside, is the skinprotecting from exterior injury, and, on the inside, is the mucousmembrane reaching from the lips to the innermost air cell of the lungs. Every organ is enveloped in its membrane. Every bone has its sheath. Everysocket is lined. Even the separate fibers of muscles have their coveringtissue. The brain and the spinal cord are triply wrapped, while the eye isonly a membranous globe filled with fluid. These membranes protect andsupport the organs they enfold, but, with that wise economy socharacteristic of nature everywhere, they have also an important functionto perform. They are the _filters_ of the body. Through their porespass alike the elements of growth, and the returning products of waste. Onone side, bathed by the blood, they choose from it suitable food for theorgan they envelop, and many of them in their tiny cells, by somemysterious process, form new products, --put the finishing touches, as itwere, upon the material ere it is deposited in the body. ] It can be seenin a piece of meat as a delicate substance lying between the layers ofmuscle, where it serves to bind together the numerous fibers of which theyare composed. 

Connective tissue yields gelatine on boiling, and is the part which tanswhen hides are manufactured into leather. It is very elastic, so that whenyou remove your finger after pressing upon the skin, no indentation isleft. [Footnote: In dropsy, this elasticity is lost by distension, andthere is a kind of "pitting, " as it is called, produced by pressure. ] Itvaries greatly in character, --from the mucous membrane, where it is softand tender, to the ligaments and tendons which it largely composes, whereit is strong and dense. [Footnote: The leather made from this tissuevaries as greatly, from the tough, thick oxhide, to the soft, pliable kidand chamois skin. ]

FAT is deposited as an oil in the cells [Footnote: So tiny are thesecells, that there are over sixty-five million in a cubic inch of fat. Asthey are kept moist, the liquid does not ooze out, but, on drying, itcomes to the surface, and thus a piece of fat feels oily when exposed tothe air. The quantity of fat varies with the state of nutrition. Incorpulent persons, the masses of fat beneath the skin, in the mesentery, on the surface of the heart and great vessels, between the muscles, and inthe neighborhood of the nerves, are considerably increased. Conversely, inthe emaciated we sometimes find beneath the skin nucleated cells, whichcontain only one oil drop. Many masses of fat which have an importantrelation to muscular actions--such as the fat of the orbit or the cheek--do not disappear in the most emaciated object. Even in starvation, thefatty substances of the brain and spinal cord are retained. --VALENTIN. ] ofthis tissue, just beneath the skin (Fig. 24), giving roundness andplumpness to the body, and acting as an excellent nonconductor for theretention of heat. It collects as pads in the hollows of the bones, aroundthe joints, and between the muscles, causing them to glide more easilyupon each other. As marrow, it nourishes the skeleton, and alsodistributes the shock of any jar the limb may sustain. 

It is noticeable, however, that fat does not gather within the cranium, the lungs, or the eyelids, where its accumulation would clog the organs. 

IV. THE TEETH. 

THE TEETH [Footnote: Although the teeth are always found in connectionwith the skeleton, and are, therefore, figured as a part of it (Fig. 1), yet they do not properly belong to the bones of the body, and are merelyset in the solid jaw to insure solidity. They are hard, and resemble bonymatter, yet they are neither true bone nor are they formed in the samemanner. "They are properly appendages of the mucous membrane, and aredeveloped from it. "--LEIDY. "They belong to the Tegumentary System, which, speaking generally of animals, includes teeth, nails, horns, scales, andhairs. "--MARSHALL. They are therefore classed with the mucous membrane, asare the nails and hair with the skin. ] are thirty-two in all, --there beingeight in each half jaw, similarly shaped and arranged. In each set ofeight, the two nearest the middle of the jaw have wide, sharp, chisel-likeedges, fit for cutting, and hence are called _incisors_. The next onecorresponds to the great tearing or holding tooth of the dog, and isstyled the _canine_, or eye-tooth. The next two have broader crowns, with two points, or cusps, and are hence termed the _bicuspids_. Theremaining three are much broader, and, as they are used to crush the food, are called the _grinders_, or _molars_. The incisors andeyeteeth have one fang, or root; the others have two or three fangs. 

THE MILK TEETH. --We are provided with two sets of teeth. The first, ormilk teeth, are small and only twenty in number. In each half jaw thereare two incisors, one canine, and two molars. The middle incisors areusually cut about the age of seven months, the others at nine months, thefirst molars at twelve months, the canines at eighteen months, and theremaining molars at two or three years of age. The lower teeth precede thecorresponding upper ones. The time often varies, but the order seldom. 

THE PERMANENT TEETH. --At six years, when the first set is usually stillperfect, the jaws contain the crowns of all the second, except the wisdomteeth. About this age, to meet the wants of the growing body, the crownsof the permanent set begin to press against the roots of the milk teeth, which, becoming absorbed, leave the loosened teeth to drop out, while thenew ones rise and occupy their places. [Footnote: If the milk teeth, donot promptly loosen on the appearance of the second set, the former shouldbe at once removed to permit the permanent teeth to assume their naturalplaces. If any fail to come in regularly, or if they crowd the others, acompetent dentist should be consulted. ]

FIG. 25. 

[Illustration: _The teeth at the age of six and one half years. _ I, _the incisors;_ O, _the canine;_ M, _the molars; the lastmolar is the first of the permanent teeth;_ F, _sacs of the permanentincisors;_ C, _of the canine;_ B, _of the bicuspids;_ N, _of the second molar; the sac of the third molar is empty. _--MARSHALL. ]

The central incisors appear at about seven years of age; the others ateight; the first bicuspids at nine, the second at ten; the canines ateleven or twelve; the second [Footnote: The first molar appears muchearlier. (See Fig. 25. )] molars at twelve or thirteen, and the last, orwisdom teeth, are sometimes delayed until the twenty-second year, or evenlater. 

STRUCTURE OF THE TEETH. --The interior of the tooth consists principally of_dentine_, a dense substance resembling bone. [Footnote: In the tuskof the elephant this is known as ivory. ] The crown of the tooth, which isexposed to wear, is protected by a sheath of _enamel_. This is ahard, glistening, white substance, containing only two and a half per centof animal matter. The fang is covered by a thin layer of true bone(cement). 

FIG. 26. 

[Illustration: _Vertical section of a Molar Tooth, moderatelymagnified. _ a, _enamel of the crown, the lines of which indicate thearrangement of its columns;_ b, _dentine;_ c, _cement;_ d, _pulp cavity. _]

At the center of the tooth is a cavity filled with a soft, reddish-white, pulpy substance full of blood vessels and nerves. This pulp is verysensitive, and toothache is caused by its irritation. 

THE FITTING OF THE TOOTH INTO THE JAW is a most admirable contrivance. Itis not set like a nail in wood, having the fang in contact with the bone;but the socket is lined with a membrane which forms a soft cushion. Whilethis is in a healthy state, it deadens the force of any shock, but, wheninflamed, it becomes the seat of excruciating pain. 

THE DECAY OF THE TEETH [Footnote: Unlike the other portions of the body, there is no provision made for any change in the permanent teeth. Thatpart, however, which is thus during life most liable to change, afterdeath resists it the longest. In deep-sea dredgings teeth are found whenall traces of the frame to which they belonged have disappeared. Yet hardand incorruptible as they seem, their permanence is only relative. Exposedto injury and disease, they break or decay. Even if they escape accident, they yet wear at the crown, are absorbed at the fang, and, in time, dropout, thus affording another of the many signs of the limitationsProvidence has fixed to the endurance of our bodies and the length of ourlives. ] is commonly caused (1) by portions of the food which becomeentangled between them, and, on account of the heat and moisture, quicklydecompose; and (2) by the saliva, as it evaporates, leaving on the teeth asediment, which we call tartar. This collects organic matter that rapidlychanges, and also affords a soil in which a sort of fungus speedilysprings up. From both these causes, the breath becomes offensive, and theteeth are injured. 

PRESERVATION OF THE TEETH. --Children should early be taught to brush theirteeth at least every morning with tepid water, and twice a week with whitecastile soap and powdered orris root, or with some dentifrice recommendedby a responsible dentist. They should also be instructed to remove theparticles of food from between the teeth, after each meal, by means of aquill or wooden toothpick. 

The enamel once injured is never restored, and the whole interior of thetooth is exposed to decay. We should not, therefore, crack hard nuts, bitethread, or use metal toothpicks, gritty tooth powders, or any acid which"sets the teeth on edge, " _i. E. _. That acts upon the enamel. It iswell also to have the teeth examined yearly by a dentist, that any smallorifice may be filled, and further decay prevented. 

V. THE GLANDS OF THE SKIN. 

1. THE OIL GLANDS are clusters of tiny sacs which secrete an oil thatflows along the duct to the root of the hair, and thence oozes out on thecuticle (Fig. 24). [Footnote: This secretion is said to vary in differentpersons, and on that account the dog is enabled to trace his master by thescent. ] This is nature's efficient hair-dressing, and also keeps the skinsoft and flexible. These glands are not usually found where there is nohair, as on the palm of the hand, and hence at those points only can waterreadily soak through the skin into the body. They are of considerable sizeon the face, especially about the nose. When obstructed, their contentsbecome hard and dark-colored, and are vulgarly called "worms. " [Footnote:Though they are not alive, yet, under the microscope, they are sometimesfound to contain a curious parasite, called the pimple mite, which issupposed to consume the superabundant secretion. ]

II. THE PERSPIRATORY GLANDS are fine tubes about 1/300 of an inch indiameter, and a quarter of an inch in length, which run through the cutis, and then coil up in little balls (Fig. 24). They are found in all parts ofthe body, and in almost incredible numbers. In the palm of the hand, thereare about two thousand eight hundred in a single square inch. On the backof the neck and trunk, where they are fewest, there are yet four hundredto the square inch. The total number on the body of an adult is estimatedat about two and a half million. If they were laid end to end, they wouldextend nearly ten miles. [Footnote: The current statement, that they wouldextend twenty-eight miles, is undoubtedly an exaggeration. Krauseestimates the total number at 2, 381, 248, and the length of each coil, whenunraveled, at 1/10 of an inch, which would make the total length much lessthan even the statement in the text. Seguin states that the proportion ofimpurities thrown off by the skin and the lungs, is eleven to seven. ] Themouths of these glands--"pores, " as we commonly call them--may be seenwith a pocket lens along the fine ridges which cover the palm of the hand. 

THE PERSPIRATION. --From these openings, there constantly passes a vapor, forming what we call the insensible perspiration. Exercise or heat causesit to flow more freely, when it condenses on the surface in drops. Theperspiration consists of about ninety-nine parts water, and one part solidmatter. The amount varies greatly, but on the average is, for an adult, not far from two pounds per day. Any suppression of this constant drainagewill lead to disagreeable and even dangerous results. If it be entirelyand permanently checked, death will inevitably ensue. [Footnote: Once, onan occasion of great solemnity at Rome, a child was, it is said, completely covered with gold leaf, closely applied to the skin, so as torepresent, according to the idea of that age, the golden glory of an angelor seraph. In a few hours, after contributing to this pageant, the childdied; the cause being suffocation, from stopping the exhalation of theskin; although, in the ignorance of the common people of those days, thedeath was attributed to the anger of the Deity, and looked upon as acircumstance of evil omen. ]

THE ABSORBING POWER OF THE SKIN. --We have already described two uses ofthe skin: (1) Its _protective_, (2) its _exhaling_, and now wecome to (3) its _absorbing_ power. This is not so noticeable as theothers, and yet it can be illustrated. Persons frequently poison theirhands with the common wood ivy. Contagious diseases are taken by touchinga patient, or even his clothing, especially if there be a crack in thecuticle. [Footnote: If one is called upon to handle a dead body, it iswell, especially if the person has died of a contagious disease, to rubthe hand with lard or olive oil. Poisonous matter has been fatallyabsorbed through the breaking of the cuticle by a hangnail, or a simplescratch. There is a story that Bonaparte, when a lieutenant of artillery, in the heat of battle, seized the rammer and worked the gun of anartilleryman who had fallen. From the wood which the soldier had used, Bonaparte absorbed a poison that gave him a skin disease, by which he wasannoyed the remainder of his life. ] Painters absorb so much lead throughthe pores of their hands that they are attacked with colic. [Footnote:Cosmetics, hair dyes, etc. , are exceedingly injurious, not only becausethey tend to fill the pores of the skin, but because they often containpoisonous matters that may be absorbed into the system, especially if theyare in a solution. ] Snuff and lard are frequently rubbed on the chest of achild suffering with the croup, to produce vomiting. It is said thatseamen in want of water drench their clothing in salt spray, when the skinwill absorb enough moisture to quench thirst (see Lymphatic System). 

By carefully conducted experiments, it has been found that the skin actsin the same way as the lungs (see Respiration) in absorbing oxygen fromthe air, and giving off carbonic acid to a small but appreciable amount. Indeed, the skin has not inaptly been styled the third lung. Hence, theimportance of absolute cleanliness and a frequent ablution of the entirebody. 

VI. HYGIENE. 

HINTS ABOUT WASHING AND BATHING. --The moment of rising from bed is theproper time for the full wash or bath with which one should commence theday. The body is then warm, and can endure moderately cold water betterthan at any other time; it is relaxed, and needs bracing; and the nerves, deadened by the night's repose, require a gentle stimulus. If the systembe strong enough to resist the shock, cold water is the most invigorating;if not, a tepid bath will answer. [Footnote: Many persons have not theconveniences for a bath. To them, the following plan, which the author hasdaily employed for years, is commended. The necessities are: a basin fullof soft water, a mild soap, a large sponge or a piece of flannel, and twotowels--one soft, the other rough. The temperature of the water shouldvary with the season of the year--cold in summer and tepid in winter. Rubquickly the entire body with the wet sponge or flannel. (If moreagreeable, wash and wipe only a part at a time, protecting the rest incold weather with portions of clothing. ) Dry the skin gently with a softtowel, and when quite dry, with the rough towel or flesh brush rub thebody briskly four or five minutes till the skin is all aglow. The chestand abdomen need the principal rubbing. The roughness of the towel shouldbe accommodated to the condition of the skin. Enough friction, however, must be given to produce at least a gentle warmth, indicative of thereaction necessary to prevent subsequent chill or languor. An invalid willfind it exceedingly beneficial if a stout, vigorous person produce thereaction by rubbing with the hands. ]

Before dressing, the whole body should be thoroughly rubbed with a coarsetowel or flesh brush. At first, the friction may be unpleasant, but thissensitiveness will soon be overcome, and the keenest pleasure be felt inthe lively glow which follows. A bath should not be taken just before norimmediately after a meal, as it will interfere with the digestion of thefood. Soap should be employed occasionally, but its frequent use tends tomake the skin dry and hard. 

REACTION. --After taking a cold bath, there should be a prompt reaction. When the surface is chilled by cold water, the blood sets to the heart andother vital organs, exciting them to more vigorous action, and then, beingthrown back to the surface, it reddens, warms, and stimulates the skin toan unwonted degree. This is called the reaction, and in it lies theinvigorating influence of the cold bath. When, on the contrary, the skinis heated by a hot bath, the blood is drawn to the surface, less bloodgoes to the heart, the circulation decreases, and languor ensues. A dashof cold water is both necessary and refreshing at the close of a hot bath. [Footnote: The Russians are very fond of vapor baths, taken in thefollowing manner. A large room is heated by stoves. Red-hot stones beingbrought in, water is thrown upon them, filling the room with steam. Thebathers sit on benches until they perspire profusely, when they are rubbedwith soapsuds and dashed with cold water. Sometimes, while in this stateof excessive perspiration, they run out of doors and leap into snowbanks. ]

If, after a cold bath, there be felt no glow of warmth, but only achilliness and depression, we are thereby warned that either proper meanswere not taken to bring on this reaction, or that the circulation is notvigorous enough to make such a bath beneficial. The general effect of acool bath is exhilarating, and that of a warm one depressing. [Footnote:The sudden plunge into a cold bath is good for the strong and healthy, buttoo severe for the delicate. One should always wet first the face, neck, and chest. It is extremely injurious to stand in a bath with only the feetand the lower limbs covered by the water, for the blood is thus sent fromthe extremities to the heart and internal organs, and they become soburdened that reaction may be out of their power. A brisk walk, or athorough rubbing of the skin, before a cold bath or swim, adds greatly toits value and pleasure. ] Hence the latter should not ordinarily be takenoftener than once a week, while the former may be enjoyed daily. (See p. 289. )

SEA BATHING is exceedingly stimulating, on account of the action of thesalt and the exciting surroundings. Twenty minutes is the utmost limit forbathing or swimming in salt or fresh water. A chilly sensation should bethe signal for instant removal. It is better to leave while the glow andbuoyancy which follow the first plunge are still felt. Gentle exerciseafter a bath is beneficial. 

CLOTHING in winter, to keep us warm, should repel the external cold andretain the heat of the body. In summer, to keep us cool, it should notabsorb the rays of the sun, and should permit the passage of the heat ofthe body. At all seasons, it should be porous, to give ready escape to theperspiration, and a free admission of air to the skin. We can readilyapply these essential conditions to the different kinds of clothing. 

_Linen_ is soft to the touch, and is a good conductor of heat. Henceit is pleasant for summer wear, but, being apt to chill the surface toorapidly, it should not be worn next the skin. 

_Cotton_ is a poorer conductor of heat and absorber of moisture, andis therefore warmer than linen. It is sufficiently cool for summer wear, and affords better protection against sudden changes. 

_Woolen_ absorbs moisture slowly, and contains much air in its pores. It is therefore a poor conductor of heat, and guards the wearer againstthe vicissitudes of our climate. 

The outer clothing may be adapted largely to ornament, and may be variedto suit our fancy and the requirements of society. The underclothingshould always be sufficient to keep us warm. Woolen should be worn nextthe skin at all times; light gossamer garments in the heat of summer, andwarm, porous flannels in midwinter. 

Light-colored clothing is not only cooler in summer, but warmer in winter. As the warmth of clothing depends greatly on the amount of air containedin its fibers, fine, loose, porous cloth with a plenty of nap is best forwinter wear. Firm and heavy goods are not necessarily the warmest. Fursare the perfection of winter clothing, since they combine warmth withlightness. Two light woolen garments are warmer than one heavy one, asthere is between them a layer of nonconducting air. 

All the body except the head should be equally protected by clothing. Whatever fashion may dictate, no part covered to-day can be uncoveredtonight or to-morrow, except at the peril of health. It is a mostbarbarous and cruel custom to leave the limbs of little childrenunprotected, when adults would shiver at the very thought of exposure. Equally so is it for children to be thinly clad for the purpose ofhardening them. To go shivering with cold is not the way to increase one'spower of endurance. The system is made more vigorous by exercise and food;not by exposure. In winter, we should wear warm shoes with thick soles, and rubbers when it is damp. At night, and after exercise, we requireextra clothing. (See p. 295. )

DISEASES, ETC. --l. _Erysipelas_ is an inflammation (see Inflammation)of the skin, and often begins in a spot not larger than a pin head, whichspreads with great rapidity. It is very commonly checked by theapplication of a solution of iodine. The burning and contracting sensationmay be relieved by cloths wrung out of hot water. 

2. _Eczema_ (Salt Rheum, etc. ) is of constitutional origin. It ischaracterized by an itching, burning, reddened eruption, in which a serousdischarge exudes and dries into crusts or scales. The skin thickens inpatches, and painful fissures are formed, which are irritated by exposureto air or water. Eczema denotes debility. It occurs in various forms, and, like erysipelas, should be treated by a physician. 

3. _Corns_ are thickened cuticle, caused by pressure or friction. They most frequently occur on the feet; but are produced on theshoemaker's knee by constant hammering, and on the soldier's shoulder bythe rubbing of his musket. This hard portion irritates the sensitive cutisbeneath, and so causes pain. A corn will soften in hot water, when it maybe pared with a sharp knife. If the cause be removed, the corn will notreturn. 

4. _Ingrowing Nails_ are caused by pressure, which forces the edge ofthe toe nail into the flesh. They may be cured by carefully cutting awaythe part which has mal-grown, and then scraping the back of the nail tillit is thin, making a small incision in the center, at the top. The twoportions, uniting, will draw away the nail from the flesh at the edge. Ingrowing nails may be prevented by wearing broad-toed shoes. 

5. _Warts_ are overgrown papillæ (Fig. 24). They may generally beremoved by the application of glacial acetic acid, or a drop of nitricacid, repeated until the entire structure is softened. Care must be takento keep the acid from touching the neighboring skin. The capriciouscharacter of warts has given rise to the popular delusion concerning theinfluence of charms upon them. 

6. _Chilblain_ is a local inflammation affecting generally the feet, the hands, or the lobes of the ear. Liability to it usually passes awaywith manhood. It is not caused by "freezing the feet, " as many suppose, though attacks are brought on, or aggravated, by exposure to cold, followed by sudden warming. Chilblain is subject to daily congestion (seeCongestion), manifested by itching, soreness, etc. , commonly occurring atnight. The best preventive is a uniform temperature, and carefulprotection against the cold by warm clothing, especially for the feet. 

PRACTICAL QUESTIONS. 

1. If a hair be plucked out, will another grow in its place?

2. What causes the hair to "stand on end" when we are frightened?

3. Why is the skin roughened by riding in the cold?

4. Why is the back of a washerwoman's hand less water-soaked than thepalm?

5. What would be the length of the perspiratory tubes in a single squareinch of the palm, if placed end to end?

6. What colored clothing is best adapted to all seasons?

7. What is the effect of paint and powder on the skin?

8. Is waterproof clothing healthful for constant wear?

9. Why are rubbers cold to the feet?

10. Why does the heat seem oppressive when the air is moist?

11. Why is friction of the skin invigorating after a cold bath?

12. Why does the hair of domestic animals become roughened in winter?

13. Why do fowls spread their feathers before they perch for the night?

14. How can an extensive burn produce congestion of the lungs?

15. Why do we perspire so profusely after drinking cold water?

16. How can we best prevent skin diseases, colds, and rheumatism?

17. What causes the difference between the hard hand of a blacksmith andthe soft hand of a woman?

18. Why should a painter avoid getting paint on the palm of his hand?

19. Why should we not use the soap or the soiled towel at a hotel?

20. Which teeth cut like a pair of scissors?

21. Which teeth cut like a chisel?

22. Which should be clothed the warmer, a merchant or a farmer? 23. Whyshould we not crack nuts with our teeth?

24. Do the edges of the upper and the lower teeth meet?

25. When fatigued, would you take a cold bath?

26. Why is the outer surface of a kid glove finer than the inner?

27. Why will a brunette endure the sun's rays better than a blonde?

28. Does patent leather form a healthful covering for the feet?

29. Why are men more frequently bald than women?

30. On what part of the head does baldness commonly occur? Why?

31. What does the combination in our teeth of canines and grinders suggestas to the character of our food?

32. Is a staid, formal promenade suitable exercise?

33. Is there any danger in changing the warm clothing of our daily wearfor the thin one of a party?

34. Should we retain our overcoat, shawl, or furs when we come into a warmroom?

35. Which should bathe the oftener, students or outdoor laborers?

36. Is abundant perspiration injurious?

37. How often should the ablution of the entire body be performed?

38. Why is cold water better than warm, for our daily ablution?

39. Why should our clothing always fit loosely?

40. Why should we take special pains to avoid clothing that is colored bypoisonous dyestuffs? (See p. 296. )

41. What general principles should guide us as to the length and frequencyof baths In salt or fresh water?

42. What is the beneficial effect of exercise upon the functions of theskin?

43. How can we best show our admiration and respect for the human body?

44. Why is the scar of a severe wound upon a negro sometimes white?

IV. 

RESPIRATION AND THE VOICE. 

"The smooth soft air with pulse-like wavesFlows murmuring through its hidden caves, Whose streams of brightening purple rush, Fired with a new and livelier blush;While all their burden of decayThe ebbing current steals away. "

ANALYSIS OF RESPIRATION AND THE VOICE. 

_| 1. The Larnyx. _ | 2. The Vocal Cords. | 1. ORGANS OF VOICE. . . . . | 3. Different Tones of Voice. | | 4. Speech. | |_5. Formation of Vocal Sounds. | _| | 1. The Trachea. | | 2. The Bronchial Tubes. | 2. ORGANS OF RESPIRA- | 3. The Cells. | TION. . . . . . . . . | 4. The Lung Wrapping. | |_5. The Cilia. | _| | 1. Inspiration. | 3. HOW WE BREATHE. . . . . . |_2. Expiration. | _| | 1. Sighing. | | 2. Coughing. | | 3. Sneezing. | 4. MODIFICATIONS OF | 4. Snoring. | THE BREATH. . . . . . . | 5. Laughing, and Crying. | | 6. Hiccough. | |_7. Yawning. || 5. CAPACITY OF THE LUNGS. | _| | 1. The Need of Air. | | 2. Action of Air in the Lungs. | | 3. Tests of the Breath. | | 4. Analysis of Expired Air. | | 5. Effect of Rebreathed Air. | | _| 6. HYGIENE. . . . . . . . . . . . . | | a. _The Sources of| | | Impurity. _| | | b. _The Sick Room. _| | 6. Concerning | c. _The Sitting Room. _| | the Need of | d. _The Bedroom. _| |_ Ventilation. | e. _The Church. _| | f. _The Schoolroom. _| | g. _How we should| |_ Ventilate. _|| 7. THE WONDERS OF RESPIRATION. | _| | 1. Constriction of the Lungs. | | 2. Bronchitis. | | 3. Pleurisy. | | 4. Pneumonia. |_8. DISEASES. . . . . . . . . . . . | 5. Consumption| 6. Asphyxia. | 7. Diptheria. | 8. Croup. |_9. Stammering. 

RESPIRATION AND THE VOICE. 

The Organs of Respiration and the Voice are the _larynx_, the_trachea_, and the _lungs_. 

DESCRIPTION OF THE ORGANS OF THE VOICE. --l. _The Larynx_. --In theneck, is a prominence sometimes called Adam's apple. It is the front ofthe _larynx_. This is a small triangular, cartilaginous box, placedjust below the root of the tongue, and at the top of the windpipe. Theopening into it from the throat is called the _glottis_; and thecover, the _epiglottis_ (_epi_, upon; _glotta_, the tongue). Thelatter is a spoon-shaped lid, which opens when we breathe, but, bya nice arrangement, shuts when we try to swallow, and so lets ourfood slip over it into the _œsophagus_ (e-sof'-a-gus), the tube leadingfrom the pharynx to the stomach (Fig. 27). 

If we laugh or talk when we swallow, our food is apt to "go the wrongway, " _i. E. _, little particles pass into the larynx, and thetickling sensation which they produce forces us to cough in order to expelthe intruders. 

2. _The Vocal Cords_. --On each side of the _glottis_ are the so-called _vocal cords_. They are not really cords, but merely elasticmembranes projecting from the sides of the box across the opening. [Footnote: The cartilages and vocal cords may be readily seen in thelarynx of an ox or sheep. If the flesh be cut off, the cartilages willdry, and will keep for years. ] When not in use, they spread apart andleave a V-shaped orifice (Fig. 28), through which the air passes to andfrom the lungs. If the cords are tightened, the edges approach sometimeswithin 1/100 of an inch of each other, and, being thrown into vibration, cause corresponding vibrations in the current of air. Thus sound isproduced in the same manner as by the vibrations of the tongues of anaccordion, or the strings of a violin, only in this case the strings arescarcely an inch long. 

FIG. 27. 

[Illustration: _Passage to the Œsophagus and Windpipe. _ c, _thetongue;_ d, _the soft palate, ending in_ g, _the uvula;_ h, _the epiglottis;_ i, _the glottis;_ I, _the œsophagus;_ f, _the pharynx. _]

DIFFERENT TONES OF THE VOICE. --The higher tones of the voice are producedwhen the cords are short, tight, and closely in contact; the lower, by theopposite conditions. Loudness is regulated by the quantity of air andforce of expulsion. A falsetto voice is thought to be the result of apeculiarity in the pharynx (Fig. 27) at the back part of the nose; it ismore probably produced by some muscular maneuver not yet fully understood. When boys are about fourteen years of age, the larynx enlarges, and thecords grow proportionately longer and coarser; hence, the voice becomesdeeper, or, as we say, "changes. " The peculiar harshness of the voice atthis time seems to be due to a congestion of the mucous membrane of thecords. The change may occur very suddenly, the voice breaking in a singlenight. 

FIG. 28. 

[Illustration: e, e, _the vocal cords;_ d, _the epiglottis. _]

Speech is voice modulated by the lips, tongue, [Footnote: The tongue isstyled the "unruly member, " and held responsible for all the tattling ofthe world; but when the tongue is removed, the adjacent organs in some waylargely supply the deficiency, so that speech is still possible. Huxleydescribes the conversation of a man who had two and one half inches of histongue preserved in spirits, and yet could converse intelligibly. Only thetwo letters _t_ and _d_ were beyond his power; the articulationof these involves the employment of the tip of the tongue; hence, "tin" heconverted into "fin, " and "dog" into "thog. "] palate, and teeth. [Footnote: An artificial larynx may be made by using elastic bands torepresent the vocal cords, and by placing above them chambers which bytheir resonance will produce the same effect as the cavities lying abovethe larynx. An artificial speaking machine was constructed by Kempelen, which could pronounce such sentences as, "I love you with all my heart, "in different languages, by simply touching the proper keys. ] Speech andvoice are commonly associated, but speech may exist without the voice, forwhen we whisper we articulate the words, although there is novocalization, _i. E. _, no action of the larynx. [Footnote: We canobserve this by placing the hand on the throat, and noticing the absenceof vibrations when we whisper, and their presence when we talk. Thedifference between vocalization and non-vocalization is seen in a sigh anda groan, the latter being the former vocalized. Whistling is a pure mouthsound, and does not depend on the voice. Laughter is vocal, being theaspirated vowels, a, e, or o, convulsively repeated. ] (See p. 297. )

FIG. 29. 

[Illustration: _The Lungs, showing the Larynx. _ A, _thewindpipe;_ B, _the bronchial tubes. _]

FORMATION OF VOCAL SOUNDS. --The method of modulating voice into speech maybe seen by producing the pure vowel sounds _a, e_, etc. , from oneexpiration, the mouth being kept open while the form of the aperture ischanged for each vowel by the tongue and the lips. _H_ is only anexplosion, or forcible throwing of a vowel sound from the mouth. [Footnote: When, in sounding a vowel, the sound coincides with a suddenchange in the position of the vocal cords from one of divergence to one ofapproximation, the vowel is pronounced with the _spiritus asper_. When the vocal cords are brought together before the blast of air begins, the vowel is pronounced with the _spiritus lenis. _--FOSTER. ]

The consonants, or short sounds, may also be made without interrupting thecurrent of air, by various modifications of the vocal organs. In soundingsingly any one of the letters, we can detect its peculiar requirements. Thus _m_ and _n_ can be made only by blocking the air in themouth and sending it through the nose; _l_ lets the air escape at thesides of the tongue; _r_ needs a vibratory movement of the tongue;_b_ and _p_ stop the breath at the lips; _k_ and _g_ (hard), at theback of the palate. Consonants like _b_ and _d_ are abrupt, or, like_l_ and _s_, continuous. Those made by the lips are termed _labials_;those by pressing the tongue against the teeth, _dentals_; those by thetongue, _linguals_. 

The child gains speech slowly, first learning to pronounce the vowel_a_, the consonants _b, m_, and _p_, and then their unions --_ba, ma, pa_. 

DESCRIPTION OF THE ORGANS OF RESPIRATION. --Beneath the larynx is thewindpipe, or _trachea_ (see Fig. 29), so called because of itsroughness. It is strengthened by C-shaped cartilages with the openingsbehind, where they are attached to the œsophagus. At the lower end, thetrachea divides into two branches, called the right and left_bronchi_. These subdivide in the small bronchial tubes, which ramifythrough the lungs like the branches of a tree, the tiny twigs of which atlast end in clusters of cells so small that there are six hundred millionin all. This cellular structure renders the lungs exceedingly soft, elastic, and sponge-like. [Footnote: The lungs of slaughtered animals arevulgarly called "lights, " probably on account of their lightness. They aresimilar in structure to those of man. They will float on water, and if asmall piece be forcibly squeezed between the fingers (notice the creakingsound it gives), it will retain sufficient air to make it buoyant. ]

FIG. 30. 

[Illustration: _Bronchial Tubes, with clusters of cells. _]

The stiff, cartilaginous rings, so noticeable in the rough surface of thetrachea and the bronchi, disappear as we reach the smaller bronchialtubes, so that while the former are kept constantly open for the freeadmission of air, the latter are provided with elastic fibers by whichthey may be almost closed. 

WRAPPING OF THE LUNGS. --The lungs are invested with a double covering--the_pleura_--one layer being attached to the lungs and the other to thewalls of the chest. It secretes a fluid which lubricates it, so that thelayers glide upon each other with perfect ease. [Footnote: These pleuralsacs are distinct and closed; hence, when the ribs are raised, a partialvacuum being formed in the sacs, air rushes in, and distends the pulmonarylobules. ] The lungs are lined with mucous membrane, exceedingly delicateand sensitive to the presence of anything except pure air. We have allnoticed this when we have breathed any thing offensive. 

FIG. 31. 

[Illustration: A, _the heart;_ B, _the lungs drawn aside to showthe internal organs;_ C, _the diaphragm;_ D, _the liver;_ E, _the gall cyst;_ F, _the stomach;_ G, _ the small intestines;_ H, _the transverse colon. _]

THE CILIA. --Along the air passages are minute filaments (_cilia_, Fig. 32), which are in constant motion, like a field of grain stirred by agentle breeze. They serve to fan the air in the lungs, and produce anoutward current, which is useful in catching dust and fine particles sweptinward with the breath. 

HOW WE BREATHE. --Respiration consists of two acts--taking in the air, or_inspiration_, and expelling the air, or _expiration_. 

FIG. 32. 

[Illustration: B, _a section of the mucous membrane, showing the ciliarising from the peculiar epithelial cells on the outside of the mucousmembrane lining the tubes;_ A, _a single cell more highlymagnified. _]

1. _Inspiration_. --When we draw in a full breath, we straighten thespine and throw the head and shoulders back, so as to give the greatestadvantage to the muscles. [Footnote: If we examine the bony cage of thethorax or chest in Fig. 8, we shall see that the position of the ribs mayalter its capacity in two ways. 

1. As they run obliquely downward from the spine, if the sternum orbreastbone be lifted in front, the diameter of the chest will beincreased. 

2. The ribs are fastened by elastic cartilages, which stretch as themuscles that lift the ribs contract, and so increase the breadth of thechest. ]

At the same time, the diaphragm [Footnote: The diaphragm is the muscularpartition between the chest and the abdomen. It is always convex towardthe former, and concave toward the latter (Fig. 31). Long muscular fibersextend from its center toward the ribs in front and the spine at the back. When these contract, they depress and flatten the diaphragm; when theyrelax, it becomes convex again. In the former case, the bowels are presseddownward and the abdomen pushed outward; in the latter, the bowels springupward, and the abdomen is drawn inward. ] descends and presses the wallsof the abdomen outward. Both these processes increase the size of thechest. Thereupon, the elastic lungs expand to occupy the extra space, while the air, rushing in through the windpipe, pours along the bronchialtubes and crowds into every cell. [Footnote: It is said that in drawing afull breath, the muscles exert a force equal to raising a weight of sevenhundred and fifty pounds. When we are about to make a great effort, as instriking a heavy blow, we naturally take a deep inspiration, and shut theglottis. The confined air makes the chest tense and firm, and enables usto exert a greater force. As we let slip the blow, the glottis opens andthe air escapes, often with a curious aspirated sound as is noticeable inworkmen. To make a good shot with a rifle, we should take aim with a fullchest and tight breath, since then the arms will have a steadier support. ]

2. _Expiration_. --When we forcibly expel the air from our lungs, theoperation is reversed. We bend forward, draw in the walls of the abdomen, and press the diaphragm upward, while the ribs are pulled downward, --alltogether diminishing the size of the chest, and forcing the air outward. 

Ordinary, quiet breathing is performed mainly by the diaphragm, --onebreath to every four beats of the heart, or eighteen per minute. (See p. 299. )

MODIFICATIONS OF THE BREATH. --_Sighing_ is merely a prolongedinspiration followed by an audible expiration. _Coughing_ is aviolent expiration in which the air is driven through the mouth. _Sneezing_ differs from coughing, the air being forced through thenose. _Snoring_ is produced by the passage of the breath through thepharynx when the tongue and soft palate are in certain positions. [Footnote: The soft palate must have fallen back in such a manner asnearly or quite to close the entrance to the nasal cavity from the throat, and the tongue must also be thrown back so far as to leave only a narrowopening between it and the soft palate. The noise is produced by the airbeing forced either inward or outward through this opening. A snoreresults also when, with a closed mouth, the air is forced between the softpalate and the back wall of the pharynx into the nasal cavity. With deepbreathing, perhaps accompanied by a variation in the position of the softpalate, a rattling noise may be heard in addition to the snoring, which isdue to a vibration of the soft palate. --F. A. FERNALD, in "How we Sneeze, Laugh, Stammer, and Sigh. "--_Popular Science Monthly_, Feb. , 1884. ]_Laughing_ and _crying_ are very much alike. The expression ofthe face is necessary to distinguish between them. The sounds are producedby short, rapid contractions of the diaphragm. _Hiccough_ is confinedto inspiration. It is caused by a contraction of the diaphragm and aconstriction of the glottis; the current of air just entering, as itstrikes the closed glottis, gives rise to the well-known sound. _Yawning_, or _gaping_, is like sighing. [Footnote: Theusefulness of a yawn lies in bringing up the arrears, as it were, ofrespiration, when it has fallen behindhand, either through fatigue orclose attention to other occupation. The stretching of the jaws and limbsmay also serve to equalize the nervous influence, certain muscles havingbecome uneasy on account of being stretched or contracted for a longtime. ] It is distinguished by a wide opening of the mouth and a deep, profound inspiration. Both processes furnish additional air, and thereforeprobably meet a demand of the system for more oxygen. Frequently, however, they are like laughing, sobbing, etc. , merely a sort of contagion, whichruns through an audience, and seems almost irresistible. 

THE CAPACITY OF THE LUNGS. --If we take a deep inspiration, and thenforcibly exhale all the air we can expel from the lungs, this amount, which is termed the _breathing capacity_, will bear a very closecorrespondence to our stature. For a man of medium height (five feet eightinches) it will be about two hundred and thirty cubic inches, [Footnote:Of this amount, one hundred cubic inches can be forced in only by an extraeffort, and is available for emergencies, or for purposes of training, asin singing, climbing, etc. It is of great importance, since, if thecapacity of the lungs only equaled our daily wants, the least obstructionwould prove fatal. ] or a gallon, and for each inch of height between fiveand six feet there will be an increase of eight cubic inches. In addition, it is found that the lungs contain about one hundred cubic inches whichcan not be expelled, thus making their entire contents about three hundredand thirty cubic inches, or eleven pints. The extra amount always on handin the lungs is of great value, since thereby the action of the air goeson continuously, even during a violent expiration. In ordinary breathing, only about twenty or thirty cubic inches (less than a pint) of air pass inand out. 

THE NEED OF AIR. --The body needs food, clothing, sunshine, bathing, and. Drink; but none of these wants is so pressing as that for air. The otherdemands may be met by occasional supplies, but air must be furnished everymoment or we die. Now the vital element of the atmosphere is oxygen gas. [Footnote: See "Steele's Popular Chemistry, " p. 30. The atmosphereconsists of one fifth oxygen and four fifths nitrogen. The former is theactive element; and the latter, the passive. Oxygen alone would be toostimulating, and must be restrained by the neutral nitrogen. Separately, either element of the air would kill us. ] This is a stimulating, life-giving principle. No tonic will so invigorate as a few full, deep breathsof cold, pure air. Every organ will glow with the energy of the fieryoxygen. 

ACTION OF THE AIR IN THE LUNGS. --In the delicate cells of the lungs, theair gives up its oxygen to the blood, and receives in turn carbonic-acid[Footnote: More properly _Carbon dioxide_. ] gas and water, foul withwaste matter which the blood has picked up in its circulation through thebody. The blood, thus purified and laden with the inspiring oxygen, goesbounding through the system, while the air we exhale carries off theimpurities. In this process, the blood changes from purple to red. If weexamine our breath, we can readily see what it has removed from the blood. 

TESTS OF THE BREATH. --1. Breathe into a jar, and on lowering into it alighted candle, the flame will be instantly extinguished; thus indicatingthe presence of carbonic-acid gas. 2. Breathe upon a mirror, and a film ofmoisture will show the vapor. [Footnote: There is a close relation betweenthe functions of the skin, the lungs, and the kidneys--the scavengers ofthe body. They all carry off water from the blood, and when the functionof one of the three is, in this respect, interfered with, the others arecalled upon to perform its functions. When the function of perspiration isderanged, the lungs and kidneys are required to perform heavier duty, andthis may lead to disease (see p. 62). ] 3. If breath be confined in abottle, the animal matter will decompose and give off an offensive odor. 

ANALYSIS OF THE EXPIRED AIR shows that it has lost about twenty-five percent of its oxygen, and gained an equal amount of carbonic-acid gas, besides moisture, and organic impurities. Our breath, then, is air robbedof its vitality, and containing in its place a gas as fatal to life[Footnote: Carbonic-acid gas can not be breathed when undiluted, as theglottis closes and forbids its passage into the lungs. Air containing onlythree or four per cent acts as a narcotic poison (MILLER), and a muchsmaller proportion will have an injurious effect. The great danger, however, lies in the organic particles constantly exhaled from the lungsand the skin, which, it is believed, are often direct and active poisons. ]as it is to a flame, and effete matter which is disagreeable to the smell, injurious to the health, and which may contain the germs of seriousdisease. 

THE EVIL EFFECT OF REBREATHING the air can not be overestimated. We takeback into our bodies that which has just been rejected. The bloodthereupon leaves the lungs, bearing, not the invigorating oxygen, butrefuse matter to obstruct the whole system. We soon feel the effect. Themuscles become inactive. The blood stagnates. The heart acts slowly. Thefood is undigested. The brain is clogged. The head aches. Instances offatal results are only too frequent. [Footnote: During the English war inIndia, in the eighteenth century, one hundred and forty-six prisoners wereshut up in a room scarcely large enough to hold them. The air could enteronly by two narrow windows. At the end of eight hours, but twenty-threepersons remained alive, and these were in a most deplorable condition. This prison is well called "The Black Hole of Calcutta. "--Percy relatesthat after the battle of Austerlitz, three hundred Russian prisoners wereconfined in a cavern, where two hundred and sixty of them perished in afew hours. --The stupid captain of the ship _Londonderry_, during astorm at sea, shut the hatches. There were only seven cubic feet of spaceleft for each person, and in six hours ninety of the passengers weredead. ] The constant breathing of even the slightly impure air of ourhouses can not but tend to undermine the health. The blood is notpurified, and is thus in a condition to receive the seeds of disease atany time. The system uninspired by the energizing oxygen is sensitive tocold. The pale cheek, the lusterless eye, the languid step, speak but tooplainly of oxygen starvation. In such a soil, catarrh, scrofula, andkindred diseases run riot. [Footnote: One not very strong, or unablepowerfully to resist conditions unfavorable to health, and with apredisposition to lung disease, will be sure, sooner or later, by partiallung starvation and blood poisoning, to develop pulmonary consumption. _The lack of what is so abundant and so cheap--good, pure air--isunquestionably the one great cause of this terrible disease_. --BLACK'S_Ten Laws of Health_. ]

CONCERNING THE NEED FOR VENTILATION. --The foul air which passes off fromthe lungs and through the pores of the skin does not fall to the floor, but diffuses itself through the surrounding atmosphere. A single breathwill to a trifling but certain extent taint the air of a whole room. [Footnote: This grows out of a well-known philosophical principle calledthe Diffusion of Gases, whereby two gases tend to mix in exactproportions, no matter what may be the quantity of each. --STEELE'S_Popular Chemistry, _ p. 86, and _Popular Physics, _ p. 52. ] Alight will vitiate as much air as a dozen persons. Many breaths and lightstherefore rapidly unfit the air for our use. 

The perfection of ventilation is reached when the air of a room is as pureas that out of doors. To accomplish this result, it is necessary to allowfor each person six hundred cubic feet of space, while ventilation isstill going on in the best manner known. 

In spite of these well-known facts, scarcely any pains are taken to supplyfresh air, while the doors and windows where the life-giving oxygen mightcreep in are hermetically stopped. 

How often is this true of the sick room. Yet here the danger of bad air isintensified. The expired breath of the patient is peculiarly threateningto himself as well as to others. Nature is seeking to throw off the poisonof the disease. The scavengers of the body are all at work. The breath andthe insensible perspiration are loaded with impurities. [Footnote: Thefloating dust in the air, revealed to us by the sunbeam shining through acrack in the blinds, shows the abundance of these impurities, and also thepresence of germs which, lodging in the lungs, may implant disease, unlessthrown off by a vigorous constitution. "On uncovering a scarlet feverpatient, a cloud of fine dust is seen to rise from the body--contagiousdust, that for days will retain its poisonous properties. "--YOUMANS. (Seep. 300. )] The odor is oftentimes exceedingly offensive. Sick and wellalike need an abundance of fresh air. But, too often, it is the only wantnot supplied. 

Our sitting rooms, heated by furnaces or red-hot stoves, generally have nomeans of ventilation, or, if provided, they are seldom used. A window isoccasionally dropped to give a little relief, as if pure air were ararity, and must be doled out to the suffering lungs in morsels, insteadof full and constant draughts. The inmates are starved by scanty lungfood, and stupefied by foul air. The process goes on year by year. Theweakened and poisoned body at last succumbs to disease, while we, in ourblindness and ignorance, talk of the mysterious Providence which thusuntimely cuts down the brightest intellects. The truth is, death is oftensimply the penalty for violating nature's laws. Bad air begets disease;disease begets death. 

In our churches, the foul air left by the congregation on Sunday is shutup during the week, and heated for the next Lord's day, when the peopleassemble to rebreathe the polluted atmosphere. They are thus forced, withevery breath they take, to violate the physical laws of Him whom they meetto worship, --laws written not three thousand years ago upon Mount Sinai ontables of stone, but to-day engraved in the constitution of their ownliving, breathing bodies. On brains benumbed and starving for oxygen, thepurest truth and the highest eloquence fall with little force. 

We sleep in a small bedroom from which every breath of fresh air isexcluded, because we believe night air to be unhealthy, [Footnote: Thereis a singular prejudice against the night air. Yet, as FlorenceNightingale aptly says, what other air can we breathe at night? We thenhave the choice between foul air within and pure air without. For, inlarge cities especially, the night air is far more wholesome than that ofthe daytime. To secure fresh air at night, we must open the windows of ourbedroom. ] and so we breathe its dozen hogsheads of air over and overagain, and then wonder why we awaken in the morning so dull andunrefreshed! Return to our room after inhaling the fresh, morning air, andthe fetid odor we meet on opening the door, is convincing proof how wehave poisoned our lungs during the night. 

Each room should be supplied with two thousand feet of fresh air per hourfor every person it contains. Our ingenuity ought to find some way ofdoing this advantageously and pleasantly. A moiety of the care we devoteto delicate articles of food, drink, and dress would abundantly meet thisprime necessity of our bodies. 

Open the windows a little at the top and the bottom. Put on plenty ofclothing to keep warm by day and by night, and then let the inspiringoxygen come in as freely as God has given it. Pure air is the cheapestnecessity and luxury of life. Let it not be the rarest!

SCHOOLROOM VENTILATION. --Who, on going from the open air of a clear, bracing winter's day, into a crowded schoolroom, late in the session, hasnot noticed the disagreeable odor, and been for a moment nauseated andhalf stifled by the oppressive atmosphere! It is not strange. See how manycauses here combine to pollute the air. If the room is heated by a stove, quantities of carbonic-oxide and carbonic-acid gases, as well as otherproducts of combustion, driven by downward drafts in the flue, escapethrough seams and cracks and the occasionally opened door of the stove. Inthe case of a furnace, the same effect is too often experienced, and theodor of coal gas is a common one, especially when the fire is replenished. The insensible perspiration is more active in children than in adults;they, moreover, rush in with their clothing saturated with theperspiration induced by their sports; so that, on the average, each pupil, during school hours, loads the air with about half a pint of aqueousvapor. The children come, oftentimes, from homes that are close, ill-ventilated, and uncleanly; and frequently from sick rooms, bringing intheir clothing the germs of disease. (See p. 304. ) Some of the pupils mayeven bear traces of illness, or have unsound organs, and so their breathand exhalations be poisonous. 

In addition to all this, the air is filled with dust brought in and keptastir by many busy feet; with ashes floating from the stove or furnace;and especially with chalk dust. The modern method of teaching requires alarge amount of blackboard work, and the air of the schoolroom is thusloaded with chalk particles. These collect in the nasal passages, and theupper part of the larynx, and irritate the membrane, perhaps laying thefoundation of catarrh. 

The usual schoolroom atmosphere bears in the pupils the natural fruit offrequent headaches, inattention, weariness, and stupor; but in the teacherits frightful influence is most apparent. His labor is severe, his worryof mind is constant, and, when he finishes his day's work, he is generallytoo tired to take proper physical exercise. He consequently labors on withimpaired health, or is forced to abandon his profession. 

Instead of six hundred feet of space being allowed for each pupil, asperfect ventilation demands--the lowest estimate being two hundred andfifty feet--often not over one hundred feet are afforded. Instead of twothousand cubic feet of fresh air being supplied every hour for eachperson, and as much foul air removed, which, all physiologists assert, isneeded for perfect health, perhaps no means of ventilation at all areprovided, and none is secured except what an occasionally opened door, orthe benevolent cracks and chinks in the building furnish the sufferinglungs. [Footnote: Imagine fifty pupils put into a class room thirty feetlong, twenty-five feet wide, and ten feet high. This would generally beconsidered a very liberal provision. Such a room contains seven thousandfive hundred cubic feet of air. But it furnishes only one hundred andfifty feet of space for each pupil. Allowing ten cubic feet of air perpupil each minute, in fifteen minutes after assembling, the entireatmosphere of the room is tainted, and unfit to be rebreathed. The demandof health is that at least one thousand five hundred cubic feet of pureair should be admitted into this room every minute, and as much beremoved. ]

HOW SHALL WE VENTILATE?--The usual method of ventilation depends upon thefact that hot air is lighter than cold air, and so the cold air tends, bythe force of gravity, to fall and compel the warm air to rise. Thus, if weopen the door of a heated room, and hold a lighted candle first at thetop, and then at the bottom, we can see, by the deflection of the flame, that there is a current of air setting outward at the top, and anothersetting inward at the bottom of the opening. A handkerchief held loosely, or the smoke of a smoldering match, in front of a fireplace will show acurrent of air passing up the chimney; this is caused by the difference oftemperature between the air in the room and the outside atmosphere. _Upon this difference of temperature, all ordinary ventilation isbased_. [Footnote: Public buildings are sometimes ventilated bymechanical means, _i. E. _, immense fans which are turned bymachinery, and thus set the air in motion. Such methods are, however, expensive, and rarely adopted, except where power is also used for otherpurposes. ] A proper treatment of this subject and its practicalapplications, would require a book by itself. There is room here for onlya few general statements and suggestions. 

1. Two openings are always necessary to produce a thorough change of air. (See "Popular Chemistry, " p. 70. ) Put a lighted candle in a bottle. Theflame will soon be extinguished. The oxygen of the little air in thebottle is burned out, and carbonic acid has taken its place. Now placeover the mouth of the bottle a lamp chimney, and insert in the chimney astrip of cardboard, thus dividing the passage. On relighting the candle, it will burn freely. The smoke of a bit of smoldering paper will show thattwo opposite currents of air are established, one setting into the bottle, the other outward. 

2. In the winter, when our schoolrooms, churches, public halls, etc. , areheated artificially, ventilation is comparatively easy if properlyarranged. [Footnote: For the escape of bad air, Dr. Bell suggests that anefficient foul-air shaft may be fitted to the commonest of stoves bysimply inclosing the stovepipe in a jacket--that is, in a pipe two orthree inches greater in diameter. This should be braced round thestovepipe and left open at the end next the stove. At its entrance intothe chimney, a perforated collar should separate it from the stovepipe. ]The required difference of temperature is kept up with little difficulty. The fresh air admitted to the room should then be heated [Footnote:Ventilation is change of air, and, unless scientifically arranged, andespecially unless the incoming volume of air be warmed in cold weather, such change of atmosphere means cold currents, with their attendant trainof catarrhs, bronchitis, neuralgia, rheumatism, and all the evils thatspring from these diseases. The raw, damp, frosty air of our ever-changingwinter temperature ought not to have uncontrolled and constant ingress toour dwellings. Air out of doors is suited to out of door habits. It ishealthy and bracing when the body is coated and wrapped, and prepared tomeet it, and when exercise can be taken to keep up the circulation; but tolive under cover is to live artificially, and such essential conditionsmust be observed as suit an abnormal state. All the evils attaching toventilation, as it is generally effected, spring from the neglect of thisconsistency. --_Westminster Review_. ] either by a furnace, or bypassing over a stove, or through a coil of steam pipes. This cold airshould always be taken directly from out of doors, and not from a cellar, or from under a piazza, where contamination is possible. 

3. In order to remove the impure air, there should be ventilators providedat or near the floor, opening into air shafts, or pipes leading upwardthrough the roof, with proper orifices at the top. These ventilating pipesshould be heated artificially so as to produce a draught. They may formone of the flues of a chimney in which there is a constant fire; or becarried upward in a large flue through the center of which runs the smokepipe of the furnace or stove; [Footnote: This plan has been adopted in thenewer school buildings of Elmira, N. Y. The older buildings were providedwith ventilating pipes, not heated artificially, and hence of no service. These pipes are rendered effective, however, by conducting them into asmall room in the garret, heated by a coal stove. From this room, a largeexit pipe leads to the roof, where it terminates in an Emerson'sventilator. So strong a draught is thus established that throughout thebuilding air is taken from the floors, and consequently the cooler portionof the rooms, at a velocity of three to five feet per second or onehundred and eighty to three hundred cubic feet per minute for each squarefoot of flue opening. In perpendicular flues, heated throughout with asmoke flue from the furnace, ten feet per second is attained. ] or theventilating pipe be itself conveyed through the center of the largerchimney flue. If the register for hot air be on the floor at one side ofthe room, two or more ventilators may be placed near the floor on theopposite side. The warm air will thus make the complete circuit of theroom, and thoroughly warm it before passing out. 

If the ventilating shaft be not heated artificially; the ventilator mustbe placed at the top of the room in order that the hot air may escapethrough it, thus producing an upward draught. But the objection to thismethod is that it allows the warmer air to escape, while economy requiresthat the cooler air at the bottom of the room should be removed and thewarm air be made to descend, thus securing uniformity of temperature. 

4. In the summer, ventilation may be commonly provided for by openingwindows _at the top and the bottom_, on the sheltered side of thebuilding, so as to avoid draughts of air injurious to the occupants. On adull, still, hot day, when there is little difference of temperaturebetween the inner and the outer air, ventilation can be secured only byhaving a fire provided in the ventilating shaft; this, by exhausting theair from the room, will cause a fresh current to pour in through the openwindows. At recess, all the children should, if the weather permit, besent out of doors, to allow their clothing to be exposed to the purifyinginfluence of the open air; meantime, the windows should be thrown wideopen, that the room may be thoroughly ventilated during their absence. Inbad weather, rapid marching or calisthenic exercises will furnishexercise, and also permit the airing of the room. 

5. The school and the church are the centers for spreading contagiousdiseases. The former offers especially dangerous facilities for scatteringdisease germs. Great pains, therefore, should be taken to exclude pupilsattacked by or recovering from diphtheria, scarlet fever, whooping cough, etc. , and even those who live in houses where such sickness exists. 

6. In our houses [Footnote: The air of our homes is often contaminated bydecaying vegetables and other filth in the cellar; by bad air drawn upfrom the soil into the cellar, by the powerful draughts that our firescreate; by defective gas and waste pipes that let the foul air fromcesspool or sewer spread through the house; and by piles of refuse, orpuddles of slops emptied at the back door. Too often, also, the water inour wells, or in the streams that supply our towns and cities, receivesthe drainage from outhouses and barnyards, and so introduces into oursystems, in the liquid--and thus easily assimilated--form, the mostdangerous poisons. The question of sanitary precautions is one thatpresses upon every observant mind, and demands constant and thoughtfulattention. (See p. 305. )] open fireplaces are efficient ventilators, andthey should never be closed for any cause. Fresh air admitted by a hot-airregister and impure air passed out by a chimney, form a simple andthorough system. Our sleeping apartments demand especial care. As soon asthe occupants leave the room, the bedclothes should be removed, and laidon the backs of chairs to air; the bed be shaken up; and the windowsthrown open. In the summer, the windows may be closed before the sun ishigh; the house is then left filled with the cool morning air. In damp andcold weather, a fire should be lighted in sleeping apartments, particularly if used by children [Footnote: In winter, children shouldalways be given a moderately warm, well-ventilated bedroom, with light, fleecy bed coverings. Says a recent English writer: "The loving care whichprescribes for children a cold bedroom and a hot, sweltering bed is of thenature that kills. Buried in blankets, their delicate skins becomeoverheated and relaxed, while they are irritated by perspiration; at thesame time, the most delicate tissues of all, in the lungs, are dealingwith air abnormally frigid. The poor little victims of combined ignoranceand kindness thus toss and dream, feverish and troubled, under a mass ofbedclothes, while the well-meaning mother, soothed by a bedroom fire, slumbers peacefully through this working out of the sad process of the'survival of the fittest. '"] or delicate persons, to dry the bedclothing, and also to prevent a chill on the part of the occupants. It is notnecessary to go shivering to bed in order to harden one's constitution. 

WONDERS OF RESPIRATION. --The perfection of the organs of respirationchallenges our admiration. So delicate are they that the least pressurewould cause exquisite pain, yet tons of air surge to and fro through theirintricate passages, and bathe their innermost cells. We yearly perform atleast seven million acts of breathing, inhaling one hundred thousand cubicfeet of air, and purifying over three thousand five hundred tons of blood. This gigantic process goes on constantly, never wearies or worries us, andwe wonder at it only when science reveals to us its magnitude. Inaddition, by a wise economy, the process of respiration is made tosubserve a second use no less important, and the air we exhale, passingthrough the organs of voice, is transformed into prayers of faith, songsof hope, and words of social cheer. 

FIG. 33. 

[Illustration: A, _the natural position of the internal organs. _ B_when deformed by tight lacing Marshall says that the liver and thestomach have, in this way, been forced downward almost as low as thepelvis. _]

DISEASES, ETC. --1. _Constriction of the Lungs_ is produced by tightclothing. The ribs are thus forced inward, the size of the chest isdiminished, and the amount of inhaled air decreased. Stiff clothing, andespecially a garment that will not admit of a full breath withoutinconvenience, will prevent that free movement of the ribs so essential tohealth. Any infraction of the laws of respiration, even though it befashionable, will result in diminished vitality and vigor, and will befearfully punished by sickness and weakness through the whole life. 

2. _Bronchitis_ (bron-ki'-tis) is an inflammation (see Inflammation)of the mucous membrane of the bronchial tubes. It is accompanied by anincreased secretion of mucus, and consequent coughing. 

3. _Pleurisy_ is an inflammation of the pleura. It is sometimescaused by an injury to the ribs, and results in a secretion of waterwithin the membrane. 

4. _Pneumonia_ (_pneuma_, breath) is an inflammation of thelungs, affecting chiefly the air cells. 

5. _Consumption_ is a disease which destroys the substance of thelungs. Like other lung difficulties, it is caused largely by a want ofpure air, a liberal supply of which is the best treatment that can beprescribed for it. [Footnote: If I were seriously ill of consumption, Iwould live outdoors day and night, except in rainy weather or midwinter;then I would sleep in an unplastered log house. Physic has no nutriment, gaspings for air can not cure you, monkey capers in a gymnasium can notcure you, stimulants can not cure you. What consumptives want is pure air, not physic, plenty of meat and plenty of bread. --DR. MARSHALL HALL. ]

6. _Asphyxia_ (as-fix'-i-a). --When a person is drowned, strangled, orchoked in any way, what is called asphyxia occurs. The face turns black;the veins become turgid; insensibility and often convulsions ensue. Ifrelief is not secured within a few minutes, death will be inevitable. [Footnote: The lack of oxygen, and the presence of carbonic-acid gas, arethe combined causes. Oxygen starvation and carbonic-acid poisoning, eachfatal in itself, work together to destroy life. ] (See p. 264. )

7. _Diphtheria_ (_diphthera_, a membrane) is characterized byfever, debility, and a peculiar sore throat, in which exuding fibrinousmatter forms a grayish white membrane, which afterward decomposes with afetid odor. Its sudden and insidious approach, contagious character, andfrequent fatality, render it an exceedingly dreaded disease. Adiphtheritic patient should be quarantined, and everything connected withthe sick room thoroughly disinfected. 

8. _Croup_, which often attacks young children, is an inflammation ofthe mucous membrane of the larynx and trachea. It is commonly preceded bya cold. The child sneezes, coughs, and is hoarse, but the attackfrequently comes on suddenly, and usually in the night. It is accompaniedby a peculiar "brassy, " ringing cough, which, once heard, can never bemistaken. It may prove fatal within a few hours. (See p. 260. )

9. _Stammering_ depends, not on defects of the muscles, but on a wantof due control of the mind. When a stammerer is not too conscious of hislack, and tries to form his words slowly, he speaks plainly, and may singwell, for then his words must follow one another in rhythmic time. Manypersons who stammer in common conversation can talk with fluency whenmaking a speech. The stammerer should seek to discover the cause of hisdifficulty, and to overcome it by vocal and respiratory exercise, especially by speaking only after a full inspiration, and during a long, slow expiration. 

PRACTICAL QUESTIONS. 

1. What is the philosophy of "the change of voice" in a boy?

2. Why can we see our breath on a frosty morning?

3. When a law of health and a law of fashion conflict, which should weobey?

4. If we use a "bunk" bed, should we pack away the clothes when we firstrise in the morning?

5. Why should a clothespress be well ventilated?

6. Should the weight of our clothing hang from the waist, or the shoulder?

7. Describe the effects of living in an overheated room. 

8. What habits impair the power of the lungs?

9. For full, easy breathing in singing, should we use the diaphragm andlower ribs, or the upper ribs alone?

10. Why is it better to breathe through the nose than the mouth?

11. Why should not a speaker talk while returning home on a cold nightafter a lecture?

12. What part of the body needs the loosest clothing?

13. What part needs the warmest?

14. Why is a "spare bed" generally unhealthful?

15. Is there any good in sighing?

16. Should a hat be thoroughly ventilated? How?

17. Why do the lungs of people who live in cities become of a gray color?

18. How would you convince a person that a bedroom should be aired?[Footnote: "If the condensed breath collected on the cool windowpanes of aroom where a number of persons have been assembled, be burned, a smell asof singed hair will show the presence of organic matter; and if thecondensed breath be allowed to remain on the windows for a few days, itwill be found, on examination by the microscope, that it is alive withanimalculæ. "]

19. What persons are most liable to catarrhs, consumption, etc. ?

20. If a person is plunged under water, will it enter his lungs?

21. Are bed curtains healthful?

22. Why do some people take "short breaths" after a meal?

23 What is the special value of public parks?

24. Can a person become used to bad air, so that it will not injure him?

25. Why do we gape when we are sleepy?

26. Is a fashionable waist a model of art in sculpture or painting?

27. Should a fireplace be closed? [Footnote: Thousands of lives would besaved if all fireplaces were kept open. If you are so fortunate as to havea fireplace in your room, paint it when not in use, put a bouquet of freshflowers in it every morning, if you please, or do anything to make itattractive, but never _close it_; better use the fireboards forkindling wood. It would be scarcely more absurd to take a piece ofelegantly-tinted court-plaster and stop up the nose, trusting to theaccidental opening and shutting of the mouth for fresh air, because youthought it spoiled the looks of your face to have two such great, uglyholes in it, than to stop your fireplace with elegantly-tinted paper, or aJapanese fan, because it looks better. --Leeds. ]

28. Why does embarrassment or fright cause a stammerer to stutter stillmore painfully?

29. In the organs of voice, what parts have somewhat the same effect asthe case of a violin and the sounding-board of a piano?

30. Why should we be careful not to "take the breath of a sick person"?

31. What special care should be taken with regard to keeping a cellarclean?

32. How is the air strained as it passes into the lungs?

33. Can one really "draw the air into his lungs"?

34. How often do we breathe?

35. Describe some approved method of ventilation. 

36. What is at once the floor of the chest and the roof of the abdomen?

37. What would you do in a case of apparent death by drowning, or by coalgas? (See p. 264. )

38. What would you do in a case of croup, while the doctor was coming?(See p. 260. )

39. How would you treat a severe burn? (See p. 257. )

40. Describe the various ways in which the water in a well is liable tobecome unwholesome. 

FIG. 34. 

[Illustration]

V. 

THE CIRCULATION. 

"No rest this throbbing slave may ask, Forever quivering o'er his task, While far and wide a crimson jetLeaps forth to fill the woven net, Which in unnumber'd crossing tidesThe flood of burning life divides, Then, kindling each decaying part, Creeps back to find the throbbing heart. "

HOLMES. 

ANALYSIS OF THE CIRCULATION

__ | 1. Its Composition. | 1. THE BLOOD | 2. Its Uses. | | 3. Transfusion. | |_4. Coagulation| _| | 1. _Description. _| | 2. _Movements. _| | 3. _Auricles and Ventricles. _| _ | _| | 1. The | | a. Need of. | | Heart. | | b. Tricuspid and| | | | Bicuspid. | | | 4. _The | c. The Strengthen-| | | Valves. _ | ing of the| | | | Valves. | | | | d. Semilunar| | |_ |_ Valves. | | _| 2. ORGANS OF THE | 2. The | 1. _Description. _| CIRCULATION | Arteries | 2. _The Arterial System. _| | |_3. _The Pulse. _| | _| | 3. The | 1. _General Description. _| | Veins |_2. _Valves. _| | _| | 4. The | 1. _Description. _| | Capilla-| 2. _Use. _| |_ ries |_3. _Under the Microscope. _| _| | 1. The Lesser. | 3. THE CIRCULATION. | 2. The Greater. | |_3. The Velocity of the Blood. | _| 4. THE HEAT OF THE | 1. Distribution. | BODY. |_2. Regulation. || 5. LIFE BY DEATH. || 6. CHANGE OF OUR BODIES. || 7. THE THREE VITAL ORGANS. || 8. WONDERS OF THE HEART. | _| | 1. Description| 9. THE LYMPHATIC | 2. The Glands. | CIRCULATION. | 3. The Lymph. | |_4. The Office of the Lymphatics. | _| | 1. Congestion. | | 2. Inflammation. | | 3. Bleeding. | 10. DISEASES. | 4. Scrofula. | | 5. A Cold. | |_6. Catarrh. | _| | 1. Effect of Alcohol upon the Circulation. | 11. ALCOHOLIC | 2. Effect of Alcohol upon the Heart. | DRINKS AND | 3. Effect of Alcohol upon the Membrane. |_ NARCOTICS. | 4. Effect of Alcohol upon the Blood. |_5. Effect of Alcohol upon the Lungs. 

THE CIRCULATION. 

THE ORGANS OF THE CIRCULATION are the _heart_, the _arteries_, the _veins_, and the _capillaries_. 

FIG. 35. 

[Illustration: A, _corpuscles of human blood, highly magnified;_ B, _corpuscles in the blood of an animal (a non mammal). _]

THE BLOOD is the liquid by means of which the circulation is effected. Itpermeates every part of the body, except the cuticle, nails, hair, etc. The average quantity in each person is about eighteen pounds. [Footnote:It is difficult to estimate the exact amount, and therefore authoritiesdisagree. Foster places it at about one thirteenth of the body weight. ] Itis composed of a thin, colorless liquid, the _plasma_, filled withred disks or cells, [Footnote: There is also one white globular cell toevery three or four hundred red ones. The blood is no more red than thewater of a stream would be if you were to fill it with little red fishes. Suppose the fishes to be very, very small--as small as a grain of sand--and closely crowded together through the whole depth of the stream; thewater would look quite red, would it not? And this is the way in which, blood looks red--only observe one thing; a grain of sand is a mountain incomparison with the little red fishes in the blood. If I were to tell youthey measured about 1/3500 of an inch in diameter, you would not be muchwiser; so I prefer saying (by way of giving you a more perfect idea oftheir minuteness) that there would be about a million in such a drop ofblood as would hang on the point of a needle. I say so on the authority ofa scientific microscopist--M. Bouillet. Not that he has ever countedthem, as you may suppose, any more than I have done; but this is as nearan approach as can be made by calculation to the size of 1/3500 part of aninch in diameter. --JEAN MACE. ] so small that about three thousand fivehundred placed side by side would measure only an inch, and it would takesixteen thousand laid flatwise upon one another to make a column of thatheight. Under the microscope, they are found to be rounded at the edge andconcave on both sides. [Footnote: By pricking the end of the finger with aneedle, we can obtain a drop for examination. Place it on the slide, coverwith a glass, and put it at once under the microscope. The red disks willbe seen to group themselves in rows, while the white disks will seem todraw apart, and to be constantly changing their form. After a gradualevaporation, the crystals (Fig. 36) may be seen. In animals, they havevarious, though distinctive forms. ] They have a tendency to collect inpiles like rolls of coin. The size and shape vary in the blood ofdifferent animals. [Footnote: Authorities differ greatly in their estimateof the size of the disks (corpuscles) in human blood. The fact is that thesize varies in different persons, probably also in the same individual. Many of the best microscopists therefore hesitate to state whether aparticular specimen of blood belonged to a human being or to an animal. Others claim that they can distinguish with accuracy. Evidently, thequestion is one of great uncertainty. The following statement of the sizeof the cells in different animals is taken from Gulliver's tables: Cat, 1/4404 of an inch in diameter; whale, 1/3100; mouse, 1/3614; hog, 1/4230;camel, 1/3123; sheep, 1/3352; horse, 1/4800; Virginia deer, 1/5038; dog-faced baboon, 1/4861; brown baboon, 1/3493; red monkey, 1/3396; blackmonkey, 1/3530. ] Disks are continually forming in the blood, and areconstantly dying--twenty million at every breath. --DRAPER. 

The plasma also contains fibrin, [Footnote: it is usual to say that fibrinis contained in the blood. It probably does not exist as such, but thereare present in the blood certain substances known as _paraglobulin_and _fibrinogen_, which by the action of a third substance, _fibrinferment_ under certain circumstances, form fibrin and so causecoagulation. The exact nature of the process by which fibrin is producedby these three factors is not understood--See Foster's _Text Book ofPhysiology_, p 22. ] albumin--which is found nearly pure in the white ofan egg--and various mineral substances, as iron, [Footnote: Enough ironhas been found in the ashes of a burned body to form a mourning ring. ]lime, magnesia, phosphorus, potash, etc. 

FIG. 36. 

[Illustration: _Blood Crystals_]

USES OF THE BLOOD. --The blood has been called "liquid flesh"; but it ismore than that, since it contains the materials for making every organ. The plasma is rich in mineral matter for the bones, and in albumen for themuscles. The red disks are the air cells of the blood. They contain theoxygen so essential to every operation of life. Wherever there is work tobe done or repairs to be made, there the oxygen is needed. It stimulatesto action, and tears down all that is worn out. In this process, itcombines with and actually burns out parts of the muscles and othertissues, as wood is burned in the stove. [Footnote: For the sake ofsimplicity, perhaps to conceal our own ignorance, we call this process"burning. " The simile of a fire is good so far as it goes. But as to thereal nature of the change which the physiologist briefly terms"oxidation, " we know nothing. This much only can be asserted positively. Astream of oxygen is carried by the blood to the muscles (in fact to everytissue in the body), while, from the muscles the blood carries away astream of carbonic acid and water. But what takes place in the muscles, when and what chemical change occurs, no one can tell. We see the firstand the last stage. We know that contraction of the muscles somehow comesabout, oxygen disappears, carbonic acid appears, energy is released, andforce is exhibited as motion, heat, and electricity. But the intermediatestep is hidden. 

There are certain theories advanced, however, that are worth considering. Some physiologists hold that the muscle has the power of taking up theoxygen from the _hemoglobin_ (a body that comprises ninety per centof the red corpuscles when dried, and is the oxygen carrier of the blood), and fixing it, as well as the raw material (food) furnished by the blood, thus forming a true contractile substance. The breaking down ordecomposition of this contractile substance in the muscle, sets free itspotential energy. The process is gentle so long as the muscle is at rest, but becomes excessive and violent when contraction occurs. (See "Foster'sPhysiology, " p. 118. ) It is also believed by some that the chemical changein the muscle partakes of a fermentive character; that, under theinfluence of the proper ferments, the substances break up into other andsimpler products, thus setting free heat and force; and that this chemicalchange is followed by a secondary oxidation by the oxygen in the arterialblood, thereby forming carbonic acid and water, as in all putrefactiveprocesses. But these and other views are not as yet fully understood;while they utterly fail to tell us how a collection of simple cells, filled merely with a semifluid mass of matter, can contract and set freemuscular power. The commonness of this act hides from us its wonderfulnature. But here, hidden in the cell--Nature's tiny laboratory--lies themystery of life. Before its closed door we ponder in vain, confessing theunskillfulness of our labor, and fearing all the while lest the _Secretof the Cell_ will always elude our search. ] The blood, now foul withthe burned matter, the refuse of this fire, is caught up by thecirculation, and whirled back to the lungs, where it is purified, andagain sent bounding on its way. 

There are then two different kinds of the blood in the body: the red orarterial, and the dark or venous. 

TRANSFUSION. --As the blood is really the "vital fluid" it would seem thatfeeble persons might be restored to vigor by infusing healthy blood intotheir veins. This hypothesis, so valuable in its possible results inprolonging human life, has been carefully tested. Animals which haveceased to breathe have thus had their vitality recalled. In theseventeenth century the theory became a subject of special investigation. A maniac was restored to reason by the blood of a calf, and the mostextravagant hopes were entertained. But many fatal accidents occurring, experiments upon human beings were forbidden by law, and transfusion soonfell into disuse. It has, however, been successfully practiced in severalcases within the last few years, and is a method still in repute forsaving lives. 

COAGULATION. --When blood is exposed to the air, it coagulates. This iscaused by the solidifying of the fibrin, which entangling the disks, formsthe "clot. " The remaining clear, yellow liquid is the _serum_. Thevalue of this peculiar property of the blood can hardly be overestimated. The coagulation soon checks all ordinary cases of bleeding. [Footnote: Inthe case of the lower animals, which have no means of stopping hemorrhagesas we have, the coagulation is generally still more rapid. In some speciesof birds it takes place almost instantaneously. ] When a wound is made, andbleeding commences, the fibrin forms a temporary plug, as it were, whichis absorbed when the healing process is finished. Thus we see how a Divineforesight has provided not only for the ordinary wants of the body, butalso for the accidents to which it is liable. [Footnote: The fibrin is notan essential ingredient of the blood. All the functions of life areregularly performed in people whose blood lacks fibrin; and, in cases oftransfusion, where blood deprived of its fibrin was used, the vivifyinginfluence seemed to be the same. Its office, therefore, must mainly be tostanch any hemorrhage which may occur. --FLINT. ]

FIG. 37. 

[Illustration: _The Heart. _ A, _the right ventricle;_ B, _theleft ventricle;_ C, _the right auricle;_ D, _the left auricle. _]

THE HEART is the engine which propels the blood. It is a hollow, pear-shaped muscle, about the size of the fist. It hangs, point downward, justto the left of the center of the chest. (See Fig. 31. ) It is inclosed in aloose sac of serous membrane, [Footnote: The mucous membrane lines theopen cavities of the body; the serous, the closed. The pericardium is asac composed of two layers--a fibrous membrane on the outside, and aserous one on the inside. The latter covers the external surface of theheart, and is reflected back upon itself in order to form, like all themembranes of this nature, a sac without an opening. The heart is thuscovered by the pericardial sac, but not contained inside its cavity. Acorrect idea may be formed of the disposition of the pericardium aroundthe heart by recalling a very common and very convenient, though nowdiscarded headdress, the cotton nightcap. The pericardium incloses theheart exactly as this cap covered the heads of our forefathers. --_Wonders of the Human Body_. ] called the pericardium (_peri_, about; and _kardia_, the heart). This secretes a lubricating fluid, and is smooth as satin. 

THE MOVEMENTS OF THE HEART consist of an alternate contraction andexpansion. The former is called the _sys'-to-le_, and the latter the_di-as'-to-le_. During the diastole, the blood flows into the heart, to be expelled by the systole. The alternation of these movementsconstitutes the beating of the heart which we hear so distinctly betweenthe fifth and sixth ribs. [Footnote: Two sounds are heard if we put ourear over the heart, --the first and longer as the blood is leading theorgan, the second as it falls into the pockets of the two arteries, andthe valves then striking together cause it. The first sound is mainly thenoise made by the muscular tissue. During the first, the two ventriclescontract; during the second the two auricles do so. The hand may feel theheart striking the ribs as it contracts, --a feeling called the impulse, or, if quicker and stronger than usual, palpitation. This is not always asign of disease, but in hypochondriacs is often an effect of the mind onthe nerves of the heart. --MAPOTHER]

FIG. 38. 

[Illustration: _Chambers of the Heart_ A, _right ventricle;_ B, _left ventricle, _ C, _right auricle, _ D, _left auricle, _ E, _tricuspid valve, _ F, _bicuspid valve;_ G, _semilunar valves, _ H, _valve of the aorta;_ I, _inferior vena cava, _ K, _superior venacava, _ L, L, _pulmonary veins. _]

THE AURICLES AND VENTRICLES--The heart is divided into four chambers. Inan adult, each holds about a wineglassful. The upper ones, from appendageson the outside resembling the ears of a dog, are called _auricles(aures_, ears). Are termed _ventricles_. The auricle and ventricleon each side communicate with each other, but the right and left halves ofthe heart are entirely distinct, and perform different offices. The leftside propels the red blood; and the right, the dark. The auricles aremerely reservoirs to receive the blood (the left auricle, as it filters inbright and pure from the lungs; the right, as it returns dark and foulfrom the tour of the body), and to furnish it to the ventricles as theyneed. Their work being so light, their walls are comparatively thin andweak. On the other hand, the ventricles force the blood (the left, to allparts of the body; the right, to the lungs), and are, therefore, made verystrong. As the left ventricle drives the blood so much farther than theright, it is correspondingly thicker and stronger. 

NEED OF VALVES IN THE HEART. --As the auricles do not need to contract withmuch force simply to empty their contents into the ventricles below them, there is no demand for any special contrivance to prevent the blood fromsetting back the wrong way. Indeed, it would naturally run down into theventricle, which is at that moment open to receive it. But, when thestrong ventricles contract, especially the left one, which must drive theblood to the extremities, some arrangement is necessary to prevent it fromreturning into the auricle. Besides, when they expand, the "suction power"would tend to draw back again from the arteries all the blood just forcedout. This difficulty is obviated by means of little doors, or valves, which will not let it go the wrong way. [Footnote: The heart of an ox or asheep may be used to show the chambers and valves. The aorta should be cutas far as possible from the heart, and then by pumping in water theperfection of these valves will be finely exhibited. Cutting the heartacross near the middle will show the greater thickness of the leftventricle. ]

THE TRICUSPID AND BICUSPID VALVES. --At the opening into the rightventricle, is a valve consisting of three folds or flaps of membrane, whence it is called the _tricuspid_ valve (_tri_, three; and_cuspides_, points), and in the left ventricle, one containing twoflaps, and named the _bicuspid_ valve. These hang so loosely as tooppose no resistance to the passage of the blood into the ventricles; but, if any attempts to go the other way, it gets between the flaps and thewalls of the heart, and, driving them outward, closes the orifice. 

FIG. 39. 

[Illustration: _Diagram showing the peculiar Fibrous Structure of theHeart and the Shape of the Valves. _ A, _tricuspid valve, _ B, _bicuspid valve;_ C, _semilunar valves of the aorta;_ D, _semilunar valves of the pulmonary artery. _]

THESE FLAPS ARE STRENGTHENED like sails by slender cords, which preventtheir being pressed back through the opening. If the cords were attacheddirectly to the walls of the heart, they would be loosened in the systole, and so become useless when most needed. They are, therefore, fastened tolittle muscular pillars projecting from the sides of the ventricle; whenthat contracts, the pillars contract also, and thus the cords are heldtight. 

THE SEMILUNAR VALVES. --In the passages outward from the ventricles, arevalves, called from their peculiar half-moon shape _semilunar_ valves(_semi_, half; _Luna_, Moon). Each consists of three littlepocket-shaped folds of membrane, with their openings in the directionwhich the blood is to take. When it sets back, they fill, and, swellingout, close the passage (Fig. 40). 

THE ARTERIES [Footnote: _Aer, _ air; and _tereo, _ I contain--sonamed because after death they contain air only, and hence the ancientssupposed them to be air tubes leading through the body. ] are the tube-likecanals which convey the blood _from_ the heart. They carry the redblood (see note, p. 119). They are composed of an elastic tissue, whichyields at every throb of the heart, and then slowly contracting again, keeps up the motion of the blood until the next systole. The elasticity ofthe arteries acts like the air chamber of a fire engine, which convertsthe intermittent jerks of the brakes or pump into the steady stream of thehose nozzle. 

The arteries sometimes communicate by means of branches or by meshes ofloops, so that if the blood be blocked in one, it can pass round throughanother, and so get by the obstacle. [Footnote: This occurs especiallyabout the joints, where it serves to maintain the circulation during thebending of a limb, or when the main artery is obstructed by disease orinjury, or has been tied by the surgeon. In the last case, the smalladjacent arteries gradually enlarge, and form what is called a collateralcirculation. ] When an artery penetrates a muscle, it is often protected bya sheath or by fibrous rings, which prevent its being pulled out of placeor compressed by the play of the muscles. 

The arteries are generally located as far as possible beneath the surface, out of harm's way, and hence are found closely hugging the bones orcreeping through safe passages provided for them. They are generallynearly straight, and take the shortest routes to the parts which they areto supply with blood. 

THE ARTERIAL SYSTEM starts from the left ventricle by a single trunk--the_aorta_--which, after giving off branches to the head, sweeps back ofthe chest with a bold curve--the _arch of the aorta_ (_c_, Fig. 34)--and thence runs downward (_f_), dividing and subdividing, like atree, into numberless branches, which, at last, penetrate every nook andcorner of the body. 

THE PULSE. --At the wrist (_k_, radial artery) and on the temple(temporal artery) we can feel the expansion of the artery by each littlewave of blood set in motion by the contraction of the heart. In health, there are about seventy-two [Footnote: This number varies much with age, sex, and individuals. Napoleon's pulse is said to have been only forty, while it is not infrequent to find a healthy pulse at one hundred or over. In general, the pulse is quicker in children and in old people than in themiddle-aged; in short persons than in tall; in women than in men. Shamemakes the heart send more blood to the blushing cheek, and fear almoststops it. The will can not check the heart. There is said, however, tohave been a notable exception to this in the case of one Colonel Townsend, of Dublin, who, after having succeeded several times in stopping thepulsation, at last lost his life in the act. ] pulsations per minute. Theyincrease with excitement or inflammation, weaken with loss of vigor, andare modified by nearly every disease. The physician, therefore, finds thepulse a good index of the state of the system and the character of thedisorder. (See p. 314. )

THE VEINS are the tube-like canals which convey the blood _to_ theheart. [Footnote: There is one exception to the general course of theveins. The _portal_ vein carries the blood from the digestive organsto the liver, where it is acted upon, thence poured into the ascendingvena cava, and goes back to the heart. ] They carry the dark or venousblood (note, p. 119). As they do not receive the direct impulse of theheart, their walls are made much thinner and less elastic than those ofthe arteries. At first small, they increase in size and diminish in numberas they gradually pour into one another, like tiny rills collecting toform two rivers, the vena cava ascending and the vena cava descending(_l, m_, Fig. 34), which empty into the right auricle. 

Some of the veins creep along under the skin, where they can be seen, asin the back of the hand; while others accompany the arteries, some ofwhich have two or more of these companions. 

VALVES similar in construction to those already described (the semilunarvalves of the heart, page 114) are placed at convenient intervals, inorder to guide the blood in its course, and prevent its setting backward. [Footnote: Too much standing, or tight elastics, often cause the veins inthe leg to swell, so that the valves can not work; the veins then become_varicose_, or permanently enlarged, and, if they burst, the bleedingmay be profuse and even dangerous. Raising the leg and pressing the fingeron the bleeding spot will stay it. Walking does not encourage thisdisease, for the active muscles force on the venous blood. Clerks who aresubject to varicose veins should have seats behind the counters where theymay rest when not actually employed. A deep breath helps the flow in theveins, and a wound may suck in air with fatal effect. A maimed horse ismost mercifully killed by blowing a bubble of air into the veins of hisneck. As the deep-sea pressure would burst valves, the whale has none;hence a small wound by the harpoon causes him to bleed to death. --MAPOTHER. ] We can easily examine the working of these valves. On baringthe arm, blue veins may be seen running along the arm toward the hand. Their diameter is tolerably even, and they gradually decrease in size. Ifnow the finger be pressed on the upper part of one of these veins, andthen passed downward so as to drive its blood backward, swellings likelittle knots will make their appearance. Each of these marks the locationof a valve, which is closed by the blood we push before our finger. Removethe pressure, and the valve will swing open, the blood set forward, andthe vein collapse to its former size. 

FIG. 40. 

[Illustration: _Valves of the Veins. _]

THE CAPILLARIES (_capillus, _ a hair) form a fine network of tubes, connecting the ends of the arteries with the veins. They blend, however, with the extremities of these two systems, so that it is not easy to telljust where an artery ends and a vein begins. So closely are they placed, that we can not prick the flesh with a needle without injuring, perhaps, hundreds of them. The air cells of the blood deposit there their oxygen, and receive carbonic acid, while in the delicate capillaries of the lungs[Footnote: The capillary tubes are there so fine that the disks of theblood have to go one by one, and are sadly squeezed at that. However, their elasticity enables them to resume their old shape as soon as theyhave escaped from this labyrinth. ] they give up their load of carbonicacid in exchange for oxygen. 

FIG. 41. 

[Illustration: _Circulation of the Blood in the Web of a Frog's Foot, highly magnified. _ A, _an artery;_ B, _capillaries crowded withdisks, owing to a rupture just above, where the disks are jammed into anadjacent mesh;_ C, _a deeper vein; the black spots are pigmentcells. _]

If, by means of a microscope, we examine the transparent web of a frog'sfoot, we can trace the route of the blood. [Footnote: With small splintsand twine, a frog's foot can be easily stretched and tied so that thetransparent web can be placed on the table of the microscope. ] It is anexperiment of wonderful interest. The crimson stream, propelled by theheart, rushes through the arteries, until it reaches the intricate meshesof the capillaries. Here it breaks into a thousand tiny rills. We can seethe disks winding in single file through the devious passages, dartinghither and thither, now pausing, swaying to and fro with an uncertainmotion, and anon dashing ahead, until, at last, gathered in the veins, theblood sets steadily back on its return to the heart. 

THE CIRCULATION [Footnote: The circulation of the blood was discovered byHarvey in 1619. For several years, he did not dare to publish his belief. When it became known, he was bitterly persecuted, and his practice as aphysician greatly decreased in consequence. He lived, however, to see histheory universally adopted, and his name honored. Harvey is said to havedeclared that no man over forty years of age accepted his views. ] consistsof two parts--the _lesser_, and the _greater_. 

FIG. 42. 

[Illustration: _Diagram illustrating the Circulation of the Blood. _--MARSHALL. A, _vena cava descending (superior);_ Z, _vena cavaascending (inferior);_ C, _right auricle;_ D, _right ventricle;_ E, _pulmonary artery;_ F P, _lungs and pulmonary veins;_ G, _left auricle;_H, _left ventricle;_ I, K, _aorta. _]

1. _The Lesser Circulation_. --The dark blood from the veins collectsin the right auricle, and, going through the tricuspid valve, empties intothe right ventricle. Thence it is driven past the semilunar valves, through the pulmonary artery, to the lungs. After circulating through thefine capillaries of the air cells contained in the lungs, it is returned, bright and red, through the four pulmonary veins, [Footnote: It isnoticeable that the pulmonary set of veins circulates red blood, and thepulmonary set of arteries circulates dark blood. Both are connected withthe lungs. ] to the left auricle. 

2. _The Greater Circulation_. --From the left auricle, the blood isforced past the bicuspid valve to the left ventricle; thence it is driventhrough the semilunar valves into the great aorta, the main trunk of thearterial system. Passing through the arteries, capillaries, and veins, itreturns through the venæ cavæ, ascending and descending, gathers again inthe right auricle, and so completes the "grand round" of the body. Boththese circulations are going on constantly, as the two auricles contract, and the two ventricles expand simultaneously, and _vice versa_. 

THE VELOCITY OF THE BLOOD varies so much in different parts of the body, and is influenced by so many circumstances, that it can not be calculatedwith any degree of accuracy. It has been estimated that a portion of theblood will make the tour of the body in about twenty-three seconds(FLINT), and that the entire mass passes through the heart in from one totwo minutes. [Footnote: The total amount of blood in an adult of averageweight is about eighteen pounds. Dividing this by five ounces, thequantity discharged by the left ventricle at each systole, gives fifty-eight pulsations as the number necessary to transmit all the blood in thebody. This, however, is an extremely unreliable basis of calculation, asthe rapidity of the blood is itself so variable. Chauvreau has shown byexperiments with his instrument that, corresponding to the first dilationof the vessels, the blood moves with immense rapidity; following this, thecurrent suddenly becomes nearly arrested; this is succeeded by a secondacceleration in the current, not quite so rapid as the first; and afterthis there is a gradual decline in the rapidity to the time of the nextpulsation. ] (See p. 314. )

DISTRIBUTION AND REGULATION OF THE HEAT OF THE BODY. --1. _Distribution_. --The natural temperature is not far from 98°. [Footnote: The average temperature is, however, easily departed from. Through some trivial cause the cooling agencies may be interfered with, and then, the heating processes getting the superiority, a hightemperature or fever comes on. Or the reverse may ensue. In Asiaticcholera, the constitution of the blood is so changed that its disks can nolonger carry oxygen into the system, the heat-making processes are put astop to, and, the temperature declining, the body becomes of a marblecoldness, characteristic of that terrible disease. --DRAPER. ] This ismaintained, as we have already seen, by the action of the oxygen withinus. Each capillary tube is a tiny stove, where oxygen is combining withthe tissues of the body (see note, p. 107). Every contraction of a muscledevelops heat, the latent heat being set free by the breaking up of thetissue. The warmth so produced is distributed by the circulation of theblood. Thus the arteries, veins, and capillaries form a series of hot-water pipes, through which the heated liquid is forced by a pump--theheart--while the heat is kept up, not by a central furnace and boiler, butby a multitude of little fires placed here and there along its course. 

2. _Regulation_. --The temperature of the body is regulated by meansof the pores of the skin and the mucous membrane in the air passages. Whenthe system becomes too warm, the blood vessels on the surface expand, theblood fills them, the fluid exudes into the perspiratory glands, pours outupon the exterior, and by evaporation cools the body. [Footnote: Just aswater sprinkled on the floor cools a room. --_Popular Physics_, p. 255. ] When the temperature of the body is too low, the vessels contract, less blood goes to the surface, the perspiration decreases, and the lossof heat by evaporation diminishes. [Footnote: Thus one is enabled to gointo an oven where bread is baking, or into the arctic regions where themountains are snow and the rivers ice. Even by these extremes thetemperature of the blood will be but slightly affected. In the one case, the flood gates of perspiration will be opened and the superfluous heatexpended in turning the water to vapor; and, in the other, they will betightly closed and all the heat retained. ]

LIFE BY DEATH. --The body is being incessantly corroded, and portions borneaway by the tireless oxygen. The scales of the epidermis are constantlyfalling off and being replaced by secretion from the cutis. The disks ofthe blood die, and new ones spring into being. On the continuance of thisinterchange depend our health and vigor. Every act is a destructive one. Not a bend of the finger, not a wink of the eye, not a thought of thebrain but is at some expense of the machine itself. Every process of lifeis thus a process of death. The more rapidly this change goes on, andfresh, vigorous tissue takes the place of the old, the more elasticity andstrength we possess. 

CHANGE OF OUR BODIES. --There is a belief that our bodies change once inseven years. From the nature of the case, the rate must vary with thelabor we perform; the organs most used altering oftenest. Probably theparts of the body in incessant employment are entirely reorganized manytimes within a single year. [Footnote: To use a homely simile, our bodiesare like the Irishman's knife, which, after having had several new blades, and at least one new handle, was yet the same old knife. ]

THE THREE VITAL ORGANS. --Death is produced by the stoppage of the actionof any one of the three organs--the heart, the lungs, or the brain. Theyhave, therefore, been termed the "Tripod of Life. " Really, however, asHuxley has remarked, "Life has but two legs to stand upon. " If respirationand circulation be kept up artificially, the removal of the brain will notproduce death. [Footnote: When death really does take place, _i. E. _, when the vital organs are stopped, it is noticeable that the tissues donot die for some time thereafter. If suitable stimulants be applied, asthe galvanic battery, transfusion of blood, etc. , the muscles may be madeto contract, and many of the phenomena of life be exhibited. Dr. Brown-Sequard thus produced muscular action in the hand of a criminal, fourteenhours after his execution. ]

WONDERS OF THE HEART. --The ancients thought the heart to be the seat oflove. There were located the purity and goodness as well as the evilpassions of the soul. [Footnote: Our common words, hearty, large-hearted, courage (_cor_, the heart), are remains of this fanciful theory. ]Modern science has found the seat of the mental powers to be in the brain. But while it has thus robbed the heart of its romance, it has revealedwonders which eclipse all the mysteries of the past. This marvelous littleengine throbs on continually at the rate of one hundred thousand beats perday, forty millions per year, often three billions without a single stop. It is the most powerful of machines. "Its daily work is equal to one thirdthat of all the muscles. If it should expend its entire force in liftingits own weight vertically, it would rise twenty thousand feet in an hour. "[Footnote: "The greatest exploit ever accomplished by a locomotive, was tolift itself through less than one eighth of that distance. " Vast andconstant as is this process, so perfect is the machinery, that there arepersons who do not even know where the heart lies until disease oraccident reveals its location. ] Its vitality is amazing. The most tirelessof organs while life exists, it is one of the last to yield when lifeexpires. So long as a flutter lingers at the heart, we know the spark ofbeing is not quite extinguished, and there is hope of restoration. Duringa life such as we sometimes see, it has propelled half a million tons ofblood, yet repaired itself as it has wasted, during its patient, unfaltering labor. The play of its valves and the rhythm of its throb havenever failed until, at the command of the great Master Workman, the"wheels of life have stood still. " [Footnote: Our brains are seventy-five-year clocks. The Angel of Life winds them up once for all, then closes thecase, and gives the key into the hand of the Angel of the Resurrection. Ticktack! Ticktack! go the wheels of thought; our will can not stop them, they can not stop themselves; sleep can not stop them; madness only makesthem go faster; death alone can break into the case, and, seizing theever-swinging pendulum which we call the heart, silence at last theclicking of the terrible escapement we have carried so long beneath ourwrinkled foreheads. --HOLMES. ]

FIG. 43. 

[Illustration: _Lymphatics of the Head and Neck, showing the Glands, and, _ B, _the thoracic duct as it empties into the left innominatevein at the junction of the left jugular and subclavian veins. _]

THE LYMPHATIC CIRCULATION is intimately connected with that of the blood. It is, however, more delicate in its organization, and less thoroughlyunderstood. Nearly every part of the body is permeated by a second seriesof capillaries, closely interlaced with the blood capillaries alreadydescribed, and termed the Lymphatic system. The larger number convergeinto the thoracic duct--a small tube, about the size of a goose quill, which empties into the great veins of the neck (Fig. 43). Along theircourse the lymphatics frequently pass through _glands_, --hard, pinkish bodies of all sizes, from that of a hemp seed to an almond. Theseglands are often enlarged by disease, and then are easily felt. 

_The Lymph_, which circulates through the lymphatics like bloodthrough the veins, is a thin, colorless liquid, very like the serum. Thisfluid, probably in great measure an overflow from the blood vessels, isgathered up by the lymphatics, undergoes in the glands some process ofpreparation not well understood, and is then returned to the circulation. 

FIG. 44. 

[Illustration: _Lymphatics in the Leg, with Glands at the Hip_. ]

OFFICE OF THE LYMPHATICS. --It is thought that portions of the waste matterof the body capable of further use are thus, by a wise economy, retainedand elaborated in the system. 

The _lacteals_, a class of lymphatics which will be described underDigestion (p. 166), aid in taking up the food; after a meal they becomemilk white. In the lungs, the lymphatics are abundant; sometimes absorbingthe poison of disease, and diffusing it through the system. [Footnote:Persons have thus been poisoned by tiny particles of arsenic whichevaporate from green wall paper, and float in the air. ]

The lymphatics of the skin we have already spoken of as producing thephenomena of absorption, [Footnote: Pain is often relieved by injectingunder the cuticle a solution of morphine, which is taken up by theabsorbents, and so carried through the system. ] Nature in her effort toheal a cut deposits an excess of matter to fill up the breach. Soon, thelymphatics go to work and remove the surplus material to other parts ofthe body. 

Animals that hibernate are supported during the winter by the fat whichtheir absorbents carry into the circulation from the extra supply theyhave laid up during the summer. In famine or in sickness, a manunconsciously consumes his own flesh. 

DISEASES, ETC. --l. _Congestion_ is an unnatural accumulation of bloodin any part of the body. The excess is indicated by the redness. If we putour feet in hot water, the capillaries will expand by the heat, and theblood will set that way to fill them. The red nose and purplish face ofthe drunkard show a congestion of the capillaries. Those vessels have losttheir power of contraction, and so are permanently increased in size andfilled with blood. Blushing is a temporary congestion. The capillariesbeing expanded only for an instant by the nervous excitement, contractagain and expel the blood. [Footnote: Blushing is a purely localmodification of the circulation of this kind, and it will be instructiveto consider how a blush is brought about. An emotion--sometimespleasurable, sometimes painful--takes possession of the mind; thereupon ahot flush is felt, the skin grows red, and according to the intensity ofthe emotion these changes are confined to the cheeks only, or extend tothe "roots of the hair, " or "all over. " What is the cause of thesechanges? The blood is a red and a hot fluid; the skin reddens and growshot, because its vessels contain an increased quantity of this red and hotfluid; and its vessels contain more, because the small arteries suddenlydilate, the natural moderate contraction of their muscles being supersededby a state of relaxation. In other words, the action of the nerves whichcause this muscular contraction is suspended. On the other hand, in manypeople, extreme terror causes the skin to grow cold, and the face toappear pale and pinched. Under these circumstances, in fact, the supply ofblood to the skin is greatly diminished, in consequence of an excessivestimulation of the nerves of the small arteries, which causes them tocontract and so to cut off the supply of blood more or less completely. --Huxley's _Physiology_. ]

2. _Inflammation_ means simply a burning. If there is irritation oran injury at any spot, the blood sets thither and reddens it. This extrasupply, both by its presence and the friction of the swiftly movingcurrents, produces heat. The pressure of the distended vessels upon thenerves frets them, and produces pain. The swelling stretches the walls ofthe blood vessels, and the serum or lymph oozes through. The fourcharacteristics of an inflammation are redness, heat, pain, and swelling. 

3. _Bleeding_, if from an artery, will be of red blood, and will comein jets; [Footnote: The elasticity of the arteries (p. 114) is a physicalproperty, as may easily be shown by removing one from a dead body. If theywere rigid and unyielding, a considerable portion of the heart's forcewould be uselessly expended against their walls. Their expansion is apassive state, and depends on the pressure of the blood within them; buttheir vital contractility is an active property. --The intermittentmovement of the blood through the arteries is strikingly shown in themanner in which they bleed when wounded. When an artery is cut across, theblood spurts out with great force to a distance of several feet, but theflow is not continuous. It escapes in a series of jets, the long, slenderscarlet stream rising and falling with each beat of the heart, and thispulsation of the blood stream tells at once that it comes from a woundedartery. But as the blood traverses these elastic tubes, the abruptness ofthe heart's stroke becomes gradually broken and the current equalized, sothat the greater the distance from the heart the less obvious is thepulsation, until at length in the capillaries the rate of the streambecomes uniform. ] if from the veins, it will be of dark blood, and willflow in a steady stream. If only a small vessel be severed, it may bechecked by a piece of cloth held or bound firmly upon the wound. If alarge trunk be cut, especially in a limb, make a knot in a handkerchiefand tie it loosely about the limb; then, placing the knot on the limb, with a short stick twist the handkerchief tightly enough to stop the flow. If you have a piece of cloth to use as a pad, the knot will beunnecessary. If it be an artery that is cut, the pressure should beapplied between the wound and the heart; if a vein, beyond the wound. Ifyou are alone, and are severely wounded, or in an emergency, like arailroad accident, use the remedy which has saved many a life upon thebattlefield--bind or hold a handful of dry earth upon the wound, elevatethe part, and await surgical assistance. 

4. _Scrofula_ is generally inherited. It is a disease affecting thelymphatic glands, most commonly those of the neck, forming "kernels, " asthey are called. It is, however, liable to attack any organ. Personsinheriting this disease can hope to ward off its insidious approaches onlyby the utmost care in diet and exercise; by the use of pure air and warmclothing, and by avoiding late hours and undue stimulus of all kinds. Probably the most fatal and common excitants of the latent seeds ofscrofula are insufficient or improper food, and want of ventilation. 

5. _A COLD_. --We put on a thinner dress than usual, or, when heated, sit in a cool place. The skin is chilled, and the perspiration checked. The blood, no longer cleansed and reduced in volume by the drainagethrough the pores, sets to the lungs for purification. That organ isoppressed, breathing becomes difficult, and the extra mucus secreted bythe irritated surface of the membrane is thrown off by coughing. Themucous membrane of the nasal chamber sympathizes with the difficulty, andwe have "a cold in the head, " or a catarrh. In general, the excess ofblood seeks the weakest point, and develops there any latent disease[Footnote: A party go out for a walk and are caught in a rain, or, cominghome heated from some close assembly, throw off their coats to enjoy thedeliciously cool breeze. The next day, one has a fever, another a slightheadache, another pleurisy, another pneumonia, another rheumatism, whilesome of the number escape without any ill feeling whatever. The last hadvital force sufficient to withstand the disturbance, but in the othersthere were various weak points, and to these the excess of blood has gone, producing congestion. ] Where one person has been killed in battle, thousands have died of colds. 

To restore the equipoise must be the object of all treatment. We put thefeet in hot water and they soon become red and gorged with the blood whichis thus called from the congested organs. Hot footbaths have savedmultitudes of lives. It is well in case of a sudden cold to go immediatelyto bed, and with hot drinks and extra clothing open the pores, and inducefree perspiration. This calls the blood to the surface, and, by equalizingand diminishing the volume of the circulation, affords relief. [Footnote:Severe colds may often be relieved in their first stages by using lemonsfreely during the day, and taking at night fifteen or twenty grains ofsodium bromide. Great care, however, should be observed in employing thelatter remedy, except under the advice of a physician. ]

6. _Catarrh_ commonly manifests itself by the symptoms known as thoseof a "cold in the head, " and is produced by the same causes. It is aninflammation of the mucous membrane lining the nasal and bronchialpassages. One going out from the hot dry air of a furnace-heated room intothe cold damp atmosphere of our climate can hardly avoid irritating andinflaming this tender membrane. If our rooms were heated less intensely, and ventilated more thoroughly, so that we had not the present hothousesensitiveness to cold air, this disease would be far less universal, andperhaps would disappear entirely. [Footnote: Dr. Gray gives the followingtable:

=====================================================================Rooms Occupied by Letter-press Printers. | Number | Subject to| per cent | Catarrh| Spitting || Blood. |------------------------------------------+------------+-------------104 men having less than 500 cubic feet | |of air to breathe | 12. 50 | 12. 50| |115 men having from 500 to 600 cubic feet | |of air to breathe | 4. 35 | 3. 58| |101 men having more than 600 cubic feet | |of air to breathe | 3. 96 | 1. 98---------------------------------------------------------------------](See p. 315. )

ALCOHOLIC DRINKS AND NARCOTICS. 

1. ALCOHOL. 

That we may understand fully the effect of alcohol upon the human system, let us first consider its nature and the process by which harmless fruitsand grains are made to produce a substance so unlike themselves in itsdeleterious effects. 

HOW ALCOHOL IS MADE. --When any substance containing sugar, as fruit juice, is caused to ferment, the elements of which the sugar is composed, viz. , hydrogen, carbon, and oxygen, so rearrange themselves as to form carbondioxide (carbonic acid), alcohol, and certain volatile oils and ethers. [Footnote: The precise relation between chemical phenomena and thephysiological functions of the organic ferment is still to be discovered;and all that has been said, written, and brought forward to decide thequestion, need experimental proof. --SCHÜTZENBERGER. ] The carbonic acidpartly evaporates and partly remains in the liquor; the alcohol is thepoisonous or intoxicating principle, while the oils and ethers impart thepeculiar flavor and odor. Thus wine is fermented grape juice, and cider isfermented apple juice, each having its distinctive taste and smell, andeach containing, as one product of fermentation, more or less of theinebriating alcohol. Wines are also made from other fruits and vegetables, such as oranges, currants, tomatoes, and rhubarb, but the alcohol whichthey contain is of the same nature in all cases, whether the fermentedliquor has been manufactured in great quantities, by large presses, or bya simple domestic process for home consumption. It is important toremember this fact, as many people do not associate alcohol with suchbeverages as domestic wines and home-brewed ales, whereas it is alwayspresent with the same treacherous qualities which attach to it everywhere. An apple is a wholesome and useful fruit, and its simple juice, fragrantand refreshing, is a delight to the palate; but apple juice converted intocider and allowed to enter upon alcoholic fermentation, loses itsinnocence, and becomes a dangerous drink, because it is the nature of thealcohol it now contains to create an appetite for more alcohol. (See p. 185. )

WHAT IS A FERMENT?--Ferments, of which there are many varieties in nature, are minute living organisms analogous to the microscopic objects calledbacteria or microbes, [Footnote: There is no well-defined limit betweenferments and bacteria, any more than between ferments and fungi, or again, between fungi and bacteria. Their smaller size is the principal differencewhich separates bacteria from ferments, although there are bacteria oflarge size, such as are so frequently found in the mouth of even a healthyman, and which much resemble in their mode of growth some of the lowerfungi. --Trouessart. ] of which we have heard much in late years, especiallyin connection with the famous researches and experiments of the greatFrench investigator, M. Pasteur. He tells us that "Every fermentation hasits specific ferment. This minute being produces the transformation whichconstitutes fermentation by breathing the oxygen of the substance to befermented, or by appropriating for an instant the whole substance, thendestroying it by what may be termed the secretion of the fermentedproducts. " [Footnote: What we call spontaneous fermentation often occurs, as when apple juice turns to hard cider by simple exposure to the air. Science teaches us, however, that this change is always effected by theaction of the busy little ferments which, wandering about, drop into theliquid, begin their rapid propagation, and, in the act of growing, evolvethe products of the fermentation. "If the above liquids be left only incontact with air which has been passed through a red-hot platinum tube, and thus the living sporules destroyed; or if the air be simply filteredby passing through cotton wool, and the sporules prevented from cominginto the liquid, it is found that these fermentable liquids may bepreserved for any length of time without undergoing the slightestchange. "--Roscoe. ] The effect, therefore, of fermentation is to changeentirely the character of the substance upon which it acts; hence it is anerror to assume that fermented liquors, as beer, wine, and cider, are safedrinks because the grains or fruits from which they are produced arehealthful foods. 

YEAST is a ferment which causes alcoholic fermentation. It consists ofmicroscopic plants, which increase by the formation of multitudes of tinycells not more than 1/2400 of an inch in diameter. In the brewing of beerthey grow in great abundance, making common brewer's yeast. Ferments ortheir spores float in the air ready to enter any fermentable liquid, andunder favorable conditions they multiply with great activity and energy. The favorable conditions include the presence of oxygen or sugar;[Footnote: Yeast, like ordinary plants, buds and multiplies even in theabsence of fermentable sugar, when it is furnished with free oxygen. Thismultiplication, however, is favored by the presence of sugar, which is amore appropriate element than non-fermentable hydrocarbon compounds. Yeastis also able to bud and multiply in the absence of free oxygen, but inthis case a fermentable substance is indispensable. --SCHÜTZENBERGER'S_Fermentation_. ] oxygen being, as we know, necessary for thedevelopment and the reproduction of all cell life (p. 107), and fermentshaving the power to resolve sugar, which penetrates by endosmose into theinterior of the cell, into alcohol, carbonic acid, glycerine, succinicacid, and oxygen. 

BEER. --The barley used for making beer is first malted, _i. E. _, sprouted, to turn a part of its starch into sugar. When this process hasgone far enough, it is checked by heating the grain in a kiln until thegerm is destroyed. The malt is then crushed, steeped, and fermented withhops and yeast. The sugar gradually disappears, alcohol is formed, andcarbonic acid escapes into the air. The beer is then put into casks, whereit undergoes a second, slower fermentation, and the carbonic acid gathers;when the liquor is drawn, this gas bubbles to the surface, giving to thebeer its sparkling, foamy look. 

WINE is generally made from the juice of the grape. The juice, or_must_, as it is called, is placed in vats in the cellar, where thelow temperature favors a slow fermentation. If all the sugar be convertedinto alcohol and carbonic-acid gas, a dry wine will remain; if thefermentation be checked, a sweet wine will result; and if the wine bebottled while the change is still going on, a brisk effervescing liquorlike champagne, will be formed. All these are dangerous beverages becauseof the alcohol they contain. 

DISTILLATION. --Alcohol is so volatile that, by the application of heat, itcan be driven off as a vapor from the fermented liquid in which it hasbeen produced. Steam and various fragrant substances will accompany it, and, if they are collected and condensed in a cool receiver, a new andstronger liquor will be formed, having a distinctive odor. 

In this way whiskey is distilled from fermented corn, rye, barley, orpotatoes; the alcohol of commerce is distilled from whiskey; brandy, fromwine; rum, from fermented molasses; and gin, from fermented barley andrye, afterward distilled with juniper berries. 

VARIETIES AND PROPERTIES OF ALCOHOL. --There are several varieties ofalcohol produced from distillation of various substances. Thus MethylAlcohol is obtained from the decomposition of hard wood when exposed tointense heat with little or no oxygen present. It is a light, volatileliquid, which closely resembles ordinary alcohol in all its properties. Itis used in the manufacture of aniline dyes, in making varnishes, and forburning in spirit lamps. Amyl Alcohol [Footnote: The odor of amylicalcohol is sweet, nauseous, and heavy. The sensation of its presenceremains long. In taste it is burning and acrid, and it is itselfpractically insoluble in water. When it is diluted with common alcohol itdissolves freely in water, and gives a soft and rather unctuous flavor, Imay call it a fruity flavor, something like that of ripe pears. Amylalcohol, introduced as an adulterant, is an extremely dangerous additionto ordinary alcohol, in whatever form it is presented. From the quantitiesof it imported into this country, it is believed to be employed largely inthe adulteration of wines and spirits. --RICHARDSON. ] is the chiefconstituent of "fusel oil, " found in whiskey distilled from potatoes. Itis often present in common alcohol, giving a slightly unpleasant odor whenit evaporates from the hand. Fusel oil is extremely poisonous and lastingin its effects, so that when contained in liquors it greatly increasestheir destructive and intoxicating properties. 

Ethyl Alcohol, which is that which we have described as obtained fromfermentation of fruits and grains, is the ordinary alcohol of commerce. Wehave spoken of its volatility. This property permits it to pass into vaporat 56° Fahr. It boils at 173° Fahr. (Water boils at 212°. ) Like MethylAlcohol, it burns without smoke and with great heat, [Footnote: Pour alittle alcohol into a saucer and apply an ignited match. The liquid willsuddenly take fire, burning with intense heat, but feeble light. In thisprocess, alcohol takes up oxygen from the air, forming carbonic-acid gas, and water. --Hold a red-hot coil of platinum wire in a goblet containing afew drops of alcohol, and a peculiar odor will be noticed. It denotes theformation of _aldehyde_--a substance produced in the slow oxidationof alcohol. Still further oxidized, the alcohol would be changed into_acetic acid_--the sour principle of vinegar. --Put the white of anegg--nearly pure albumen--into a cup, and pour upon it some alcohol, oreven strong brandy; the fluid albumen will coagulate, becoming hard andsolid. In this connection, it is well to remember that albumen iscontained in our food, while the brain is largely an albuminoussubstance. ] and is therefore of much value in the arts. Its great solventpower over fats and mixed oils renders it a useful agent in manyindustrial operations. It is also a powerful antiseptic, and no one whovisits a museum of natural history will be likely to forget the rows ofbottles within which float reptilian and batrachian specimens, preservedin alcohol. 

To alcohol, also, we are indebted for various anæsthetic agents, which, when not abused (p. 340), are of inestimable value. Thus, if certainproportions of alcohol and nitric acid be mixed together and heated, nitrite of amyl, so serviceable in relieving the agonizing spasms peculiarto that dread disease, angina pectoris, will be obtained. If, instead ofnitric, we use sulphuric acid, we shall get ether; if chlorine be passedthrough alcohol, hydrate of chloral is the result; and, if chloride oflime and alcohol be treated together, the outcome is chloroform. 

One of the most striking properties of alcohol, and one which we shallhereafter consider in its disastrous effects upon the tissues of our body, is its affinity for water. [Footnote: Suppose, then, a certain measure ofalcohol be taken into the stomach, it will be absorbed there, but, previous to absorption, it will have to undergo a proper degree ofdilution with water; for there is this peculiarity respecting alcohol whenit is separated by an animal membrane from a watery fluid like the blood, that it will not pass through the membrane until it has become charged, toa given point of dilution, with water. Alcohol is itself, in fact, sogreedy for water that it will pick it up from watery textures, and deprivethem of it until, by its saturation, its power of reception is exhausted, after which it will diffuse into the current of circulating fluid. 

To illustrate this fact of dilution I perform a simple experiment. Into abladder is placed a mixture consisting of equal parts of alcohol anddistilled water. Into the neck of the bladder a long glass tube isinserted and firmly tied. Then the bladder is immersed in a saline fluidrepresenting an artificial serum of blood. The result is, that the alcoholin the bladder absorbs water from the surrounding saline solution, andthereby a column of fluid passes up into the glass tube. A second mixtureof alcohol and water, in the proportion this time of one part of alcoholto two of water, is put into another bladder immersed in like manner in anartificial serum. In this instance a little fluid also passes from theoutside into the bladder, so that there is a rise of water in the tube, but less than in the previous instance. A third mixture, consisting of onepart of alcohol with three parts of water, is placed in another littlebladder, and is also suspended in the artificial serum. In this case thereis, for a time, a small rise of fluid in the tube connected with thebladder; but after a while, owing to the dilution which took place, acurrent from within outward sets in, and the tube becomes empty. Thus eachbladder charged originally with the same quantity of fluid contains atlast a different quantity. The first contains more than it did originally, the second only a little more, the third a little less. From the third, absorption takes place, and if I keep changing and replacing the outerfluid which surrounds the bladder with fresh serum, I can in time, owingto the double current of water into the bladder through its coats, and ofwater and alcohol out of the bladder into the serum, remove all thealcohol. In this way it is removed from the stomach into the circulatingblood after it has been swallowed. When we dilute alcohol with waterbefore drinking it, we quicken its absorption. If we do not dilute itsufficiently, it is diluted in the stomach by transudation of water in thestomach, until the required reduction for its absorption; the current thensets in toward the blood, and passes into the circulating canals by theveins. --RICHARDSON. ] When strong alcohol is exposed to the air, it absorbsmoisture and becomes diluted; at the same time, the spirit itselfevaporates. The commercial or proof spirit is about one half water; thestrongest holds five per cent; and to obtain absolute or waterlessalcohol, requires careful distillation in connection with some substance, as lime, that has a still greater affinity for water, and so can despoilthe alcohol. 

ALCOHOL IN ITS DESTRUCTIVE RELATION TO PLANT AND ANIMAL LIFE. --If we poura little quantity of strong spirits upon a growing plant in our garden orconservatory, we shall soon see it shrivel and die. If we apply it toinsects or small reptiles which we may have captured for specimens in ourcabinet, the same potent poison will procure for them a speedy death. Ifwe force one of our domestic animals to take habitual doses of it, theanimal will not only strongly protest against the unnatural and nauseouspotion, but it will gradually sicken and lose all power for usefulness. "If I wished, " says a distinguished English physician, "by scientificexperiment to spoil for work the most perfect specimen of a workinganimal, say a horse, without inflicting mechanical injury, I could chooseno better agent for the purpose of the experiment than alcohol. "[Footnote: "The effects produced by alcohol are common, so far as I candiscover, to every animal. Alcohol is a universal intoxicant, and in thehigher orders of animals is capable of inducing the most systematicphenomena of disease. But it is reserved for man himself to exhibit thesephenomena in their purest form, and to present, through them, in themorbid conditions belonging to his age, a distinct pathology. Bad as thisis, it might be worse; for if the evils of alcohol were made to extendequally to animals lower than man, we should soon have none that weretamable, none that were workable, and none that were eatable. "]

ALCOHOL IN WINE, BEER, AND CIDER IDENTICAL WITH ALCOHOL IN ARDENTSPIRITS. --In all liquors the active principle is alcohol. It comprisesfrom six to eight per cent of ale and porter, seven to seventeen per centof wine, and forty to fifty per cent of brandy and whiskey. All these maytherefore be considered as alcohol more or less diluted with water andflavored with various aromatics. The taste of different liquors--asbrandy, gin, beer, cider, etc. --may vary greatly, but they all producecertain physiological effects, due to their common ingredient--alcohol. "In whatever form it enters, " says Dr. Richardson, "whether as spirit, wine, or ale, matters little when its specific influence is kept steadilyin view. To say this man only drinks ale, that man only drinks wine, whilea third drinks spirits, is merely to say, when the apology is unclothed, that all drink the same danger. " In other words, the poisonous nature ofalcohol, and the effects which result when it is taken into the stomach, are definite and immutable facts, which are not dependent upon anyparticular name or disguise under which the poison finds entrance. 

We shall learn, as we study the influence of alcohol upon the humansystem, that one of its most subtle characteristics is the progressiveappetite for itself (p. 185) which it induces, an appetite which, in manycases, is formed long before its unhappy subject is aware of his danger. The intelligent pupil, who knows how to reason from cause to effect, needshardly to be told, in view of this physical truth, of the peril that liesin the first draught of _any_ fermented liquor, even though it be soseemingly harmless as a glass of home-brewed beer or "slightly-beaded"cider. Few of us really understand our own inherent weakness or thehereditary proclivities (p. 186) that may be lurking in our blood, readyto master us when opportunity invites; but we may be tolerably certainthat if we resolutely refuse to tamper with cider, beer, or wine, we shallnot fall into temptation before rum, gin, or brandy. Since we know that inall fermented beverages there is present the same treacherous element, alcohol, we are truly wise only when we decline to measure arms in any waywith an enemy so seductive in its advances, so insidious in its influence, and so terrible in its triumph. [Footnote: Aside from all considerationsof physical, mental, and moral injury wrought by the use of alcoholicdrinks, every young man may well take into account the damaging effect ofsuch a dangerous habit upon his business prospects. Careful business menare becoming more and more unwilling to take into their employ any personaddicted to liquor drinking. Within the past few years the officers ofseveral railroads, having found that a considerable portion of theirlosses could be directly traced to the drinking habits of some one or moreof their employés, have ordered the dismissal of all persons in theirservice who were known to use intoxicants, with the additional provisionthat persons thus discharged should never be reinstated. Many Easternmanufactories have adopted similar rules. All mercantile agencies nowreport the habits of business men in this respect, and some life insurancecompanies refuse to insure habitual drinkers, regarding such risks as"extra-hazardous. "]

Let us now consider the physiological effects of alcohol upon the organsimmediately connected with the circulation of the blood. 

GENERAL EFFECT OF ALCOHOL UPON THE CIRCULATION. --During the experimentdescribed on page 118, the influence of alcohol upon the blood may bebeautifully tested. Place on the web of the frog's foot a drop of dilutespirit. The blood vessels immediately expand--an effect known as"_Vascular enlargement_. " Channels before unseen open, and the blooddisks fly along at a brisker rate. Next, touch the membrane with a drop ofpure spirit. The blood channels quickly contract; the cells slacken theirspeed; and, finally, all motion ceases. The flesh shrivels up and dies. The circulation thus stopped is stopped forever. The part affected will intime slough off. Alcohol has killed it. 

The influence of alcohol upon the human system is very similar. Whenstrong, as in spirits, it acts as an irritant, narcotic poison (p. 142, note). Diluted, as in fermented liquors, it dilates the blood vessels, quickens the circulation, hastens the heart throbs, and accelerates therespiration. 

THE EFFECT OF ALCOHOL UPON THE HEART. --What means this rapid flow of theblood? It shows that the heart is overworking. The nerves that lead to theminute capillaries and regulate the passage of the vital current throughthe extreme parts of the body, are paralyzed by this active narcotic. Thetiny blood vessels at once expand. This "Vascular enlargement" removes theresistance to the passage of the blood, and a rapid beating of the heartresults. [Footnote: Dr. B. W. Richardson's experiments tend to prove thatthis apparently stimulating action of alcohol upon the heart is due to theparalysis of the nerves that control the capillaries (Note, p. 208), whichordinarily check the flow of the blood (p. 117). The heart, like othermuscles under the influence of alcohol, really loses power, and contractsless vigorously (p. 183). Dr. Palmer, of the University of Michigan, alsoclaimed that alcohol, in fact, diminishes the strength of the heart. Prof. Martin, of Johns Hopkins University, from a series of carefully conductedexperiments upon dogs, concluded that blood containing one fourth per centof alcohol almost invariably diminishes within a minute the work done bythe heart; blood containing one half per cent always diminishes it, andmay reduce the amount pumped out by the left ventricle so that it is notsufficient to supply the coronary arteries. One hundred years ago, alcoholwas always spoken of as a stimulant. Modern experiment and investigationchallenged that definition, and it is now classified as a narcotic. Thereare, however, able physicians who maintain that, taken in small doses, andunder certain physical conditions, it has the effect of a stimulant. Allagree that, when taken in any amount, it tends to create an appetite formore. ]

Careful experiments show that two ounces of alcohol--an amount containedin the daily potations of a very moderate ale or whiskey drinker--increasethe heart beats six thousand in twenty-four hours;--a degree of workrepresented by that of lifting up a weight of seven tons to a height ofone foot. Reducing this sum to ounces and dividing, we find that the heartis driven to do extra work equivalent to lifting seven ounces one foothigh one thousand four hundred and ninety-three times each hour! No wonderthat the drinker feels a reaction, a physical languor, after the earliesteffects of his indulgence have passed away. The heart flags, the brain andthe muscles feel exhausted, and rest and sleep are imperatively demanded. During this time of excitement, the machinery of life has really been"running down. " "It is hard work, " says Richardson, "to fight againstalcohol; harder than rowing, walking, wrestling, coal heaving, or thetreadmill itself. "

All this is only the first effect of alcohol upon the heart. Long-continued use of this disturbing agent causes a "Degeneration of themuscular fiber, " [Footnote: This "Degeneration" of the various tissues ofthe body, we shall find, as we proceed, is one of the most marked effectsof alcoholized blood. The change consists in an excess of liquid, or, morecommonly, in a deposit of fat. This fatty matter is not an increase of theorgan, but it takes the place of a part of its fiber, thus weakening thestructure, and reducing the power of the tissue to perform its function. Almost everywhere in the body we thus find cells--muscle cells, livercells, nerve cells, as the case may be--changing one by one, under theinfluence of this potent disorganizer, into unhealthy fat cells. "Alcoholhas been well termed, " says the _London Lancet_, "the 'Genius ofDegeneration. '"

The cause of this degeneration can be easily explained. The increasedactivity of the circulation compels a correspondingly increased activityof the cell changes: but the essential condition of healthful change--thepresence of additional oxygen--is wanting (see p. 143), and the operationis imperfectly performed. --BRODIE. ] so that the heart loses its old powerto drive the blood, and, after a time, fails to respond even to the spurof the excitant that has urged it to ruin. 

INFLUENCE UPON THE MEMBRANES. --The flush of the face and the bloodshoteye, that are such noticeable effects of even a small quantity of liquor, indicate the condition of all the internal organs. The delicate linings ofthe stomach, heart, brain, liver, and lungs are reddened, and every tinyvein is inflamed, like the blushing nose itself. If the use of liquor ishabitual, this "Vascular enlargement, " that at first slowly passed awayafter each indulgence, becomes permanent, and now the discolored, blotchedskin reveals the state of the entire mucous membrane. 

We learned on page 55 what a peculiar office the membrane fills innourishing the organs it enwraps. Anything that disturbs its delicatestructure must mar its efficiency. Alcohol has a wonderful affinity forwater. To satisfy this greed, it will absorb moisture from the tissueswith which it comes in contact, as well as from their lubricating juices. The enlargement of the blood vessels and their permanent congestion mustinterfere with the filtering action of the membrane. In time, all themembranes become dry, thickened, and hardened; they then shrink upon thesensitive nerve, or stiffen the joint, or enfeeble the muscle. Thefunction of these membranes being deranged, they will not furnish theorgans with perfected material, and the clogged pores will no longerfilter their natural fluids. Every organ in the body will feel thischange. 

EFFECT UPON THE BLOOD. [Footnote: Alcohol acts upon the oxygen carrier, the coloring matter of the red corpuscles, causing it to settle in onepart of the globule, or even to leave the corpuscle, and deposit itself inother elements of the blood. Thus the red corpuscle may become colorless, distorted, shrunken, and even entirely broken up--Dr. G. B. HARRIMAN. ]--From the stomach, alcohol passes directly into the circulation, and so, ina few minutes, is swept through the entire system. If it be present insufficient amount and strength, its eager desire for water will lead it toabsorb moisture from the red corpuscles, causing them to shrink, changetheir form, harden, and lose some of their ability to carry oxygen; it mayeven make them adhere in masses, and so hinder their passage through thetiny capillaries. --RICHARDSON. 

With most persons who indulge freely in alcoholic drinks, the blood isthin, the avidity of alcohol for water causing the burning thirst sofamiliar to all drinkers, and hence the use of enormous quantities ofwater, oftener of beer, which unnaturally dilutes the blood. The bloodthen easily flows from a wound, and renders an accident or surgicaloperation very dangerous. 

When the blood tends, as in other cases of an excessive use of spirits, tocoagulate in the capillaries, [Footnote: The blood is rendered undulythin, or is coagulated, according to the amount of alcohol that is carriedinto the circulatory system. "The spirit may fix the water with thefibrin, and thus destroy the power of coagulation; or it may extract thewater so determinately as to produce coagulation. This explains why, inacute cases of poisoning by alcohol, the blood is sometimes found quitefluid, at other times firmly coagulated in the vessels. "--B. W. RICHARDSON. ]

Reckless persons have sometimes drunk a large quantity of liquor for awager, and, as the result of their folly, have died instantly. The wholeof the blood in the heart having coagulated, the circulation was stopped, and death inevitably ensued. ] there is a liability of an obstruction tothe flow of the vital current through the heart, liver, lungs, etc. , thatmay cause disease, and in the brain may lay the foundation of paralysis, or, in extreme cases, of apoplexy. 

Wherever the alcoholized blood goes through the body, it bathes thedelicate cells with an irritating narcotic poison, instead of a bland, nutritious substance. 

EFFECT UPON THE LUNGS. --Here we can see how certainly the presence ofalcohol interferes with the red corpuscles in their task of carryingoxygen. "Even so small a quantity as one part of alcohol to five hundredof the blood will materially check the absorption of oxygen in the lungs. "

The cells, unable to take up oxygen, retain their carbonic-acid gas, andso return from the lungs, carrying back, to poison the system, the refusematter the body has sought to throw off. Thus the lungs no longer furnishproperly oxygenized blood. 

The rapid stroke of the heart, already spoken of, is followed by acorresponding quickening of the respiration. The flush of the cheek isrepeated in the reddened mucous membrane lining the lungs. 

When this "Vascular enlargement" becomes permanent, and the highlyalbuminous membrane of the air cells is hardened and thickened as well ascongested, the Osmose of the gases to and fro through its pores can nolonger be prompt and free as before. Even when the effect passes off in afew days after the occasional indulgence, there has been, during thattime, a diminished supply of the life-giving oxygen furnished to thesystem; weakness follows, and, in the case of hard drinkers, there is amarked liability to epidemics. [Footnote: There is no doubt that alcoholalters and impairs tissues so that they are more prone to disease. --DR. G. K. SABINE. A volume of statistics could be filled with quotations like thefollowing: "Mr. Huber, who saw in one town in Russia two thousand onehundred and sixty persons perish with the cholera in twenty days, said:'It is a most remarkable circumstance that persons given to drink havebeen swept away like flies. In Tiflis, with twenty thousand inhabitants, every drunkard has fallen, --all are dead, not one remaining. '"]

Physicians tell us, also, that there is a peculiar form of consumptionknown as Alcoholic Phthisis caused by long-continued and excessive use ofliquor. It generally attacks those whose splendid physique has enabledthem to "drink deep" with apparent impunity. This type of consumptionappears late in life and is considered incurable. Severe cases ofpneumonia are also generally fatal with inebriates. [Footnote: TheInfluence of Alcohol is continued in the chapter on Digestion. ]

PRACTICAL QUESTIONS. 

1. Why does a dry, cold atmosphere favorably affect catarrh?

2. Why should we put on extra covering when we lie down to sleep?

3. Is it well to throw off our coats or shawls when we come in heated froma long walk?

4. Why are close-fitting collars or neckties injurious?

5. Which side of the heart is the more liable to inflammation?

6. What gives the toper his red nose?

7. Why does not the arm die when the surgeon ties the principal arteryleading to it?

8. When a fowl is angry, why does its comb redden?

9. Why does a fat man endure cold better than a lean one?

10. Why does one become thin, during a long sickness?

11. What would you do if you should come home "wet to the skin"?

12. When the cold air strikes the face, why does it first blanch and thenflush?

13. What must be the effect of tight lacing upon the circulation of theblood?

14. Do you know the position of the large arteries in the limbs, so thatin case of accident you could stop the flow of blood?

15. When a person is said to be good-hearted, is it a physical truth?

16. Why does a hot footbath relieve the headache?

17. Why does the body of a drowned or strangled person turn blue?

18. What are the little "kernels" in the armpits?

19. When we are excessively warm, would the thermometer show any rise oftemperature in the body?

20. What forces besides that of the heart aid in propelling the blood?

21. Why can the pulse be best felt in the wrist?22. Why are starving people exceedingly sensitive to any jar?

23. Why will friction, an application of horse-radish leaves, or a blisterrelieve internal congestion?

24. Why are students very liable to cold feet?

25. Is the proverb that "blood is thicker than water" literally true?

26. What is the effect upon the circulation of "holding the breath"?

27. Which side of the heart is the stronger?

28. How is the heart itself nourished? [Footnote: The coronary artery, springing from the aorta just after its origin, carries blood to themuscular walls of the heart; the venous blood comes back through thecoronary veins, and empties directly into the right auricle. ]

29. Does any venous blood reach the heart without coming through the venæcavæ?

30. What would you do, in the absence of a surgeon, in the case of asevere wound? (See p. 258. )

31. What would you do in the case of a fever? (See p. 263. )

32. What is the most injurious effect of alcohol upon the blood?

33. Are our bodies the same from day to day?

34. Show how life comes by death. 

35. Is not the truth just stated as applicable to moral and intellectual, as to physical life?

36. What vein begins and ends with capillaries? _Ans_. The portalvein commences with capillaries in the digestive organs, and ends with thesame kind of vessels in the liver. (See p. 166. )

37. By what process is alcohol always formed? Does it exist in nature?

38. What percentage of alcohol is contained in the different kinds ofliquor?

39. Does cider possess the same intoxicating principle as brandy?

40. Describe the general properties of alcohol. 

41. Show that alcohol is a narcotic poison. 

42. If alcohol is not a stimulant, how does it cause the heart tooverwork?

43. Why is the skin of a drunkard always red and blotched?

44. What danger is there in occasionally using alcoholic drinks?

45. What is meant by a fatty degeneration of the heart?

46. What keeps the blood in circulation between the beats of the heart?

47. What is the office of the capillaries? (See note, p. 373. )

48. Does alcohol interfere with this function?

49. How does alcohol interfere with the regular office of the membranes?

50. How does it check the process of oxidation?

VI. 

DIGESTION AND FOOD. 

"A man puts some ashes in a hill of corn and thereby doubles its yield. Then he says, 'My ashes have I turned into corn. ' Weak from his labor, heeats of his corn, and new life comes to him. Again, he says, 'I havechanged my corn into a man. ' This also he feels to be the truth. 

"It is the problem of the body, remember, that we are discussing. A man ismore than the body; to confound the body and the man is worse thanconfounding the body and the clothing. "--JOHN DARBY. 

ANALYSIS OF DIGESTION AND FOOD

_| 1. WHY WE NEED FOOD. || 2. WHAT FOOD DOES. | _ _| | 1. Nitrogenous. |_a. _The Sugars. _| 3. KINDS OF FOOD. . . . | 2. Carbonaceous. . . . |_b. _The Fats. _| |_3. Minerals| | 4. ONE KIND is INSUFFICIENT. || 5. OBJECT OF DIGESTION. | _| | --General Description| | _ | | 1. Mastication and | a. _The Saliva. _| | Insalvation. . . . . . | b. _Process of| | |_ Swallowing. _| | _ | | | a. _The Stomach. _| | 2. Gastric | b. _The Gastric| | Digestion. . . . . . . . | Juice. _| | |_c. _The Chyme_| 6. PROCESSES OF | _| DIGESTION. . . . . . . . | | --Description| | | a. _The Bile_| | 3. Intestional | b. _The Pancreatic| | Digestion. . . . . . . . | Juice. _| | | c. _The Small| | |_ Intestine. _| | _| | | a. _By the Veins. _| | 4. Absorption. . . . . . . | b. _By the| |_ |_ Lacteals. _|| 7. COMPLEXITY OF THE PROCESS OF DIGESTION. | _| | 1. Length of Time required. | | _ | | | a. _Beef. _| | | b. _Mutton. _| | | c. _Lamb. _| | 2. Value of dif- | d. _Pork. _| | ferent kinds | e. _Fish. _| | of food. . . . . . . . . | f. _Milk. _| | | g. _Cheese. _| | |_h. _Eggs, etc. _| | _| 8. HYGIENE. . . . . . . . . . | | a. _Coffee. _| | 3. The Stimulants. . . | b. _Tea. _| | |_C. _Chocolate. _| | 4. Cooking of Food. | | 5. Rapid Eating. | | 6. Quantity and Quality of Food. | | 7. When Food should be taken. | | 8. How Food should be taken. | |_9. Need of a Variety|| 9. THE WONDERS OF DIGESTION. | _| | 1. Dyspepsia. | 10. DISEASES. . . . . . . . |_2. The Mumps. | _| | 1. Is Alcohol a Food?| | 2. Effect upon the Digestion. | | 3. Effect upon the Liver. | 11. ALCOHOLIC | 4. Effect upon the Kidneys. | DRINKS AND | 5. Does Alcohol impart heat?| NARCOTICS. . . . . . . | 6. Does Alcohol impart strength?|_ | 7. The Effect upon the Waste of the Body. | 8. Alcohol creates a progressive appetite| for itself. |_9. Law of Heredity. 

DIGESTION AND FOOD. 

WHY WE NEED FOOD. --We have learned that our bodies are constantly givingoff waste matter--the products of the fire, or oxidation, as the chemistterms the change going on within us (Note, p. 107). A man without foodwill starve to death in a few days, _i. E. _, the oxygen will haveconsumed all the available flesh of his body. [Footnote: The storiescurrent in the newspapers of persons who live for years without food, are, of course, untrue. The case of the Welsh Fasting Girl, which excitedgeneral interest throughout Great Britain, and was extensively copied inour own press, is in point. She had succeeded in deceiving not only thepublic, but, as some claim, her own parents. At last a strict watch wasset by day and night, precluding the possibility of her receiving any foodexcept at the hands of the committee, from whom she steadily refused it. In a few days she died from actual starvation. The youth of the girl, theapparent honesty of the parents, and the tragical sequel, make it one ofthe most remarkable cases of the kind on record. ] To replace the dailyoutgo, we need about two and a quarter pounds of food, and three pints ofdrink. [Footnote: Every cell in the tissues is full of matter ready to setfree at call its stored-up energy--derived from the meat, bread, andvegetables we have eaten. This energy will pass off quietly when theorgans are in comparative rest, but violently when the muscles contractwith force. When we send an order through a nerve to any part of the body, a series of tiny explosions run the entire length of the nerve, just asfire runs through a train of gunpowder. The muscle receives the stimulus, and, contracting, liberates its energy. The cells of nerve or muscle, whose contents have thus exploded, as it were, are useless, and must becarried off by the blood, just as ashes must be swept from the hearth, andnew fuel be supplied to keep up a fire. ]

Including the eight hundred pounds of oxygen taken from the air, a manuses in a year about a ton and a half of material. [Footnote: Thefollowing is the daily ration of a United States soldier. It is said to bethe most generous in the world:

Bread or flour . . . . . . . . . 22 ounces. Fresh or salt beef (or pork or bacon, 12 oz. ) . 20 "Potatoes (three times per week) . . . . . 16 "Rice . . . . . . . . . . . 1. 6 "Coffee (or tea, 0. 24 oz. ) . . . . . . 1. 6 "Sugar . . . . . . . . . . . 2. 4 "Beans . . . . . . . . . . . 0. 64 gill. Vinegar . . . . . . . . . . 0. 32 "Salt . . . . . . . . . . . . 0. 16 "]

Yet during this entire time his weight may have been nearly uniform. [Footnote: If, however, he were kept on the scale pan of a sensitivebalance, he would find that his weight is constantly changing, increasingwith each meal, and then gradually decreasing. ] Our bodies are but molds, in which a certain quantity of matter, checked for a time on its ceaselessround, receives a definite form. They may be likened, says Huxley, to aneddy in the river, which retains its shape for a while, yet every instanteach particle of water is changing. 

WHAT FOOD DOES. --We make no force ourselves. We can only use that whichnature provides for us. [Footnote: We draw from Nature at once oursubstance, and the force by which we operate upon her; being, so far, parts of her great system, immersed in it for a short time and to a smallextent. Enfolding us, as it were, within her arms, Nature lends us herforces to expend; we receive them, and pass them on, giving them theimpress of our will, and bending them to our designs, for a little while;and then--Yes; then it is all one. The great procession pauses not, norflags a moment, for our fall. The powers which Nature lent to us sheresumes to herself, or lends, it may be, to another; the use which we havemade of them, or might have made and did not, is written in her bookforever. --_Health and its Conditions_. ] All our strength comes fromthe food we eat. Food is force--that is, it contains a latent power whichit gives up when it is decomposed. [Footnote: This force is chemicalaffinity. It binds together the molecules which compose the food we eat. When oxygen tears the molecules to pieces and makes them up into smallerones, the force is set free. As we shall learn in Physics, it can beturned, into heat, muscular motion, electricity, etc. The principle thatthe different kinds of force can be changed into one another without loss, is called the Conservation of Energy, and is one of the grandestdiscoveries of modern science. --_Popular Physics_, pages 35, 39, 278. ] Oxygen is the magic key which unlocks for our use this hidden store. [Footnote: We have spoken of the mystery that envelops the process of theconversion of food force into muscular force (note, p. 107). Allphysiologists agree that muscular power has its source in the chemicaldecomposition of certain substances whereby their potential energy isreleased. Probably some of the food undergoes this chemical change beforeit passes out of the alimentary canal; possibly some is broken up by theoxygen while it is being swept along by the blood; but, probably by farthe largest part is converted into the various tissues of the body, andfinally becomes a waste product only after there takes place in the tissueitself that chemical disorganization that sets free its stored-up power. --FOSTER'S _Physiology_. ] Putting food into our bodies is like placinga tense spring within a watch; every motion of the body is only a newdirection given to this food force, as every movement of the hand on thedial is but the manifestation of the power of the bent spring in thewatch. We use the pent-up energies of meat, bread, and vegetables whichare placed at our service, and transfer them to a higher theater ofaction. [Footnote: It is a grand thought that we can thus transform whatis common and gross into the refined and spiritual; that out of wavingwheat, wasting flesh, running water, and dead minerals, we can realize theglorious possibilities of human life. ]

KINDS OF FOOD NEEDED. --From what has been said it is clear that, in orderto produce heat and force, we need something that will burn, _i. E. _, with which oxygen can combine. Experiment has proved that to build upevery organ, and keep the body in the best condition, we require threekinds of food. 

1. _Nitrogenous Food_. --As nitrogen is a prominent constituent of thetissues of the body, food which contains it is therefore necessary totheir growth and repair. [Footnote: Since this kind of food closelyresembles albumen, it is sometimes called _Albuminous_. The termProteid is also used. ] The most common forms are whites of eggs--which arenearly pure albumen; casein--the chief constituent of cheese; lean meat;and gluten--the viscid substance which gives tenacity to dough. Bodieshaving a great deal of nitrogen readily oxidize. Hence the peculiarcharacter of the quick-changing, force-exciting muscle. 

2. _Carbonaceous Food_--_i. E. _, food containing much carbon--consists of two kinds, viz. , the _sugars_, and the _fats_. 

(1) The _sugars_ contain hydrogen and oxygen in the proportion toform water, and about the same amount of carbon. They may, therefore, beconsidered as water, with carbon diffused through it. In digestion, starchand gum are changed to sugar, and so are ranked with this class. 

(2) The _fats_ are like the sugars in composition, but contain lessoxygen, and not in the proportion to form water. They combine with moreoxygen in burning, and so give off more heat. 

The non-nitrogenous elements of the food have, however, other uses than todevelop heat. [Footnote: The heat they produce in burning may be turnedinto motion of the muscles, according to the principle of the Conservationof Energy (p. 153, note); while all the structures of the body in theiroxidation develop heat. ] Fat is essential to the assimilation of the food, while sugar and starch aid in digestion and may be converted into fat. [Footnote: In Turkey, the ladies of the harem are fed on honey and thickgruel, to make flesh, which is considered to enhance their beauty. Thenegroes on the sugar plantations of the South always grow fat during thesugar-making season. ] Fat and carbonaceous material both enter into thecomposition of the various tissues, and when, by the breaking up of thecontractile substance of the muscle, their latent energy is set free, theybecome the source of muscular force, as well as heat. While the tendencyof the albuminous food is to excite chemical action, and hence the releaseof energy, the fats and carbonaceous food may be laid up in the body toserve as a storehouse of energy to supply future needs. 

3. _Mineral Matters_. --Food should contain water, and certain commonminerals, such as iron, [Footnote: While the body can build up a solidfrom liquid materials on the one hand, on the other it can pour ironthrough its veins and reduce the hardest textures to blood. --HINTON. ]sulphur, magnesia, phosphorus, salt, and potash. About three pints ofwater are needed daily to dissolve the food and carry it through thecirculation, to float off waste matter, to lubricate the tissues, and byevaporation to cool the system (see p. 317). It also enters largely intothe composition of the body. A man weighing one hundred and fifty-fourpounds contains one hundred pounds of water, about twelve gallons--enough, if rightly arranged, to drown him. [Footnote: It is said that Blumenbachhad a perfect mummy of an adult Teneriffian, which with the visceraweighed only seven and a half pounds. ]

Iron goes to the blood disks; lime combines with phosphoric and carbonicacids to give solidity to the bones and teeth; phosphorus is essential tothe activity of the brain. Salt is necessary to the secretion of some ofthe digestive fluids, and also to aid in working off from the system itswaste products. These various minerals, except iron--sometimes given as amedicine, and salt--universally used as a condiment, [Footnote: Animalswill travel long distances to obtain salt. Men will barter gold for it;indeed, among the Gallas and on the coast of Sierra Leone, brothers willsell their sisters, husbands their wives, and parents their children forsalt. In the district of Accra, on the gold coast of Africa, a handful ofsalt is the most valuable thing upon earth after gold, and will purchase aslave. Mungo Park tells us that with the Mandingoes and Bambaras the useof salt is such a luxury that to say of a man "he flavors his food withsalt, " it is to imply that he is rich; and children will suck a piece ofrock salt as if it were sugar. No stronger mark of respect or affectioncan be shown in Muscovy, than the sending of salt from the tables of therich to their poorer friends. In the book of Leviticus it is expresslycommanded as one of the ordinances of Moses, that every oblation of meatupon the altar shall be seasoned with salt, without lacking; and hence itis called the Salt of the Covenant of God. The Greeks and Romans also usedsalt in their sacrificial cakes; and it is still used in the services ofthe Latin church--the "_parva mica_" or pinch of salt, being in theceremony of baptism, put into the child's mouth, while the priest says, "Receive the salt of wisdom, and may it be a propitiation to thee foreternal life. " Everywhere and almost always, indeed, it has been regardedas emblematical of wisdom, wit, and immortality. To taste a man's salt, was to be bound by the rites of hospitality; and no oath was more solemnthan that which was sworn upon bread and salt. To sprinkle the meat withsalt was to drive away the devil, and to this day, nothing is more unluckythan to spill the salt. --LETHEBY, _On Food_. ] are contained insmall, but sufficient quantities in meat, bread, and vegetables. 

ONE KIND OF FOOD IS INSUFFICIENT. --A person fed on starch alone, woulddie. It would be a clear case of nitrogen starvation. On the other hand, as nitrogenous food contains carbon, the elements of water, and variousmineral matters, life could be supported on that alone. But such aprodigious quantity of lean meat, for example, would be required tofurnish the other elements, that not only would it be very expensive, butit is likely that after a time the labor of digestion would be tooonerous, and the system would give up the task in despair. The need of adiet containing both nitrogenous and carbonaceous elements is shown in thefact that even in the tropical regions oil is relished as a dressing uponsalad. Instinct everywhere suggests the blending. Butter is used withbread; rice is boiled with milk; cheese is eaten with macaroni, and beansare baked with pork. 

FIG. 45. 

[Illustration: _The Stomach and Intestines. _ 1, _stomach;_ 2, _duodenum;_ 3, _small intestine;_ 4, _termination of theileum;_ 5, _cœcum;_ 6, _vermiforn appendix;_ 7, _ascendingcolon;_ 8, _transverse colon;_ 9, _descending colon;_ 10, _sigmoid flexure of the colon;_ 11, _rectum;_ 12, _spleen--agland whose action is not understood. _--LEIDY'S _Anatomy. _]

THE OBJECT OF DIGESTION. --If our food were cast directly into the blood, it could not be used. For example, although the chemist can not seewherein the albumen of the egg differs from the albumen of the blood, yetif it be injected into the veins it is unavailable for the purposesrequired, and is thrown out again. In the course of digestion the food ismodified in various ways whereby it is fitted for the use of the body, into which it is finally incorporated. We call this change of food intoflesh _assimilation_, a name for a work done solely by the vitalorgans, and so mysterious in its nature that the wisest physiologist getsonly glimpses here and there of its operations. 

THE GENERAL PLAN OF DIGESTION. --Nature has provided for this purpose anentire laboratory, furnished with a chemist's outfit of knives, mortars, baths, chemicals, filters, etc. The food is (1) chewed, mixed with thesaliva in the mouth, and swallowed; (2) it is acted upon by the gastricjuice in the stomach; (3) it is passed into the intestines, where itreceives the bile, pancreatic juice, and other liquids which completelydissolve it; [Footnote: Digestion, says Berzelius, is a process ofrinsing. The digestive apparatus secretes, and again absorbs with the foodwhich it has dissolved, not less than three gallons of liquid per day. --BARNARD, BIDDER, SCHMIDT, and others. ] (4) the nourishing part is absorbedin the stomach and intestines, and thence thrown into the blood vessels, whence it is whirled through the body by the torrent of the circulation. These processes take place within the _alimentary canal_, a narrowtortuous tube which commences at the mouth, and is about thirty feet long. [Footnote: The digestive apparatus is lined with mucous membrane thatpossesses functions similar to those of the outer skin. It absorbs certainsubstances and rejects waste matter. On account of this close connectionbetween the inner and the outer skin, it is not surprising to find that inthe lowest animals digestion is performed by means of the external skin. The amœba, which is merely a gelatinous mass, when it takes its food, extemporizes a stomach for the occasion. It simply wraps itself around themorsel, and, like an animated apple dumpling with the apple for food andthe crust for animal, goes on with the process until the operation iscompleted, when it unrolls itself again and lets the indigestible residueescape. The common hydra of our brooks can live when turned inside out, like a glove; either side serving for skin or stomach, as necessityrequires. ]

FIG. 46. 

[Illustration: _The Parotid--one of the salivary glands. _]

I. MASTICATION AND INSALIVATION. --l. _The Saliva_. --The food whilebeing cut and ground by the teeth is mixed with the saliva. This is athin, colorless, frothy, slightly alkaline liquid, secreted [Footnote: Bysecretion is meant merely a separation or picking out from the blood. ] bythe mucous membrane lining the mouth, and by three pairs of salivaryglands (parotid, submaxillary, and sublingual) opening into the mouththrough ducts, or tubes. The amount varies, but on the average is aboutthree pounds per day, and in health is always sufficient to keep the mouthmoist. [Footnote: The presence and often the thought of food will "makeone's mouth water. " Fear checks the flow of saliva, and hence the EastIndians sometimes attempt to detect theft by making those who aresuspected chew rice. The person from whom it comes out driest is adjudgedthe thief. ] It softens and dissolves the food, and thus enables us to getthe flavor or taste of what we eat. It contains a peculiar organicprinciple called _ptyalin_, [Footnote: One part of ptyalin willconvert eight thousand parts of starch into sugar. --MIALEE. 

The saliva has no chemical action on the fats or the albuminous bodies. Its frothiness enables it to carry oxygen into the stomach, and this isthought to be of service. The action of the ptyalin commences with greatpromptness, and sugar has been detected, it is said, within half a minuteafter the starch was placed in the mouth. The process, however, is notfinished there, but continues after reaching the stomach. --VALENTIN. Thesaliva thus prepares a small portion of food for absorption at once, andso insures at the very beginning of the operation of digestion a supply offorce-producing material for the immediate use of the system. ] which, acting upon the starch of the food, changes it into glucose or grapesugar. 

2. _The Process of Swallowing. _--The food thus finely pulverized, softened, and so lubricated by the viscid saliva as to prevent friction asit passes over the delicate membranes, is conveyed by the tongue and cheekto the back of the mouth. The soft palate lifts to close the nasalopening; the epiglottis shuts down, and along this bridge the food isborne, without danger of falling into the windpipe or escaping into thenose. The muscular bands of the throat now seize it and take it beyond ourcontrol. The fibers of the œsophagus contract above, while they are laxbelow, and convey the food by a worm-like motion into the stomach. [Footnote: We can observe the peculiar motion of the œsophagus by watchinga horse's neck when he is drinking. ]

II. GASTRIC DIGESTION. --1. _The Stomach_ is an irregular expansion ofthe digestive tube. Its shape has been compared to that of a bagpipe. Itholds about three pints, though it is susceptible of some distension. Itis composed of an inner, mucous membrane, which secretes the digestivefluids; an outer, smooth, well-lubricated serous one, which preventsfriction, and between them a stout, muscular coat. The last consists oftwo principal layers of longitudinal and circular fibers. When thesecontract, they produce a peculiar churning motion, called the_peristaltic_ (_peri_, round; _stallein_, to arrange) movement, whichthoroughly mixes the contents of the stomach. At the farther end, themuscular fibers contract and form a gateway, the _pylorus_ (a gate), as it is called, which carefully guards the exit, and allows no foodto pass from the stomach until properly prepared. [Footnote: With awise discretion, however, it opens for buttons, coins, etc. , swallowedby accident; and when we overload the stomach, it seems to become weary ofconstantly denying egress, and, finally, giving up in despair, letseverything through. ]

FIG. 47. 

[Illustration: _Diagram of the Digestion of the Food. Notice how thefood is submitted to the action of alkaline, acid, and then alkalinefluids. (See note, p. _ 165. )]

2. _The Gastric Juice_. --The lining of the stomach is soft, velvety, and of a pinkish hue; but, as soon as food is admitted, the blood vesselsfill, the surface becomes of a bright red, and soon there exudes from thegastric glands a thin, colorless fluid--the gastric juice. (See p. 319. )This is secreted to the amount of twelve pounds per day. [Footnote: Theamount secreted by a healthy adult is variously estimated from five tothirty-seven pounds. As it is reabsorbed by the blood, there is no loss. ]Its acidity is probably due to muriatic or lactic acid--the acid of sourmilk. It contains a peculiar organic principle called _pepsin_[Footnote: Pepsin is prepared and sold as an article of commerce. The bestis said to be made from the stomachs of young, healthy pigs, which, justbefore being killed, are excited with savory food that they are notallowed to eat. One grain is sufficient to dissolve eight hundred grainsof coagulated white of egg. A temperature of 130° renders pepsin inert. ](_peptein_, to digest), which acts as a ferment to produce changes inthe food, without being itself modified. 

The flow of gastric juice is influenced by various circumstances. Coldwater checks it for a time, and ice for a longer period. Anger, fatigue, and anxiety delay and even suspend the secretion. The gastric juice has noeffect on the fats or the sugars of the food; its influence being mainlyconfined to the albuminous bodies, which it so changes that they becomesoluble in water. [Footnote: The question is often asked why the stomachitself is not digested by the gastric juice, since it belongs to thealbuminous substances. Some have assigned as the probable reason that lifeprotects that organ, and assert that living tissues can not be digested;but the fallacy of this has been clearly shown by experiments that havebeen made with living tissues in the course of scientific research. Thelatest opinion is that the blood which circulates so freely through thevessels of the lining of the stomach, being alkaline, protects the tissueagainst the acidity of the gastric juice. ]

The food, reduced by the action of the gastric juice to a grayish, soupymass, called _chyme_ (kime), escapes through that jealously guardeddoor, the pylorus. 

Fig. 48. 

[Illustration: _A vertical Section of the Duodenum, highlymagnified. _ 1, _a fold-like villus;_ 2, epithelium, or cuticle;_3, _orifices of intestinal glands;_ 5, _orifice of duodenal glands;_4, 7, _more highly magnified sections of the cells of a duodenal gland. _]

III. INTESTINAL DIGESTION--The structure of the intestines is like thatof the stomach. There is the same outer, smooth, serous membrane(peritoneum) to prevent friction, the lining of mucous membrane to secretethe digestive fluids, and the muscular coating to push the food forward. The intestines are divided into the _small_ and the _large_. Thefirst part of the former opens out of the stomach, and is called the_du-o-de'-num_, as its length is equal to the breadth of twelvefingers. Here the chyme is acted upon by the _bile_, and the_pancreatic juice_. 

FIG. 49. 

[Illustration: _The Mucous Membrane of the Ilium, highly magnified. _1, _cellular structure of the epithelium, or outer layer;_ 2, _avein;_ 3, _fibrous layer;_ 4, _villi covered with epithelium;_ 5, _a villus in section, showing its lining of epithelium, with itsblood vessels and lymphatics;_ 6, _a villus partially uncovered;_7, _a villus stripped of its epithelium;_ 8, _lymphatics or lacteals;_9, _orifices of the glands opening between the villi;_ 10, 11, 12, _glands;_ 13, _capillaries surrounding the orifices of the gland. _]

1. _The Bile_ is secreted by the liver. This gland weighs about fourpounds, and is the largest in the body. It is located on the right side, below the diaphragm. The bile is of a dark, golden color, and bittertaste. About three pounds are secreted per day. When not needed fordigestion, it is stored in the gall cyst. [Footnote: A gall bladder can beobtained from a butcher, and the contents kept in a bottle forexamination. ] Its action on the food, though not fully understood, isnecessary to life. [Footnote: The bile is produced, unlike all the otheranimal secretions, from venous blood; that is, the already contaminatedblood of the portal vein. Its complete suppression produces symptoms ofpoisoning analogous to those which follow the stoppage of respiration, andthe patient dies, usually in a comatose condition, at the end of ten ortwelve days. --DALTON. The alkaline bile neutralizes the acid contents ofthe stomach as they flow into the duodenum, and thus prepares the way forthe pancreatic juice. It has also a slight emulsifying power (note, p. 167). ]

2. _The Pancreatic Juice_ is a secretion of the pancreas, or"sweetbread"--a gland nearly as large as the hand, lying behind thestomach. It is alkaline, and contains a ferment called _trypsin_. This juice has the power of changing starch to sugar. Its main work, however, is in breaking up the globules of fat into myriads of minuteparticles, that mix freely with water, and remain suspended in it likebutter in new milk. The whole mass now assumes a milky look, whence it istermed _chyle_ (kile) and passes on to the small intestine. [Footnote: It is curious to observe that while the gastric juice isdecidedly acid, the fluids with which the food next comes into contact arealkaline. It is thus submitted to the operation alternately of alkaline, acid, and again of alkaline secretions. In the herbivora there is also asecond acid juice. The reason of these alternations is not known, but itcan hardly be doubted that they serve to make the digestion of the foodmore perfect. And although the solvent power of the gastric juice isplaced in abeyance when its acidity is neutralized by the alkaline fluids, yet it appears to be the case here, as in respect to the saliva, thateffects are produced by the mixture of the various secretions which arepoured together into the digestive tube, that would not result from eitheralone. --HINTON. ]

3. _The Small Intestine_ is an intricately folded tube, about twentyfeet long, and from an inch to an inch and one half in diameter. As thechyle passes through this tortuous channel, it receives along the entireroute secretions which seem to combine the action of all the previousones--starch, fat, and albumen being equally affected. 

IV. ABSORPTION is performed in two ways, by the _veins_, and the_lacteals_. (1. ) The veins in the stomach [Footnote: The veins andthe lacteals are separated from the food by a thin, moist membrane, through the pores of which the fluid food rapidly passes, in accordancewith a beautiful law ("Popular Physics, " p. 53) called the _Osmose_of liquids. If two liquids of different densities are separated by ananimal membrane, they will mix with considerable force. There is a similarlaw regulating the interchange of gases through a porous partition, inobedience to which the carbonic acid of the blood, and the oxygen of thelungs, are exchanged through the thin membrane of the air cells. ]immediately begin to take up the water, salt, grape sugar, and othersubstances that need no special preparation. The starch and the albuminousbodies are also absorbed as they are properly digested, and this processcontinues along the whole length of the alimentary canal. In the smallintestine, there is a multitude of tiny projections (_villi_) fromthe folds of the mucous membrane, more than seven thousand to the squareinch, giving it a soft, velvety look. These little rootlets, reaching outinto the milky fluid, drink into their minute blood vessels the nutritiouspart of every sort of food. (2. )The lacteals [Footnote: From _lac_, milk, because of the milky look given to their contents by the chyle. ] (p. 126), a set of vessels starting in the villi side by side with the veins, absorb the principal part of the fat. They convey the chyle through thelymphatics and the thoracic duct (Fig. 43) to the veins, and so within thesweep of the circulation. 

The Portal Vein [Footnote: So named because it enters the liver by a sortof gateway. ] carries to the liver the food absorbed by the veins of thestomach and the villi of the intestines. On the way, it is greatlymodified by the action of the blood itself. In the cells of the liver, itundergoes as mysterious a process as that performed by the lymphaticglands, and is then cast into the circulation. [Footnote: In these cells, the sugar is changed into a kind of starch called _glycogen_. This isinsoluble, and so is stored up in the liver, and even in the substance ofthe muscles, until it is needed by the body, when it is once moreconverted into soluble sugar and taken up by the circulation. The liveralso changes the waste and surplus albuminous matter into bile, and intourea and uric acid--the forms in which nitrogenized waste is excreted bythe kidneys. ] The food, potent with force, is now buried in that river oflife from which the body springs momentarily afresh. 

THE COMPLEXITY of the process of digestion, as compared with thesimplicity of respiration and circulation, is very marked. The mechanicaloperation of mastication; the lubrication of the food by mucus; theprovision for the security of the respiratory organs; the grasping by themuscles of the throat; the churning movement of the stomach; theguardianship of the pylorus; the timely introduction by safe and protectedchannels of the saliva, the gastric juice, the bile, the pancreatic juice, and the intestinal fluids, each with its special adaptation; the curiousperistaltic motion of the intestines; the twofold absorption by the veinsand the lacteals; the final transformation in the lymphatics, the portalvein, and the liver, --all these present a complexity of detail, thenecessity of which can be explained only when we reflect upon the varietyof the substances we use for food, and the importance of its thoroughpreparation before it is allowed to enter the blood. 

THE LENGTH OF TIME REQUIRED for digesting a full meal is from two to fourhours. It varies with the kind of food, state of the system, perfection ofmastication, etc. In the celebrated observations made upon Alexis St. Martin [Footnote: In 1822, Alexis St. Martin, a Canadian in the employ ofthe American Fur Company, was accidentally shot in the left side. Twoyears after, the wound was entirely healed, leaving, however, an openingabout two and a half inches in circumference into the stomach. Throughthis the mucous membrane protruded, forming a kind of valve whichprevented the discharge of food, but could be readily depressed by thefinger, thus exposing the interior. For several years he was under thecare of Dr. Beaumont, a skillful physician, who experimented upon him bygiving various kinds of food, and watching their digestion through thisopening. By means of these observations, and others performed on KatherineKutt, a woman who had a similar aperture in the stomach, we have veryimportant information as to the digestibility of different kinds of food. ]by Dr. Beaumont, his stomach was found empty in two and a half hours aftera meal of roast turkey, potatoes, and bread. Pigs' feet and boiled ricewere disposed of in an hour. Fresh, sweet apples took one and a halfhours; boiled milk, two hours; and unboiled, a quarter of an hour longer. In eggs, which occupied the same time, the case was reversed, --raw onesbeing digested sooner than cooked. Roast beef and mutton required threeand three and a quarter hours respectively; veal, salt beef, and broiledchicken remained for four hours; and roast pork enjoyed the badpreeminence of needing five and a quarter hours. 

VALUE OF THE DIFFERENT KINDS OF FOOD. --_Beef_ and _Mutton_possess the greatest nutritive value of any of the meats. _Lamb_ isless strengthening, but more delicate. Like the young of all animals, itshould be thoroughly cooked, and at a high temperature, properly todevelop its delicious flavor. _Pork_ has much carbon. It sometimescontains a parasite called trichina, which may be transferred to the humansystem, producing disease and often death. The only preventive is thoroughcooking. _Fish_ is more watery than flesh, and many find it difficultof digestion. Like meat, it loses its mineral constituents and naturaljuices when salted, and is much less nourishing. Oysters are highlynutritious, but are more easily assimilated when raw than when cooked. _Milk_ is a model food, as it contains albumen, starch, fat, andmineral matter. No other single substance can sustain life for so long atime. _Cheese_ is very nourishing--one pound being equal in value totwo of meat, but it is not adapted to a weak stomach. (See p. 322. )_Eggs_ are most easily digested when the white is barely coagulatedand the yolk is unchanged. _Bread_ [Footnote: Very fresh bread, warmbiscuit, etc. , are condensed by mastication into a pasty mass that is noteasily penetrated by the gastric juice, and hence they are not healthful. In Germany bread is not allowed to be sold at the baker's till it istwenty-four hours old--a wise provision for those who have not strength toresist temptation. This rule of eating may well be adopted by every onewho cares more for his health than for a gratification of his appetite. ]should be made of unbolted flour. The bran of wheat furnishes the mineralmatter we need in our bones and teeth, gives the bulk so essential to theproper distension of the organs, and by its roughness gently stimulatesthem to action. _Corn_ is rich in fat. It contains, however, moreindigestible matter than any other grain, except oats, and is lessnutritious than wheat. [Footnote: Persons unaccustomed to the use of cornfind it liable to produce derangement of the digestive organs. This wasmade fearfully apparent in the prisons of Andersonville during the latecivil war. The vegetable food of the Federal prisoners had hitherto beenchiefly wheat bread and potatoes--the corn bread so extensively used atthe South being quite new to most of them as a constant article of diet. It soon became not only loathsome, but productive of serious diseases. Onthe other hand, it was the principal article in the rations of theConfederate soldiers, to whom habit made it a nutritious and wholesomeform of food, as was shown by their endurance. --FLINT, _Physiology ofMan_, Vol. II, page 41. ] The _Potato_ is two thirds water, --therest being mainly starch. _Ripe Fruits_, and those vegetables usuallyeaten raw, dilute the more concentrated food, and also supply the bloodwith acids, which are cooling in summer, and useful, perhaps, inassimilation. 

THE STIMULANTS. --_Coffee_ is about half nitrogen, and the rest fatty, saccharine, and mineral substances. It is, therefore, of much nutritivevalue, especially when taken with milk and sugar. Its peculiar stimulatingproperty is due to a principle called _caffeine_. Its aroma isdeveloped by browning, but destroyed by burning. No other substance sosoon relieves the sense of fatigue. [Footnote: In the late civil war, thefirst desire of the soldiers upon halting after a wearisome march, was tomake a cup of coffee. This was taken without milk, and often withoutsugar, yet was always welcome. ] Taken in moderation, it clears theintellect, tranquilizes the nerves, and usually leaves no unpleasantreaction. It serves also as a kind of negative food, since it retards theprocess of waste. 

In some cases, however, it produces a rush of blood to the head, andshould be at once discarded. At the close of a full meal it hindersdigestion, and at night produces wakefulness. In youth, when the vitalpowers are strong, and the functions of nature prompt in rallying fromfatigue, it is not needed, and may be injurious in stimulating a sensitiveorganization. 

_Tea_ possesses an active principle called _theine_. When usedmoderately, its effects are similar to those of coffee, except that itexerts an astringent action. It contains tannin, which, if the tea isstrong, coagulates the albumen of the food--_tans_ it--and thusdelays digestion. In excess, tea causes nervous tremor, disturbed sleep, palpitation of the heart, and indigestion. [Footnote: Tea and coffeeshould be made with, boiling water, but should not be boiled afterward. During the "steeping" process, so customary in this country, the volatilearoma is lost and a bitter principle extracted. In both England and Chinait is usual to infuse tea directly in the urn from which it is to bedrawn. The tannin in tea is shown when a drop falls on a knife blade. Theblack spot is a tannate of iron--a compound of the acid in the tea and themetal. ] (See p. 322. )

_Chocolate_ contains much fat, and also nitrogenous matter resemblingalbumen. Its active principle, _theobromine_, [Footnote: It is saidthat Linnæus, the great botanist, was so fond of chocolate that he namedthe cocoa tree "Theobroma, " the food of the gods. ] has some of theproperties of caffeine and theine. 

THE COOKING OF FOOD breaks the little cells, and softens the fibers ofwhich it is composed. In broiling or roasting meat, it should be exposedto a strong heat at once, in order to coagulate the albumen upon theoutside, and thus prevent the escape of the nutritious juices. The cookingmay then be finished at a lower temperature. The same principle applies toboiling meat. In making soups, on the contrary, the heat should be appliedslowly, and should reach the boiling point for only a few moments at theclose. This prevents the coagulation of the albumen. Frying is anunhealthful mode of cooking food, as thereby the fat becomes partiallydisorganized. 

RAPID EATING produces many evil results. 1. There is not enough salivamixed with the food; 2. The coarse pieces resist the action of thedigestive fluids; 3. The food is washed down with drinks that dilute thegastric juice, and hinder its work; 4. We do not appreciate the quantitywe eat until the stomach is overloaded; 5. Failing to get the taste of ourfood, we think it insipid, and hence use condiments that overstimulate thedigestive organs. In these various ways the appetite becomes depraved, thestomach vexed, the system overworked, and the foundation of dyspepsia islaid. [Footnote: When one is compelled to eat in a hurry, as at a railwaystation, he would do well to confine himself principally to meat; and todilute this concentrated food with fruit, crackers, etc. , taken afterwardmore leisurely. ] (See p. 324. )

THE QUANTITY AND QUALITY OF FOOD required vary with the age and habits ofeach individual. The diet of a child [Footnote: In youth, repair exceedswaste; hence the body grows rapidly, and the form is plump. In middlelife, repair and waste equal each other, and growth ceases. In old age, waste exceeds repair; hence the powers are enfeebled and the skin lies inwrinkles on the shrunken form. ] should be largely vegetable, and moreabundant than that of an aged person. A sedentary occupation necessitatesless food than an outdoor life. One accustomed to manual labor, onentering school, should practice self-denial until his system becomesfitted to the new order of things. He should not, however, fall into theopposite error. We read of great men who have lived on bread and water, and the conscientious student sometimes thinks that, to be great, he, too, must starve himself. [Footnote: As Dr. Holland well remarks, thedispensation of sawdust has passed away. If we desire a horse to win therace, we must give him plenty of oats. ] On the contrary, many of thegreatest workers are the greatest eaters. A powerful engine needs acorresponding furnace. Only, we should be careful not to use more fuelthan is needed to run the machine. (See p. 325. )

The season should modify our diet. In winter, we need highly carbonaceousfood, plenty of meat, fat, etc. ; but in summer we should temper the heatin our corporeal stoves with fruits and vegetables. 

The climate also has its necessities. The inhabitants of the frigid northhave an almost insatiable longing for fat. [Footnote: Dr. Hayes, thearctic explorer, says, that the daily ration of the Esquimaux was fromtwelve to fifteen pounds of meat, one third being fat. On one occasion, hesaw a man eat ten pounds of walrus flesh and blubber at a single meal. Thelow temperature had a remarkable effect on the members of his own party, and some of them were in the habit of drinking the contents of the oilkettle with evident relish. Other travelers narrate the most incrediblestories of the voracity of the inhabitants of arctic regions. Saritcheff, a Russian admiral, tells of a man who in his presence ate, at a meal, amess of twenty-eight pounds of boiled rice and butter, although he hadalready partaken of his breakfast. Captain Cochrane further adds, innarrating this statement, that he has himself seen three of the savagesconsume a reindeer at a sitting. ] Thus, in 1812, when the Allies enteredParis, the Cossacks drank all the oil from the lamps, and left the streetsin darkness. In tropical regions, a low, unstimulating diet of fruitsforms the chief dependence. [Footnote: A natural appetite for a particularkind of food is an expression not only of desire, but of fitness. Thus thecraving of childhood for sugar indicates a need of the system. It isquestionable how far it is proper to force or persuade one to eat thatwhich he disrelishes, or his stomach loathes. Life within is linked withlife without. Each organ requires its peculiar nutriment, and there isoften a peculiar influence demanded of which we can have no notice exceptby natural instinct. Yet, as we are creatures of habit and impulse, weneed common sense and good judgment to correct the too often waywardpromptings of an artificial craving. ]

WHEN FOOD SHOULD BE TAKEN. --On taking food, the blood sets at once to thealimentary canal, and the energies are fixed upon the proper performanceof this work. We should not, therefore, undertake hard study, labor, orexercise directly after a hearty meal. We should give the stomach at leasthalf an hour. He who toils with brain or muscle, and thus centers theblood in any particular organ, before eating should allow time for thecirculation to become equalized. There should be an interval of four tofive hours between our regular meals, and there should be no lunchingbetween times. With young children, where the vital processes are morerapid, less time may intervene. As a general rule, nothing should be eatenwithin two or three hours of retiring. (See p 336. )

HOW FOOD SHOULD BE TAKEN. --A good laugh is the best of sauces. Themealtime should be the happiest hour of the day. Care and grief are thebitter foes of digestion. A cheerful face and a light heart are friends tolong life, and nowhere do they serve us better than at the table. Goddesigned that we should enjoy eating, and that, having stopped beforesatiety was reached, we should have the satisfaction always attendant on agood work well done. 

NEED OF VARIETY. --Careful investigations have shown that any one kind offood, however nutritious in itself, fails after a time to preserve thehighest working power of the body. Our appetite palls when we confine ourdiet to a regular routine. Nature demands variety, and she has furnishedthe means of gratifying it. [Footnote: She opens her hand, and pours forthto man the treasures of every land and every sea, because she would giveto him a wide and vigorous life, participant of all variety. For him thecornfields wave their golden grain--wheat, rye, oats, maize, or rice, eachdifferent, but alike sufficing. Freely for him the palm, the date, thebanana, the breadfruit tree, the pine, spread out a harvest on the air;and pleasant apple, plum, or peach solicit his ready hand. Beneath hisfoot lie stored the starch of the potato, the gluten of the turnip, thesugar of the beet; while all the intermediate space is rich with juicyherbs. 

Nature bids him eat and be merry; adding to his feast the solid flesh ofbird, and beast, and fish, prepared as victims for the sacrifice: firmmuscle to make strong the arm of toil, in the industrious temperate zone;and massive ribs of fat to kindle inward fires for the sad dwellers underarctic skies. --_Health and its Conditions_. --HINTON. ]

THE WONDERS OF DIGESTION. --We can understand much of the process ofdigestion. We can look into the stomach and trace its various steps. Indeed, the chemist can reproduce in his laboratory many of theoperations; "a step further, " as Fontenelle has said, "and he wouldsurprise nature in the very act. " Just here, when he seems so successful, he is compelled to pause. At the threshold of life the wisest physiologistreverently admires, wonders, and worships. 

How strange is this transformation of food to flesh! We make a meal ofmeat, vegetables, and drink. Ground by the teeth, mixed by the stomach, dissolved by the digestive fluids, it is swept through the body. Eachorgan, as it passes, snatches its particular food. Within the cells of thetissues [Footnote: As the body is composed of individual organs, and eachorgan of separate tissues, so each tissue is made up of minute cells. Eachcell is a little world by itself, too small to be seen by the naked eye, but open to the microscope. It has its own form and constitution as muchas a special organ in the body. It absorbs from the blood such food assuits its purposes. Moreover, the number of cells in an organ is asconstant as the number of organs. As the organs expand with the growth ofthe body, so the cells of each tissue enlarge, but shrink again with ageand the decline of life. Life begins and ends in a cell. --See_Appletons' Cyclopedia_, Art. "Absorption. "] it is transformed intothe soft, sensitive brain, or the hard, callous bone; into briny tears, orbland saliva, or acrid perspiration; bile for digestion, oil for the hair, nails for the fingers, and flesh for the cheek. 

Within us is an Almighty Architect, who superintends a thousand builders, which make in a way past all human comprehension, here a fiber of amuscle, there a filament of a nerve; here constructing a bone, thereuniting a tendon, --fashioning each with scrupulous care and unerringnicety. [Footnote: See COOKE'S _Religion and Chemistry_, page 236. ]So, without sound of builder or stroke of hammer, goes up, day by day, thebody--the glorious temple of the soul. 

DISEASES ETC. --1. _Dyspepsia_, or indigestion of food, is generallycaused by an overtaxing of the digestive organs. Too much food is used, and the entire system is burdened by the excess. Meals are taken atirregular hours, when the fluids are not ready. A hearty supper is eatenwhen the body, wearied with the day's labor, demands rest. The appetitecraves no food when the digestion is enfeebled, but stimulants andcondiments excite it, and the unwilling organs are oppressed by that whichthey can not properly manage. 

Strong tea, alcoholic drinks, and tobacco derange the alimentary function. 

Too great variety of dishes, rich food, tempting flavors, --all lead to anoverloading of the stomach. This patient, long-suffering member at lastwears out. Pain, discomfort, diseases of the digestive organs, andinsufficient nutrition are the penalties of violated laws. (See p. 328. )

2. _The Mumps_ are an inflammation of the parotid and submaxillaryglands (see p. 159). The disease is generally epidemic, and is believed tobe contagious; the patient should therefore be carefully secluded for thesake of others as well as himself. The swelling may be allowed to take itscourse. Relief from pain is often experienced by applying flannels wrungout of hot water. Great care should be used not to check the inflammation, and, on first going out after recovery, not to take cold. 

ALCOHOLIC DRINKS AND NARCOTICS. 

1. ALCOHOL (Continued from p. 147). 

RELATION OF ALCOHOL TO THE DIGESTIVE ORGANS. --_Is Alcohol a Food?_ Toanswer this question, let us make a comparison. If you receive into yourstomach a piece of bread or beef, Nature welcomes its presence. The juicesof the system at once take hold of it, dissolve it, and transform it forthe uses of the body. A million tiny fingers (lacteals and veins) reachout to grasp it, work it over, and carry it into the circulation. Theblood bears it onward wherever it is needed to mend or to build "The houseyou live in. " Soon, it is no longer bread or beef; it is flesh on yourarm; its chemical energy is imparted to you, and it becomes your strength. 

If, on the other hand, you take into your stomach a little alcohol, itreceives no such welcome. Nature treats it as a poison, and seeks to ridherself of the intruder as soon as possible. [Footnote: Food is digested, alcohol is not. Food warms the blood, directly or indirectly; alcohollowers the temperature. Food nourishes the body, in the sense ofassimilating itself to the tissues; alcohol does not. Food makes blood;alcohol never does anything more innocent than mixing with it. Food feedsthe blood cells; alcohol destroys them. Food excites, in health, to normalaction only; alcohol tends to inflammation and disease. Food gives forceto the body; alcohol excites reaction and wastes force, in the firstplace, and in the second, as a true narcotic, represses vital action andcorresponding nutrition. --If alcohol does not act like food, neither doesit behave like water. Water is the subtle but innocent vehicle ofcirculation, which dissolves the solid food, holds in play the chemicaland vital reactions of the tissues, conveys the nutritive solutions fromcell to cell, from tube to tube, and carries off and expels the effetematter. Water neither irritates tissue, wastes force, nor suppresses vitalaction: whereas alcohol does all three. Alcohol hardens solid tissue, thickens the blood, narcotizes the nerves, and in every conceivabledirection antagonizes the operation and function of water--LEES. ] Thejuices of the system will flow from every pore to dilute and weaken it, and to prevent its shriveling up the delicate membranes with which itcomes in contact. The veins will take it up and bear it rapidly throughthe system. Every organ of elimination, all the scavengers of the body--the lungs, the kidneys, the perspiration glands, at once set to work tothrow off the enemy. So surely is this the case, that the breath of aperson who has drunk only a single glass of the lightest beer will betraythe fact. 

The alcohol thus eliminated is entirely unchanged. Nature apparently makesno effort to appropriate it. [Footnote: It was formerly a questionconsiderably discussed, whether alcohol exists in the brain, or in thefluid found in the ventricles, in intoxicated persons. This was settled byPercy, who found alcohol in the brain and liver of dogs poisoned withalcohol, and of men who had died after excessive drinking. In theseexperiments, the presence of alcohol was determined by distillation, andthe distilled substance burned with a blue flame, and dissolved camphor. --FLINT'S _Physiology of Man_. ] It courses everywhere through thecirculation, and into the great organs, with all its propertiesunmodified. 

Alcohol, then, is not, like bread or beef, taken hold of, broken up by themysterious process of digestion, and used by the body. [Footnote: Becauseof the difficulties of such an experiment, we have not yet been able toaccount satisfactorily by the excretions for all the alcohol taken intothe stomach. This remains as yet one of the unsolved problems ofphysiological chemistry. To collect the whole of the insensibleperspiration, for example, is well-nigh impossible. It was supposed at onetime that a part of the alcohol is oxidized--_i. E. _, burned, in thesystem. But such a process would impart heat, and it is now proved thatalcohol cools, instead of warms, the blood. Moreover, the closest analysisfails to detect in the circulation any trace of the products of alcoholiccombustion, such as aldehyde and acetic acid. "The fact, " says Flint, "that alcohol is always eliminated, even when drunk in minute quantity, and that its elimination continues for a considerable time, graduallydiminishing, renders it probable that all that is taken into the body isremoved. "] "It can not therefore be regarded as an aliment, " or food. --FLINT. "Beer, wine, and spirits, " says Liebig, "contain no element capableof entering into the composition of the blood or the muscular fiber. "[Footnote: The small amount of nutritive substance, chiefly sugar derivedfrom the grain or fruit used in the manufacture of beer or wine, can not, of course, be compared with that contained in bread or beef at the samecost. Liebig says, in his Letters on Chemistry, "We can prove, withmathematical certainty, that as much flour as can lie on the point of atable knife is more nutritious than eight quarts of the best Bavarianbeer. "] "That alcohol is incapable of forming any part of the body, "remarks Cameron, "is admitted by all physiologists. It can not beconverted into brain, nerve, muscle, or blood. "

EFFECT UPON THE DIGESTION. [Footnote: The medical value of alcohol in itsrelations to digestion is not discussed in this book. The experiments ofDr. Henry Munroe, of Hull, published in the London _Medical Journal_, are here summarized as showing that the tendency to retard digestion iscommon to all forms of alcoholic drinks. 

_______________________________________________________________________Finely Minced | | | |Beef | 2d Hour | 4th Hour | 6th Hour |_______________________________________________________________________I. | | Digesting | |Gastric Juice | Beef | and | Beef much |and _water_. | opaque. | separating. | loosened. |_______________________________________________________________________| | Slightly | Slight |II. | No alteration | opaque, but | coating on |Gastric Juice | perceptible. | beef | beef. |with _alcohol_. | | unchanged. | |_______________________________________________________________________III. | | Cloudy, | beef |Gastric Juice | No change. | with fur | partly |and _pale ale_. | | on beef. | loosened. |_____________________________________________________________________________________________________________________________Finely Minced | | |Beef | 8th Hour | 10th Hour |______________________________________________________I. | | |Gastric Juice | Beef | Broken up |and _water_. | opaque. | into shreds. |______________________________________________________| | Solid on |II. | No visible | cooling |Gastric Juice | change. | _Pepsin_ |with _alcohol_. | | precipitated. |______________________________________________________III. | | No digestion |Gastric Juice | No further | _Pepsin_ |and _pale ale_. | change. | precipitated. |______________________________________________________]

--Experiments tend to prove that alcohol coagulates and precipitates thepepsin from the gastric juice, and so puts a stop to its great work in theprocess of digestion. 

The greed of alcohol for water causes it to imbibe moisture from thetissues and juices, and to inflame the delicate mucous membrane. It showsthe power of Nature to adapt herself to circumstances, that the soft, velvety lining of the throat and stomach should come at length to endurethe presence of a fiery liquid which, undiluted, would soon shrivel anddestroy it. In self-defense, the juices pour in to weaken the alcohol, andit is soon hurried into the circulation. Before this can be done, "it mustabsorb about three times its bulk of water"; hence, very strong liquor maybe retained in the stomach long enough to interfere seriously with thedigestion, and to injure the lining coat. Habitual use of alcoholpermanently dilates the blood vessels; thickens and hardens the membranes;in some cases, ulcerates the surface; and, finally, "so weakens theassimilation that the proper supply of food can not be appropriated. "--FLINT. [Footnote: The case of St. Martin (p. 168) gave an excellentopportunity to watch the action of alcohol upon the stomach. Dr. Beaumontsummarized his experiments thus: "The free, ordinary use of anyintoxicating liquor, when continued for some days, invariably producedinflammation, ulcerous patches, and, finally, a discharge of morbid mattertinged with blood. " Yet St. Martin never complained of pain in hisstomach, the narcotic influence of the alcohol preventing the signal ofdanger that Nature ordinarily gives. ]

EFFECT UPON THE LIVER. --Alcohol is carried by the portal vein directly tothe liver. This organ, after the brain, holds the largest share. Theinfluence of the poison is here easily traced. "The color of the bile issoon changed from yellow to green, and even to black;" the connectivetissue between the lobules becomes inflamed; and, in the case of aconfirmed drunkard, hardened and shrunk, the surface often assuming anodulated appearance known as the "hobnailed liver. " Morbid matter issometimes deposited, causing what is called "Fatty degeneration, " so thatthe liver is increased to twice or thrice its natural size. 

EFFECT UPON THE KIDNEYS. --The kidneys, like the liver, are liable in timeto undergo, through the influence of alcohol, a "Fatty degeneration, " inwhich the cells become filled with particles of fat; [Footnote: Disabledby the fatty deposits, the kidneys are unable to separate the waste mattercoming to them for elimination from the system. The poisonous material ispoured back into the circulation, and often delirium ensues. --HUBBARD. Richardson states that his experience "is to the effect that seven out ofevery eight instances of kidney disease are attributable to alcohol. "] thevessels lose their contractility; and, worst of all, the membranes may beso modified as to allow the albuminous part of the blood to filter throughthem, and so to rob the body of one of its most valuable constituents. [Footnote: This deterioration of structure frequently gives rise to whatis known as "Bright's Disease. "--RICHARDSON. ]

DOES ALCOHOL IMPART HEAT?--During the first flush after drinking wine, forexample, a sense of warmth is felt. This is due to the tides of warm bloodthat are being sent to the surface of the body, owing to the vascularenlargement and to the rapid pumping of the heart. There is, however, nofresh heat developed. On the contrary, the bringing the blood to thesurface causes it to cool faster, reaction sets in, a chilliness isexperienced as one becomes sober, and a delicate thermometer placed underthe tongue of the inebriate may show a fall of even two degrees below thestandard temperature of the body. Several hours are required to restorethe usual heat. 

As early as 1850, Dr. N. S. Davis, of Chicago, ex-President of theAmerican Medical Association, instituted an extensive series ofexperiments to determine the effect of the different articles of food anddrinks on the temperature of the system. He conclusively proved that, during the digestion of all kinds of food, the temperature of the body isincreased, but when alcohol is taken, either in the form of fermented ordistilled beverages, the temperature begins to fall within a half hour, and continues to decrease for two or three hours, and that the reductionof temperature, in extent as well as in duration, is in exact proportionto the amount of alcohol taken. 

It naturally follows that, contrary to the accepted opinion, liquor doesnot fortify against cold. The experience of travelers at the Northcoincides with that of Dr. Hayes, the Arctic explorer, who says: "Whilefat is absolutely essential to the inhabitants and travelers in arcticcountries, alcohol is, in almost any shape, not only completely useless, but positively injurious. I have known strong, able-bodied men to becomeutterly incapable of resisting cold in consequence of the long-continueduse of alcoholic drink. "

DOES ALCOHOL IMPART STRENGTH?--Experience shows that alcohol weakens thepower of undergoing severe bodily exertion. [Footnote: Dr. McRae, inspeaking of Arctic exploration, at the meeting of the American Associationfor the Advancement of Science, held at Montreal in 1856, said: "Themoment that a man had swallowed a drink of spirits, it was certain thathis day's work was nearly at an end. It was absolutely necessary that therule of total abstinence be rigidly enforced, if we would accomplish ourday's task. The use of liquor as a beverage when we had work on hand, inthat terrific cold, was out of the question. "] Men who are in training forrunning, rowing, and other contests where great strength is required, denythemselves all liquors, even when they are ordinarily accustomed to theiruse. 

Dr. Richardson made some interesting experiments to show the influence ofalcohol upon muscular contraction. He carefully weighted the hind leg of afrog, and, by means of electricity, stimulating the muscle to its utmostpower of contraction, he found out how much the frog could lift. Thenadministering alcohol, he discovered that the response of the muscle tothe electrical current became feebler and feebler, as the narcotic beganto take effect, until, at last, the animal could raise less than half theamount it lifted by the natural contraction when uninfluenced by alcohol. 

EFFECT UPON THE WASTE OF THE BODY. --The tendency of alcohol is to cause aformation of an unstable substance resembling fat, [Footnote: Themolecular deposits equalizing the waste of the system do not go onregularly under the influence of alcohol; the tissues are not kept up totheir standard; and, in time, their composition is changed by a deposit ofan amorphous matter resembling fat. This is an unstable substance, and thefunctions of animal life all retrograde. --HUBBARD, _The Opium Habit andAlcoholism_. ] and so the use of liquor for even a short time willincrease the weight. But a more marked influence is to check the ordinarywaste of the system, so that "the amount of carbonic acid exhaled from thelungs may be reduced as much as thirty to fifty per cent. "--HINTON. Thelife process is one of incessant change. Its rapidity is essential tovigor and strength. When the functions are in full play, each organ isbeing constantly torn down, and as constantly rebuilt with the materialsfurnished from our food. Anything that checks this oxidation of thetissues, or hinders the deposition of new matter, disturbs the vitalfunctions. Both these results are the inevitable effects of alcohol; for, since the blood contains less oxygen and more carbonic acid, and the powerof assimilating the food is decreased, it follows that every process ofwaste and repair must be correspondingly weakened. The person using liquorconsequently needs less bread and beef, and so alcohol seems to him afood--a radical error, as we have shown. 

ALCOHOL CREATES A PROGRESSIVE APPETITE FOR ITSELF. --When liquor is taken, even in the most moderate quantity, it soon becomes necessary, and thenarises a craving demand for an increased amount to produce the originaleffect. No food creates this constantly augmenting want. A cup of milkdrank at dinner does not lead one to go on, day by day, drinking more andmore milk, until to get milk becomes the one great longing of the wholebeing. Yet this is the almost universal effect of alcohol. Hunger issatisfied by any nutritious food: the dram-drinker's thirst demandsalcohol. The common experience of mankind teaches us the imminent perilthat attends the formation of this progressive poison habit. A singleglass taken as a tonic may lead to the drunkard's grave. 

Worse than this, the alcoholic craving may be transmitted from father toson, and young persons often find themselves cursed with a terribledisease known as alcoholism--a keen, morbid appetite for liquor thatdemands gratification at any cost--stamped upon their very being throughthe reckless indulgence of this habit on the part of some one of theirancestors. [Footnote: The American Medical Association, at their meetingin St. Paul, Minnesota (1883), restated in a series of resolutions theirconviction, that "alcohol should be classed with other powerful drugs;that when prescribed medically, it should be done with conscientiouscaution and a sense of great responsibility; that used as a beverage it isproductive of a large amount of physical and mental disease; that it_entails diseased and enfeebled constitutions upon offspring_, andthat it is the cause of a large percentage of the crime and pauperism ofour large cities and country. "]

THE LAW OF HEREDITY is, in this connection, well worth consideration. "Theworld is beginning to perceive, " says Francis Galton, "that the life ofeach individual is, in some real sense, a continuation of the lives of hisancestors. " "Each of us is the footing up of a double column of figuresthat goes back to the first pair. " "We are omnibuses, " remarks Holmes, "inwhich all our ancestors ride. " We inherit from our parents our features, our physical vigor, our mental faculties, and even much of our moralcharacter. Often, when one generation is skipped, the qualities willreappear in the following one. The virtues, as well as the vices, of ourforefathers, have added to, or subtracted from, the strength of our brainand muscle. The evil tendencies of our natures, which it is the struggleof our lives to resist, constitute a part of our heirlooms from the past. Our descendants, in turn, will have reason to bless us only if we handdown to them a pure healthy physical, mental, and moral being. 

"There is a marked tendency in nature to transmit all diseased conditions. Thus, the children of consumptive parents are apt to be consumptives. Butof all agents, alcohol is the most potent in establishing a heredity thatexhibits itself in the destruction of mind and body. [Footnote: Nearly allthe diseases springing from indulgence in distilled and fermented liquorsare liable to become hereditary, and to descend to at least three or fourgenerations, unless starved out by uncompromising abstinence. But thedistressing aspect of the heredity of alcohol is the transmitted drink-crave. This is no dream of an enthusiast, but the result of a natural law. Men and women upon whom this dread inheritance has been forced areeverywhere around us, bravely struggling to lead a sober life. --DR. NORMAN KERR. ] Its malign influence was observed by the ancients longbefore the production of whiskey or brandy, or other distilled liquors, and when fermented liquors or wines only were known. Aristotle says, 'Drunken women have children like unto themselves, ' and Plutarch remarks, 'One drunkard is the father of another. ' The drunkard by inheritance is amore helpless slave than his progenitor, and his children are morehelpless still, unless on the mother's side there is an untainted blood. For there is not only a propensity transmitted, but an actual disease ofthe nervous system. "--DR. WILLARD PARKER. [Footnote: The subject ofalcohol is continued in the chapter on the Nervous System. ]

PRACTICAL QUESTIONS. 

1. How do clothing and shelter economize food?

2. Is it well to take a long walk before breakfast?

3. Why is warm food easier to digest than cold?

4. Why is salt beef less nutritious than fresh? [Footnote: The FrenchAcademicians found that flesh soaked in water so as to deprive it of itsmineral matter and juices, lost its nutritive value, and that animals fedon it soon died. Indeed, for all purposes of nutrition, Liebig said it wasno better than stones, and the utmost torments of hunger were hardlysufficient to induce them to continue the diet. There was plenty ofnutritive food, but there was no medium for its solution and absorption, and hence it was useless. ] 5. What should be the food of a man recoveringfrom a fever?

6. Is a cup of black coffee a healthful close to a hearty dinner?

7. Should iced water be used at a meal?

8. Why is strong tea or coffee injurious?

9. Should food or drink be taken hot?

10. Are fruitcakes, rich pastry, and puddings wholesome?

11. Why are warm biscuit and bread hard of digestion?

12. Should any stimulants be used in youth?

13. Why should bread be made spongy?

14. Which should remain longer in the mouth, bread or meat?

15. Why should cold water be used in making soup, and hot water in boilingmeat?

16. Name the injurious effects of overeating. 

17. Why do not buckwheat cakes, with syrup and butter, taste as well inJuly as in January?

18. Why is a late supper injurious?

19. What makes a man "bilious"?

20. What is the best remedy? _Ans_. Diet to give the organs rest, andactive exercise to arouse the secretions and the circulation. 

21. What is the practical use of hunger?

22. How can jugglers drink when standing on their heads?

23. Why do we relish butter on bread?

24. What would you do if you had taken arsenic by mistake? (See Appendix. )

25. Why should ham and sausage be thoroughly cooked?

26. Why do we wish butter on fish, eggs with tapioca, oil on salad, andmilk with rice?

27. Explain the relation of food to exercise. 

28. How do you explain the difference in the manner of eating betweencarnivorous and herbivorous animals?

29. Why is a child's face plump and an old man's wrinkled?

30. Show how life depends on repair and waste. 

31. What is the difference between the decay of the teeth and the constantdecay of the body?

32. Should biscuit and cake containing yellow spots of soda be eaten?

33. Tell how the body is composed of organs, how organs are made up oftissues, and how tissues consist of cells. 

34. Why do we not need to drink three pints of water per day?

35. Why, during a pestilence, are those who use liquors as a beverage thefirst, and often the only victims?

36. What two secretions seem to have the same general use?

37. How may the digestive organs be strengthened?

38. Is the old rule, "after dinner sit awhile, " a good one?

39. What would you do if you had taken laudanum by mistake? Paris Green?Sugar of lead? Oxalic acid? Phosphorus from matches? Ammonia? Corrosivesublimate? (See p. 265. )

40. What is the simplest way to produce vomiting, so essential in case ofaccidental poisoning?

41. In what way does alcohol interfere with the digestion?

42. Is alcohol assimilated?

43. What is the effect of alcohol on the albuminous substances?

44. Is there any nourishment in beer?

45. Show how the excessive use of alcohol may first increase, and, afterward, decrease, the size of the liver. 

46. Will liquor help one to endure cold and exposure?

47. What is a fatty degeneration of the kidneys?

48. Contrast the action of alcohol and water in the body. 

49. Is alcohol, in any proper sense of the term, a food?

50. Does liquor strengthen the muscles of a working man?

51. Is liquor a wholesome "tonic"?

52. Is it a good plan to take a glass of liquor before dinner?

VII. 

THE NERVOUS SYSTEM. 

"Mark then the cloven sphere that holdsAll thoughts in its mysterious folds, That feels sensation's faintest thrill, And flashes forth the sovereign will;Think on the stormy world that dwellsLock'd in its dim and clustering cells;The lightning gleams of power it shedsAlong its hollow, glassy threads!"

"As a king sits high above his subjects upon his throne, and from itspeaks behests that all obey, so from the throne of the brain cells is allthe kingdom of a man directed, controlled, and influenced. For thisoccupant, the eyes watch, the ears hear, the tongue tastes, the nostrilssmell, the skin feels. For it, language is exhausted of its treasures, andlife of its experience; locomotion is accomplished, and quiet insured. When it wills, body and spirit are goaded like overdriven horses. When itallows, rest and sleep may come for recuperation. In short, the slightestpenetration may not fail to perceive that all other parts obey this part, and are but ministers to its necessities. "--Odd Hours of a Physician. ANALYSIS OF THE NERVOUS SYSTEM. 

_| 1. THE STRUCTURE| _| _ | 1. _Description. _| | 1. The Brain. . . . . . . . | 2. _The Cerebrum. _| | |_3. _The Cerebellum. _| | _| | 2. The Spinal Cord. . | 1. _Its Composition. _| | |_2. _Medulla Oblongata. _| | _| 2. ORGANS OF | | 1. _Description. _| THE NERV- | | 2. _Motory and Sensory. _| OUS SYSTEM. . | | 3. _Transfer of Pain. _| | | 4. _The Spinal Nerves--| | | 31 Pairs. _| |_3. The Nerves. . . . . . . | 5. _The Cranial Nerves--| | 12 Pairs. _| | 6. _Sympathetic System. _| | 7. _Crossing of Cords. _| | 8. _Reflex Action. _| | 9. _Uses of Reflex| |_ Action_| _| | 1. Brain Exercise. | | 2. Connection between Brain Growth and Body Growth. | 3. HYGIENE. . . . . | 3. Sleep. | | 4. Effect of Sleeping Draughts. | |_5. Sunlight. || 4. WONDERS OF THE BRAIN. | _| | 1. Alcohol (Con'd. )| | _ | 1. _Stage of Excitement. _| || | 2. _Stage of Muscular| || | Weakness. _| || 1. Effect of Alco- | 3. _Stage of Mental| || hol upon the | Weakness. _| || Nervous System | 4. _Stage of Unconscious-| || |_ ness. _| ||| || 2. Effect upon the Brain| ||_3. Effect upon the Mental and Moral Powers. | || | 2. Tobacco. | | _| || 1. Constituents of Tobacco. | 5. ALCOHOLIC || 2. Physiological Effects. | DRINKS AND|| 3. Possible Disturbances produced by Smoking. |_ NARCOTICS. || 4. Influence upon the Nervous System. || 5. Is Tobacco a Food?||_6. Influence of Tobacco on Youth. | _| | 1. _Description. _| 3. Opium. . . . . . . . . . . . | 2. _Physiological| |_ Effects. _| 4. Chloral Hydrate. | 5. Chloroform. |_6. Cocaine. 

THE NERVOUS SYSTEM. [Footnote: The organs of circulation, respiration, anddigestion, of which we have already spoken, are often called thevegetative functions, because they belong also to the vegetable kingdom. Plants have a circulation of sap through their cells corresponding to thatof the blood through the capillaries. They breathe the air through theirleaves, which act the part of lungs, and they take in food which theychange into their own structure by a process which answers to that ofdigestion. The plant, however, is a mere collection of parts incapable ofany combined action. On the other hand, the animal has a nervous systemwhich binds all the organs together. ]

STRUCTURE. --The nervous system includes the _brain_, the _spinalcord_, and the _nerves_. It is composed of two kinds of matter--the _white_, and the _gray_. The former consists of minute, milk-white, glistening fibers, sometimes as small as 1/25000 of an inch indiameter; the latter is made up of small, ashen-colored cells, forming apulp-like substance of the consistency of blancmange. [Footnote: Inaddition to the cells, the gray substance contains also nerve fiberscontinuous with the white fibers, but generally much smaller. These formhalf the bulk of the gray substance of the spinal cord, and a large partof the deeper layer of the gray matter in the brain. --LEIDY'S_Anatomy_, p. 507. ] This is often gathered in little masses, termedganglions (_ganglion_, a knot), because, when a nerve passes througha group of the cells, they give it the appearance of a knot. The nervefibers are conductors, while the gray cells are generators, of nervousforce. [Footnote: What this force is we do not know. In some respects itis like electricity, but, in others, it differs materially. Its velocityis about thirty three meters per second. --_Popular Physics_, p. 244, Note. ] The ganglia, or nervous centers, answer to the stations along atelegraphic line, where messages are received and transmitted, and thefibers correspond to the wires that communicate between different parts. 

FIG. 50. 

[Illustration: _The Nervous System. _ A, _cerebrum_; B, _cerebellum. _]

The BRAIN is the seat of the mind. [Footnote: In proportion to the restof the nervous matter in the body, it is larger in man than in any of thelower animals. It is the function which the brain performs thatdistinguishes man from all other animals, and it is by the action of hisbrain that he becomes a conscious, intelligent, and responsible being. Thebrain is the seat of that knowledge which we express when we say _I_. I know it, I feel it, I saw it, are expressions of our individualconsciousness, the seat of which is the brain. It is when the brain is atrest in sleep that there is least consciousness. The brain may be putunder the influence of poisons, such as alcohol and chloroform, and thenthe body is without consciousness. From these and other facts the brain isregarded as the seat of _consciousness_. --LANKESTER. ] Its averageweight is about fifty ounces. [Footnote: Cuvier's brain weighed 64 1/2ounces; Webster's, 53 1/2 ounces; James Fisk's, 58 ounces; Ruloff's, 59ounces; an idiot's, 19 ounces. See Table in FLINT'S _NervousSystem_. ] It is egg-shaped, and, soft and yielding, fills closely thecavity of the skull. It reposes securely on a water bed, being surroundedby a double membrane _(arachnoid)_, delicate as a spider's web, whichforms a closed sac filled, like the spaces in the brain itself, with aliquid resembling water. Within this, and closely investing the brain, isa fine tissue (_pia mater_), with a mesh of blood vessels which dipsdown into the hollows, and bathes them so copiously that it uses one fifthof the entire circulation of the body. Around the whole is wrapped a toughmembrane (_dura mater_), which lines the bony box of the skull, andseparates the various parts of the organ by strong partitions. The brainconsists of two parts--the _cerebrum_, and the _cerebellum_. 

The CEREBRUM fills the front and upper part of the skull, and comprisesabout seven eighths of the entire weight of the brain. As animals rise inthe scale of life, this higher part makes its appearance. It is a mass ofwhite fibers, with cells of gray matter sprinkled on the outside, orlodged here and there in ganglia. It is so curiously wrinkled and foldedas strikingly to resemble the meat of an English walnut. This structuregives a large surface for the gray matter, --sometimes as much as sixhundred and seventy square inches. The convolutions are not noticeable inan infant, but increase with the growth of the mind, their depth andintricacy being characteristic of high mental power. 

FIG. 51. 

[Illustration: _Surface of the Cerebrum. _]

The cerebrum is divided into two hemispheres, connected beneath by fibersof white matter. Thus we have two brains, [Footnote: This doubleness hasgiven rise to some curious speculations. In the case of the hand, eye, etc, we know that the sensation is made more sure. Thus we can see withone eye, but not so well as with both. It is perhaps the same with thebrain. We may sometimes carry on a train of thought, "build an air castle"with one half of our brain, while the other half looks on and watches theoperation; or, we may read and at the same time think of something else. So in delirium, a patient often imagines himself two persons, thus showinga want of harmony between the two halves. --DRAPER, _HumanPhysiology_, p. 320. ] as well as two hands and two eyes. This providesus with a surplus of brains, as it were, which can be drawn upon in anemergency. A large part of one hemisphere has been destroyed withoutparticularly injuring the mental powers, [Footnote: A pointed iron bar, three and a half feet long and one inch and a quarter in diameter, wasdriven by the premature blasting of a rock completely through the side ofthe head of a man who was present. It entered below the temple, and madeits exit at the top of the forehead, just about the middle line. The manwas at first stunned, and lay in a delirious, semistupefied state forabout three weeks. At the end of sixteen months, however, he was inperfect health, with wounds healed and mental and bodily functionsunimpaired, except that sight was lost in the eye of the injured side. --DALTON. It is noticeable, however, that the man became changed indisposition, fickle, impatient of restraint, and profane, which he was notbefore. He died epileptic, nearly thirteen years after the injury. Thetamping iron and the skull are preserved in the Warren Anatomical Museum, Boston. ]--just as a person has been blind in one eye for a long timewithout having discovered his loss. The cerebrum is the center ofintelligence and thought. [Footnote: In man, the cerebrum presents animmense preponderance in weight over other portions of the brain; in someof the lower animals, the cerebrum is even less in weight than thecerebellum. Another interesting point is the development of cerebralconvolutions in certain animals, by which the relative amount of graymatter is increased. In fishes, reptiles, and birds, the surface of thehemispheres is smooth; but, in many mammalia, especially in thoseremarkable for intelligence, the cerebrum presents a greater or lessnumber of convolutions, as it does in the human subject. --FLINT. Theaverage weight of the human brain in proportion to the entire body isabout 1 to 36. The average of mammalia is 1 to 186; of birds, 1 to 212; ofreptiles, 1 to 1, 321; and of fishes, 1 to 5, 668. There are some animals inwhich the weight of the brain bears a higher proportion to the body thanit does in man; thus in the blue-headed tit, the proportion is as 1 to 12;in the goldfinch, as 1 to 24; and in the field mouse, as 1 to 31. "It doesnot hence follow, however, that the _cerebrum_ is larger inproportion; in fact, it is probably not nearly so large; for in birds androdent animals the sensory ganglia form a very considerable portion of theentire brain. M. Baillarger has shown that the _surface_ and the_bulk_ of the cerebral hemispheres are so far from bearing anyconstant proportion to each other in different animals that, notwithstanding the depth of the convolutions in the human cerebrum, itsbulk is two and a half times as great in proportion to its surface as itis in the rabbit, the surface of whose cerebrum is smooth. The _size_of the cerebrum, considered alone, is not, however, a fair test of itsintellectual power. This depends upon the quantity of _vesicularmatter_ which it contains, as evinced not only by superficial area, butby the number and depth of the convolutions and by the thickness of thecortical layer. "--CARPENTER. ] Persons in whom it is seriously injured ordiseased often become unable to converse intelligently, both frominability to remember words and from loss of power to articulate them. 

THE CEREBELLUM lies below the cerebrum, and in the back part of the head(Fig. 50). It is about the size of a small fist. Its structure is similarto that of the brain proper, but instead of convolutions it has parallelridges, which, letting the gray matter down deeply into the white matterwithin, give it a peculiar appearance, called the _arbor vitæ_, ortree of life (Fig. 55). This part of the brain is the center for thecontrol of the voluntary muscles, [Footnote: The exact nature of thefunctions of the cerebellum is one of those problems concerning whichthere is no unanimity of opinion amongst physiologists. It may bepremised, however, that the knowledge we at present possess does enable usto come to one very important conclusion with respect to the functions ofthe cerebellum, --it enables us to say that this organ has no independentfunction either in the province of mind or in the province of motility. And we may perhaps safely affirm still further, that the cerebellum ismuch more intimately concerned with the production of bodily movementsthan with the evolution of mental phenomena. The anatomical distinctnessof the cerebellum from the larger brain and other parts of the nervoussystem is more apparent than real. . . . That there is an habitual communityof action between the cerebellum and the spinal cord is, I believe, doubted by none, and the fact that an intimate functional relationshipexists between the cerebrum and the cerebellum is shown by thecircumstance that atrophy of one cerebral hemisphere entails acorresponding atrophy of the opposite half of the cerebellum. Thesubordinate or supplementary nature of the cerebellar function, however, in this latter relation seems equally well shown by the fact that atrophyof one side of the cerebellum (when it occurs as the primary event) doesnot entail any appreciable wasting in the opposite half of the cerebrum. What other conclusion can be drawn? If the cutting off of certain cerebralstimuli leads to a wasting of the opposite half of the cerebellum, thiswould seem to show that each half of the cerebellum is naturally calledinto activity in response to, or conjointly with, the opposite cerebralhemisphere. Whilst conversely, if atrophy of one half of the cerebellumdoes not entail a relative diminution in the opposite cerebral hemisphere, this would go to show that the cerebral hemispheres do not act in responseto cerebellar stimuli, since their nutrition does not suffer when suchstimuli are certainly absent. The action of the cerebrum is thereforeshown to be primary, whilst that of the cerebellum is secondary orsubordinate in the performance of those functions in which they are bothconcerned. --H. CHARLTON BASTIAN, _Paralysis from Brain Disease_. ]particularly those of locomotion. Persons in whom it is injured ordiseased walk with tottering and uncertain movements as if intoxicated, and can not perform any orderly work. 

THE SPINAL CORD occupies the cavity of the backbone. It is protected bythe same membranes as the brain, but, unlike it, the white matter is onthe outside, and the gray matter is within. Deep fissures separate it intohalves (Fig. 50), which are, however, joined by a bridge of the samesubstance. Just as it starts from the brain, there is an expansion calledthe _medulla oblongata_ (Fig. 55). 

THE NERVES are glistening, silvery threads, composed, like the spinalcord, of white matter without and gray within. They ramify to all parts ofthe body. Often they are very near each other, yet are perfectly distinct, each conveying its own impression. [Footnote: Press two fingers together, and, closing the eyes, let some one pass the point of a pin lightly fromone to the other; you will be able to tell which is touched, yet if thenerves came in contact with each other anywhere in their long route to thebrain, you could not thus distinguish. ] Those which carry the orders ofthe mind to the different organs are called the _motory_ nerves;while those which bring back impressions which they receive are styled_sensory_ nerves. If the sensory nerve leading to any part be cut, all sensation in that spot will be lost, while motion will remain; if themotory nerve be cut, all motion will be destroyed, while sensation willexist as before. 

TRANSFER OF PAIN. --Strictly speaking, pain is not in any organ, but in themind, since only that can feel. When any nerve brings news to the brain ofan injury, the mind refers the pain to the end of the nerve. A familiarillustration is seen in the "funny bone" behind the elbow. Here the nerve(_ulnar_) gives sensation to the third and fourth fingers, in which, if this bone be struck, the pain will seem to be. Long after a limb hasbeen amputated, pain will be felt in it, as if it still formed a part ofthe body--any injury in the stump being referred to the point to which thenerve formerly led. [Footnote: Only about five per cent. Of those whosuffer amputation lose the feeling of the part taken away. There issomething tragical, almost ghastly, in the idea of a spirit limb hauntinga man through his life, and betraying him in unguarded moments into someeffort, the failure of which suddenly reminds him of his loss. A gallantfellow, who had left an arm at Shiloh, once, when riding, attempted to usehis lost hand to grasp the reins while with the other he struck his horse. A terrible fall was the result of his mistake. When the current of abattery is applied to the nerves of an arm stump, the irritation iscarried to the brain, and referred to all the regions of the lost limb. Onone occasion a man's shoulder was thus electrized three inches above thepoint where the limb was cut off. For two years he had ceased to beconscious of his limb. As the electric current passed through, the man, who had been profoundly ignorant of its possible effects, started up, crying, "Oh, the hand! the hand!" and tried to seize it with the livinggrasp of the sound fingers. No resurrection of the dead could have beenmore startling. --DR. MITCHELL _on "Phantom Limbs" in Lippincott'sMagazine_. ]

The nerves are divided into three general classes--the _spinal_, the_cranial_, and the _sympathetic_. 

FIG. 54. 

[Illustration: P, _posterior root of a spinal nerve;_ G, _ganglion;_ A, _anterior root;_ S, _spinal nerve. The whiteportions of the figure represent the white fibers; and the dark, thegray. _]

THE SPINAL NERVES, of which there are thirty-one pairs, issue from thespinal cord through apertures provided for them in the backbone. Eachnerve arises by two roots; the anterior is the motory, and the posteriorthe sensory one. The posterior alone connects directly with the graymatter of the cord, and has a small ganglion of gray matter of its own ata little distance from its origin. These roots soon unite, _i. E_. , are bound up in one sheath, though they preserve their special functions. When the posterior root of a nerve is cut, the animal loses the power offeeling, and when the anterior root is cut, that of motion. 

THE CRANIAL NERVES, twelve pairs in number, spring from the lower part ofthe brain and the medulla oblongata. 

1. The _olfactory_, or first pair of nerves, ramify through thenostrils, and are the nerves of smell. 

2. The _optic_, or second pair of nerves, pass to the eyeballs, andare the nerves of vision. 

3, 4, 6. The _motores oculi_ (eye movers) are three pairs of nervesused to move the eyes. 

5. The _trifacial_, or fifth pair of nerves, divide each into threebranches--hence the name--the first to the upper part of the face, eyes, and nose; the second to the upper jaw and teeth; the third to the lowerjaw and the mouth, where it forms the nerve of taste. These nerves areimplicated when we have the toothache or neuralgia. 

7. The _facial_, or seventh pair of nerves, are distributed over theface, and give it expression. [Footnote: If it is palsied, on one sidethere will be a blank, while the other side will laugh or cry, and thewhole face will look funny indeed. There were some cruel people in themiddle ages who used to cut the nerve and deform children's faces in thisway, for the purpose of making money of them at shows. When this nerve waswrongly supposed to be the seat of neuralgia, or tic douloureux, it wasoften cut by surgeons. The patient suffered many dangers, and no relief ofpain was gained. --MAPOTHER. ]

FIG. 55. 

[Illustration: _The Brain and the origin of the twelve pairs of CranialNerves. _ F, E, _the cerebrum;_ D, _the cerebellum, showing thearbor vitæ;_ G, _the eye;_ H, _the medulla oblongata;_ A, _the spinal cord;_ C and B, _the first two pairs of spinalnerves. _]

8. The _auditory_, or eighth pair of nerves, go to the ears, and arethe nerves of hearing. 

9. The _glos-so-pha-ryn'-ge-al_, or ninth pair of nerves, aredistributed over the mucous membrane of the pharynx, tonsils, etc. 

10. The _pneu-mo-gas'-tric_, or tenth pair of nerves, preside overthe larynx, lungs, liver, stomach, and one branch extends to the heart. This is the only nerve which goes so far from the head. 

11. The _accessory_, or eleventh pair of nerves, rise from the spinalcord, run up to the medulla oblongata, and thence leave the skull at thesame opening with the ninth and tenth pairs. They regulate the vocalmovements of the larynx. 

12. The _hyp-o-glos'-sal_, or twelfth pair of nerves, give motion tothe tongue. 

FIG. 56. 

[Illustration: _Spinal Nerve, Sympathetic Cord, and the Network ofSympathetic Nerves around the Internal Organs_. K, _aorta;_ A, _œophagus;_ B, _diaphragm;_ C, _stomach. _]

THE SYMPATHETIC SYSTEM contains the nerves of organic life. It consists ofa double chain of ganglia on either side of the backbone, extending intothe chest and abdomen. From, these, delicate nerves, generally soft and ofa grayish color, run to the organs on which life depends--the heart, lungs, stomach, etc. --to the blood vessels, and to the spinal and cranialnerves over the body. Thus the entire system is bound together with cordsof sympathy, so that, "if one member suffers, all the members suffer withit. "

Here lies the secret of the control exercised by the brain over all thevital operations. Every organ responds to its changing moods, especiallythose of respiration, circulation, digestion, and secretion, --processesintimately linked with this system, and controlled by it. (See p. 330. )

CROSSING OF CORDS. --Each half of the body is presided over, not by its ownhalf of the brain, but that of the opposite side. The motory nerves, asthey descend from the brain, in the medulla oblongata, cross each other tothe opposite side of the spinal cord. So the motor nerves of the rightside of the body are connected with the left side of the brain, and_vice versa_. Thus a derangement in one half of the brain mayparalyze the opposite half of the body. The nerves going to the face donot thus cross, and therefore the face may be motionless on one side, andthe limbs on the other. Each of the sensory fibers of the spinal nervescrosses over to the opposite side of the spinal cord, and so ascends tothe brain; an injury to the spinal cord may, therefore, cause a loss ofmotion in one leg and of feeling in the other. 

REFLEX ACTION. --Since the gray matter generates the nervous force, aganglion is capable of receiving an impression, and of sending back or_reflecting_ it so as to excite the muscles to action. This is donewithout the consciousness of the mind. [Footnote: Instances of anunconscious working of the mind are abundant. An illustration, oftenquoted, is given, as follows, by Dr. Abercrombie, in his _IntellectualPowers_:

"A lawyer had been excessively perplexed about a very complicatedquestion. An opinion was required from him, but the question was one ofsuch difficulty that he felt very uncertain how he should render it. Thedecision had to be given at a certain time, and he awoke in the morning ofthat day with a feeling of great distress. He said to his wife, 'I had adream, and the whole thing was clearly arranged before my mind, and Iwould give anything to recover the train of thought. ' His wife said tohim, 'Go and look on your table. ' She had seen him get up in the night andgo to his table and sit down and write. He did so, and found there theopinion which he had been most earnestly endeavoring to recover, lying inhis own handwriting. There was no doubt about it whatever. "

In this case the action of the brain was clearly automatic, _i. E. _, reflex. The lawyer had worried his brain by his anxiety, and thusprevented his mind from doing its best. But it had received an impulse ina certain direction, and when left to itself, worked out the result. (SeeAppendix for other illustrations. )] Thus we wink involuntarily at a flashof light or a threatened blow. [Footnote: A very eminent chemist a fewyears ago was making an experiment upon some extremely explosive compoundwhich he had discovered. He had a small quantity of this compound in abottle, and was holding it up to the light, looking at it intently; andwhether it was a shake of the bottle or the warmth of his hand, I do notknow, but it exploded in his hand, and the bottle was shivered into amillion of minute fragments, which were driven in every direction. Hisfirst impression was that they had penetrated his eyes, but to his intenserelief he found presently that they had only struck the outside of hiseyelids. You may conceive how infinitesimally short the interval wasbetween the explosion of the bottle and the particles reaching his eyes;and yet in that interval the impression had been made upon his sight, themandate of the reflex action, so to speak, had gone forth, the muscles ofhis eyelids had been called into action, and he had closed his eyelidsbefore the particles had reached them, and in this manner his eyes weresaved. You see what a wonderful proof this is of the way in which theautomatic action of our nervous apparatus enters into the sustenance ofour lives, and the protection of our most important organs from injury. --DR. CARPENTER. ] We start at a sudden sound. We jump back from a precipicebefore the mind has time to reason upon the danger. The spinal cordconducts certain impressions to the brain, but responds to others withouttroubling that organ. [Footnote: There is a story told of a man, who, having injured his spinal cord, had lost feeling and motion in his lowerextremities. Dr. John Hunter experimented upon him. Tickling his feet, heasked him if he felt it; the man, pointing to his limbs, which werekicking vigorously about, answered, "No, but you see my legs do. "Illustrations of this independent action of the spinal cord are common inanimals. A headless wasp will ply its sting energetically. A fowl, afterits head is cut off, will flap its wings and jump about as if in pain, although, of course, all sensation has ceased. "A water beetle, having hadits head removed, remained motionless as long as it rested on a drysurface, but when cast into water, it executed the usual swimming motionswith great energy and rapidity, striking all its comrades to one side byits violence, and persisting in these for more than half an hour. "] Themedulla oblongata carries on the process of respiration. The greatsympathetic system binds together all the organs of the body. 

USES OF REFLEX ACTION. --We breathe eighteen times every minute; we standerect without a consciousness of effort; [Footnote: In this way we accountfor the perilous feats performed by the somnambulist. He is not conscious, as his operations are not directed by the cerebrum, but by the othernervous centers. Were he to attempt their repetition when awake, theemotion of fear might render it impossible. ] we walk, eat, digest, and atthe same time carry on a train of thought. Our brain is thus emancipatedfrom the petty detail of life. If we were obliged to attend to everybreath, every pulsation of the heart, every wink of the eye, our timewould be wasted in keeping alive. Mere standing would require our entireattention. Besides, an act which at first demands all our thought soonrequires less, and at last becomes mechanical, [Footnote: "As every oneknows, " says Huxley, "it takes a soldier a long time to learn his drill--for instance, to put himself into the attitude of 'attention' at theinstant the word of command is heard. But, after a time, the sound of theword gives rise to the act, whether the soldier be thinking of it or not. There is a story, which is credible enough, though it may not be true, ofa practical joker, who, seeing a discharged veteran carrying home hisdinner, suddenly called out 'Attention!' whereupon the man instantlybrought his hands down and lost his mutton and potatoes in the gutter. Thedrill had been thorough, and its effects had become embodied in the man'snervous structure. "] as we say, _i. E. _, reflex. Thus we play afamiliar tune upon an instrument and carry on a conversation at the sametime. All the possibilities of an education and the power of forminghabits are based upon this principle. No act we perform ends with itself. It leaves behind it in the nervous centers a tendency to do the same thingagain. Our physical being thus conspires to fix upon us the habits of agood or an evil life. Our very thoughts are written in our muscles, sothat the expression of our face and even our features grow into harmonywith the life we live. 

BRAIN EXERCISE. --The nervous system demands its life and activity. Themind grows by what it feeds on. One who reads mainly light literature, whololls on the sofa or worries through the platitudes of an idle orfashionable life, decays mentally; his system loses tone, and physicalweakness follows mental poverty. On the other hand, an excessive use ofthe mind withdraws force from the body, whose weakness, reacting on thebrain, produces gradual decay and serious diseases. (See p. 331. )

The brain grows by the growth of the body. The body grows through goodfood, fresh air, and work and rest in suitable proportion. For the fulldevelopment and perfect use of a strong mind, a strong body is essential. Hence, in seeking to expand and store the intellect, we should be equallythoughtful of the growth and health of the body. 

SLEEP [Footnote: Sleep procured by medicine is rarely as beneficial asthat secured naturally. The disturbance to the nervous system is oftensufficient to counterbalance all the good results. The habit of seekingsleep in this way, without the advice of a physician, is to be mostearnestly deprecated. The dose must be constantly increased to produce theeffect, and thus great injury may be caused. Often, too, where laudanum ormorphine is used, the person unconsciously comes into a terrible and fatalbondage. (See p. 342. ) Especially should infants never be dosed withcordials, as is a common family practice. The damage done to helplesschildhood by the ignorant and reckless use of soothing syrups is frightfulto contemplate. All the ordinary sleeping draughts have life-destroyingproperties, as is proved by the fatal effects of an overdose. At the best, they paralyze the nerve centers, disorder the digestion, and poison theblood. Their promiscuous use is therefore full of danger. ] is as essentialas food. During the day, the process of tearing down goes on; during thenight, the work of building up should make good the loss. In youth moresleep is needed than in old age, when nature makes few permanent repairs, and is content with temporary expedients. The number of hours required forsleep must be decided by each person. Napoleon took only five hours, butmost people need from six to eight hours, --brain workers even more. Ingeneral, one should sleep until he naturally wakes. If one's rest bebroken, it should be made up as soon as possible. (See p. 334. )

SUNLIGHT. --The influence of the sun's rays upon the nervous system is verymarked. [Footnote: The necessity of light for young children is not halfappreciated. Many of their diseases, and nearly all the cadaverous looksof those brought up in great cities, are ascribable to the deficiency oflight and air. When we see the glass room of the photographers in everystreet, in the topmost story, we grudge them their application to what isoften a mere personal vanity. Why should not a nursery be constructed inthe same manner? If parents knew the value of light to the skin, especially to children of a scrofulous tendency, we should have plenty ofthese glass house nurseries, where children might run about in a propertemperature, free from much of that clothing which at present seals up theskin--that great supplementary lung--against sunlight and oxygen. Theywould save many a weakly child who now perishes from lack of thesenecessaries of infant life. --DR. WINTER. ] It is said also to have theeffect of developing red disks in the blood. All vigor and activity comefrom the sun. Vegetables grown in subdued light have a bleached and fadedlook. An infant kept in absolute darkness would grow into a shapelessidiot. That room is the healthiest to which the sun has the freest access. Epidemics frequently attack the inhabitants of the shady side of a street, and exempt those on the sunny side. If, on a slight indisposition, weshould go out into the open air and bright sunlight, instead of shuttingourselves up in a close, dark chamber, we might often avoid a seriousillness. The sun bath is doubtless a most efficient remedy for manydiseases. Our window blinds and curtains should be thrown back and open, and we should let the blessed air and sun stream in to invigorate andcheer. No house buried in shade, and no room with darkened windows, is fitfor human habitation. In damp and darkness, lies in wait almost everydisease to which flesh is heir. The sun is their only successful foe. (Seep. 336. )

WONDERS OF THE BRAIN. --After having seen the beautiful contrivances andthe exquisite delicacy of the lower organs, it is natural to suppose thatwhen we come to the brain we should find the most elaborate machinery. Howsurprising, then, it is to have revealed to us only cells and fibers! Thebrain is the least solid and most unsubstantial looking organ in the body. Eighty per cent of water, seven of albumen, some fat, and a few minorsubstances constitute the instrument which rules the world. Strangest ofall, the brain, which is the seat of sensation, is itself withoutsensation. Every nerve, every part of the spinal cord, is keenly alive tothe slightest touch, yet "the brain may be cut, burned, or electrifiedwithout producing pain. "

ALCOHOLIC DRINKS AND NARCOTICS. 

ALCOHOL (Continued from p. 187). 

EFFECT UPON THE NERVOUS SYSTEM. --In the progressive influence of alcoholupon the nervous system, there are, according to the researches of Dr. Richardson, four successive stages. 

1. THE STAGE OF EXCITEMENT. [Footnote: The pupil should be careful to notehere that alcohol does not act upon the heart directly, and cause it tocontract with more force. The idea that alcohol gives energy and activityto the muscles is entirely false. It really, as we have seen (p. 183), weakens muscular contraction. The enfeeblement begins in the first stage, and continues in the other stages with increased effect. The heart beatsquickly merely because the resistance of the minute controlling vessels istaken off, and it works without being under proper regulation. _What iscalled a stimulation or excitement is, in absolute fact, a relaxation, apartial paralysis_ of one of the most important mechanisms in theanimal body. Alcohol should be ranked among the narcotics. --RICHARDSON. ]--The first effect of alcohol, as we have already described on page 144, isto paralyze the nerves that lead to the extreme and minute blood vessels, and so regulate the passage of the blood through the capillary system. Thevital force, thus drawn into the nervous centers, drives the machinery oflife with tremendous energy. The heart jumps like the mainspring of awatch when the resistance of the wheels is removed. The blood surgesthrough the body with increased force. Every capillary tube in the systemis swollen and flushed, like the reddened nose and cheek. 

In all this there is exhilaration, but no nourishment; there is animation, but no permanent power conferred on brain or muscle. Alcohol may cheer forthe moment. It may set the sluggish blood in motion, start the flow ofthought, and excite a temporary gayety. "It may enable a wearied or feebleorganism to do brisk work for a short time. It may make the brain brieflybrilliant. It may excite muscle to quick action, but it does nothing atits own cost, fills up nothing it has destroyed, and itself leads todestruction. " Even the mental activity it has excited is an unsafe stateof mind, for that just poise of the faculties so essential to goodjudgment is disturbed by the presence of the intruder. Johnson wellremarked, "Wine improves conversation by taking the edge off theunderstanding. "

2. THE STAGE OF MUSCULAR WEAKNESS. --If the action of the alcohol be stillcontinued, the spinal cord is next affected by this powerful narcotic. Thecontrol of some of the muscles is lost. Those of the lower lip usuallyfail first, then those of the lower limbs, and the staggering, uncertainsteps betray the result. The muscles themselves, also, become feebler asthe power of contraction diminishes. The temperature, which, for a time, was slightly increased, soon begins to fall as the heat is radiated; thebody is cooled, and the well-known "alcoholic chill" is felt. 

3. THE STAGE OF MENTAL WEAKNESS. --The cerebrum is now implicated. Theideal and emotional faculties are quickened, while the will is weakened. The center of thought being overpowered, the mind is a chaos. Ideas flockin thick and fast. The tongue is loosened. The judgment loses its hold onthe acts. The reason giving way, the animal instincts generally assume themastery of the man. The hidden nature comes to the surface. All the glossof education and social restraint falls off, and the lower nature standsrevealed. The coward shows himself more craven, the braggart moreboastful, the bold more daring, and the cruel more brutal. The inebriateis liable to become the perpetrator of any outrage that the slightestprovocation may suggest. 

4. THE STAGE OF UNCONSCIOUSNESS. --At last, prostration ensues, and thewild, mad revel of the drunkard ends with utter senselessness. In commonspeech, the man is "dead drunk. " Brain and spinal cord are both benumbed. Fortunately, the two nervous centers which supply the heart and thediaphragm are the slowest to be influenced. So, even in this final stage, the breathing and the circulation still go on, though the other organshave stopped. Were it not for this, every person thoroughly intoxicatedwould die. [Footnote: Cold has a wonderful influence in hastening thisstage, so that a person, previously only in the first stage of excitement, on going outdoors on a winter night, may rapidly sink into a lethargy(become _comatose_), fall, and die. He is then commonly said to haveperished with cold. The signs of this coma are of great practicalimportance, since so many persons die in police stations and elsewhere whoare really comatose, when they are supposed to be only sound asleep. Thepulse is slow, and almost imperceptible. The face is pale, and the skincold. "If the arm be pinched, it is not moved; if the eyeballs aretouched, the lids will not sink. " The respiration becomes slower andslower, and, if the person dies, it is because liquid collects in thebronchial tubes, and stops the passage of the air. The man then actuallydrowns in his own secretions. ]

EFFECT UPON THE BRAIN. --Alcohol seems to have a special affinity for thebrain. This organ absorbs more than any other, and its delicate structureis correspondingly affected. The "Vascular enlargement" here reaches itsheight. The tiny vessels become clogged with blood that is unfitted tonourish, because loaded with carbonic acid, and deprived of the usualquantity of the life-giving oxygen. --HINTON. The brain is, in the languageof the physiologist, malfunctioned. The mind but slowly rallies from thestupor of the fourth stage, and a sense of dullness and depression remainsto show with what difficulty the fatigued organ recovers its normalcondition. So marked is the effect of the narcotic poison, that someauthorities hold that "a once thoroughly intoxicated brain never fullybecomes what it was before. "

In time, the free use of liquor hardens and thickens the membraneenveloping the nervous matter; the nerve corpuscles undergo a "Fattydegeneration"; the blood vessels lose their elasticity; and the vitalfluid, flowing less freely through the obstructed channels, fails toafford the old-time nourishment. The consequent deterioration of thenervous substance--the organ of thought--shows itself in the weakened mind[Footnote: The habitual use of fermented liquors, even to an extent farshort of what is necessary to produce intoxication, injures the body, anddiminishes the mental power. --Sir Henry Thompson. ] that we so often noticein a person accustomed to drink, and at last lays the foundation ofvarious nervous disorders--epilepsy, paralysis, and insanity. [Footnote:Casper, the great statistician of Berlin, says: "So far as that city isconcerned, one third of the insane coming from the poorer classes, weremade so by spirit drinking. "] The law of heredity here again assertsitself, and the inebriate's children often inherit the disease which hehas escaped. 

Chief among the consequences of this perverted and imperfect nutrition ofthe brain is that intermediate state between intoxication and insanity, well known as Delirium Tremens. "It is characterized by a low, restlessactivity of the cerebrum, manifesting itself in muttering delirium, withoccasional paroxysms of greater violence. The victim almost alwaysapprehends some direful calamity; he imagines his bed to be covered withloathsome reptiles; he sees the walls of his apartment crowded with foulspecters; and he imagines his friends and attendants to be fiends come todrag him down to a fiery abyss beneath. "--CARPENTER. (See p. 287. )

INFLUENCE UPON THE MENTAL AND MORAL POWERS. --So intimate is the relationbetween the body and the mind, that an injury to one harms the other. Theeffect of alcoholized blood is to weaken the will. The one habituallyunder its influence often shocks us by his indecision and his readiness tobreak a promise to reform. The truth is, he has lost, in a measure, hispower of self-control. At last, he becomes physically unable to resist thecraving demand of his morbid appetite. 

Other faculties share in this mental wreck. The intellectual visionbecomes less penetrating, the decisions of the mind less reliable, and thegrasp of thought less vigorous. The logic grows muddy. A thriftless, reckless feeling is developed. Ere long, self-respect is lost, and thenambition ceases to allure, and the high spirit sinks. 

Along with this mental deterioration comes also a failure of the moralsense. The fine fiber of character undergoes a "degeneration" as certainas that of the muscles themselves. Broken promises tell of a loweredstandard of veracity, and a dulled sense of honor, quite as much as of animpaired will. Under the subtle influence of the ever-present poison, signs of spiritual weakness multiply fast. Conscience is lulled to rest. Reason is enfeebled. Customary restraints are easily thrown off. Thesensibilities are blunted. There is less ability to appreciate nice shadesof right and wrong. Great moral principles and motives lose their power toinfluence. The judgment fools with duty. The future no longer reaches backits hand to guide the present. The better nature has lost its supremacy. 

The wretched victim of appetite will now gratify his tyrannical passionfor drink at any expense of deceit or crime. He becomes the blindinstrument of his insane impulses, and commits acts from which he wouldonce have shrunk with horror. [Footnote: Richardson sums up the variousdiseases caused by alcohol, as follows: "(_a_). Diseases of the brainand nervous system, indicated by such names as apoplexy, epilepsy, paralysis, vertigo, softening of the brain, delirium tremens, dipsomaniaor inordinate craving for drink, loss of memory, and that general failureof the mental power, called dementia. (_b_). Diseases of the lungs:one form of consumption, congestion, and subsequent bronchitis. (_c_). Diseases of the heart: irregular beat, feebleness of themuscular walls, dilatation, disease of the valves. (_d_). Diseases ofthe blood: scurvy, excess of water or dropsy, separation of fibrin. (_e_). Diseases of the stomach: feebleness of the stomach, indigestion, flatulency, irritation, and sometimes inflammation. (_f_). Diseases of the bowels: relaxation or purging, irritation. (_g_). Diseases of the liver: congestion, hardening and shrinking, cirrhosis. (_h_). Diseases of the kidneys: change of structure intofatty or waxy-like condition and other results leading to dropsy, orsometimes to fatal sleep. (_i_). Diseases of the muscles: fattychange in the muscles, by which they lose their power for proper activecontraction. (_j_). Diseases of the membranes of the body: thickeningand loss of elasticity, by which the parts wrapped up in the membrane areimpaired for use, and premature decay is induced. "] Sometimes he eventakes a malignant pleasure in injuring those whom Nature has ordained heshould protect. [Footnote: It has been argued that a man should not bepunished for any crime he may commit during intoxication, but rather forknowingly giving up the reins of reason and conscience, and thussubjecting himself to the rule of his evil passions. Voluntarily tostimulate the mind and put it into a condition where it may drive one toruin, is very like the act of an engineer who should get up steam in hisengine, and then, having opened the valves, desert his post, and let themonster go thundering down the track to sure destruction. Certain personsare thrown into the stage of mental weakness by a single glass of liquor. How can they be excused when the fact of their peculiar liability lendsadditional force to the argument of abstemiousness, and they know thattheir only safety lies in total abstinence?--CARPENTER'S_Physiology. _]

2. TOBACCO. 

The Constituents of Tobacco Smoke are numerous, but the prominent ones arecarbonic-acid, carbonic-oxide, and ammonia gases; carbon, or soot; andnicotine. The proportion of these substances varies with different kindsof tobacco, the pipe used, and the rapidity of the combustion. Carbonicacid tends to produce sleepiness and headache. Carbonic oxide, inaddition, causes a tremulous movement of the muscles, and so of the heart. Ammonia bites the tongue of the smoker, excites the salivary glands, andcauses dryness of the mouth and throat. Nicotine is a powerful poison. Theamount contained in one or two strong cigars, if thrown directly into theblood, would cause death. Nicotine itself is complex, yielding a volatilesubstance that gives the odor to the breath and clothing; and also abitter extract which produces the sickening taste of an old pipe. Insmoking, some of the nicotine is decomposed, forming pyridine, picoline, and other poisonous alkaloids. [Footnote: The analysis of tobacco as givenby different authorities varies greatly. The one stated in the textsuffices for the purposes of this chapter. Von Eulenberg names severalother products of the combustion. One hundred pounds of the dry leaf mayyield as high as seven pounds of nicotine. Havana tobacco contains abouttwo per cent, and Virginia about six per cent. --See JOHNSTON & CHURCH'S_Chemistry of Common Life_, and MILLER'S _Organic Chemistry_. ]

PHYSIOLOGICAL EFFECTS. --The poison of tobacco, set free by the processeither of chewing or smoking, when for the first time it is swept throughthe system by the blood, powerfully affects the body. Nausea is felt, andthe stomach seeks to throw off the offending substance. The brain isinflamed, and headache follows. The motor nerves becoming irritated, giddiness ensues. Thus Nature earnestly protests against the formation ofthis habit. But, after repeated trials, the system adjusts itself to thenew conditions. A "tolerance" of the poison is finally established, andsmoking causes none of the former symptoms. Such powerful substances cannot, however, be constantly inhaled without producing marked changes. Thethree great eliminating organs--the lungs, the skin, and the kidneys--throw off a large part of the products, but much remains in the system. When the presence of the poison is constant, and especially when thesmoking or chewing is excessive, the disturbance that at first is merelyfunctional, must necessarily, in many cases at least, lead to a chronicderangement. 

Probably in this, as in the case of other deleterious articles of diet, the strong and healthy will seem to escape entirely, while the weak andthose predisposed to disease will be injured in direct proportion to theextent of the indulgence. Those whose employment leads to active, outdoorwork, will show no sign of nicotine poisoning, while the man of sedentaryhabits will sooner or later be the victim of dyspepsia, sleeplessness, nervousness, paralysis, or other organic difficulties. Even where the userof tobacco himself escapes harm, the law of heredity asserts itself, andthe innocent offspring only too often inherit an impaired constitution, and a tendency to nervous complaints. 

THE VARIOUS DISTURBANCES produced in different individuals andconstitutions by smoking have been summed up by Dr. Richardson as follows:"(_a_) In the blood, it causes undue fluidity, and change in the redcorpuscles; (_b_) in the stomach, it gives rise to debility, nausea, and vomiting; (_c_) in the mucous membrane of the mouth, it producesenlargement and soreness of the tonsils--smoker's sore throat--redness, dryness, and occasional peeling of the membrane, and either unnaturalfirmness and contraction, or sponginess of the gums; and, where the piperests on the lips, oftentimes 'epithelial cancer'; (_d_) in theheart, it causes debility of the organ, and irregular action; (_e_)in the bronchial surface of the lungs, when that is already irritable, itsustains irritation, and increases the cough; (_f_) in the organs ofsense, it produces dilation of the pupils of the eye, confusion of vision, bright lines, luminous or cobweb specks, and long retention of images onthe retina, with analogous symptoms affecting the ear, viz. , inability todefine sounds clearly, and the occurrence of a sharp, ringing noise like awhistle; (_g_) in the brain, it impairs the activity of the organ, oppressing it if it be nourished, but soothing it if it be exhausted;(_h_) it leads to paralysis in the motor and sympathetic nerves, andto over-secretion from the glands which the sympathetic nerves control. "

IS TOBACCO A FOOD?--Here, as in the case of alcohol, the reply is anegative one. Tobacco manifests no characteristic of a food. It can notimpart to the blood an atom of nutritive matter for building up the body. It does not add to, but rather subtracts from, the total vital force. Itconfers no potential power upon muscle or brain. It stimulates by cuttingoff the nervous supply from the extremities and concentrating it upon thecenters. But stimulation is not nourishment; it is only a rapid spendingof the capital stock. There is no greater error than to mistake theexciting of an organ for its strengthening. 

THE INFLUENCE UPON YOUTH. --Here, too, science utters no doubtful voice. Experience asserts only one conviction. _Tobacco retards the developmentof mind and body. _ [Footnote: Cigarettes are especially injurious fromthe irritating smoke of the paper covering, taken into the lungs, and alsobecause the poison fumes of the tobacco are more directly inhaled. In caseof the cheap cigarettes often smoked by boys the ingredients used areharmful, while one revolts at the thought of the filthy materials, refusecigar stumps, etc. , employed in their manufacture. ] The law of nature isthat of steady growth. It can not admit of a daily, even though it bemerely a functional, disturbance that weakens the digestion, that causesthe heart to labor excessively, that prevents the perfect oxidation of theblood, that interferes with the assimilation, and that deranges thenervous system. [Footnote: There is one influence of tobacco that everyyoung man should understand. In many cases, like alcohol, it seems toblunt the sensibilities, and to make its user careless of the rights andfeelings of others. This is often noticed in common life. We meeteverywhere "devotees of the weed, " who, ignoring the fact that tobacco isdisagreeable to many persons, think only of the gratification of theirselfish appetite. They smoke or chew in any place or company. They permitthe cigar fumes to blow into the faces of passers-by. They sit where thewind carries the smoke of their pipes so that others must inhale it. Theyexpectorate upon the floor of cars, hotels, and even private homes. Theytake no pains to remove the odor that lingers about their person andclothing. They force all who happen to be near, their companions, theirfellow-travelers, to inhale the nauseating odor of tobacco. Everythingmust be sacrificed to the one primal necessity of such persons--a smoke. Now, a young man just beginning life, with his fortune to make, and hissuccess to achieve, can not afford to burden himself with a habit that iscostly, that will make his presence offensive to many persons, and thatmay perhaps render him less sensitive to the best influences andperceptions of manhood. ] No one has a right thus to check and disturbcontinually the regular processes of his physical and mental progress. Hence, the young man (especially if he be of a nervous, sensitiveorganization) who uses tobacco deliberately diminishes the possible energywith which he might commence the work of life; [Footnote: In thePolytechnic School at Paris, the pupils were divided into two classes--thesmokers, and the non-smokers. The latter not only excelled on the entranceexaminations, but during the entire course of study. Dr. Decaisne examinedthirty-eight boys who smoked, and found twenty-seven of them diseased fromnicotine poisoning. So long ago as 1868, in consequence of these results, the Minister of Public Instruction forbade the use of tobacco by thepupils. 

Dr. Gihon, medical director of the Naval Academy at Annapolis, in hisreport for 1881, says: "The most important matter in the health history ofthe students is that relating to tobacco, and its interdiction isabsolutely essential to their future health and usefulness. In this view Ihave been sustained by my colleagues, and by all sanitarians in civil andmilitary life whose views I have been able to obtain. "] while he comesunder the bondage of a habit that may become stronger than his will, andunder the influence of a narcotic that may beguile his faculties and palsyhis strength at the very moment when every power should be awake. 

Another peril still lies in the wake of this masterful poison habit. Tobacco causes thirst and depression that only too often and naturallylead to the use of liquor. (See p. 338. )

3. OPIUM. 

Opium is the dried juice of the poppy. In Eastern countries, this floweris cultivated in immense fields for the sake of this product. When a cutis made in the poppy head, a tiny tear of milky juice exudes, and hardens. These little drops are gathered and prepared for the market, an acreyielding, it is said, about twenty-five pounds. Throughout the East, opiumis generally smoked; but in Western countries laudanum and paregoric(tinctures of opium), and morphine--a powerful alkaloid contained inopium, are generally used. The drug itself is also eaten. 

PHYSIOLOGICAL EFFECT. --Opium, in its various forms, acts directly upon thenerves, a small dose quieting pain, and a larger one soothing to sleep. Itarouses the brain, and fires the imagination to a wonderful pitch. [Footnote: So far as its effects are concerned, it matters little in whatform opium is taken, whether solid as in pills, liquid as in laudanum, orvaporized, as when inhaled from a pipe. The opium slave is characterizedby trembling steps, a curved spine, sunken glassy eyes, sallow witheredfeatures, and often by contraction of the muscles of the neck and fingers. In the East, when the drug ceases its influence, the opium eater renews itwith corrosive sublimate till, finally, this also fails of effect, and hegradually sinks into the grave. ] The reaction from this unnatural excitantis correspondingly depressing; and the melancholy, the "overwhelminghorror" that ensues, calls for a renewal of the stimulus. The dose must begradually increased to produce the original exhilaration. [Footnote: Thevictim of opium is bound to a drug from which he derives no benefits, butwhich slowly deprives him of health and happiness, finally to end inidiocy or premature death. Whatever the victim's condition or surroundingsmay be, the opium must be taken at certain times with inexorableregularity. The liquor or tobacco user can, for a time, go without the useof these agents, and no regular hours are necessary. During sickness, andmore especially during the eruptive fevers, he does not desire tobacco orliquor. The opium eater has no such reprieves; his dose must be taken, and, in painful complications affecting the stomach, a large increase isdemanded to sustain the system. If, in forming the habit, two doses aretaken each day, the victim is obliged to maintain that number. It is theunceasing, everlasting slavery of regularity that humiliates opium eatersby a sense of their own weakness. --HUBBARD _on The Opium Habit andAlcoholism. _] The seductive nature of the drug leads the unfortunatevictim on step by step until he finds himself fast bound in the fetters ofone of the most tyrannical habits known to man. 

To go on is to wreck all one's powers--physical and mental. To throw offthe habit, requires a determination that but few possess. Yet even whenthe custom is broken, the system is long in recovering from the shock. There seems to be a failure of every organ. The digestion is weakened, food is no longer relished, the muscles waste, the skin shrivels, thenervous centers are paralyzed, and a premature old age comes on apace. DeQuincey, four months after he had cast away the opium bonds, wrote, "Thinkof me as one still agitated, writhing, throbbing, palpitating, shattered. "

No person can be too careful in the use of laudanum, paregoric, andmorphine. They may be taken on a physician's prescription as a sedativefrom racking pain, [Footnote: Many persons learn to inject morphinebeneath the skin by means of a "hypodermic syringe. " The operation ispainless, and seems an innocent one. It throws the narcotic directly intothe circulation, and relief from pain is often almost instantaneous. Butthe danger of forming the opium habit is not lessened, and the effect ofusing the drug in this form for a long time is just as injurious as opiumsmoking itself. Opium in one of its forms enters largely into thecomposition of many of the painkillers and patent medicines so freelyadvertised for domestic use in the present day, and for this reason thegreatest care is needed in having recourse to any of them. Taken, perhaps, in the first instance, to alleviate the torments of neuralgia ortoothache, what proves to be a remedy soon becomes a source ofgratification, which the wretchedness that follows on abstinence rendersincreasingly difficult to lay aside. The same must be said of bromide ofpotassium and hydrate of chloral, frequently resorted to as a remedy forsleeplessness: the system quickly becomes habituated to their use, andthey can then be relinquished only at the cost of much suffering. Indeed, the last mentioned of these two drugs obtains over the mind a power whichmay be compared to that of opium, and is, moreover, liable to occasion thedisease known as chloralism, by which the system ultimately becomes acomplete wreck. Looking at the whole question of the medicinal use ofnarcotics, it is perhaps not too much to say that they should never beemployed except with the authority of a competent medical adviser. --_Chambers's Journal_. ] but if followed up for any length of time, thepowerful habit may be formed ere one is aware. Then comes the opiumeater's grave, or the opium eater's struggle for life!

4. CHLORAL HYDRATE. 

CHLORAL HYDRATE is a drug frequently used to cause sleep. It leaves behindno headache or lassitude, as is often the case with morphine. It is, however, a treacherous remedy. It is cumulative in its effects, _i. E. _, even a small and harmless dose, persisted in for a long period, may produce a gradual accumulation of evil results that in the end willprove fatal. 

THE PHYSIOLOGICAL EFFECT of its prolonged use is very marked. The appetitebecomes capricious. The secretions are unnatural. Nausea and flatulencyoften ensue. Then the nervous system is involved. The heart is affected. Sleep, instead of responding to the drug, as at first, is broken anddisturbed. The eyesight fails. The circulation is enfeebled, and the pulsebecomes weak, rapid, and irregular. There is a tendency to fainting and todifficult respiration. Sometimes the impoverished blood induces a diseaseresembling scurvy, the ends of the fingers ulcerate, and the face isdisfigured by blotches. An excessive dose may result in death. 

Prolonged habitual use of chloral hydrate tends to debase the mind andmorals of the subject in the same manner as indulgence in alcohol, ether, or chloroform. 

5. CHLOROFORM. 

CHLOROFORM is an artificial product generally obtained, by distillation, from a mixture of chloride of lime, water, and alcohol. It was discoveredin 1831 by Samuel Guthrie, of Sackett's Harbor, New York. It is acolorless, transparent volatile liquid, with a strong ethereal odor. 

PHYSIOLOGICAL EFFECT. --Chloroform is a powerful anæsthetic, which, wheninhaled, causes a temporary paralysis of the nervous system, and thus acomplete insensibility to pain. There is great peril attending its use, even in the hands of the most skillful and experienced practitioners. Itis sometimes prescribed by a physician, and afterward (as in the case oflaudanum, morphine, and chloral) the sufferer, charmed with the releasefrom pain and the peaceful slumber secured, buys the Lethean liquid forhimself. Its use soon becomes an apparent necessity. The craving for thenarcotic at a stated time is almost irresistible. The patient, compelledto give up the use of chloroform, will demand, entreat, pray for anotherdose, in a heartrending manner, never to be forgotten. Paleness anddebility, the earliest symptoms, are followed by mental prostration. Familiarity with this dangerous drug begets carelessness, and its victimsare frequently found dead in their beds, with the handkerchief from whichthey inhaled the volatile poison clutched in their lifeless hands. 

6. COCAINE. 

Cocaine is an alkaloid prepared from the erythroxylon coca, a shrub, fiveor six feet high, found wild in the mountainous regions of Ecuador andPeru, where it is also cultivated by the natives. The South AmericanIndians, for centuries, have chewed coca leaves as a stimulant, but thehighly poisonous principle, now called cocaine, to which the plant owesits peculiar effects, was not discovered till 1859. Within a few yearsthis drug has come into favor as an agent to produce local anæsthesia, andhas proved exceedingly valuable in surgical operations upon the eye andother sensitive organs. It has already, however, been diverted from itslegitimate use as a benefaction, and to the other evils of the day is nowadded the "cocaine habit, " which is, perhaps, even more dangerous anddifficult to abandon than either the alcohol or the opium habit. 

PHYSIOLOGICAL EFFECT. --Applied locally, cocaine greatly lessens and evenannihilates pain. Taken internally, it acts as a powerful stimulant to thenervous system, its physiological action being similar to that of theine(p. 170), caffeine, and theobromine. Used hypodermically, its immediateeffect, says one to whom it was thus administered, is to cause "greatpallor of countenance, profuse frontal perspiration, sunken eyes, enlargedpupils, lessened sensitiveness of the cornea and conjunctiva, loweredarterial tension, and a feeble pulse and heart beat. Under its influence Icould not reason. Everything seemed to run through my brain, and in vain Isummoned all my will power to overcome an overwhelming sleepiness. " A fewdoses of this drug will in some persons produce temporary insanity. Usedto excess, it leads to permanent madness or idiocy. "Cocaine, " says awriter in the _Medical Review_, "is a dangerous therapeutic toy not tobe used as a sensational plaything. If it should come into as general useas the other intoxicants of its class, it will help to fill the asylums, inebriate and insane. "

PRACTICAL QUESTIONS. 

1. Why is the pain of incipient hip disease frequently felt in the knee?

2. Why does a child require more sleep than an aged person?

3. When you put your finger in the palm of a sleeping child, why will hegrasp it?

4. How may we strengthen the brain?

5. What is the object of pain?

6. Why will a blow on the stomach sometimes stop the heart?

7. How long will it take for the brain of a man six feet high to receivenews of an injury to his foot, and to reply?

8. How can we grow beautiful?

9. Why do intestinal worms sometimes affect a child's sight?

10. Is there any indication of character in physiognomy?

11. When one's finger is burned, where is the ache?

12. Is a generally closed parlor a healthful room?

13. Why can an idle scholar read his lesson and at the same time count themarbles in his pocket?

14. In amputating a limb, what part, when divided, will cause the keenestpain?

15. What is the effect of bad air on nervous people?

16. Is there any truth in the proverb that "he who sleeps dines"?

17. What does a high, wide forehead indicate?

18. How does indigestion frequently cause a headache?

19. What is the cause of one's foot being "asleep"? [Footnote: Here thenervous force is prevented from passing by compression. Just how this isdone, or what is kept from passing, we can not tell. If a current ofelectricity were moving through a rubber tube full of mercury, a slightsqueeze would interrupt it. These cases may depend on the same generalprinciple, but we can not assert it. --HUXLEY. The tingling sensationcaused by the compression is transferred to the foot, whence the nervestarts. ]

20. When an injury to the nose has been remedied by transplanting skinfrom the forehead, why is a touch to the former felt in the latter?

21. Are closely curtained windows healthful?

22. Why, in falling from a height, do the limbs instinctively take aposition to defend the important organs?

23. What causes the pylorus to open and close at the right time?

24. Why is pleasant exercise most beneficial?

25. Why does grief cause one to lose his appetite?

26. Why should we never study directly after dinner?

27. What produces the peristaltic movement of the stomach?

28. Why is a healthy child so restless and full of mischief?

29. Why is a slight blow on the back of a rabbit's neck fatal?

30. Why can one walk and carry on a conversation at the same time?

31. What are the dangers of overstudy?

32. What is the influence of idleness upon the brain?

33. State the close relation which exists between physical and mentalhealth and disease. 

34. In what consists the value of the power of habit?

35. How many pairs of nerves supply the eye?

36. Describe the reflex actions in reading aloud. 

37. Under what circumstances does paralysis occur?

38. If the eyelids of a profound sleeper were raised, and a candle broughtnear, would the iris contract?

39. How does one cough in his sleep?

40. Give illustrations of the unconscious action of the brain. 

41. Is chewing tobacco more injurious than smoking?

42. Ought a man to retire from business while his faculties are stillunimpaired?

43. Which is the more exhaustive to the brain, worry or severe mentalapplication?

44. Is it a blessing to be placed beyond the necessity for work?

45. Show how anger, hate, and the other degrading passions are destructiveto the brain. [Footnote: "One of the surest means for keeping the body andmind in perfect health consists in learning to hold the passions insubservience to the reasoning faculties. This rule applies to everypassion. Man, distinguished from all other animals by the peculiarity thathis reason is placed above his passions to be the director of his will, can protect himself from every mere animal degradation resulting frompassionate excitement. The education of the man should be directed not tosuppress such passions as are ennobling, but to bring all undergovernance, and specially to subdue those most destructive passions, anger, hate, and fear. "]

46. Are not amusements, to repair the waste of the nervous energy, especially needed by persons whose life is one of care and toil?

47. Is not severe mental labor incompatible with a rapidly growing body?

48. How shall we induce the system to perform all its functions regularly

49. How does alcohol interfere with the action of the nerves?

50. What is the general effect of alcohol upon the character?

51. Does alcohol tend to produce clearness and vigor of thought?

52. What is the general effect of alcohol on the muscles?

53. Does alcohol have any effect on the bones? The skin?

54. What is the cause of the "alcoholic chill"?

55. Show how alcohol tends to develop man's lower, rather than his higher, nature. 

56. When we wish really to strengthen the brain, should we use alcohol?

57. Why is alcohol used to preserve anatomical specimens?

58. What is meant by an inherited taste for liquor?

59. Ought a person to be punished for a crime committed duringintoxication?

60. Should a boy ever smoke?

61. To what extent are we responsible for the health of our body?

62. Why does alcohol tend to collect in the brain?

63. Does the use of alcohol tend to increase crime and poverty?

VIII. 

THE SPECIAL SENSES. 

"See how yon beam of seeming whiteIs braided, out of seven-hued light;Yet in those lucid globes no rayBy any chance shall break astray. Hark, how the rolling surge of sound, Arches and spirals circling round, Wakes the hush'd spirit through thine earWith music it is heaven to hear. "

HOLMES. 

"Let us remember that if we get a glimpse of the details of naturalphenomena, and of those movements which constitute life, it is not inconsidering them as a whole, but in analyzing them as far as our limitedmeans will permit. In the vibrations of the globe of air which surroundsour planet, as in the undulations of the ether which fills the immensityof space, it is always by molecules which are intangible for us, put inmotion by nature, always by the infinitely little, that she acts inexciting the organs of sense, and she has modeled these organs in aproportion which enables them to partake in the movement which sheimpresses upon the universe. She can paint with equal facility on afraction of a line of space on the retina, the grandest landscape or thenervelets of a rose leaf; the celestial vault on which Sirius is but aluminous point, or the sparkling dust of a butterfly's wing; the roar ofthe tempest, the roll of thunder, the echo of an avalanche, find equalplace in the labyrinth whose almost imperceptible cavities seem destinedto receive only the most delicate sounds. "

_ _| 1. THE TOUCH. . . | 1. Description of the Organ. | |_2. Its Uses. | _| 2. THE TASTE. . . | 1. Description of the Organ. | |_2. Its Uses. | _| 3. THE SMELL. . . | 1. Description of the Organ. | |_2. Its Uses. | _ _| | 1. Description of the | a. _External Ear. _| | Organ. . . . . . . . . . . . . . . | b. _Middle Ear. _| 4. THE HEARING. | |_c. _Internal Ear. _| | 2. How we Hear| |_3. Hygiene of the Ear. | _| | 1. Description of the Organ. | | 2. Eyelids, and Tears. | | 3. Structure of the Retina. |_5. THE SIGHT. . . | 4. How we see. | 5. The Use of the Crystalline Lens. | 6. Near and Far Sight. | 7. Color Blindness. |_8. Hygiene of the Eyes. 

THE SPECIAL SENSES

1. TOUCH. 

DESCRIPTION. --Touch is sometimes called the "common sense, " since itsnerves are spread over the whole body. It is most delicate, however, inthe point of the tongue and the tips of the fingers. The surface of thecutis is covered with minute, conical projections called _papillæ_(Fig. 24). [Footnote: In the palm of the hand, where there are at leasttwelve thousand in a square inch, we can see the fine ridges along whichthey are arranged. ] Each one of these papillæ contains its tiny nervetwigs, which receive the impression and transmit it to the brain, wherethe perception is produced. 

USES. --Touch is the first of the senses used by a child. By it we obtainour idea of solidity, and throughout life rectify all other sensations. Thus, when we see anything curious, our first desire is to handle it. 

The sensation of touch is generally relied upon, yet, if we hold a marblein the manner shown in Fig. 57, it will seem like two marbles; and if wetouch the fingers thus crossed to our tongue, we shall seem to feel twotongues. Again, if we close our eyes and let another person move one ofour fingers over a plane surface, first lightly, then with greaterpressure, and then lightly again, we shall think the surface concave. 

FIG. 57. 

[Illustration:]

This organ is capable of wonderful cultivation. The physician acquires bypractice the _tactus eruditus_, or learned touch, which is often ofgreat service, while the delicacy of touch possessed by the blind almostcompensates the loss of the absent sense. [Footnote: The sympathy betweenthe different organs shows how they all combine to make a home for themind. When one sense fails, the others endeavor to remedy the defect. Itis touching to see how the blind man gets along without eyes, and the deafwithout ears. Cuthbert, though blind, was the most efficient polisher oftelescopic mirrors in London. Saunderson, the successor of Newton asprofessor of mathematics at Cambridge, could distinguish between real andspurious medals. There is an instance recorded of a blind man who couldrecognize colors. The author knew one who could tell when he wasapproaching a tree, by what he described as the "different feeling of theair. "] (See p. 346. )

2. TASTE. 

DESCRIPTION. --This sense is located in the papillæ of the tongue andpalate. These papillaæ start up when tasting, as you can see by placing adrop of vinegar on another person's tongue, or your own before a mirror. The velvety look of this organ is given by hair-like projections of thecuticle upon some of the papillæ. They absorb the liquid to be tasted, andconvey it to the nerves. [Footnote: An insoluble substance is thereforetasteless. ] The back of the tongue is most sensitive to salt and bittersubstances, and, as this part is supplied by the ninth pair of nerves(Fig. 56), in sympathy with the stomach, such flavors, by sympathy, oftenproduce vomiting. The edges of the tongue are most sensitive to sweet andsour substances, and as this part is supplied by the fifth pair of nerves, which also goes to the face, an acid, by sympathy, distorts thecountenance. 

FIG. 58. 

[Illustration: _The Tongue, showing the several kinds of Papillæ--theconical_ (D) _the whip like_ (K, I), _the circumvallate or entrenched_(H, L); E, F, G, _nerves;_ C, _glottis. _--LANKESTER. ]

THE USE OF THE TASTE was originally to guide in the selection of food;but this sense has become so depraved by condiments and the force of habitthat it would be a difficult task to tell what are one's natural tastes. 

3. SMELL. [Footnote: The sense of smell is so intimately connected withthat of taste that we often fail to distinguish between them. Garlic, vanilla, coffee and various spices, which seem to have such distincttaste, have really a powerful odor, but a feeble flavor. ]

DESCRIPTION. --The nose, the seat of the sense of smell, is composed ofcartilage covered with muscles and skin, and joined to the skull by smallbones. The nostrils open at the back into the pharynx, and are lined by acontinuation of the mucous membrane of the throat. The olfactory nerves(first pair, Fig. 55) enter through a sieve-like, bony plate at the roofof the nose, and are distributed over the inner surface of the twoolfactory chambers. (See p. 346. ) The object to be smelled need not touchthe nose, but tiny particles borne on the air enter the nasal passages. [Footnote: Three quarters of a grain of musk placed in a room will cause apowerful smell for a considerable length of time without any sensiblediminution in weight, and the box in which musk has been placed retainsthe perfume for almost an indefinite period. Haller relates that somepapers which had been perfumed by a grain of ambergris, were still veryodoriferous after a lapse of forty years. Odors are transported by the airto a considerable distance. A dog recognizes his master's approach bysmell even when he is far away; and we are assured by navigators that thewinds bring the delicious odors of the balmy forests of Ceylon to adistance of ten leagues from the coast. Even after making due allowancefor the effects of the imagination, it is certain that odors act as anexcitant on the brain, which may be dangerous when long continued. Theyare especially dreaded by the Roman women. It is well known that inancient times the women of Rome indulged in a most immoderate use of bathsand perfumes; but those of our times have nothing in common with them inthis respect; and the words of a lady are quoted, who said on admiring anartificial rose, "It is all the more beautiful that it has no smell. " Weare warned by the proverb not to discuss colors or tastes, and we may addodors also. Men and nations differ singularly in this respect. TheLaplander and the Esquimaux find the smell of fish oil delicious. Wrangelsays his compatriots, the Russians, are very fond of the odor of pickledcabbage, which forms an important part of their food; and asafœtida, it issaid, is used as a condiment in Persia, and, in spite of its name, thereare persons who do not find its odor disagreeable any more than that ofvalerian. --_Wonders of the Human body_. ]

FIG. 59. 

[Illustration: A, b, c, d, _interior of the nose, which is lined by amucous membrane;_ n, _the nose;_ e, _the wing of the nose;_q, _the nose bones;_ o, _the upper lip;_ g, _section of theupper jaw-bone;_ h, _the upper part of the mouth, or hard palate;_m, _frontal bone of the skull;_ k, _the ganglion or bulb of theolfactory nerve in the skull, from which are seen the branches of thenerve passing in all directions. _]

THE USES of the sense of smell are to guide us in the choice of our food, and to warn us against bad air, and unhealthy localities. (See p. 348. )

4. HEARING. 

DESCRIPTION. --The ear is divided into the _external_, _middle_, and _internal_ ear. 

1. _The External Ear_ is a sheet of cartilage curiously folded forcatching sound. The auditory canal, _B_, or tube of this ear trumpet, is about an inch long. Across the lower end is stretched _the membraneof the tympanum_ or drum, which is kept soft by a fluid wax. 

FIG. 60. 

[Illustration: _The Ear. _]

2. _The Middle Ear_ is a cavity, at the bottom of which is theEustachian tube, _G_, leading to the mouth. Across this chamber hangsa chain of three singular little bones, _C_, named from their shapethe _hammer_, the _anvil_, and the _stirrup_. All togetherthese tiny bones weigh only a few grains, yet they are covered by aperiosteum, are supplied with blood vessels, and they articulate withperfect joints (one a ball-and-socket, the other a hinge), having synovialmembranes, cartilages, ligaments, and muscles. 

3. _The Internal Ear_, or labyrinth, as it is sometimes called fromits complex character, is hollowed out of the solid bone. In front, is thevestibule or antechamber, _A_, about as large as a grain of wheat;from it open three _semicircular canals_, _D_, and the windingstair of the _cochlea_, or snail shell, _E_. Here expand thedelicate fibrils of the auditory nerve. Floating in the liquid which fillsthe labyrinth is a little bag containing hair-like bristles, fine sand, and two ear stones (_otoliths_). All these knocking against the endsof the nerves, serve to increase any impulse given to the liquid in whichthey lie. Finally, to complete this delicate apparatus, in the cochlea areminute tendrils, named the fibers of Corti, from their discoverer. Theseare regularly arranged, --the longest at the bottom, and the shortest atthe top. Could this spiral plate, which coils two and a half times around, be unrolled and made to stand upright, it would form a beautifulmicroscopic harp of three thousand strings. If it were possible to strikethese cords as one can the keyboard of a piano, he could produce in themind of the person experimented upon every variety of tone which the earcan distinguish. 

HOW WE HEAR. --Whenever one body strikes another in the air, waves areproduced, just as when we throw a stone into the water a series ofconcentric circles surrounds the spot where it sinks. These waves of airstrike upon the membrane. This vibrates, and sends the motion along thechain of bones in the middle ear to the fluids of the labyrinth. Herebristles, sand, and stones pound away, and the wondrous harp of thecochlea, catching up the pulsations, [Footnote: The original motion isconstantly modified by the medium through which it passes. The bristles, otoliths, and Cortian fibers of the ear, and the rods and cones of the eye(p. 239) serve to convert the vibrations into pulsations which act asstimuli of the appropriate nerve. The molecular change thus produced inthe nerve fibers is propagated to the brain. --See _PopluarPhysics_, p. 182. ] carries them to the fibers of the auditory nerve, which conveys them to the brain, and gives to the mind the idea of sound. 

CARE OF THE EAR. --The delicacy of the ear is such that it needs thegreatest care. Cold water should not be allowed to enter the auditorycanal. If the wax accumulate, never remove it with a hard instrument, lestthe delicate membrane be injured, but with a little warm water, afterwhich turn the head to let the water run out, and wipe the ear dry. Thehair around the ears should never be left wet, as it may chill thissensitive organ. If an insect get in the external ear, pour in a littleoil to kill it, and then remove with tepid water. The object of theEustachian tube is to admit air into the ear, and thus equalize thepressure on the membrane. If it become closed by a cold, or if, from anycause, the pressure be made unequal, so as to produce an unpleasantfeeling in the ear, relief may often be obtained by grasping the nose andforcibly swallowing. (See p. 350. )

5. SIGHT. 

FIG. 61. 

[Illustration: _The Eye. _]

DESCRIPTION. --The eye is lodged in a bony cavity, protected by theoverhanging brow. It is a globe, about an inch in diameter. The ball iscovered by three coats--(l) the _sclerotic_, _d_, a tough, hornycasing, which gives shape to the eye, the convex, transparent part infront forming a window, the _cornea_, _d_; (2) the _choroid_, _e_, ablack lining, to absorb the superfluous light [Footnote: Neither whiterabbits nor albinos have this black lining, and hence their sight isconfused. ] and (3) the _retina_, _b_, a membrane in which expand fibersof the _optic nerve_, _o_. The _crystalline lens_, _a_, brings the raysof light to a focus on the retina. The lens is kept in place by theciliary processes, _g_, arranged like the rays in the disk of a passionflower. Between the cornea and the crystalline lens is a limpid fluidtermed the _aqueous humor_; while the _vitreous humor_--a transparent, jelly-like liquid fills the space (_h_) back of the crystalline lens. The pupil, _k_, is a hole in the colored, muscular curtain, _i_, the_iris_ (rainbow). (See p. 352. )

FIG. 62. 

[Illustration: _The Eyelashes and the Tear Glands. _]

EYELIDS AND TEARS. --The eyelids are close-fitting shutters to screen theeye. The inner side is lined with a mucous membrane that is exceedinglysensitive, and thus aids in protecting the eye from any irritatingsubstance. The looseness of the skin favors swelling from inflammation orthe effusion of blood, as in a "black eye. " The eyelashes serve as a kindof sieve to exclude the dust, and, with the lids, to shield against ablinding light. Just within the lashes are oil glands, which lubricate theedges of the lids, and prevent them from adhering to each other. The tearor _lachrymal_ gland, _G_, is an oblong body lodged in the bonywall of the orbit. It empties by several ducts upon the inner surface, atthe outer edge of the upper eyelid. Thence the tears, washing the eye, runinto the _lachrymal lake_, _D_, a little basin with a roundedborder fitted for their reception. On each side of this lake two canals, _C_, _C_, drain off the overplus through the duct, _B_, into the nose. In old age and in disease, these canals fail to conduct thetears away, and hence the lachrymal lake overflows upon the face. 

FIG. 63. 

[Illustration: _Structure of the Retina. _]

STRUCTURE OF THE RETINA. --In Fig. 63 is shown a section of the retina, greatly magnified, since this membrane never exceeds 1/80 an inch inthickness. On the inner surface next to the vitreous humor, is a liningmembrane not shown in the cut. Next to the choroid and comprising about1/4 the entire thickness of the retina, is a multitude of transparent, colorless, microscopic rods, _a_, evenly arranged and packed side byside, like the seeds on the disk of a sunflower. Among them, at regularintervals, are interspersed the cones, _b_. Delicate nerve fiberspass from the ends of the rods and cones, each expanding into a granularbody, _c_, thence weaving a mesh, _d_, and again expanding intothe granules, _f_. Last is a layer of fine nerve fibers, _g_, and gray, ganglionic cells, _h_, like the gray matter of the brain, whence filaments extend into _i_, the fibers of the optic nerve. (Seep. 354. )

The layer of rods and cones is to the eye what the bristles, otoliths, andCortian fibers are to the ear. Indeed, the nerve itself is insensible tolight. At the point where it enters the eye, there are no rods and cones, and this is called the _blind spot_. A simple experiment willillustrate the fact. Hold this book directly before the face, and, closingthe left eye, look steadily with the right at the left-hand circle in Fig. 64. Move the book back and forth, and a point will be found where theright-hand circle vanishes from sight. At that moment its light falls uponthe spot where the rods and cones are lacking. 

FIG. 64. 

[Illustration:]

HOW WE SEE. --There is believed to be a kind of universal atmosphere, termed _ether_, filling all space. This substance is infinitely moresubtle than the air, and occupies its pores, as well as those of all othersubstances. As sound is caused by waves in the atmosphere, so light isproduced by waves in the ether. A lamplight, for example, sets in motionwaves of ether, which pass in through the pupil of the eye, to the retina, where the rods and cones transmit the vibration through the optic nerve tothe brain, and then the mind perceives the light. (Note, p. 236. )

THE USE OF THE CRYSTALLINE LENS. [Footnote: The uses of the eye and earare dependent upon the principles of Optics and Acoustics. They aretherefore best treated in Physics. ]--A convex lens, as a common burningglass, bends the rays of light which pass through it, so that they meet ata point called the _focus_. The crystalline lens converges the raysof light which enter the eye, and brings them to a focus on the retina. [Footnote: The cornea and the humors of the eye act in the same manner asthe crystalline lens, but not so powerfully. ] The healthy lens has a powerof changing its convexity so as to adapt [Footnote: The simplest way ofexperimenting on the "adjustment of the eye" is to stick two stout needlesupright into a straight piece of wood, --not exactly, but nearly in thesame straight line, so that, on applying the eye to one end of the pieceof wood, one needle (A) shall be seen about six inches off, and the other(B) just on one side of it, at twelve inches distance. If the observerlooks at the needle B he will find that he sees it very distinctly, andwithout the least sense of effort; but the image of A is blurred, and moreor less double. Now, let him try to make this blurred image of the needleA distinct. He will find he can do so readily enough, but that the act isaccompanied by a sense of fatigue. And in proportion as A becomesdistinct, B will become blurred. Nor will any effort enable him to see Aand B distinctly at the same time. --HUXLEY. ] itself to near and to distantobjects. (See Fig. 66. )

FIG. 65. 

[Illustration: _Diagram showing how an image of an object is formed uponthe Retina by the Crystalline Lens. _]

NEAR AND FAR SIGHT. --If the lens be too convex, it will bring the rays toa focus before they reach the retina; if too flat, they will reach theretina before coming to a focus. In either case, the sight will beindistinct. A more common defect, however, is in the shape of the globe ofthe eye, which is either flattened or elongated. In the former case (see_G_, Fig. 67), objects at a distance can be seen most distinctly--hence that is called farsightedness. [Footnote: This should not beconfounded with the long sight of old people, which is caused by thestiffness of the ciliary muscles, whereby the lens can not adapt itself tothe varying distances of objects. ] In the latter, objects near by areclearer, and hence this is termed nearsightedness. Farsightedness isremedied by convex glasses; nearsightedness, by concave. When glasses willimprove the sight they should be worn; [Footnote: Dr. Henry W. Williams, the celebrated ophthalmologist, says that, in some cases, glasses are morenecessary at six or eight years of age than to the majority of healthyeyes at sixty. Sometimes children find accidentally that they can seebetter through grandmother's spectacles. They should then be supplied withtheir own. ] any delay will be liable to injure the eyes, by strainingtheir already impaired power. Cataract is a disease in which there is anopacity of the crystalline lens or its capsules, which obscures thevision. The lens may be caused to be absorbed, or may be removed by askillful surgeon and the defect remedied by wearing convex glasses. 

FIG. 66. 

[Illustration: _Adjustment of the Crystalline Lens. _--A, _for farobjects, and_ B, _for near. _]

FIG. 67. 

[Illustration: _Diagram illustrating the position of the Retina. _--B, _in natural sight;_ G, _in far sight; and_ C, _in near sight. _]

COLOR-BLIND PERSONS receive only two of the three elementary colorsensations (green, red, violet). The spectrum appears to them to consistof two decidedly different colors, with a band of neutral tint between. The extreme red end is invisible, and a bright scarlet and a deep greenappear alike. They are unable to distinguish between the leaves of acherry tree and its fruit by the color of the two, and see no differencebetween blue and yellow cloth. Whittier, the poet, it is said, could nottell red from green unless in direct sunlight. Once he patched somedamaged wall paper in his library by matching a green vine in the patternwith one of a bright autumnal crimson. This defect in the eye is oftenunnoticed, and many railway accidents have doubtless happened through aninability to detect the color of signal lights. 

CARE OF THE EYES. --The shape of the eye can not be changed by rubbing andpressing it, as many suppose, but the sight may thus be fatally injured. Children troubled by nearsightedness should not lean forward at theirwork, as thereby the vessels of the eye become overcharged with blood. They should avoid fine print, and try, in every possible way, to sparetheir eyes. If middle age be reached without especial difficulty of sight, the person is comparatively safe. Most cases of squinting are caused bylongsightedness, the muscles being strained in the effort to obtaindistinct vision. In childhood, it may be cured by a competent surgeon, whowill generally cut the muscle that draws the eye out of place. 

After any severe illness, especially after measles, scarlatina, or typhoidfever, the eyes should be used with extreme caution, since they share inthe general debility of the body, and recover their strength slowly. Healthy eyes even should never be used to read fine print or by a dimlight. Serious injury may be caused by an imprudence of this kind. Readingupon the cars is also a fruitful source of harm. The lens, striving toadapt itself to the incessantly varying distance of the page, soon becomeswearied. Whenever the eyes begin to ache, it is a warning that they arebeing overtaxed and need rest. 

Objects that get into the eye should be removed before they causeinflammation; rubbing in the meantime only irritates and increases thesensitiveness. If the eye be shut for a few moments, so as to let thetears accumulate, and the upper lid be then lifted by taking hold of it atthe center, the cinder or dust is often washed away at once. Triflingobjects can be removed by simply drawing the upper lid as far as possibleover the lower one; when the lid flies back to its place, the frictionwill detach any light substance. If it becomes necessary, turn the upperlid over a pencil, and the intruder may then be wiped off with ahandkerchief. "Eye-stones" are a popular delusion. When they seem to takeout a cinder, it is only because they raise the eyelid, and allow thetears to wash it out. No one should ever use an eyewash, except by medicaladvice. The eye is too delicate an organ to be trifled with, and when anydisease is suspected, a reliable physician should be consulted. This isespecially necessary, since, when one eye is injured, the other, bysympathy, is liable to become inflamed, and perhaps be destroyed. 

When reading or working, the _light should be at the left side, or atthe rear; never in front_. 

The constant increase of defective eyesight among the pupils in ourschools is an alarming fact. Dr. Agnew considers that our schoolrooms arefast making us a spectacle-using people. Nearsightedness seems to increasefrom class to class, until in the upper departments, there are sometimesas high as fifty per cent of the pupils thus afflicted. The causes are(1), desks so placed as to make the light from the windows shine directlyinto the eyes of the scholars; (2), cross lights from opposite windows;(3), insufficient light; (4), small type that strains the eyes; and (5), the position of the pupil as he bends over his desk or slate, causing theblood to settle in his eyes. All these causes can be remedied; theposition of the desks can be changed; windows can be shaded, or new onesinserted; books and newspapers that try the eyes can be rejected; andevery pupil can be taught how to sit at study. 

PRACTICAL QUESTIONS. 

1. Why does a laundress test the temperature of her flatiron by holding itnear her cheek?

2. When we are cold, why do we spread the palms of our hands before thefire?

3. What is meant by a "furred tongue"?

4. Why has sand or sulphur no taste?

5. What was the origin of the word palatable?

6. Why does a cold in the head injure the flavor of our coffee?

7. Name some so-called flavors that are really sensations of touch. 

8. What is the object of the hairs in the nostrils?

9. What use does the nose subserve in the process of respiration?

10. Why do we sometimes hold the nose when we take unpleasant medicine?

11. Why was the nose placed over the mouth?

12. Describe how the hand is adapted to be the instrument of touch. 

13. Besides being the organ of taste, what use does the tongue subserve?

14. Why is not the act of tasting complete until we swallow?

15. Why do all things have the same flavor when one's tongue is "furred"by fever?

16. Which sense is the more useful--hearing or sight?

17. Which coat is the white of the eye?

18. What makes the difference in the color of eyes?

19. Why do we snuff the air when we wish to obtain a distinct smell?

20. Why do red-hot iron and frozen mercury (-40°) produce the samesensation?

21. Why can an elderly person drink tea which to a child would beunbearably hot?

22. Why does an old man hold his paper so far from his eyes?

23. Would you rather be punished on the tips of your fingers than on thepalm of your hand?

24. What is the object of the eyelashes? Are the hairs straight?

25. What is the use of winking?

26. When you wink, do the eyelids touch at once along their whole length?Why?

27. How many rows of hairs are there in the eyelashes?

28. Do all nations have eyes of the same shape?

29. Why does snuff taking cause a flow of tears?

30. Why does a fall cause one to "see stars"?

31. Why can we not see with the nose, or smell with the eyes?

32. What causes the roughness of a cat's tongue?

33. Is the cuticle essential to touch?

34. Can one tickle himself?

35. Why does a bitter taste often produce vomiting?

36. Is there any danger in looking "crosseyed" for fun?

37. Should schoolroom desks face a window?

38. Why do we look at a person to whom we are listening attentively?

39. Do we really feel with our fingers?

40. Is the eye a perfect sphere? (See Fig. 61. )

41. How often do we wink?

42. Why is the interior of a telescope or microscope often painted black?

43. What is "the apple of the eye"?

44. What form of glasses do old people require?

45. Should we ever wash our ears with cold water?

46. What is the object of the winding passages in the nose?

47. Can a smoker tell in the dark, whether or not his cigar is lighted?

48. Will a nerve reunite after it has been cut?

49. Will the sight give us an idea of solidity? [Footnote: A case occurreda few years ago, in London, where a friend of my own performed anoperation upon a young woman who had been born blind, and, though anattempt had been made in early years to cure her, it had failed. She wasable just to distinguish large objects, the general shadow, as it were, without any distinct perception of form, and to distinguish light fromdarkness. She could work well with her needle by the touch, and could useher scissors and bodkin and other implements by the training of her hand, so to speak, alone Well, my friend happened to see her, and he examinedher eyes, and told her that he thought he could get her sight restored; atany rate, it was worth a trial. The operation succeeded; and, being a manof intelligence and quite aware of the interest of such a case, hecarefully studied and observed it; and he completely confirmed all thathad been previously laid down by the experience of similar cases. Therewas one little incident which will give you an idea of the education whichis required for what you would suppose is a thing perfectly simple andobvious. She could not distinguish by sight the things that she wasperfectly familiar with by the touch, at least when they were firstpresented to her eyes. She could not recognize even a pair of scissors. Now, you would have supposed that a pair of scissors, of all things in theworld, having been continually used by her, and their form having becomeperfectly familiar to her hands, would have been most readily recognizedby her sight; and yet she did not know what they were; she had not an ideauntil she was told, and then she laughed, as she said, at her ownstupidity. No stupidity at all; she had never learned it, and it was oneof those things which she could not know without learning. One of theearliest cases of this kind was related by the celebrated Cheselden, asurgeon of the early part of last century. Cheselden relates how a youthjust in this condition had been accustomed to play with a cat and a dog;but for some time after he attained his sight he never could tell whichwas which, and used to be continually making mistakes. One day, beingrather ashamed of himself for having called the cat the dog, he took upthe cat in his arms and looked at her very attentively for some timestroking her all the while; and in this way he associated the impressionderived from the touch, and made himself master (so to speak) of the wholeidea of the animal. He then put the cat down, saying: "Now, puss, I shallknow you another time. "--CARPENTER. ]

50. Why can a skillful surgeon determinate the condition of the brain andother internal organs by examining the interior of the eye? [Footnote:This is done by means of an instrument called the ophthalmoscope. Light isthrown into the eye with a concave mirror, and the interior of the organexamined with a lens. ]

51. Is there any truth in the idea that the image of the murderer can beseen in the eye of the dead victim?

52. What is the length of the optic nerve? _Ans_. About three fourthsof an inch. 

53. Why does an injury to one eye generally affect the other eye?_Ans_. The optic nerves give off no branches in passing from theirorigin in two ganglia situated between the cerebrum and the cerebellum, and their termination in the eyeballs; but, in the middle of their course, they _decussate_, or unite in one mass. The fibers of the two nerveshere pass from side to side, and intermingle. The two ganglia are alsounited directly by fibers. Thus the eyes are not really separate organs ofsight, but a kind of double organ to perform, a single function. 

IX. 

HEALTH AND DISEASE. --DEATH AND DECAY. 

"Health is the vital principle of bliss. "

THOMSON. 

"There are three wicks to the lamp of a man's life: brain, blood, andbreath. Press the brain a little, its light goes out, followed by both theothers. Stop the heart a minute, and out go all three of the wicks. Chokethe air out of the lungs, and presently the fluid ceases to supply theother centers of flame, and all is soon stagnation, cold, and darkness. "

O. W. HOLMES. 

"Calmly he looked on either Life, and hereSaw nothing to regret, or there to fear;From Nature's temp'rate feast rose satisfy'd, Thank'd Heaven that he had lived, and that he died. "

POPE. 

HEALTH AND DISEASE. --DEATH AND DECAY. 

VALUE OF HEALTH. --The body is the instrument which the mind uses. If it bedulled or nicked, the effect of the best labor will be impaired. Thegrandest gifts of mind or fortune are comparatively valueless unless therebe a healthy body to use and enjoy them. The beggar, sturdy and brave withhis outdoor life, is really happier than the rich man in his palace withthe gout to twinge him amid his pleasures. The day has gone by whendelicacy is considered an element of beauty. Weakness is timid andirresolute; strength is full of force and energy. Weakness walks orcreeps; strength speeds the race, wins the goal, and rejoices in thevictory. 

FALSE IDEAS OF DISEASE. --It was formerly supposed that diseases werecaused by evil spirits, who entered the body, and deranged its action. Incantations, spells, etc. , were resorted to in order to drive them out. By others, disease was thought to come arbitrarily, or as a specialvisitation of an overruling power. Hence, it was to be removed by fastingand prayer. Modern science teaches us that disease is not a thing, but astate. When our food is properly assimilated, the waste matter promptlyexcreted, and all the organs work in harmony, we are well; when anyderangement of these functions occurs, we are sick. Sickness is discord, as health is concord. If we abuse or misuse any instrument, we impair itsability to produce a perfect harmony. A suffering body is simply thepenalty of violated law. 

PREVENTION OF DISEASE. --Doubtless a large proportion of the ills which nowafflict and rob us of so much time and pleasure might easily be avoided. Aproper knowledge and observance of hygienic laws would greatly lessen thenumber of such diseases as consumption, catarrh, gout, rheumatism, dyspepsia, etc. There are parts of England where one half the children diebefore they are five years old. Every physiologist knows that at leastnine tenths of these lives could be saved by an observance of the simplelaws of health. Professor Bennet, in a lecture at Edinburgh, estimatedthat one hundred thousand persons die annually in Great Britain fromcauses easily preventable. 

With the advance of science, the causes of many diseases have beendetermined. Vaccination has been found to prevent or mitigate the ravagesof smallpox. Scurvy, formerly so fatal among sailors that it was deemed "amysterious infliction of Divine Justice against which man strives invain, " is now entirely avoided by the use of vegetables or lime juice. Cholera, whose approach still strikes dread, and for which there is noknown specific, is but the penalty for filthy streets, bad drainage, andovercrowded tenements, and may be controlled, if not prevented, bysuitable sanitary measures. It was, no doubt, the intention that we shouldwear out by the general decay of all the organs, [Footnote: So long as thephenomena of waste and repair are in harmony--so long, in other words, asthe builder follows the scavenger--so long man exists in integrity andrepair--just, indeed, as houses exist. Derange nutrition, and at oncedegeneration, or rather let us say, alteration begins. Alas! that we areso ignorant that there are many things about our house, which, seeingthem, weaken, we know not how to strengthen. About the brick and themortar, the frame and the rafters, we are not unlearned; but within aremany complexities, many chinks and crannies, full in themselves ofsecondary chinks and crannies, and these so small, so deep, so recessed, that it happens every day that the destroyer settles himself in some placeso obscure, that, while he kills, he laughs at defiance. You or I meetwith an accident in our watch. We consult the watchmaker, and he repairsthe injury. If we were all that watchmakers, like ourselves, should be, aman could be made to keep time until he died from old age or annihilatingaccident. This I firmly and fully believe. --_Odd Hours of aPhysician_. ] rather than by the giving out of any single part, and thatall should work together harmoniously until the vital force is exhausted. 

CURE OF DISEASE. --The first step in the cure of any disease is to obey thelaw of health which has been violated. If medicine be taken, it is not todestroy the disease, since that is not a thing to be destroyed, but tohold the deranged action in check while nature repairs the injury, andagain brings the system into harmonious movement. This tendency of natureis our chief reliance. The best physicians are coming to have diminishedconfidence in medicine itself, and to place greater dependence uponsanitary and hygienic measures, and upon the efforts which nature alwaysmakes to repair injuries and soothe disordered action. They endeavor onlyto give to nature a fair chance, and sometimes to assist her by theintelligent employment of proper medicines. The indiscriminate use ofpatent nostrums and sovereign remedies of whose constituents we knownothing, and by which powerful drugs are imbibed at haphazard, can not betoo greatly deprecated. When one needs medicine, he needs also a competentphysician to advise its use. 

DEATH AND DECAY. --By a mystery we can not understand, life is linked withdeath, and out of the decay of our bodies they, day by day, spring afresh. At last the vital force which has held death and decay in bondage, andcompelled them to minister to our growth, and to serve the needs of ourlife, faints and yields the struggle. These powers which have so long timebeen our servants, gather about our dying couch, and their last officesusher us into the new life and the grander possibilities of the world tocome. This last birth, we who see the fading, not the dawning, life, calldeath. 

"O Father! grant Thy love divine, To make these mystic temples Thine, When wasting age and wearying strifeHave sapp'd the leaning walls of life;When darkness gathers over all, And the last tottering pillars fall, Take the poor dust Thy mercy warms, And mold it into heavenly forms. "

HOLMES. 

HINTS ABOUT THE SICK ROOM

A SICK ROOM should be the lightest and cheeriest in the house. A small, close, dark bedroom or a recess is bad enough for one in health, butunendurable for a sick person. In a case of fever, and in many acutediseases, it should be remote from the noise of the family; but when oneis recovering from an accident, and in all attacks where quiet is notneeded, the patient may be where he can amuse himself by watching themovements of the household, or looking out upon the street. 

_The ventilation must be thorough. _ Bad air will poison both the sickand the well. A fireplace is, therefore, desirable. Windows should openeasily. By carefully protecting the patient with extra blankets, the roommay be frequently aired. If there be no direct draught, much may be doneto change the air, by simply swinging an outer door to and fro many times. 

A bare floor, with strips of carpet here and there to deaden noise, iscleanest, and keeps the air freest from dust. Cane-bottomed chairs arepreferable to upholstered ones. All unnecessary furniture should beremoved out of the way. A straw bed or a mattress is better than feathers. The bed hangings, lace curtains, etc. , should be taken down. Creakinghinges should be oiled. Sperm candles are better than kerosene lamps. 

_Never whisper in a sick room. _ All necessary conversation should becarried on in the usual tone of voice. Do not call a physicianunnecessarily, but if one be employed, _obey his directionsimplicitly_. Never give nostrums overofficious friends may suggest. Donot allow visitors to see the patient, except it be necessary. Neverbustle about the room, nor go on tiptoe, but move in a quiet, ordinaryway. Do not keep the bottles in the continued sight of the sick person. Never let drinking water stand in the room. 

Do not raise the patient's head to drink, but have a cup with a longspout, or use a bent tube, or even a straw. Do not tempt the appetite whenit craves no food. Bathe frequently, but let the physician prescribe themethod. Give written directions to the watchers. Have all medicinescarefully marked. Remove all soiled clothing, etc. , at once from the room. Change the linen much oftener than in health. When you wish to change thesheets, and the patient is unable to rise, roll the under sheet tightlylengthwise to the middle of the bed; put on the clean sheet, with half itswidth folded up, closely to the other roll; lift the patient on to thenewly-made part, remove the soiled sheet, and then spread oat the cleanone. 

DISINFECTANTS. 

Remember, first, that deodorizers and disinfectants are not the same. Abad smell, for instance, may be smothered by some more powerful odor, while its cause remains uninfluenced. Bear also in mind the fact that nodeodorizer and no disinfectant can take the place of perfect cleanlinessand thorough ventilation. No purifyer can rival the oxygen contained instrong and continued currents of fresh, cold air, and every disinfectantfinds an indispensable ally in floods of scalding water. 

An excellent disinfectant may be made by dissolving in a pail of watereither of the following: (1), a quarter of a pound of sulphate of zinc andtwo ounces of common salt for each gallon of water; (2), a pound and ahalf of copperas, for each gallon of water. Towels, bed linen, handkerchiefs, etc. , should be soaked at least an hour, in a solution ofthe first kind, and then be boiled, before washing. [Footnote: It is_best_ to burn all articles which have been in contact with personssick with contagious or infectious diseases. 

In using the zinc solution, place the articles in it as soon as they areremoved from the patient, and before they are taken from the room; ifpracticable, have the solution boiling hot at the time. In fumigatingapartments, all the openings should be made as nearly air-tight aspossible. The articles to be included in the fumigation should be soexposed and spread out that the sulphurous vapor may penetrate everyportion of them. For a room about ten feet square, at least two pounds ofsulphur should be used; for larger rooms, proportionally increasedquantities. Put the sulphur in iron pans supported upon bricks placed inwashtubs containing a little water, set it on fire by hot coals or withthe aid of a spoonful of alcohol, or by a long fuse set on train as thelast opening to the room is closed. Allow the apartment to remain sealedfor twenty-four hours. Great care should be taken not to inhale thepoisonous fumes in firing the sulphur. After the fumigation, allow freecurrents of air to pass through the apartment; expose all movable articlesfor as long time as may be to the sun and the wind out of doors; beat andshake the carpets, hangings, pillows, etc. 

The disinfectants and the instructions for using them, as given above, aremainly those recommended by the National Board of Health. ] Vaults, drains, vessels used in the sick room, etc. , should be disinfected by a solutionof the second kind; chloride of lime may also be used for the samepurpose. Rooms, furniture, and articles that can not be treated with thesolution of the first kind, should be thoroughly fumigated with burningsulphur. Where walls are unpapered, re-whitewash with pure, freshlyslacked quicklime, adding one pint of the best fluid carbolic acid toevery gallon of the fluid whitewash. Powdered stone lime sprinkled onfoul, wet places, or placed in pans in damp rooms, will absorb themoisture; and dry, fresh charcoal powder may be combined with it to absorbnoxious gases. 

WHAT TO DO TILL THE DOCTOR COMES. 

The following instructions are intended simply to aid in an emergency. When accidents or a sudden severe illness occur, there is necessarily, inmost cases, a longer or shorter interval before a physician can arrive. These moments are often very precious, and life may depend upon a littleknowledge and much self-possession. The instructions are therefore givenas briefly as possible, that they may be easily carried in the memory. Afew suggestions in regard to common ailments are included. 

BURNS. --When a person's clothes catch fire, quickly lay him on the ground, wrap him in a coat, mat, shawl, carpet, or in his own garments, as bestyou can to extinguish the flame. Pour on plenty of water till the half-burned clothing is cooled. Then carry the sufferer to a warm room, lay himon a table or a carpeted floor, and with a sharp knife or scissors removehis clothing. 

The treatment of a burn consists in protecting from the air. [Footnote: Itis a great mistake to suppose that salves will "draw out the fire" of aburn, or heal a bruise or cut. The vital force must unite the dividedtissue by the deposit of material and the formation of new cells. ] Anexcellent remedy is to apply soft cloths kept wet with sweet oil, or withtepid water _which contains all the "cooking soda" that it willdissolve_. Afterward dress the wound with carbolic acid salve. Wrap adry bandage upon the outside. Then remove the patient to a bed and coverwarmly. [Footnote: In case of a large burn, lose no delay in bringing aphysician. If a burn be near a joint or on the face, even if small, let adoctor see it, and do not be in any hurry about having it healed. Rememberthat with all the care and skill which can be used, contractions willsometimes take place. The danger to life from a burn or scald is not inproportion to its severity, but to its extent--that is, a small part, suchas a hand or a foot, may be burned so deeply as to cripple it for life, and yet not much endanger the general health; but a slight amount ofburning, a mere scorching, over two thirds of the body, may prove fatal. --HOPE. ] Apply cool water to a small burn till the smart ceases, and thencover with ointment. Do not remove the dressings until they become stiffand irritating; then take them from a part at a time; dress and coveragain quickly. 

CUTS, WOUNDS, ETC. --The method of stopping the bleeding has been describedon page 128. If an artery is severed, a physician should be called atonce. If the bleeding is not profuse, apply cold water until it ceases, dry the skin, draw the edges of the wound together, and secure them bystrips of adhesive plaster. Protect with an outer bandage. This dressingshould remain for several days. In the meantime wet it frequently withcool water to subdue inflammation. When suppuration begins, washoccasionally with tepid water and Castile soap. 

Dr. Woodbridge, of New York, in a recent address, gave the followingdirections as to "What to do in case of a sudden wound when the surgeon isnot at hand. " "An experienced person would naturally close the lips of thewound as quickly as possible, and apply a bandage. If the wound isbleeding freely, but no artery is spouting blood, the first thing to bedone is to wash it with water at an ordinary temperature. To every pint ofwater add either five grains of corrosive sublimate, or two and a halfteaspoonfuls of carbolic acid. If the acid is used, add two tablespoonfulsof glycerine, to prevent its irritating the wound. If there is neither ofthese articles in the house, add four tablespoonfuls of borax to thewater. Wash the wound, close it, and apply a compress of a folded squareof cotton or linen. Wet it in the solution used for washing the wound andbandage quickly and firmly. If the bleeding is profuse, a sponge dipped invery hot water and wrung out in a dry cloth should be applied as quicklyas possible. If this is not available, use ice, or cloths wrung out in icewater. If a large vein or artery is spouting, it must be stopped at onceby compression. This may be done by a rubber tube wound around the armtightly above the elbow or above the knee, where the pulse is felt tobeat; or an improvised 'tourniquet' may be used. A hard apple or a stoneis placed in a folded handkerchief, and rolled firmly in place. Thisbandage is applied so that the hard object rests on the point where theartery beats, and is then tied loosely around the arm. A stick is thrustthrough the loose bandage and turned till the flow of blood ceases. "

BLEEDING FROM THE NOSE is rarely dangerous, and often beneficial. When itbecomes necessary to stop it, sit upright and compress the nostrilsbetween the thumb and forefinger, or with the thumb press upward upon theupper lip. A piece of ice, a snowball, or a compress wet with cold watermay be applied to the back of the neck. 

A SPRAIN [Footnote: "A sprain, " says Dr. Hope, in that admirable littlebook entitled _Till the Doctor comes and How to help Him_, "is a verypainful and very serious thing. When you consider that from the tips ofthe fingers to the wrist, or from the ends of the toes to the leg, thereare not less than thirty separate bones, all tied together with straps, cords, and elastic bands, and about twenty hinges, all to be kept in goodworking order, you will not wonder at sprains being frequent and sometimesserious. "] is often more painful and dangerous than a dislocation. Wrapthe injured part in flannels wrung out of hot water, and cover with a drybandage, or, better, with oiled silk. Liniments and stimulatingapplications are injurious in the first stages, but useful when theinflammation is subdued. _Do not let the limb hang down, keep the jointstill_. Without attention to these points, no remedies are likely to beof much service. A sprained limb must be kept quiet, even after all painhas ceased. If used too soon, dangerous consequences may ensue. Manyinstances have been known in which, from premature use of an injured limb, the inflammation has been renewed and made chronic, the bones at the jointhave become permanently diseased, and amputation has been necessitated. 

DIARRHEA, CHOLERA MORBUS, ETC. , are often caused by eating indigestible ortainted food, such as unripe or decaying fruit, or stale vegetables; or bydrinking impure water or poisoned milk (see p. 321). Sometimes thedisturbance may be traced to a checking of the perspiration; but morefrequently to peculiar conditions of the atmosphere, especially in largecities. Such diseases are most prevalent in humid weather, when the daysare hot and the nights cold and moist. Especial attention should at suchtimes be paid to the diet. If an attack comes on, ascertain, if possible, its cause. You can thereby aid your physician, and, if the cause beremovable, can protect the rest of the household. If the limbs are cold, take a hot bath, followed by a thorough rubbing. Then go to bed and liequietly on the back. In ordinary cases, rest is better than medicine. Ifthere be pain, have flannels wrung out of hot water applied to theabdomen. [Footnote: If it be difficult to manage the foments, lay a hotplate over the flannels and cover with some protection. By having a changeof hot plates, the foments can be kept at a uniform high temperature. Thisplan will be found useful in all cases where foments are needed. ] Amustard poultice will serve the same purpose if more convenient. Eat nofruit, vegetables, pastry, or pork. Use water sparingly. If much thirstexist, give small pieces of ice, or limited quantities of cold tea ortoast water. Take particular pains with the diet for some days after thebowel irritation has ceased. 

CROUP. --There are two kinds of croup--true and false. True croup comes ongradually, and is less likely to excite alarm than false croup, whichcomes on suddenly. True croup is attended with fever and false membrane inthe throat; false croup is not attended with fever or false membrane. Truecroup is almost always fatal in four or five days; false croup recovers, but is liable to come on again. The great majority of cases of the so-called croup are simply cases of spasm of the glottis. "Croupy children"are those who are liable to these attacks of false croup, which are mostfrequent during the period of teething. --DR. GEO. M. BEARD. Croup occurscommonly in children between the ages of two and seven years. At thisperiod, if a child has a hollow cough, with more or less fever, flushedface, red watery eyes, and especially _if it have a hoarse voice, andshow signs of uneasiness about the throat_, send at once for a doctor. Induce mild vomiting by doses of syrup of ipecac. Put the feet in a hotmustard-and-water bath. Apply hot fomentations, rapidly renewed, to thechest and throat. A "croupy" child should be carefully shielded from allphysical excitation, sudden waking from sleep, and any punishment thattends to awaken intense fear or terror. Irritation of the air passagesthrough faulty swallowing in drinking hastily, should be guarded against. Good pure air, warm clothing, and a nourishing diet are indispensable. 

COMMON SORE THROAT. --Wrap the neck in a wet bandage, and cover withflannel or a clean woolen stocking. Gargle the throat frequently with asolution of a teaspoonful of salt in a pint of water, or thirty grains ofchlorate of potash in a wineglass of water. 

FITS, APOPLEXY, EPILEPSY, ETC. --These call for immediate action and promptmedical attendance. Children who are teething, or troubled with intestinalworms, or from various causes, are sometimes suddenly seized withconvulsions. Apply cloths wet in cold water--or, better still, ice wrappedin oiled silk--to the head, and _especially to the back of the neck_, taking care, however, that the ice or wet cloths do not remain too long. Apply mustard plasters to the stomach and legs. A full hot bath isexcellent if the cold applications fail. Endeavor to induce vomiting. Seekto determine the cause, and consult with your physician for furtherguidance. 

Apoplexy may be distinguished from a fainting fit by the red face, hotskin, and labored breathing; whereas, in a faint, the face and lips losecolor, and the skin becomes cold. In many cases, death follows so quicklyupon an apoplectic seizure, that little effectual service can be given. Call the nearest physician, loosen the clothing, and raise the head andshoulders, taking care not to bend the head forward on the neck. Keep thehead cool. Do not move the patient unnecessarily. 

In a common fainting fit, give the patient as much air as possible. Layhim flat upon the floor or ground, and keep the crowd away. 

All that can be done in a fit of epilepsy is to prevent the patient frominjuring himself; especially put something in his mouth to keep him frombiting his tongue. A cork, a piece of India rubber, or even a tightly-rolled handkerchief, placed between the teeth will answer this purpose. Give the sufferer fresh air; loosen his clothing, and place him in acomfortable position. Epilepsy may be due to various causes, --improperdiet, overexcitement, etc. Consult with a physician, and study to avoidthe occasion. 

CONCUSSION OF THE BRAIN generally arises from some contusion of the head, from violent blows, or from a shock received by the whole body inconsequence of falling from a height. In any case of injury to the headwhere insensibility ensues, a doctor should be called at once. Remove thepatient to a quiet room; loosen his clothing; strive to restorecirculation by gentle friction, using the hand or a cloth for thispurpose; apply cold water to the head, and, if the patient's body be coldand his skin clammy, put hot bottles at his feet. Ammonia may becautiously held to the nose. Beyond this, it is not safe for a non-professional to go, in case of a severe injury to the head. Concussion ismore or less serious, according to the injury which the brain hassustained; but even in slight cases, when a temporary dizziness appears tobe the only result, careful treatment should be observed both at the timeof the injury and afterward. Cases of head injury are often more grave intheir consequences than in their immediate symptoms. Sometimes the patientappears to be getting better when really he is worse. Rest and quietshould be observed for several weeks after an accident which has in anyway affected the brain. 

TOOTHACHE AND EARACHE. --Insert in the hollow tooth cotton wet withlaudanum, spirits of camphor, or chloroform. When the nerve is exposed, wet it with creosote or carbolic acid. Hot cloths or a hot brick wrappedin cloth and held to the face will often relieve the toothache. In asimilar manner treat the ear, wetting the cloth in hot water, and lettingthe vapor pass into the ear. 

CHOKING. --Ordinarily a smart blow between the shoulders, causing acompression of the chest and a sudden expulsion of the air from the lungs, will throw out the offending substance. If the person can swallow, and theobject be small, give plenty of bread or potato, and water to wash itdown. Press upon the tongue with a spoon, when, perhaps, you may see theobject, and draw it out with your thumb and finger, or a blunt pair ofscissors. If neither of these remedies avail, give an emetic of syrup ofipecac or mustard and warm water. 

FROSTBITES are frequently so sudden that one is not aware when they occur. In Canada it is not uncommon for persons meeting in the street to say, "Mind, sir, your nose looks whitish. " The blood cools and runs slowly, andthe blood vessels become choked and swollen. _Keep from the heat_. Rub the part quickly with snow, if necessary for hours, till the naturalcolor is restored. If one is benumbed with cold, take him into a coldroom, remove the wet clothes, rub the body dry, cover with blankets, andgive a little warm tea or other suitable drink. On recovering, let him bebrought to a fire gradually. [Footnote: If you are caught in a snowstorm, look for a snow bank in the lee of a hill, or a wood out of the wind, or ahollow in the plain filled with snow. Scrape out a hole big enough tocreep into, and the drifting snow will keep you warm. Men and animals havebeen preserved after days of such imprisonment. Remember that if you giveway to sleep in the open field, you will never awake. ]

FEVERS, and many acute diseases, are often preceded by a loss of appetite, headache, shivering, "pains in the bones, " indisposition to work, etc. Insuch cases, sponge with tepid water, and rub the body till all aglow. Goto bed, place hot bricks to the feet, take nothing but a little gruel orbeef tea, and drink moderately of warm, cream-of-tartar water. If you donot feel better the next morning, call a physician. If that be impossible, take a dose of castor oil or Epsom salts. 

SUNSTROKE is a sudden prostration caused by intense heat. The same effectis produced by the burning rays of the sun and the fierce fire of afurnace. When a person falls under such circumstance, place your hand onhis chest. If the skin be cool and moist, it is not a sunstroke; but if itbe dry and "biting hot, " there can be no mistake. Time is now precious. Atonce carry the sufferer to the nearest pump or hydrant, and dash coldwater on the head and chest until consciousness is restored. --DR. H. C. WOOD. 

To prevent sunstroke, wear a porous hat, and in the top of it place a wethandkerchief; also drink freely of water, not ice cold, to induce abundantperspiration. 

ASPHYXIA, or apparent death, whether produced by drowning, suffocation, bad air, or coal gas, requires very similar treatment. Send immediatelyfor blankets, dry clothing, and a physician. Treat upon the spot, if theweather be not too unfavorable. 

1. Loosen the clothing about the neck and chest, separate the jaws, andplace between them a cork or bit of wood. 

2. Turn the patient on his face, place his arm under his forehead to raisethe head, and press heavily with both hands upon the ribs to squeeze outthe water. 

3. Place the patient on his back, wipe out the mouth and nostrils, andsecure the tongue from falling backward over the throat. Kneel at hishead, grasp his arms firmly above the elbows, and pull them gently upwarduntil they meet over the head, in order to draw air into the lungs;reverse this movement to expel the air. Repeat the process about fifteentimes per minute. Alternate pressure upon the chest, and blowing air intothe mouth through a quill or with a pair of bellows, may aid your efforts. Use snuff or smelling salts, or pass hartshorn under the nose. Do not losehope quickly. Life has been restored after five hours of suspendedanimation. [Footnote: Another simple method of artificial respiration isdescribed in the _British Medical Journal_. The body of the patientis laid on the back, with clothes loosened, and the mouth and nose wiped;two bystanders pass their right hands under the body at the level of thewaist, and grasp each other's hand, then raise the body until the tips ofthe fingers and the toes of the subject alone touch the ground; countfifteen rapidly; then lower the body flat to the ground, and press theelbows to the side hard; count fifteen again; then raise the body againfor the same length of time; and so on, alternately raising and lowering. The head, arms, and legs are to be allowed to dangle down freely when thebody is raised. ]

4. When respiration is established, wrap the patient in dry, warm clothes, and rub the limbs under the blankets or over the dry clothingenergetically _toward the heart_. Apply heated flannels, bottles ofhot water, etc. , to the limbs, and mustard plasters [Footnote: The bestmustard poultice is the paper plaster now sold by every druggist. It isalways ready, and can be carried by a traveler. It has only to be dippedin water, and applied at once. ] to the chest. 

FOREIGN BODIES IN THE EAR. --Insects may be killed by dropping a littlesweet oil into the ear. Beans peas, etc. , may generally be removed by soholding the head that the affected ear will be toward the ground, and then_cautiously_ syringing tepid water into it from below. Do not usemuch force lest the tympanum be injured. If this fail, dry the ear, stickthe end of a little linen swab into thick glue, let the patient lie on oneside, put this into the ear until it touches the substance, keep it therethree quarters of an hour while it hardens, and then draw them all outtogether. Be careful that the glue does not touch the skin at any point, and that you are at work upon the right ear. Children often deceive one asto the ear which is affected. 

FOREIGN BODIES IN THE NOSE, such as beans, cherry pits, etc. , mayfrequently be removed by closing the opposite nostril, and then blowinginto the child's mouth forcibly. The air, unable to escape except throughthe affected nostril, will sweep the obstruction before it. 

ANTIDOTES TO POISONS. 

ACIDS: _Nitric_ (aqua fortis), _hydrochloric_ (muriatic), _sulphuric_ (oil of vitriol), _oxalic_, etc. --Drink a littlewater to weaken the acid, or, still better, take strong soapsuds. Stirsome magnesia in water, and drink freely. If the magnesia be not at hand, use chalk, soda, lime, whiting, soap, or even knock a piece of plasterfrom the wall, and scraping off the white outside coat pound it fine, mixwith milk or water, and drink at once. Follow with warm water, or flaxseedtea. 

ALKALIES: _Potash, soda, lye, ammonia_ (hartshorn). --Drink weakvinegar or lemon juice. Follow with castor or linseed oil, or thick cream. 

ANTIMONY: _Antimonial wine, tartar emetic_, etc. --Drink strong, greentea, and in the meantime chew the dry leaves. The direct antidote is asolution of nutgall or oak bark. 

ARSENIC: _Cobalt, Scheele's green, fly powder, ratsbane_, etc. --Give_plenty of milk, whites of eggs_, or induce vomiting by mustard andwarm water; [Footnote: See that the mustard is well mixed with the water, in the proportion of about half an ounce of the former to a pint of thelatter. ] or even soapsuds. 

BITE OF A SNAKE OR A MAD DOG. --Tie a bandage above the wound, if on alimb. Wash the bite thoroughly, and, if possible, let the person suck itstrongly. Rub some lunar caustic or potash in the wound, or heat the pointof a small poker or a steel sharpener white hot, and press it into thebite for a moment. It will scarcely cause pain, and will be effectual inarresting the absorption of the poison, unless a vein has been struck. 

COPPER: _Sulphate of copper_ (blue vitriol), _acetate of copper_(verdigris). --Take whites of eggs or soda. Use milk freely. 

LAUDANUM: _Opium, paregoric, soothing cordial, soothing syrup_, etc. --Give an emetic at once of syrup of ipecac, or mustard and warm water, etc. After vomiting, use strong coffee freely. _Keep the patientawake_ by pinching, pulling the hair, walking about, dashing water inthe face, and any expedient possible. 

LEAD: _White lead, acetate of lead_ (sugar of lead), _redlead_. --Give an emetic of syrup of ipecac, or mustard and warm water, or salt and water. Follow with a dose of Epsom salts. 

MATCHES: _Phosphorus_. --Give magnesia, chalk, whiting, or even flourin water, and follow with mucilaginous drinks. 

MERCURY: _Calomel, chloride of mercury_ (corrosive sublimate, bugpoison), _red precipitate_. --Drink milk copiously. Take the whites ofeggs, or stir flour in water, and use freely. 

NITRATE OF SILVER (lunar caustic). --Give salt and water, and follow withcastor oil. 

NITRATE OF POTASH (saltpeter, niter). --Give mustard and warm water, orsyrup of ipecac. Follow with flour and water, and cream or sweet oil. 

PRUSSIC ACID (oil of bitter almonds), _cyanide of potassium_. --Take ateaspoonful of hartshorn in a pint of water. Apply smelling salts to thenose, and dash cold water in the face. 

STING OF AN INSECT. --Apply a little hartshorn or spirits of camphor, orsoda moistened with water, or a paste of clean earth and saliva. 

SULPHATE OF IRON (green vitriol). --Give syrup of ipecac, or mustard andwarm water, or any convenient emetic; then magnesia and water. 

X. 

SELECTED READINGS

TO ILLUSTRATE AND SUPPLEMENT THE TEXT. 

_Arranged in order of the subjects to which they refer_. 

"Read not to contradict and confute, nor to believe and take for granted, nor to find talk and discourse, but to weigh, and consider. "

LORD BACON. 

"He who learns the rules of wisdom without conforming to them in his life, is like a man who labored in his fields but did not sow. "

SAADI. 

SELECTED READINGS. 

_The figures indicate the pages in the text upon which the correspondingsubjects will be found_. 

THE SKELETON. 

MAN, AS COMPARED WITH OTHER VERTEBRATE ANIMALS (p. 3). --Man, the lord ofthe animal kingdom, is constructed after the same type as the cat thatpurrs at his feet, the ox that he eats, the horse that bears his burden, the bird that sings in his cage, the snake that crawls across his pathway, the toad that hides in his garden, and the fish that swims in hisaquarium. All these are but modifications of one creative thought, showinghow the Almighty Worker delights in repeating the same chord, withinfinite variations. There are marked physical peculiarities, however, which distinguish man from the other mammals. Thus, the position of thespinal opening in the middle third of the base of the skull, therebybalancing the head and admitting an upright posture; the sigmoid S-curveof the vertebral column; the ability of opposing the well-developed thumbto the fingers; the shortened foot, the sole resting flat on the ground;the size and position of the great toe; the length of the arms, reachinghalfway from the hip to the knees; the relatively great development of thebrain; the freedom of the anterior extremities from use in locomotion, andthe consequent erect and biped position. In addition, man is the onlymammal that truly walks; that is endowed with the power of speech; andthat is cosmopolitan, readily adapting himself to extremes of heat andcold, and making his home in all parts of the globe. --STEELE'S _PopularZoology_. 

FIG. 68. 

[Illustration: _Skeleton of Orang, Chimpanzee, and Man. _]

UNION OF FRACTURES (p. 8). --In the course of a week after a fracture, there is a soft yet firm substance, something between ligament andcartilage in consistence, which surrounds the broken extremities of thebone, and adheres to it above and below. The neighboring muscles andtendons are closely attached to its surface, and the fractured extremitiesof the bone lie, as it were, loose in a cavity in the center, with a smallquantity of vascular albumen, resembling a semitransparent jelly. 

Here, then, is a kind of splint which nature contrives, and which isnearly completed within a week from the date of the accident. We call thisnew formation the _callus_. This process goes on, the surroundingsubstance becoming thicker and of still firmer consistence. In the courseof a few days more, the thin jelly which lay in contact with the brokenends of the bone has disappeared, and its place is supplied by a calluscontinuous with that which formed the original capsule. This is thetermination of the first stage of curative progress. The broken ends ofthe bones are now completely imbedded in a mass of vascular organizedsubstance or callus, something between gristle and cartilage inconsistence; and as yet there are no traces of bony matter in it. At thistime, if you remove the adventitious substance, you will find the brokenends of bone retaining exactly their original figure and presenting thesame appearance as immediately after the fracture took place. 

At the end of about three weeks, if you make a section of the callus, minute specks of earthy matter are visible, deposited in it here andthere, and at the same time some of the callus, appears to disappear onthe outside, so that the neighboring muscles and tendons no longer adhereto it. The specks of bone become larger and more numerous until theyextend into each other; and thus by degrees the whole of the callus isconverted into bone. Even at this period, however, there is not absolutebony union, for although the whole of the callus has become bone, it isnot yet identified with the old bone, and you might still pick it off witha penknife, leaving the broken extremities not materially altered fromwhat they were immediately after the injury. This may be regarded as theend of the second stage of the process by which a fracture is repaired. Now a third series of changes begins to take place. The broken extremitiesof the bones become intimately united by bony matter passing from one tothe other. The mass of new bone on the outside, formed by the ossificationof the callus, being no longer wanted, is absorbed; by degrees the wholeof it disappears, and the bone is left having the same dimensions which ithad before the occurrence of the accident. 

The process of union is completed in young persons sooner than in thoseadvanced in life; in the upper extremities sooner than in the lower; andin smaller animals more speedily than in man. In human subjects a brokenarm or forearm will be healed in from six to eight weeks, while a leg orthigh will occupy nine or ten weeks. --SIR B. C. BRODIE. 

FIG. 69. 

[Illustration: FIG. 69. A. _Monkey's Hand and Foot. _ b. _Human Handand Foot. _]

THE HAND AND THE FOOT (p. 2l). --_Man Compared with the_ _Ape_. --The peculiar prehensible power possessed by the hand of man is chieflydependent upon the size and power of the thumb, which is more developed inhim than it is in the highest apes. The thumb of the human hand can bebrought into exact opposition to the extremities of all the fingers, whether singly or in combination; while in those quadrumana which mostnearly approach man, the thumb is so short, and the fingers so muchelongated, that their tips can scarcely be brought into opposition; andthe thumb and the fingers are so weak that they can never be opposed toeach other with any degree of force. Hence, though well suited to clinground bodies of a certain size, such as the small branches of trees, theanterior extremities of the quadrumana can neither seize very minuteobjects with such precision nor support large ones with such firmness asare essential to the dexterous performance of a variety of operations forwhich the hand of man is admirably adapted. 

The human foot is, in proportion to the size of the whole body, larger, broader, and stronger than that of any other mammal, save the kangaroo. The surface of the astragalus (ankle bone) which articulates with thetibia, looks almost vertically upward, and hardly at all inward, when thesole is flat upon the ground; and the lateral facets are more nearly atright angles to this surface than in any ape. The plane of the foot isdirected at right angles to that of the leg; and its sole is concave, sothat the weight of the body falls on the summit of an arch, of which theos calcis (heel bone) and the metatarsal bones form the two points ofsupport. This arched form of the foot, and the contact of the wholeplantar surface with the ground, are particularly noticeable in man, mostof the apes having the os calcis small, straight, and more or less raisedfrom the ground, while they touch, when standing erect, with the outerside only of the foot. The function of the _hallux_, or great toe, moreover, is strikingly contrasted in man and the ape; for, while in thelatter it is nearly as opposable as the thumb, and can be used to almostthe same extent as an instrument of prehension, it chiefly serves in theformer to extend the basis of support, and to advance the body inprogression. --DR. W. B. CARPENTER. 

FIG. 70. 

[Illustration: _The Leg in standing. _]

_The Natural Flexibility of the Toes, and How it is Destroyed_. --Weoften admire the suppleness of the fingers by means of which we canperform such a variety of acts with swiftness and delicacy. Did it everoccur to you that the toes, which in most feet seem incapable of a freeand graceful motion, even when they are not stiffened and absolutelydeformed by the compression of the modern shoe, are also provided byNature with a considerable degree of flexibility? The phalanges of thetoes, though more feebly developed, have really the same movements amongthemselves as those of the fingers, and, in case of necessity, theirpowers can be strengthened and educated to a surprising degree. There arewell-known instances of persons who, born without hands, or having lostthem by accident, have successfully supplied the deficiency by acultivated use of their feet. Some of these have distinguished themselvesin the world of art. Who that has been so fortunate as to visit thePicture Gallery in Antwerp on some fine morning when the armless artist, M. Felu, was working at his easel, can forget the wonderful dexterity withwhich he wielded his brushes, mixed the oils on his palette, and shadedthe colors on his canvas, all with his agile feet? The writer wellremembers the ease and grace with which, at the close of a pleasantinterview, this cultured man put the tip of his foot into his coat pocket, drew out a visiting card, wrote his name and address upon it, andpresented it to her between his toes!

Contrast this intelligent adaptation of a delicate physical mechanism withthe barbarous treatment it too commonly receives. The Chinese are at leastconsistent. They cripple and distort the feet of their highborn daughtersuntil they crush out all the power and gracefulness of nature in theartificial formation of what they term a "golden lily"; but they neverexpect these golden-lilied women to make their withered feet useful. Withus, on the contrary, every girl would like to walk well, to display in hergeneral movements something of the "poetry of motion"; yet the absurd andarbitrary fashion of our foot gear not only makes an elastic step one ofthe rarest of accomplishments, but renders oftentimes the simple act ofwalking a painful burden. The calluses, corns, bunions, ingrowing nails, and repulsive deformities that are caused by and hidden under the narrow-toed, high-heeled instruments of torture we often wear for fashion's sakeare uncomfortable suggestions that our practices are not greatly inadvance of those of our Celestial sisters. Dowie, a sensible Scotchshoemaker, satirizes the shape of a fashionable boot as suited only to"the foot of a goose with the great toe in the middle. " The error whichmay have led to the adoption of this conventional shape appears to lie ina misconception of the natural formation of the foot, and of the relationof the two feet to each other. It is true, that when the toes are coveredwith their soft parts, the second toe appears a little longer than thefirst, and this appearance, emphasized and exaggerated, is perhapsresponsible for a practical assumption that Nature intended an even-sided, tapering foot. On the contrary, the natural foot gradually expands inbreadth from the instep to the toes and, in the skeleton itself, the greattoe is the longest. 

"There is no law of beauty, " says Dr. Ellis, "which makes it necessary toreduce the foot to even-sided symmetry. An architect required to providemore space on one than on the other side of a building would not seek toconceal or even to minimize the difference; he would seek rather toaccentuate it, and give the two sides of the structure distinctivefeatures. . . . Moreover, the sense of symmetry is, or ought to be, satisfiedby the exact correspondence of the two feet, which, taken jointly, may bedescribed as the two halves of an unequally expanded dome. "--E. B. S. 

THE MUSCLES. 

ATTACHMENT OF THE MUSCLES TO THE BONES (p. 30). --One of the two bones towhich a muscle is attached is usually less mobile than the other, so thatwhen the muscle shortens, the latter is drawn down against the former. Insuch a case, the point of attachment of the muscle to the less mobile boneis called its origin, while the point to which it is fixed on the moremobile bone is called its attachment. . . . A muscle is not always extendedbetween two contiguous bones. Occasionally, passing over one bone itattaches itself to the next. This is the case with several muscles which, originating from the pelvic bone, pass across the upper thigh bone, andattach themselves to the lower thigh bone. In such cases the muscle iscapable of two different movements: it can either stretch the knee, previously bent, so that the upper and the lower thigh bones are in astraight line; or it can raise the whole extended leg yet higher, andbring it nearer to the pelvis. But the points of origin and of attachmentof muscles may exchange offices. When both legs stand firmly on theground, the above-mentioned muscles are unable to raise the thigh;instead, on shortening, they draw down the pelvis, which now presents themore mobile point, and thus bend forward the whole upper part of the body. 

One important consequence of the attachment of the muscles to the bones isthe extension thus effected. If the limb of a dead body is placed in theposition which it ordinarily occupied during life, and if one end of amuscle is then separated from its point of attachment, it draws itselfback, and becomes shorter. The same thing happens during life, as isobservable in the operation of cutting the tendons, as practiced bysurgeons to cure curvatures. The result being the same during life andafter death this phenomenon is evidently due to the action of elasticity. It thus appears that the muscles are stretched by reason of theirattachment to the skeleton, and that, on account of their elasticity, theyare continually striving to shorten. Now, when several muscles areattached to one bone in such a way that they pull in opposite directions, the bone must assume a position in which the tension of all the muscles isbalanced, and all these tensions must combine to press together thesocketed parts with a certain force, thus evidently contributing to thestrength of the socket connection. . . . This balanced position of all thelimbs, which thus depends on the elasticity of the muscles, may beobserved during sleep, for then all active muscular action ceases. It willbe observed that the limbs are then generally slightly bent, so that theyform very obtuse angles to each other. 

Not all muscles are, however, extended between bones. The tendons of somepass into soft structures, such as the muscles of the face. In this case, also, the different muscles exercise a mutual power of extension, thoughit is but slight, and they thus effect a definite balanced position of thesoft parts, as may be observed in the position of the mouth opening in theface. --ROSENTHAL, _Muscles and Nerves_. 

MUSCULAR FIBERS (p. 3l). --The anatomical composition of flesh is verysimilar in every kind of creature, whether it be the muscle of the ox orof the fly; that is to say, there are certain tubes which are filled withminute parts or elements, and the adhesion of the tubes together makes upthe substance of the flesh. These tubes may be represented grossly byimagining the finger of a glove, to be called the sarcolemma, or muscle-fiber pouch, and this to be so small as not to be apparent to the nakedeye, but filled with nuclei and the juices peculiar to each animal. Hundreds of such fingers attached together would represent a bundle ofmuscular fibers. The tubes are of fine tissue, but are tolerablypermanent; whilst the contents are in direct communication with thecirculating blood and pursue an incessant course of chemical change andphysical renewal. --EDWARD SMITH, _Foods_. 

FIG. 71. 

[Illustration: _Smooth Muscle Fibers (300 times enlarged). _]

THE SMOOTH MUSCLE FIBERS consist of long, spindle-shaped cells, the endsof which are frequently spirally twisted, and in the center of whichexists a long, rod-shaped kernel or nucleus. Unlike striated muscle, theydo not form separate muscular masses, but occur scattered, or arranged inmore or less dense layers or strata, in almost all organs. [Footnote: Aninstance of a considerable accumulation of smooth, muscle fibers isafforded by the muscle pouch of birds, which, with the exception of theouter and inner skin coverings, consists solely of these fibers collectedin extensive layers. ] Arranged in regular order, they very frequently formwidely extending membranes, especially in such tube-shaped structures asthe blood vessels, the intestine, etc. , the walls of which are composed ofthese smooth muscle fibers. In such cases they are usually arranged in twolayers, one of which consists of ring-shaped fibers surrounding the tube, while the other consists of fibers arranged parallel to the tube. When, therefore, these muscle fibers contract, they are able both to reduce thecircumference and to shorten the length of the walls of the tube in whichthey occur. This is of great importance in the case of the smallerarteries, in which the smooth muscle fibers, arranged in the form of aring, are able greatly to contract, or even entirely to close the vessels, thus regulating the current of blood through the capillaries. In othercases, as in the intestine, they serve to set the contents of the tubes inmotion. In the latter cases the contraction does not take placesimultaneously throughout the length of the tube; but, commencing at onepoint, it continually propagates itself along fresh lengths of the tube, so that the contents are slowly driven forward. 

As a rule, such parts as are provided only with smooth muscle fibers arenot voluntarily movable, while striated muscle fibers are subject to thewill. The latter have, therefore, been also distinguished as voluntary, the former as involuntary muscles. The heart, however, exhibits anexception, for, though it is provided with striated muscle fibers, thewill has no direct influence upon it, its motions being exerted andregulated independently of the will. Moreover, the muscle fibers of theheart are peculiar in that they are destitute of sarcolemma, the nakedmuscle fibers directly touching each other. This is so far interestingthat direct irritations, if applied to some point of the heart, aretransferred to all the other muscle fibers. In addition to this, themuscle fibers of the heart are branched, but such branched fibers occuralso in other places; for example, in the tongue of the frog, where theyare branched like a tree. Smooth muscle fibers being, therefore, notsubject to the will, are caused to contract, either by local irritation, such as the pressure of the matter contained within the tubes, or by thenervous system. The contractions of striated muscle fibers are effected, in the natural course of organic life, only by the influence of thenerves. --ROSENTHAL. 

OVEREXERTION AND PERSONAL IMPRUDENCE (p. 40). --Among children there islittle danger of overexertion. When a little child reaches the point ofhealthy fatigue, he usually collapses into rest and sleep. But with youthcomes the spirit of ambition and emulation. A lad, for instance, isdetermined to win a race, to throw his opponent in a football scramble, tolift a heavier weight than his strength will warrant; or a girl isstimulated by the passion she may possess for piano playing, painting, dancing, or tennis. The moment of exhaustion comes, but the end is notaccomplished, and the will goads on the weary muscles, perhaps to onesupreme effort which terminates in a sharp and sudden illness, perhaps todays and weeks of continued and incessant application, during which thewhole system is undermined. Thus is laid the foundation for a feeble andsuffering maturity. 

To elderly people, overexertion has peculiar dangers, dependent largelyupon the changes which gradually take place in the tissues of the body. The walls of the blood vessels become less and less elastic, and more andmore brittle, as life advances, until at last they are ready to give wayfrom any severe or unusual pressure. We constantly see old peoplehastening their death by personal imprudence. An old gentleman running tocatch the morning train; an old farmer hastening to turn the strayed sheepout of a cornfield; the old sportsman having a last run with the hounds;the last pull at the oars; the last attempt of old age to play at vigorousmanhood. 

A prominent American physician has said that between the ages of forty andfifty every wise man will have ceased to run to "catch" trains or streetcars; and that between fifty and sixty he will have permanently discardedhaste of all kinds. Equal precautions should be observed by both young andold, but especially by those advanced in life, in regard to extremes ofheat, cold, or storm. William Cullen Bryant, by exposing himself to ascorching sun and refusing to permit a friend to protect him with anumbrella while delivering an address in Central Park, received injuries tohis system that carried him to his grave. Ralph Waldo Emerson, by standingin a chilling wind, contracted a cold and died. George Dawson, by goingthoughtlessly into a freezing atmosphere from the sweltering rooms of acrowded reception, took cold which resulted in pneumonia and death. Matthew Arnold, for years a sufferer from heart difficulty, in a singleinstance neglected the advice of his physician not to indulge in anyviolent exercise, made repeated attempts and finally succeeded in jumpinga fence, and in a few hours was a dead man. Roscoe Conkling braved themost terrible blizzard ever known in the east and sacrificed his life. Andyet, these were all men of exceptional prudence. Probably no other fivepersons in the world of like surroundings and vocations were more carefulof their health. In an unguarded moment their prudence left them, and theypaid the terrible penalty. --_Compiled_. 

EFFECTS OF INSUFFICIENT OUTDOOR EXERCISE UPON THE YOUNG (p. 41). --Childrendeprived of adequate outdoor exercise are always delicate, pale, andtender; or, in a figurative sense, they are like the sprig of vegetationin a dark, dank hole, --bleached and spindling. . . . An inactive indoor lifeis one of the most effectual ways of weakening the young body. It rendersthe growth unnaturally soft and tender, and thus susceptible to harm fromthe slightest causes. It hinders the garnering of strength necessary for along life, and gives to the germs of disease a resistless power over anorganization so weak and deficient. . . . Measles, scarlet fever, anddiphtheria find among such a congenial soil, and run riot among theelements of the body held together by so frail a thread. . . . Such childrenare always at the mercy of the weather. Colds and coughs are standarddisorders in winter, headaches and habitual languor in summer. . . . Thescapegoat for this result is the climate: if that was only better, mothersare sure their children's health would also be better. No, it would not bebetter: no earthly climate is good enough to preserve health and strengthunder such unnatural training. . . . Children of the laboring classes, oftendirty and imperfectly clad, seldom have colds, simply for the reason that, for the greater part of the day, they have the freedom of the streets. Itis not the dirt, it is not the rags, _but the life-giving force of anactive outdoor life_ that renders such children so strong and healthy. --BLACK, _Ten Laws of Health_. 

POPULAR MODES OF OUTDOOR EXERCISE (p. 42). --_Walking_. --Every personhas his own particular step, caused by the conformity, shape, and lengthof his bones, and the height of his body. Such a thing, then, as aregulation step is unnatural, and any attempt at equalizing the step ofindividuals of different heights must result in a loss of power. 

The moment, also, that walking comes to be _uphill_, fatigue issensibly increased. The center of gravity of the body is changed, and themuscular force necessary to provide for the change causes the fixing ofthe diaphragm, and a rigid condition of many muscles. Respiration isinterfered with, owing to the fixing of the diaphragm, and the heartbecomes affected thereby. A person with a sensitive or diseased heart can, during a walk, tell when the slightest rise in the ground occurs. We makeclimbing more exhausting from the habit we have of suspending the breath. Let the reader _hold his breath_ and run up twenty-four steps of astair, and then perform the same act _breathing freely_ and deeply. It will be found that by the first act marked breathlessness will beinduced, whereas by the latter the effect is much less. This management ofthe breath constitutes the difference between the beginner and theexperienced athlete. The enormous increase of the quantity of air consumedduring exercise will at once bring home a number of lessons. One is, thatexercise is best taken in the open air, and not in gymnasia; another, thatfree play to act for the regions of the chest and abdomen must be given. On no account must a tight belt be worn around the soft-walled abdomen. Ifa belt is preferred to braces, let it be applied below the top of thehaunch bone, where the bones can resist the pressure. 

Whatever may be the pastimes indulged in by young men, walking shouldnever be neglected. The oarsman will become "stale" unless the method ofexercise is varied; the gymnast will develop the upper part of his body, while his lower extremities will remain spindleshanks. So with all otherforms of exercise; success, in any form of game, sport, or gymnastictraining, can not be attained unless walking be freely taken. 

_Skating_ is simply an exaggerated swinging walk, with thisdifference, that the foot on which one rests is not stationary, but movesalong at a rapid rate. The benefit to the circulation, respiration, anddigestion is even greater in skating than in walking. The dangers fromskating are:

1. The giving way of the ice. Great caution should be used in regard tothe safety of a frozen pond or river. 

2. Taking cold from becoming overheated, and from subsequent inactiveexposure. Physiological knowledge will teach people that, when they beginto skate, outer wraps should be laid aside, and again put on when skatingis finished. 

3. Sprains, especially of the ankle, and other minor accidents arisingfrom falls. Ankle boots with strong uppers should be worn during skating. Those who have weak ankles ought to wear skates with ankle straps andbuckles, acme skates being relegated to those who are not afraid of going"over their foot. "

_Rowing_. --The muscles employed in rowing may be summed up under twoheads--those that are used in the forward swing, and those used in thebackward. In the _forward_ swing all the joints of the lowerextremity, the hip, knee, and ankle, are flexed; the shoulder is broughtforward; the elbow is straightened; and the wrist is first extended andthen flexed, in feathering the oar. The body is bent forward by themuscles in front of the abdomen and spinal column. In the _backward_movement the reverse takes place; the lower extremity, the hip, knee, andankle are straightened; the shoulder is pulled back; the elbow is flexed;and the wrist is held straight. The body is bent backward by the musclesat the lower part of the back, and by those of the spine in general. Itwill be seen that the enormous number of joints put into use, and thevarying positions employed, call into play nearly every muscle of thelimbs and trunk. Rowing gives more work to the muscles of the back thanany other kind of exercise. This is of the first importance to both menand women, but especially to women. The chief work of the muscles of theback is to support the body in the erect position, and the better they aredeveloped the better will the carriage be, and the less likelihood ofstooping shoulders, contracted chests, and the like. Now, the work of themuscles in supporting the body is largely relegated in women to the stays, and, in consequence, the muscles undergo wasting and fatty degeneration, in fact, atrophy; so that when the stays are left off, the muscles areunfit to support the body. Rowing exercises these muscles condemned towaste, and imparts a natural carriage to the girl's frame. In rowing, asin horseback riding, the clothing should be loose, stays left off, andflannels worn next the skin. The dress itself should be of woolen, andthere should always be in the boat a large wrap to use when one stopsrowing. The following practical rules should be observed by rowers:

1. Never row after a full meal. 

2. Stop when fatigue comes on. 

3. _Allow the breath to escape while the oar is in the water_. Anovice usually holds his breath at each stroke, and pulls so rapidly thatin a few minutes he becomes breathless, and is forced to stop. Not only isthis uncomfortable, but it is dangerous. In the case of both young andold, it may give rise to an abdominal rupture (hernia), dilation of thecavities of the heart, rupture of a heart valve, varicose veins, etc. Instead of fixing the diaphragm and holding the breath during the time ofpulling, as novices are apt to do, _do exactly the opposite_. Let thediaphragm go loose, and allow the breath to escape. 

4. Change the clothing from the skin outward as soon as the day's rowingis finished. 

5. Before retiring for the night, have a warm bath, temperature 92° Fahr. This is a specific against the aches and muscular stiffness which oftenfollow a long pull on the water. 

_Swimming_. --A word of warning is necessary in regard to thoselearning to swim in rivers. Boys at school, when they take to riverbathing, often carry it to a dangerous extent. They get into the water, and now in, now out on the bank, sometimes remain for hours. This may takeplace day after day, and if the weather continues warm and the holidayslast long enough, the boy may reduce himself to the lowest ebb offeebleness, and possibly develop the seeds of latent disease. He may evendie from the effects of this prolonged immersion and madcap exposure. 

The muscular exertion undergone during swimming, especially by those whoswim only occasionally, is very great. The experienced swimmer conserveshis strength, as do proficients at all feats, but the occasional swimmer, like the occasional rower, puts forth treble the energy required, and soonbecomes exhausted. In the first place, it is a new act for the muscles toperform; they are taken off from the beaten tracks, and are groupedtogether in new associations; hence they lack adjustment and adaptation. Again, as in other feats for which one is untrained, the heart and lungsdo not work in time. Ease and speed in swimming depend upon the attainmentof harmony in the working of the muscles, heart, and lungs. 

Diving is an accomplishment attached to swimming, which involves manydangers, and is well-nigh useless. The customary dive off a springboardinto the shallow water of a swimming bath is dangerous in the extreme. Theonly place where diving should be attempted is into deep water, at leastfifteen or twenty feet, where there is no danger of striking the bottom. 

_Lawn Tennis_. --Of all modern inventions in the way of games, lawntennis is the best. 

The dangers attendant on lawn tennis are:--

1. Overexertion, causing rupture and deranged circulation, especially inthe case of those with weak hearts, or those who, being out of condition, or too fat, suddenly engage in the game too long or too violently. 

2. Rupture of the _tendon of Achilles_, from taking a sudden bound. In such an accident the subject falls down, with a sensation as if struckwith a club on the leg. 

3. Rupture of one of the heads of the biceps in the arm. Here the armdrops helplessly, and a muscular knob rises up on the inner and upper partof the arm. 

4. The tennis arm. This trouble arises from the method of manipulating thebat. The pain is felt over the upper end of the radius. 

Many of the strains, ruptured tendons, and torn muscles in tennis playersare caused by the want of heels to tennis shoes. As, ordinarily, we walkon heels which vary from half an inch to an inch, there must be aconsiderable extra strain thrown on the muscles of the calf of the leg, when the heels are left off. Especially during a sudden spring is thisapparent, when to rise from off the heels on to the toes requires agreatly increased force. Tennis shoes should therefore have fairly deep, broad heels. 

_Horseback Riding_ is a mixed exercise, partly active and partlypassive, the lower parts of the body being in some measure employed, whilethe upper parts in easy cantering are almost wholly relaxed. It ispeculiarly suited to dyspeptics, from its direct action upon the abdominalviscera, the contents of which are stimulated by the continued agitationand succussion, consequent on the motion in riding. 

_Bicycling and Tricycling_. --While strongly recommending bicyclingand tricycling to both men and women in health, those suffering from heartor lung affections, ruptures, scrofula, joint disease, or like maladies, should not indulge in them without medical sanction. For abdominalcomplaints, such as dyspepsia, congestion of the liver, constipation, andthe like, the exercise is excellent. 

_Baseball_ is an essentially American game, which brings into playnearly all the muscles of the body. Its chief danger lies in being hit bythe hard, forcibly pitched ball, and, for weak persons, in the violence ofthe exercise. 

_Football_ is a rough-and-tumble game, suited only to that class ofboys and men, who, brimming over with animal life, take small heed of theaccidents liable to occur. 

_Light and Heavy Gymnastics_. --For wet weather, and when outdoorexercise is not practicable, gymnastics are most advisable. Boys andgirls, at the age of fifteen or sixteen, often shoot up and become talland lanky; they want filling out, and are troubled with growing pains. Even men, when tall and thin, are seldom very erect, their muscles are tooweak; and there is only one way of overcoming this weakness--by exercisingthem. Nothing more is wanted than a pair of very light Indian clubs, apair of light wooden dumb bells, a long wooden rod, and a pair of woodenrings, --the last for combined exercises. Indeed, a systematic motion ofthe body itself, without any extra artificial resistance, is quitesufficient for the purposes of physical education. In nearly all our largecities are found gymnasia, provided with competent instructors, and everyfacility for both light and heavy gymnastics. Exercise in a gymnasium isopen to the objection of being too brief and too severe, and of simplycausing an increase of muscular development. Besides, it is generallyunequal in its results, being better adapted to the cultivation ofstrength in the upper extremities and portion of the body than in thelower. Nevertheless, during inclement weather, or with persons in whom themuscles of the arms and chest are defective, moderate gymnastic exerciseis far better than no exercise. --_Compiled_. (_Mostly from "TheInfluence of Exercise" in The Book of Health_. )

THE SKIN. 

THE HAIR (p. 52). --_Baldness, and its Causes_. --Various reasons areassigned for the baldness which is so prevalent among comparatively youngmen in our country. One writer says: "The premature baldness and graynessof the Americans as a people is in great measure owing to thenonobservance of hygienic rules, and to excess of mental and physicallabor in a climate foreign to the race. " Others attribute it to the closeunventilated hats commonly worn by men. Dr. Nichols, in the _PopularScience News_, gives his opinion thus:

"In our view, it is largely due to modern methods of treatment of the hairand scalp. The erroneous idea prevails, that the skin which holds the hairfollicles and the delicate secretory organs of the scalp must be kept as'clean, ' so to speak, as the face or hands; consequently young menpatronize barbers or hairdressers, and once or twice a week they have whatis called a 'shampoo' operation performed. This consists in a thoroughscouring of the hair and scalp with dilute ammonia, water, and soap, sothat a heavy 'lather' is produced, and the glandular secretions, which arethe natural protection of the hair, and promotive of its growth, aresaponified and removed. No act could be more directly destructive of ahealthy growth of hair than this. . . . Women do not shampoo or wash the hairas often as the other sex, and consequently they are in a large degreeexempt from baldness in middle life. It is true, however, that many womenin cities make frequent visits to the hairdressers, and subject theirtresses to the 'scouring' process. If this becomes common, it will not belong before baldness will overtake the young mothers as well as thefathers, and the time will be hastened when even children will have nohair to destroy with ammonia or other caustic cosmetics. 

"The advice we have to offer to young men and maidens is, --let your hairalone; keep at a safe distance from hair-dressing rooms and drug shops, where are sold oils, alkaline substances, alcoholic mixtures, etc. , foruse upon the hair. They are all pernicious, and will do you harm. The headand hair may be washed occasionally with soft, tepid water, without soapof any kind. As a rule, the only appliances needed in the care of the hairare good combs and brushes: and they should not be used harshly, so as towound the scalp. Avoid all 'electric' and wire-made brushes. Noelectricity can be stored in a hairbrush: if it could be, it is notneeded. "

_Sudden Blanching of the Hair from Violent Emotions_. --The color ofthe hair depends mainly upon the presence of pigment granules, which rangein tint from a light yellow to an intense black. A recent investigator hassucceeded in extracting the coloring matter of the hair, and has foundthat all the different shades are produced by the mixture of three primarycolors--red, yellow, and black. "In the pure golden yellow hair there isonly the yellow pigment; in red hair the red pigment is mixed with more orless yellow, producing the various shades of red and orange; in dark hairthe black is always mixed with yellow and red, but the latter areoverpowered by the black; and it seems that even the blackest hair, suchas that of the negro, contains as much red pigment as the very reddesthair. " Hence, "if in the negro the black pigment had not been developed, the hair of all negroes would be a fiery red. "--DR. C. H. LEONARD. _TheHair: Its Diseases and Treatment_. 

The gradual disappearance of this pigment causes the gray or white hair ofold age. This natural change in color does not necessarily denote loss ofvitality in the hair, as it often continues to grow as vigorously asbefore it began to whiten. Cases of sudden blanching of the hair fromextreme grief or terror are often quoted, --those of Sir Thomas More and ofMarie Antoinette being well-known instances in point. An interestingcircumstance has been discovered with regard to such cases, namely, thatthe change of color is not dependent upon the disappearance of the pigmentof the hair, which always takes place slowly, but upon the suddendevelopment in its interior of a number of air bubbles, that hide anddestroy the effect of the pigment, which itself remains unaltered. Dr. Landois mentions the case of a German printer whom he attended, at ahospital, in the summer of 1865. 

This man had long been intemperate in his habits, in consequence of whichhe was seized with delirium tremens. The delirium, as is usual in suchcases, was of an extremely terrifying nature, and lasted four days. On theevening of the fourth day the hair was unaltered, but on the morning ofthe fifth the delirium had disappeared, and his hair, which previously wasfair, had become gray. It was examined with the microscope, when it wasfound that the pigment was still present, but that the central streak ofeach was filled with air bubbles. 

How this superabundance of air finds its way into the hair in these casesof sudden blanching, physiologists have not yet been able satisfactorilyto explain. --In this connection, however, it may be observed that airbubbles exist, more or less, in all hair, mingled with the pigmentgranules. 

The feathers of birds owe their bright colors to an oily secretioncorresponding to the pigment in hair, and microscopical observation hasrevealed the fact that when these colors fade the oily secretiondisappears, and is replaced by air. That extreme terror may blanchfeathers as well as hair is shown in the case of a poor little starling, which upon being rescued from the claws of a cat became suddenly white. 

THE NAILS (p. 54). --The nails are mere modifications of the scarfskin, their horny appearance and feeling being due to the fact that the scalesor plates of which they are composed are much harder and more closelypacked. The root of the nail lies embedded, to the extent of about thetwelfth part of an inch, in a fold of the sensitive skin, and, as may beobserved from an inspection of the part, the scarfskin is not exactlycontinuous with the nail, but projects a little above it, forming a narrowmargin. 

The nail, like the scarfskin, rests upon, and is intimately connectedwith, a structure almost identical with the sensitive skin; this is, however, thrown into ridges, which run parallel to one another, except atthe back part, where they radiate from the center of the root. Onexamining the surface of the nail, a semicircular whitish portion isdetected near its root; its color is dependent upon the fact that theridges there contain fewer blood vessels, and therefore less blood, and onaccount of its half-moon shape it is called the _lunula_. 

The nail is constantly increasing in length, owing to the formation of newcells at the root, which push it forward, while the increase in itsthickness is due to the secretion of new cells from the sensitive layerbeneath, so that the farther the nail grows from the root, the thicker itbecomes. Its nutrition, and consequently its growth, suffers in disease, the portion growing during disease being thinner than that growing inhealth; and accordingly a transverse groove is seen upon the nail, corresponding to the time of an illness. It will thus be seen that by amere examination of the nail we can astonish our friends by telling themwhen they have been ill; and it has been estimated that the nail of thethumb grows from its root to its free extremity in five months, that ofthe great toe in twenty months, so that a transverse groove in the middleof the former indicates an illness about two and a half months before, andin the middle of the latter, about ten months. 

The culture of the nails, which when perfect constitute so great a beauty, is of much importance; but the tendency is to injure them by too muchattention. The scissors should never be used except to pare the free edgeswhen they have become ragged or too long, and the folds of scarfskin whichoverlap the roots should not, as a rule, be touched, unless they befrayed, when the torn edges may be snipped off, so as to prevent theirbeing torn further, which may cause much pain, and even inflammation. Theupper surfaces of the nails should on no account be touched with theknife, as is so often done, the nailbrush being amply sufficient to keepthem clean, without impairing their smooth and polished surfaces. --HINTON. 

BATHS AND BATHING (p. 65). --_Physical Cleanliness Promotes MoralPurity_. --The old adage that cleanliness is next to godliness, musthave had its origin in the feeling of moral elevation which generallyaccompanies scrupulous bodily purity. Frequent bathing promotes purity ofmind and morals. The man who is accustomed to be physically clean shrinksinstinctively from contact with all uncleanliness. Personal neatness, whengrown into a habit, draws after it so many excellences, that it may wellbe called a social virtue. Without it, refined intercourse would beimpossible; for its neglect not only indicates a want of proper self-respect, but a disrespect of the feelings of others which argues a lowtone of the moral sense. All nations, as they advance in civilization andrefinement of manners, pay increased attention to the purity of theperson. 

What, then, shall we say of people who, after all that has been said andwritten upon the subject, seldom or never bathe, who allow the pores ofthe skin to get blocked up with a combination of dust and perspiredmatter, which is as effectual in its way as plaster to the walls of abuilding? Could they but once be tempted to taste the delights which arisefrom a perfectly clean and well-acting skin: the cheerfulness, nay, thefeeling of moral as well as physical elevation, which accompanies thesense of that cleanliness, they would soon esteem the little time andtrouble spent in the bath, and in the proper care of the surface of thebody, as time and labor very well spent--DR. STRANGE. 

The feet, particularly, should receive daily attention, if it be no morethan a vigorous rubbing with a wet cloth, followed by a dry one. After along walk, also, nothing is more refreshing, especially in summer, than agenerous footbath in cool or tepid water, followed by an entire change inshoes and stockings. This is really a necessary precaution, if the feethave become wet from the dampness of the ground; and if the walk hasheated the body so that the stockings are moist with perspiration, it isnot only an act of prudence, but an instinct of personal neatness. 

_Ancient Greek and Roman Baths_. --From the earliest historic timesthe necessity for frequent and thorough ablution has been recognized byartificial provisions for this purpose. The Greeks had "steaming baths"and "fragrant anointing oils, " as far back as Homer's time, a thousandyears before Christ, but the Romans surpassed all preceding and subsequentnations by their magnificent and luxuriously equipped Thermæ, in which abath cost less than a cent, and was often free. A full Roman bath includedhot air, dry rubbing, hot, tepid, and cold water immersions, scraping withbronze instruments, and anointing with precious perfumes. 

_The Modern Russian_ and _Turkish baths_ are the nearestapproaches we have to the Roman bath. These are found in nearly all ourlarger cities. 

_The Turkish Bath_ is conducted in a modified form in this country, generally with hot air instead of steam. Its frequent use not only tendsto keep the body in a state of perfect cleanliness, but it imparts aclear, fresh color to the complexion which is hardly attained by othermeans. 

"Its most important effect, " says a writer in the _Popular ScienceMonthly_, "is the stimulation of the emunctory action of the skin. Bythis means we are enabled to wash as it were the solid and fluid tissues, and especially the blood and skin, by passing water through them fromwithin outward to the surface of the body. Hence, in practice, one of themost essential requisites is copious draughts of water during thesweating. "

During the operation of a Turkish bath, the novice is often astonished atthe amount of effete matter eliminated from the pores of the skin. "Asurprising quantity of scarfskin, which no washing could remove, peelsoff, especially if a glove of camel's-hair or goat's-hair be used, as theyare in the East, where also the soles of the feet are scraped with pumice. The deposit of this skin of only a week's date, when collected, is oftenas large as one's fist. Much more solid matter is contained in theperspiration of those who take the bath for the first time, or after along interval. Nothing escapes through the skin, save what is noxious ifretained. This bath should never be used in case of advanced lungdiseases, great debility, acute inflammations, or persons who labor underany form of heart disease; but I think its influence is directly curativein rheumatic, gouty, and scrofulous affections, some skin diseases, andthe earlier stages of feverish colds and ague. It is said to have calmingeffects in the treatment of insanity, and the use of it was suggested fromthe heavy smell the skin of persons thus afflicted often has. "--MAPOTHER'S_Lectures on Public Health_. 

A somewhat heroic bath, used in Siberia to drive away a threatened fever, consists of a thorough parboiling, within an inch or two of a steamingfurnace, after which the subject is "drubbed and flogged for about half anhour with a bundle of birch twigs, leaf and all. " A douche of cold wateris then dashed over the exhausted bather, when he is ready to be put intobed. 

_Sea Bathing_. --Before the age of seven years, and after fifty-five, sea baths should be used with the greatest caution. All personsunaccustomed to sea bathing should begin with a warm or tepid bath, indoors, proceeding by degrees to the cold indoor bath, and then to the opensea. 

The sea bath should be taken, if possible, when the sun is shining, whenthe water has been warmed by contact with the heated sands, and neverduring the digestion of the principal meal, or late in the evening. Immediately on plunging into the water, which need not, except in personsof full habit, cover the head, brisk motion of some kind should be used. Those who can swim should do so; those who can not, should make as muchexertion of the limbs as possible, or rub the body with their hands. Thedelicate, and particularly those who are recovering from illness, shouldremove from the bath _as soon as the glow arrives;_ or, if that benot felt at all, then after _one_ plunge. 

_Danger in Bathing when Overheated_. --It is unwise to bathe whencopious perspiration has continued for an hour or more, unless the heat ofthe weather be excessive, or the sweating has been induced by loading withclothes, rather than by exertion. When much perspiration has been producedby muscular exercise, it is unsafe to bathe, because the body is sofatigued and exhausted, that the reaction can not be insured, and theeffect may be to congest the internal organs, and notably the nervecenters. The latter gives cramp. If the weather be chilly, or there be acold wind, so that the body may be rapidly cooled at the surface whileundressing, it is not safe to bathe. Under such conditions, the furtherchill of immersion in cold water will take place at the precise moment atwhich the reaction consequent upon the chill of exposure by undressingought to take place, and this second chill will not only delay oraltogether prevent the reaction, but will convert the bath from a merestimulant to a depressant, ending in the abstraction of a large amount ofanimal heat and congestion of the internal organs and nerve centers. Theaim must be to avoid two chills, and to make sure that the body is in sucha condition as to secure a quick reaction on emerging from the water, without relying too much on the possible effect of friction by rubbing. The actual temperature of the water does not affect the question so muchas its relative temperature in comparison with that of the surroundingair. It ought to be much lower than that of the air. These maxims receivea striking reenforcement from the case of a young soldier who a few daysago plunged into the river near Manchester, England, after having heatedhimself by rowing. He was immediately taken with cramps, and was drowned. When taken out, his body was found "twisted, " and the vessels of his headshowed every evidence of congestion. --_Popular Science Monthly, September, 1883_. 

_Bather's Cramp_. --Cramp is a painful and tonic muscular spasm. Itmay occur in any part of the body, but it is especially apt to take placein the lower extremities, and in its milder forms it is limited to asingle muscle. The pain is severe, and the contracted muscles are hard andexquisitely tender. In a few minutes the spasm and pain cease, leaving alocal sensation of fatigue and soreness. When cramp affects only oneextremity, no swimmer or bather endowed with average presence of mind needdrown; but when cramp seizes the whole of the voluntary muscular system, as it probably does in the worst cases, nothing in the absence of promptand efficient extraneous assistance can save the individual from drowning. [Footnote: Even this is often unavailable, as in the case of the CornellUniversity postgraduate drowned in Hall Creek, Ithaca, June 10, 1888. Inthis instance the day was hot and oppressive, and the victim sank soonafter entering the water. "His companions at once hastened to his relief, and recovered his body in a few minutes. Professor Wilder, of theUniversity, was hurriedly summoned, and every possible method was resortedto in order to induce respiration, but the vital spark had fled. An attackof cramps is supposed to have been the cause of drowning. "] Prolongationof muscular exertion, as in continued swimming, and forcible and suddenmuscular exertion, as in swimming with very vigorous and rapid strokes, are efficient and frequent causes of cramp. These muscular conditions, however, usually give rise only to the slighter and more localized forms. Serious cramp is a peril which menaces most persons with highly developedmuscles. Its most powerful and most avoidable cause is the suddenimmersion of the body, when its surface is highly heated, in water of arelatively low temperature. --_Popular Science News. _

_Protection of the Ear in Sea Bathing_. --Special attention should bepaid by bathers to the exclusion of salt water from the mouth and ears. Many cases of inflammation of the ear, followed by severe and lastingtrouble, even to deafness, are chargeable to the neglect of thisprecaution. Incoming waves should never be received in the face or theears, and the sea water which enters the ears when floating or divingshould be wiped out by soft cotton; indeed, the best plan is to plug theopenings of the ears with cotton, which is to be kept there during thebath. --_Science_. 

_How one who Knows not how to Swim can Escape Drowning_. --It is wellfor every one to learn the art of swimming, yet it is a knowledgepossessed by comparatively few people. Mr. Henry MacCormac, a writer in_Nature_, gives some common sense instructions that, if heeded, maybe of great service to those persons who, not knowing how to swim, mayfind themselves accidentally precipitated into the water. We condense fromhis article, adding some directions, as follows:

In order to escape drowning, it is necessary only to do as the brute does, namely, to walk or tread the water. The brute has no advantage over man inregard to his relative weight, and yet the man perishes while the brutesurvives. The ignorance of so simple a possibility as that of treadingwater strikes me as one of the most singular things in the history of man. Perhaps something is to be ascribed to the vague meaning which is attachedto the word _Swim_. The dog is wholly incapable of _swimming_ asa man swims, but nothing is more certain than that a man, without previoustraining or instruction, can swim just as a dog swims, and that by sodoing without fear or hesitancy, he will be just as safe as is the dog. The brute thus circumstanced continues to go on all fours, as if he wereon land, _keeping his head well out of the water_. So with the manwho wishes to save his life and can not otherwise swim. He must strikealternately, with hand and foot, --_one, two, one, two, _--withouthurry or precipitation, exactly as the brute does. Whether he be providedwith paw or hoof, the beast swims with perfect ease and buoyancy. So, too, can the human being, if he will, with the further immense advantage ofhaving a paddle-formed hand, and of being able, when tired, to resthimself by floating, an act of which the animal has no conception. Theprinted direction should be pasted up in all boathouses, on every boat, atevery bathing place, and in every school: _Tread water when you findyourself out of your depth_. This is all that need be said, unless, indeed, we add: _Float when you are tired_. To float, one needs onlyto turn upon his back, keeping--as always when in the water--the mouth andchin well up and the lungs full of air. --Every one of us, of whatever ageand however encumbered with clothing, may tread water, even in a breakingsea, with as much facility as a fourfooted animal. The position of thewater treader is, really, very much safer and better than the sprawlingattitude of the ordinary swimmer. But the chief advantage lies in the factthat we can tread water without preliminary teaching, whereas, though werecommend all to learn how to swim, it involves time and pains, entailsconsiderable fatigue, and is, after all, very seldom adequately acquired. 

HINTS ON CLOTHING (p. 67). --_Advantages of Woolen Fabrics_. --Wool ismore irritating than cotton, on account of the stiffness of the hairs withwhich it bristles; but the excitation it produces becomes a therapeuticmeans whenever the skin needs a stimulant. 

The use of wool is particularly desirable in some countries and under someconditions of life. Professor Brocchi, a writer well known for hisinvestigations in malaria, attributes the good health and vigor of theancient Romans to their habit of wearing coarse woolen clothes; when theybegan to disuse them, and to wear lighter goods and silks, they becameless vigorous and less able to resist the morbid influence of bad air. Itwas at about the time the women began to dress in notably fine tissuesthat the insalubrity of the Roman air began first to be complained of. "Inthe English army and navy, " says Dr. Balestra, "the soldiers of garrisonsin unhealthy places are obliged constantly to wear wool next to the skin, and to cover themselves with sufficient clothing, for protection againstpaludine fevers, dysentery, cholera, and other diseases. " According toPatissier, similar measures have been found effectual in preserving thehealth of workmen employed on dikes, canals, and ditches, in marshy lands;while, previous to the employment of these precautions, mortality fromfevers was considerable among them. 

Dr. Balestra has proved by direct experiments in marshy regions that thickand hairy woolen garments arrest in their down a portion of the germsborne in by the air, which thus reaches the skin filtered and purified. The ancient Romans wore ample over-garments over their tunics, and neverput them away. It is no less important to be well covered during thenight; and precautions of this kind should be recommended to all who livein a swampy country. We are sometimes astonished when we see the nativesof particularly warm countries enveloped in woolen, as the Arab in hisburnoose, or the Spanish peasant in his tobacco-colored cloak. Suchmaterials protect both against the rays of the sun and against thecoolness of the night, and are excellent regulators of heat. It isdangerously imprudent to travel in southern countries without provision ofwarm clothing. --_Revue des Deux Mondes_. 

_Weight is not Warmth_. --While speaking of the warmth of clothing forinclement weather, it would be incorrect not to speak of weight inrelation to warmth. Many persons mistake weight for warmth, and thusfeeble people are actually borne down and weakened by the excess of heavyclothing which is piled on them. Good woolen or fur fabrics retain theheat, and yet are light. When fabrics intended for sustaining warmth aremade up of cotton, the mistake of accepting weight for warmth is made. Thesame errors are often made in respect to bed coverings, and with the sameresults. 

_Poisonously Dyed Clothing_. --The introduction of wearing apparel, socks, stockings, and flannels which have been made, by new processes ofdyeing, to assume a rich red or yellow color, has led to a local diseaseof the skin, attended, in rare cases, with slight constitutional symptoms. This disease is due to the dyestuffs. The chief poisonous dyes are the redand yellow coralline, substances derived from that series of chemicalbodies which have been obtained of late years from coal tar, and commonlyknown as the aniline series. 

The coloring principle is extremely active as a local poison. It induceson the skin a reddish, slightly raised eruption of minute round pimpleswhich stud the reddened surface, and which, if the irritation be severeand long-continued, pass into vesicles discharging a thin watery ichor andproducing a superficial sore. The disease is readily curable if the causeof it be removed, and, as a general rule, it is purely local in character. I have, however, once seen it pass beyond the local stage. A younggentleman consulted me for what he considered was a rapidly developedattack of erysipelas on the chest and back. He was, indeed, covered withan intensely red rash, and he was affected with nervous symptoms, withfaintness and depression of pulse, of a singular and severe kind. I tracedboth the local eruption and the general malady to the effect of theorganic dye in a red woolen chest and back "comforter. " On removing the"comforter" all the symptoms ceased. Similar and even fatal cases havebeen known from the wearing of highly colored hose. 

_Uncleanliness of Dress_. --Uncleanly attire creates conditionsfavorable to disease. Clothing worn too long at a time becomes saturatedwith the excretions and exhalations of the body, and, by preventing thefree transpiration from the surface of the skin, induces oppression of thephysical powers and mental inactivity. This observation will be acceptedby most persons as true in respect to underclothing; it is equally true inregard to those outer garments which are often worn, unremittingly, untilthe linings, torn and soiled, are unfit altogether for contact with thecleaner garments beneath them. Health will not be clothed in dirtyraiment. They who wear such raiment suffer from trains of minorcomplaints; from oppression, dullness, headache, nausea, which, thoughtrifling in themselves, taken one by one, when put together greatly reducethat standard of perfect health by which the value of life is correctlyand effectively maintained. --RICHARDSON. 

RESPIRATION. 

THE VOCAL ORGANS. --_Musical Tones in Speaking_ (p. 76). --Voice isdivided into singing and speaking voice. One differs from the other almostas much as noises do from musical sounds. In speaking, the sounds are tooshort to be easily appreciable, and are not separated by fixed and regularintervals, like those of singing; they are linked together, generally byinsensible transitions; they are not united by the fixed relations of thegamut, and can only be noted with difficulty. That it is the shortduration of speaking sounds which distinguished them from those ofsinging, is proved by this, that if we prolong the intonation of asyllable, or utter it like a note, the musical sound becomes evident. So, if we pronounce all the syllables of a phrase in the same tone, thespeaking voice closely resembles psalm singing. Every one must havenoticed this in hearing schoolboys recite or read in a monotone, and theanalogy is complete when the last two or three syllables are pronounced ina different tone. Spoken voice is, moreover, always a chant more or lessmarked, according to the individual and the sentiment which the wordsexpress. . . . It is related of Gretry, that he amused himself by noting asexactly as possible the "Bonjour, monsieur!" (Good day, sir!) of thepersons who visited him; and these words expressed by their intonation, infact, the most opposite sentiments, in spite of the constant identity ofthe literal sense. 

_Speech without a Tongue_. --De Jussieu relates that he saw a girlfifteen years old, in Lisbon, who was born without a tongue, and yet whospoke so distinctly as not to excite in the minds of those who listened toher the least suspicion of the absence of that organ. 

The Transactions of the Royal Society of London (1742) contain an accountof a woman who had not the slightest vestige of a tongue, but who could, notwithstanding, drink, eat, and speak as well and as distinctly as anyone, and even articulate the words in singing. Other instances have beenknown where individuals, after losing a portion of the tongue by accidentor disease, have again been able to speak after a longer or shorterperiod. --LE PILEUR. 

_Stimulants and the Voice_. --"The Drinker's Throat" is a recognizedpathological condition, and the Germans have a popular phrase, "He drinkshis throat away. " Isambert has pointed out the directly local irritanteffect of both alcohol and tobacco on the throat, and also the mode bywhich these agents, on absorption into the system, re-manifest theirpresence by predisposing to local pharyngeal inflammations. Dr. Krishaberaffirms: "It is generally admitted that alcoholic beverages and tobaccoirritate the mucous membrane of the throat, directly affect the voice, andleave on it ineffaceable traces. We hold with equal certainty that tea andcoffee, although not directly affecting the voice, do so indirectly byacting on the nervous system, and through it the vocal organs, as well asby, some general nervous derangement not very pronounced, but great enoughto deprive the singer of the full powers and capabilities of his voice. "

Dr. Mackenzie says: "The influence of the general health upon the voice isvery marked. Alcohol and tobacco should never be used. The hoarse tones ofthe confirmed votary of Bacchus are due to chronic inflammation of thelining membrane of the larynx; the originally smooth surface beingroughened and thickened by the irritation of alcohol, the vocal cords haveless freedom of movement, and their vibrations are blurred, or rathermuffled, by the unevenness of their contiguous edges. "

A young American lady of marked musical gifts once asked Adelina Patti'sadvice upon preparing for the stage. She found the great singer wrapped infurs, although the weather was not severe. After hearing her visitor, Patti replied: "Are you willing to give up _everything_ for your art?If you wish to succeed, you must learn to eat moderately, take nostimulants--not even tea or coffee--keep as regular hours as possibleconsistent with your public appearance, and even deny yourself the luxuryof friends. When you hear of a great vocalist giving extravagant winesuppers, you may be sure that the singer herself takes nothing. To be asuccessful _artiste_ you must be married, soul and body, to yourart. " Like the young man to whom Christ spake, the young woman "went awaysorrowful, " and, balancing the terms, concluded to forego the contest. 

ABDOMINAL RESPIRATION (p. 8l). --It has often been stated that therespiration of woman differs from that of man, in being limited almostentirely to the chest. In order to investigate this subjectscientifically, Dr. Mays, of Philadelphia, devised an ingenious instrumentfor examining the respiration of the native Indian girls in the LincolnInstitution. The girls had not yet been subjected to the restrictions ofcivilized dress. He says:

"In all, I examined the movements of eighty-two chests, and in each casetook an abdominal and a costal tracing. The girls were partly pure andpartly mixed with white blood, and their ages ranged from between ten andtwenty years. Thus there were thirty-three full-blooded Indians, five onefourth, thirty-five one half, and two three fourths white. _Seventy-five_ showed a _decided abdominal_ type of breathing, three acostal type, and three in which both were about even. _Those who showedthe costal type, or a divergence from the abdominal type, came from themore civilized tribes_, like the Mohawks and Chippewas, and were either_one half_ or _three fourths white_; while in _no singleinstance_ did a full-blooded Indian girl possess this type ofbreathing. 

"From these observations it obviously follows that, so far as the Indianis concerned, the abdominal is the original type of respiration in bothmale and female, and that the costal type in the civilized female isdeveloped through the constricting influence of dress around the abdomen. While these tracings were taken an incident occurred which demonstratedthat abdominal constriction could modify the movements of the thoraxduring respiration. At my first visit to the institution I obtained anexceptional costal type of respiration from a full-blooded Indian girl. Atmy next visit I concluded to repeat this observation, and found that, contrary to my instructions concerning loose clothing, etc. , this girl atmy first visit had worn three tight belts around her abdomen. After thesewere removed she gave the abdominal type of breathing, which ischaracteristic of nearly all the Indian girls. "

To us these facts are invaluable. It shows the faulty construction ofmodern female dress, which restricts the motion of abdominal respiration. It explains why, as experience has taught us, it is necessary to restorethis abdominal rhythm, by proper movements, in order permanently to curethe affections of the lower portion of the trunk. It demonstratesconclusively that woman's dress, to be injurious, needs only to interferewith the proper motion of respiration, even though it exercises not theslightest compression. --_Health Record_. 

THE GERM THEORY OF DISEASE (p. 86). --_What are Disease Germs?_--Microscopical investigation has revealed throughout Nature, in the air, inwater--especially when it contains organic matter, and even within thebodies of persons and animals, myriads of infinitesimal active organismswhich live, multiply, and die in endless succession. These have been named_bacteria_ (bacterium, a rod, so called from the general rod shapefirst observed), and also _microbes_ (microbe, a small livingobject). Some investigators apply the latter term as a general one, limiting the former to such microbes as are believed to be special diseaseproducers. The "Germ Theory" teaches that the seeds or _spores_ ofbacteria, floating in the air we breathe or in the water we drink, aretaken into our bodies where, under conditions favorable to their growth, they develop, multiply, and, each after its own species, producedistinctive evil results. --Thus, according to this theory, there arespecial varieties of microbes that cause, respectively, diphtheria, erysipelas, scarlatina, cholera, etc. --One of the most common microbes innature is the bacterium of putrefaction, found everywhere in decayingorganic matter. [Footnote: This is the microbe found in impure water. Ifwe take half a glass of spring or river water, and leave it uncovered fora few days, we shall observe upon it a thin coating of what appears to bea fine dust. Place, now, a drop of this dusty water under a cover glass, and examine it under a microscope with a magnifying power of about fivehundred diameters. The revelation is astonishing. "The whole field of themicroscope is in motion; hundreds of bacteria, resembling minutetransparent worms, are swimming in every direction with an undulatorymotion like that of an eel or snake. Some are detached, others united inpairs, others in chains or chaplets or cylindrical rods. . . . All these formsrepresent the different transformations of _Bacterium termo_, or themicrobe of putrefaction. Those which are dead appear as small, rigid, andimmovable rods. "--TROUESSART. ]

By the species of microbes called ferments all fermented liquors areartificially produced (see p. 132); these also cause the "rising" ofbread. --These wonderful little existences are thus made to perform animportant part in the economy of Nature. "Nourished at the expense ofputrefying organic matter, they reduce its complex constituents intosoluble mineral substances, which they return to the soil to serve afreshfor the nourishment of similar plants. Thus they clear the surface of theearth from dead bodies and fecal matter, and from all the uselesssubstances which are the refuse of life; and thus they unite animals andplants in an endless chain. "--TROUESSART. 

_How Disease Germs Grow_. --Experiments having shown that no life isknown to spring from inanimate matter, we may reasonably suppose that justas wheat does not grow except from seed, so no disease occurs without somedisease germ to produce it. Then, again, we may logically assume that eachdisease is due to the development of a particular kind of germ. If weplant smallpox germs, we do not reap a crop of scarlatina or measles; but, just as wheat springs from wheat, each disease has its own distinctivegerms. Each comes from a parent stock, and has existed somewherepreviously. . . . Under ordinary circumstances, these germs, though nearlyalways present, are comparatively few in number, and in an extremely dryand indurated state. Hence, they may frequently enter our bodies withoutmeeting with the conditions essential to their growth; for experimentshave shown that it is very difficult to moisten them, and till they aremoistened, they do not begin to develop. In a healthy system they remaininactive. But anything tending to weaken or impair the bodily organs, furnishes favorable conditions, and thus epidemics almost always originateand are most fatal in those quarters of our great cities where dirt, squalor, and foul air render sound health almost an impossibility. . . . Having once got a beginning, epidemics rapidly spread. The germs are thensent into the air in great numbers, and in a moist state; and theprobabilities of their entering, and of their establishing themselveseven in healthy bodies, are vastly increased. . . . Climate and the weatherhave also much influence on the vitality of these germs. Cold is apreventive against some diseases, heat against others. Tyndall found thatsunlight greatly retarded and sometimes entirely prevented putrefaction;while dirt is always favorable to the growth and development of germs. _Sunshine and cleanliness are undoubtedly the best and cheapestpreventives against disease. --"Disease Germs" Chambers's Journal_. 

You know the exquisitely truthful figures employed in the New Testamentregarding leaven. A particle hid in three measures of meal leavens it all. A little leaven leaveneth the whole lump. In a similar manner a particleof contagium spreads through the human body, and may be so multiplied asto strike down whole populations. Consider the effect produced upon thesystem by a microscopic quantity of the virus of smallpox. That virus isto all intents and purposes a seed. It is sown as leaven is sown, it growsand multiplies as leaven grows and multiplies, and it always reproducesitself. . . . Contagia are living things, which demand certain elements oflife, just as inexorably as trees, or wheat, or barley; and it is notdifficult to see that a crop of a given parasite may so far use up aconstituent existing in small quantities in the body, but essential in thegrowth of the parasite, as to render the body unfit for the production ofa second crop. The soil is exhausted; and until the lost constituent isrestored, the body is protected from any further attack from the samedisorder. To exhaust a soil, however, a parasite less vigorous anddestructive than the really virulent one may suffice; and if, afterhaving, by means of a feebler organism, exhausted the soil without fatalresult, the most highly virulent parasite be introduced into the system, it will prove powerless. This, in the language of the germ theory, is thewhole secret of vaccination. --TYNDALL. 

_Disease Germs Contained in Atmospheric Dust_. --Take the extractedjuice of beef or mutton, so prepared as to be perfectly transparent, andentirely free from the living germs of bacteria. Into the clear liquid letfall the tiniest drop of an infusion charged with the bacteria ofputrefaction. Twenty-four hours subsequently, the clear extract will befound muddy throughout, the turbidity being due to swarms of bacteriagenerated by the drop with which the infusion was inoculated. At the sametime the infusion will have passed from a state of sweetness to a state ofputridity. Let a drop similar to that which has produced this effect fallinto an open wound: the juices of the living body nourish the bacteria asthe beef or mutton juice nourished them, and you have putrefactionproduced within the system. The air, as I have said, is laden withfloating matter which, when it falls upon the wound, acts substantiallylike the drop. . . . A few years ago I was bathing in an Alpine stream, and, returning to my clothes from the cascade which had been my shower bath, Islipped upon a block of granite, the sharp crystals of which stampedthemselves into my naked shin. The wound was an awkward one, but, being invigorous health at the time, I hoped for a speedy recovery. Dipping aclean pocket handkerchief into the stream, I wrapped it round the wound, limped home, and remained for four or five days quietly in bed. There wasno pain, and at the end of this time I thought myself quite fit to quit myroom. The wound, when uncovered, was found perfectly clean, uninflamed, and entirely free from pus. Placing over it a bit of gold beater's skin, Iwalked about all day. Toward evening, itching and heat were felt; a largeaccumulation of pus followed, and I was forced to go to bed again. Thewater bandage was restored, but it was powerless to check the action nowset up; arnica was applied, but it made matters worse. The inflammationincreased alarmingly, until finally I was ignobly carried on men'sshoulders down the mountain, and transported to Geneva, where, thanks tothe kindness of friends, I was immediately placed in the best medicalhands. On the morning after my arrival in Geneva, Dr. Gautier discoveredan abscess in my instep, at a distance of five inches from the wound. Thetwo were connected by a channel, or _sinus_, as it is technicallycalled, through which he was able to empty the abscess without theapplication of the lance. 

By what agency was that channel formed--what was it that thus tore asunderthe sound tissue of my instep, and kept me for six weeks a prisoner inbed? In the very room where the water dressing had been removed from mywound and the gold beater's skin applied to it, I opened this year anumber of tubes, containing perfectly clear and sweet infusions of fish, flesh, and vegetable. These hermetically sealed infusions had been exposedfor weeks, both to the sun of the Alps and to the warmth of a kitchen, without showing the slightest turbidity or signs of life. But two daysafter they were opened, the greater number of them swarmed with thebacteria of putrefaction, the germs of which had been contracted from thedust-laden air of the room. And, had the pus from my abscess beenexamined, my memory of its appearance leads me to infer that it would havebeen found equally swarming with these bacteria--that it was their germswhich got into my incautiously opened wound. They were the subtile workersthat burrowed down my shin, dug the abscess in my instep, and producedeffects which might well have proved fatal to me. --TYNDALL. 

_Disease Germs Carried in Soiled Clothing_ (p. 89). --The conveyanceof cholera germs by bodies of men moving along the lines of humancommunication, without necessarily affecting the individuals who transportthem, is now easy to understand; for it is well established that clothesor linen soiled by cholera patients may not only impart the germs withwhich they are contaminated to those who handle them when fresh, but that, after having been dried and packed, they may infect persons at anydistance who incautiously unfold them. Thus, while the nurses of cholerapatients may, with proper precautions, enjoy an absolute immunity fromattack, the disease germs may be introduced into new localities withoutany ostensible indication of their presence. It is obvious that the onlysecurity against such introduction consists in the destruction or thoroughdisinfection of every scrap of clothing or linen which has been about theperson of a cholera patient. --DR. CARPENTER. 

I have known scarlet fever to be carried by the clothing of a nurse into ahealthy family, and communicate the disease to every member of the family. I have known cholera to be communicated by the clothes of the affectedperson to the women engaged in washing the clothes. I have known smallpoxconveyed by clothes that had been made in a room where the tailor had byhis side sufferers from the terrible malady. I have seen the new cloth, out of which was to come the riding habit for some innocent child torejoice in as she first wore it, undergo the preliminary duty of formingpart of the bed clothing of another child stricken down with fever. Lastly, I have known scarlet fever, smallpox, typhus, and cholera, communicated by clothing contaminated in the laundry. --DR. RICHARDSON. 

THE SANITARY HOME (see p. 94). --1. _The Site_. --First and foremost ofall the things you are to consider, is the healthfulness of a situation. The brightest house and cheeriest outlook in nature will be made somber bythe constant presence of a doctor, and the wandering around of an unseen, but ever felt, specter in the shape of miasm. . . . Malaria-malus, bad; aria, air--means, in its common definition, simply bad air. Miasma is itssynonym, --infecting effluvia floating in the air. Because, as everybodyknows, certain places have always chills and fever associated with them, and other places have not, it follows that between such places there issome fact of difference; this fact is the presence of miasm, a cause ofdisease, having a signification associative with the locality. . . . 

Vegetation, heat, and moisture: these are the three active agents in theproduction of miasma, to which a fourth is to be added, in the influenceof non-drainage, either by the way of the atmosphere or running water. Thestrongest example of a malarious locality one might make would be insuggesting a marshy valley in a tropical climate, so overrun with fixedwater as to destroy a prolific vegetation, yet not covering it enough toprotect the garbage from the putrefying influences of the sun; thisvalley, in turn, so environed with hills as to shut off a circulation ofair. . . . Ground newly broken is not unapt to generate miasm. This resultsfrom the sudden exposure of long-buried vegetable matter to the influencesof moisture and heat. . . . It may readily be conceived that malarioussituations exist where the miasm is not sufficient in quantity to producethe effects of intermittent or bilious fever, yet where there is quiteenough of it to keep a man feeling good for nothing, --he is not sick, buthe is never well. I know of one country seat of this kind, where fortythousand dollars would not pay for the improvements put upon it, andwhere, I am free to declare, I would not think of living, even if, as aninducement, a free gift were made to me of the place. . . . Besides miasm, there are other atmospheric associations to be considered. I recall thismoment a distillery, where attempt was made to get clear of the mash bythrowing it into a running stream, with the anticipation of its beingcarried to the river, but where, on the contrary, it became a stagnantputrescent mass, impregnating the air for miles with its unendurable odor, and inducing such a typhoid tendency that half the countryside were downwith fever. . . . There are, again, situations where the filth and debris ofsewage exercise a poisoning influence on the surrounding atmosphere. Thishas its principal application to the neighborhood of cities and townsdrained into adjoining streams. London and the Thames furnish a notableillustration. A cove, attractive as it is, may prove a receptacle for theaccumulation of dead fish and other offal, which shall make untenable thecharming cottage upon the bank. A deep cove has rarely healthysurroundings, the circulation of its water being too sluggish to insurefreshness and vitality. Water, like blood, to be healthy, must be in astate of continuous movement. 

A nonobservant man, purchasing a beautiful stream, may be completelydisappointed by finding that the opacity of its water depends upon afactory, of which he had never so much as heard; he may not let hischildren bathe in it, for he may well fear for them the fate of the fishhe so plentifully finds lying dead upon the shore. A poisoned rural streamis as sad a sight as it has grown to be a common one. Always, beforebuying water, know what there is up stream, or what there is likely to be. 

Never buy a country house without seeing to it that the foundation standsupon a higher level than some channel which may drain it, and this, by theway, is not to consider alone the dry summer day on which you go first tovisit the place; you are to think of the winter and spring. Look to itthat no excess of water shall be able to drown you out; some places, whichin dry weather are glorious, are, in winter and spring, ankle deep inslush and mire, and everything about them is as wet as a soaked board. Open the front door of such a house, and a chill strikes you instantly. Afire must be kept the year round, or otherwise you live in the moisture ofa vault. Places there are of this class where the question of the waterfrom the kitchen pump comes to absorb the attention of the wholehousehold. 

No shade is an abomination. A bilious fever fattens in the sun as doesmiasm in a marshy valley. Too much shade, on the contrary, and too nearthe house, is equally of ill import; it keeps things damp, and dampness isa breeder of pestilence. An atmosphere confined about a house by too densefoliage is, like the air of an unventilated room, not fit for practicalpurposes. The sporadic poisons have an intimate relationship withdampness; miasm lives in it as does a snail in his shell. Besides this, itshuts out the cool breath of the summer nights, and makes restlessswelterers where even a blanket might be enjoyed. --DR. JOHN DARBY, _OddHours of a Physician_. 

2. _The House_. --So construct the dwelling from foundation to roofthat no dampness can result. Give to the cellar dry walls, a cement floor, and windows enough to insure constant currents of air. Insist upon such asystem of immediate and perfect sewerage as shall render contaminationimpossible. If "modern improvements" are afforded, see that the plumbingembraces the latest and most scientific sanitary inventions. Do noteconomize on this point; health, perhaps life, depends upon the perfectworking of the various traps. Having employed the most skilled andintelligent plumbers, overlook their work so that you may fully understandthe principle applied. 

Provide for ample ventilation in every apartment, above and below. Let thesleeping rooms be above stairs, and furnished with appliances for moderatewarmth in winter. Treat yourself and your family to as many fireplaces aspossible. Indulge in a spacious piazza, so placed that it will not cut offthe light from the family sitting room, and, if you can, include a balconyor two, large enough to hold a chair and a table, or a workbasket. Remember that a house is for convenience and protection _only when youcan not be in the open air_. 

3. _The kitchen and the Dust Heap. --Removal of Household Refuse_. --Ithas to be assumed, especially where servants are not carefully overlooked, that the dust heap of most houses will contain more or less decomposingorganic matter, such as bits of meat, scales and refuse of fish, tea andcoffee grounds, and the peelings of vegetables, which, though quite out ofplace in the ash heap, are apt surreptitiously to be thrown upon it. Suchmatter soon becomes offensive and even dangerous, and a few days'retention of it in warm weather constitutes a legal nuisance. Householdrefuse should be carted away as often as once in two days; in extreme hotweather, daily. Where it is inexpedient to remove it frequently, it shouldbe kept covered to the depth of two or three inches with a layer ofpowdered charcoal, or freshly burnt lime, or, at least, of clear dryearth. All soil which has become foul by the soakage of decaying orvegetable matter should be similarly treated. The refuse heap should beprotected from rain, and liquids should never be thrown upon it. Whereobnoxious matter has been allowed to accumulate, its disturbance forremoval should be conducted with special precaution, both on account ofits temporary offensiveness of odor and the more serious results which mayfollow. It can not be too distinctly understood that cleanliness, ventilation, and dryness are the best of all deodorizers. One of the firstof household regulations should be to see that no unsanitary rubbishremains in or about the dwelling. Keep the dust heap itself at thefarthest practicable remove from the house. Sow grass seed plentifullyupon the back premises, and induce tidiness in the domestics by having thekitchen door open upon a well-kept lawn. 

_Burning of Garbage_. --The easiest, quickest, and most sanitarymethod of disposing of household garbage is to burn it This plan has beenofficially recommended by the Boards of Health in various cities. Manyhousekeepers have adopted it, and find it so practicable that in New YorkCity there has become a marked decrease in the amount of household refusecollected by the scavengers. If, after every meal, the draughts of therange be opened, and all waste matter be deposited within, a few moments, or at most, a half hour, will effectually dispose of it, and prevent allthe dangers that arise from its retention and accumulation. In thecountry, where there is plenty of ground, nearly all rubbish can bedestroyed in this way and by outside fires, with the additional advantagethat the--E. R. S. 

4. _The Sewers and Drains. --How to Keep out Sewer Air_. --The mostperfectly flushed sewers that are made, under the latest and fullestsanitary light, must, owing to the constant entrance of greasy and otheradhesive material, contain more or less of particles that "stick, " andalso more or less of fungi and mold; so that here, shut away from lightand air, goes on the peculiar fermentation that fits it for the soil orhabitat of the malarial germ. These germs, the soil once ready, takepossession and multiply, whether that soil be a sewer or the blood of aperson who sits calmly unconscious in a gorgeous chamber above, with asmall continuation of the sewer extending untrapped up to his washbowl. --DR. DERBY. 

Keep constant watch of your traps and drains. Cultivate the faculty ofdetecting sewer gas in the house. Always fear a smell; trace it to itssource and provide a remedy. At the same time, bear in mind that it is notalways the foul smell that is most dangerous. There is a close, sweet odoroften present in bathrooms, and about drains, that is deadly as the Upastree. Bad air from neglected drains causes not only fevers, dysentery, anddiphtheria, but asthma and other chronic disorders. Illuminating gas, escaping from pipes and prevented from exuding by frozen earth, has beenknown to pass sidewise for some distance into houses. Thus also the airfrom cesspools and porous or broken drains finds its way, when anexamination of the household entrance to the drain fails to reveal thecause of an existing effluvia. But, however bad the drain may be outsidethe house, there is little to fear provided the gas can escape externally. Every main drain should have a ventilating pipe carried from it directlyoutside the house to the top of the highest chimney. The soil pipe insidethe house should be carried up through the roof and be open at the top. 

Digging for drains or other purposes should not be allowed when themercury stands above 60°; but if, as in repairs of pipes, it becomesnecessary to dig about the house in hot weather, let it be done in themiddle of the day, and replace the turf as speedily as possible. If thesoil be damp, or the district malarious, sprinkle quicklime upon the earthas fast as it is turned. 

_How to Clear Waste Pipes_. --The "sewer gas, " about which so much hasbeen written, and which is so justly dreaded, is not, as many suppose, theexclusive product of the sewer. Indeed, the foul and dangerous gases arenot only found in the sewers themselves, but in the unventilated wastepipes, and those which are in process of being clogged by the foul matterpassing through them. Any obstruction in the soil or waste pipes istherefore doubly dangerous, because it may produce an inflow of foul gasinto the pipe, even though the entrance to the sewer itself has beenentirely cut off. 

In pipes leading from the house to the cesspool, there is a constantaccumulation of grease. This enters as a liquid, but hardens as the watercools, and is deposited on the bottom and sides of the pipes. As theseaccumulations increase, the water way is gradually contracted, till thepipe is closed. 

When the pipe is entirely stopped, or allows the water to fall away bydrops only, proceed thus: Empty the pipe down to the trap, as far aspracticable, by "mopping up" with a cloth. If the water flows very slowly, begin when the pipe has at last emptied itself. Fill the pipe up withpotash, crowding it with a stick. Then allow hot water to trickle upon thepotash, or pour the hot water upon it in a small stream, stopping as soonas the pipe appears to be filled. As the potash dissolves and disappears, add more water. At night a little heap of potash may be placed over thehole, and water enough poured on so that a supply of strong lye will flowinto the pipe during the night. 

Pipes that have been stopped for months may be cleaned out by this method, though it may call for three or four pounds of potash. The crudest kind, however, appears to act as well as the best. If the pipe is partiallyobstructed, a lump of crude potash should be placed where water will dripslowly upon it, and so reach the pipe. As water comes in contact with thepotash, it becomes hot, thus aiding in dissolving the grease. Potash, incombination with grease, forms a "soft" or liquid soap, which easily flowsaway. It is also destructive to all animal and most mineral matters. 

Some of the most dangerous gases come from wash-basin pipes, being, perhaps, the result of the decay of the soap and the animal matter washedfrom the skin. 

When a pipe is once fairly cleaned out, the potash should be used fromtime to time, in order to dissolve the greasy deposits as they form, andcarry them forward to the cesspool or sewer. --_Artisan_. 

_What Came from a Neighbor's Cesspool_. --Keep watch not only of yourown premises, but stand on guard against those of your neighbors. Dr. Carpenter cites a case wherein "four members of a certain household wereattacked with typhoid fever, one of whom narrowly escaped with her life. The circumstances left no doubt in the mind of the attending physicianthat the malady originated in the opening of an old cesspool belonging toa neighboring house, then in course of demolition. The house in which theoutbreak took place is large and airy, and stands by itself in a mostsalubrious situation. The most careful examination failed to disclose anydefect either in its drainage or its water supply; there was no typhoid inthe neighborhood; and the milk supply was unexceptional. But theneighboring house being old, and having been occupied by a school, itsremoval had been determined on to make way for a house of higher class;and as the offensive odor emanating from the uncovered cesspool was atonce perceived in the next garden, and the outbreak of typhoid followed atthe usual interval, the case seems one which admits of no reasonablequestion. "

5. _The Cellar_. --_A Typical Bad Cellar_. --Did the reader ever, when a child, see the cellar afloat at some old home in the country? Youcreep part way down the cellar stairs with only the light of a singletallow candle, and behold by its dim glimmer an expanse of dark water, boundless as the sea. On its surface, in dire confusion, float barrels andboxes, butter firkins and washtubs, boards, planks, hoops, and staveswithout number, interspersed with apples, turnips, and cabbages, whilehalf-drowned rats and mice, scrambling up the stairway for dear life, drive you affrighted back to the kitchen. . . . Now consider the case of oneof these old farmhouse cellars that has been in use fifty years or more. In it have been stored all the potatoes, turnips, cabbages, onions, andother vegetables for family food. The milk and cream, the pork and beef, and cider and vinegar, have all met with various accidents, and from timeto time have had their juices, in various stages of decay, absorbed by thesoil of the cellar bottom. The cats have slept there to fight the rats andthe mice, who have had their little homes behind the walls for half acentury; and the sink spouts have for the same term poured into the soilclose by, their fragrant fluids. The water rushes upward and sideways intothe cellar, forming, with the savory ingredients at which we havedelicately hinted, a sort of broth, quite thin and watery at first, butgrowing thicker as the water slowly subsides and leaves its grosser partspervading the surface of the earth, walls, and partitions. All this timethe air rushes in at the openings of the cellar, and presses constantlyupward, often lifting the carpets from the floors, and is breathed day andnight by all who dwell in the house. Does it require learned doctors orboards of health to inform any rational person that these conditions areunfavorable to health?--MRS. PLUNKETT, _Women, Plumbers, andDoctors_. 

_What Came from a Crack in a Cellar Wall_. --A few years ago a Bostongentleman inherited a house, situated on one of the most desirable streetsof the city. Resolving to make a healthy as well as a beautiful home, he. Spent a large sum, and gave personal supervision to all the details of anelaborate system of plumbing. He moved in. Imagine his grief anddisappointment when member after member of his family succumbed todiphtheria, and an infant and a grown daughter died. Though so deeplysmitten, he did not lose his belief in the connection between cause andeffect. He ordered a minute investigation of the premises by experts. Aslight crack, so small as to have escaped ordinary observation, was foundin the cellar wall. Investigation of the premises next door--the inmatesof which were also suffering from diphtheria--showed a choked-up drain, which ought to have connected with the sewer, but did not. The filthy oozefrom this was pouring out, just where its effluvium and its disease germscould pass without any hindrance through the crack. 

Now that it is shown that gases pass through bricks and many kinds ofstone, it is easy to see that the sanitary welfare of one is the sanitarywelfare of all. --MRS. PLUNKETT. 

6. _The Bedroom_. --_The Bed a Night Garment_. --There is stillone of our garments to be considered, which generally is not regarded assuch. I mean the bed--that piece of clothing in which we spend such agreat part of our time. 

The bed is not only a place of rest; it is especially our sleepinggarment, and has often to make up for privations endured during the dayand the day's work, and to give us strength for to-morrow. Like our daygarments, the bed covering must be airy and warm at the same time. Wewarm the bed by our body, just as we warm our clothes, and the bed warmsthe air which is continually flowing through it from below, upward. Theregulating strata must be more powerful in their action than in our dayclothes, because during rest and sleep the metamorphosis of our tissuesand the resulting heat become less; and because in a horizontal positionwe lose more heat by an ascending current of air than in a verticalposition, where the warm ascending current is in more complete and longercontact with our upright body. 

The warmth of the bed sustains the circulation in our surface to a certaindegree for the benefit of our internal organs at a time when ourproduction of heat is at its lowest ebb. Hence the importance of the bedfor our heat and blood economy. Several days without rest in a bed notonly make us sensible of a deficiency in the recruiting of our strength, but very often produce quite noticeable perturbations in our bodilyeconomy, from which the bed would have protected us. --DR. MAX VONPETTENKOFFER. 

_Bed Ventilation_. --It often happens that the desire of the energetichousekeeper to have her work done at an early hour in the morning, causesher to leave one of the most important items of neatness undone. The mosteffectual purifying of bed and bedclothes can not take place, if theproper time is not allowed, for the free circulation of pure air, toremove all human impurities which have collected during the hours ofslumber. At least two or three hours should be allowed for the completeremoval of atoms of insensible perspiration which are absorbed by the bed. Every day the airing should be done; and, occasionally, bedding constantlyused should be carried into the open air, and left exposed to the sun andwind for half a day. --_Home and Health_. 

CIRCULATION. 

THE PULSE (p. 116). --The pulse which is felt by the finger does notcorrespond precisely with the beat of the heart, but takes place a littleafter it, and the interval is longer, the greater the distance of theartery from the heart. The beat of the artery on the inner side of theankle, for example, is a little later than the beat of the artery in thetemple. --HUXLEY. 

The pulse is increased by exertion, and thus is more rapid in a standingthan in a sitting, and in a sitting than in a lying posture. It isquickened by meals, and while varying thus from time to time during theday, is on the whole quicker in the evening than in early morning. It issaid to be quicker in summer than in winter. Even independently ofmuscular exertion, it seems to be quickened by great altitude. Its rate isalso profoundly influenced by mental conditions. --FOSTER. 

CIRCULATION OF THE BLOOD IN THE BRAIN (p. L20). --Signer Mosso, who hasbeen engaged on the subject for six years, has published some newobservations on the different conditions of the circulation of the bloodin the brain. He has had the privilege of observing three patients who hadholes in their skulls, permitting the examination of the encephalicmovements and circulation. No part of the body exhibits a pulsation sovaried in its form as the brain. The pulsation may be described astricuspid; that is, it consists of a strong beat, preceded and followed bylesser beats. It gathers strength when the brain is at work, correspondingwith the more rapid flow of blood to the organ. The increase in the volumeof the brain does not depend upon any change in the respiratory rhythm;for, if we take the pulse of the forearm simultaneously with that of thebrain, we can not perceive that the cerebral labor exercises any influenceupon the forearm, although the pulsation in the brain may be considerablymodified. The emotions have a similar effect upon the circulation of thebrain to that of cerebral labor. Signor Mosso has also observed andregistered graphically the variations of the cerebral pulse during sleep. Generally the pulses of the wrist and the brain vary oppositely. At themoment of waking, the pulse of the wrist diminishes, while that of thebrain increases. The cerebral pulsations diminish as sleep grows deeper, and at last become very weak. Outward excitations determine the samemodifications during sleep as in the waking state, without waking thesleeper. A deep inspiration always produces a diminution in the volume ofthe brain, in consequence, probably, of the increased flow of blood intothe veins of the thoracic cavity; the increase of volume in the brain, when it takes place, is, on the contrary, due to a more abundant flow ofarterial blood to the encephalus. --_Popular Science Monthly, March, 1882_. 

CATARRHAL COLDS (p. L30). --I maintain that it can be proved, with asabsolute certainty as any physiological fact admits of being proved, thatwarm, vitiated indoor air is the cause, and cold outdoor air the bestcure, of catarrh. . . . Fresh cold air is a tonic that invigorates therespiratory organs when all other stimulants fail, and, combined with armexercise and certain dietetic alternatives, it is the best remedy for alldisorders of the lungs and upper air passages. . . . A combination of thethree specifics, --exercise, abstinence, and fresh air, --will cure the mostobstinate cold. . . . Frost is such a powerful disinfectant, that in very coldnights the lung-poisoning atmosphere of few houses can resist itspurifying influence; in spite of padded doors, in spite of "weatherstrips"and double windows, it reduces the indoor temperature enough to paralyzethe floating disease germs. The penetrative force of a polar night frostexercises that function with such resistless vigor that it defies thepreventive measures of human skill; and all Arctic travelers agree thatamong the natives of Iceland, Greenland, and Labrador pulmonary diseasesare actually unknown. Protracted cold weather thus prevents epidemiccatarrhs, but during the first thaw Nature succumbs to art: smolderingstove fires add their fumes to the effluvia of the dormitory, tight-fitting doors and windows exclude the means of salvation; superstitiontriumphs; the lung poison operates, and the next morning a snuffling, coughing, and red-nosed family discuss the cause of their affliction. . . . Itis a mistake to suppose that "colds" can be propagated only by directtransmission or the breathing of recently Vitiated air. Catarrh germs, floating in the atmosphere of an ill-ventilated bedroom, may preservetheir vitality for weeks after the house has been abandoned; and the nextrenter of such a place should not move in till wide-open windows and doorsand a thorough draught of several days have removed every trace of a"musty" smell. --DR. FELIX L. OSWALD, _Remedies of Nature, PopularScience Monthly, March, 1884_. 

CATCHING COLD. --The phrase "to catch cold, " so often in the mouths ofphysicians and patients, is a curious solecism. It implies that the term"cold" denotes something positive--a sort of demon which does not catch, but is caught by the unfortunate victims. . . . If most persons outside of themedical profession were to be asked what they consider as chiefly to beavoided in the management of sick people, the answer would probably be"catching cold. " I suspect that this question would be answered in thesame way by not a few physicians. Hence it is that sick rooms are poorlyventilated, and patients are oppressed by a superabundance of garments andbedclothes. The air which patients are made to breathe, having beenalready breathed and rebreathed, is loaded with pulmonary exhalations. Cutaneous emanations are allowed to remain in contact with the body, aswell as to pervade the atmosphere. Patients not confined to the bed, especially those affected with pulmonary disease, are overloaded withclothing, which becomes saturated with perspiration, and is seldomchanged, for fear of the dreaded "cold. ". . . 

A reform is greatly needed in respect to "catching cold. " Few diseases arereferable to the agency of cold, and even the affection commonly called acold is generally caused by other agencies, or, perhaps, by a specialagent, which may prove to be a microbe. Let the axiom, _A fever patientnever catches cold_, be reiterated until it becomes a household phrase. Let the restorative influence of cool, fresh, pure atmosphere beinculcated. Let it be understood that in therapeutics, as in hygiene, thesingle word _comfort_ embodies the principles which should regulatecoverings and clothing. --AUSTIN FLINT, M. D. , _in a Lecture printed inThe New York Medical Journal_. 

DIGESTION AND FOOD. 

THE WATER WE DRINK (p. L55). --_Qualities of Pure Water_. --"A gooddrinking water, " says Dr. Simpson (in _The Water We Drink_), "shouldpossess the following physical characters: it should be entirely free fromcolor, taste, or odor; it should, moreover, be cool, well aerated, soft, bright, and entirely free from all deposit. But it should be rememberedthat a water having all these characteristics may yet be more or lesspolluted by organic matter, owing to the proximity of drains andsewers. . . . Disease has frequently been traced to the use of perfectlybright and clear water, where there was no sediment, and where the animalorganic matter was held in a state of solution. "

In the case of diseases, such as typhoid, which attack the stomach, disease germs are removed along with the excreta; and if, as is often thecase, the drainage of an infected town flows into a river, and that riveris used in some after portion of its course as a water supply, there isgreat danger of such diseases being communicated. For, however well thewater may be purified and filtered, we have no guarantee that it will notcontain some of these disease germs, which are so small that they passthrough the finest filters. It is in this way that almost all the greatcholera and typhoid epidemics have spread. --_Chambers's Journal_. 

_Well Water Often Dangerous_. --A densely crowded population soonimpregnates the soil to some depth with filth, which drains into the watercourse below, especially if such water is near the surface. This surfacewater easily penetrates a loosely walled well. Every well, therefore, should not only be widely separated from barnyards, cesspools, pens, sinks, and similar places, but should be made water-tight with cement, sothat nothing can reach its interior except water that has been filteredthrough dense beds of unpolluted ground below. If these precautions areneglected, the best and deepest well may become continually contaminatedby infiltration from the surrounding surface. This impure water, even whennot used for family drinking, is sometimes supplied to cows, or used forwashing dairy pans, or employed in diluting milk for the market, and thereare many known cases in which disease has thus been disseminated. Thus, anepidemic of typhoid fever in Cambridge, Mass. , was definitely traced to adairy which supplied the victims with milk. Upon investigation it wasfound that a short time before there had been a typhoid patient in thefarmhouse, and that the well from which water was taken to wash the milkpans had become contaminated with the specific poison brought into it fromthe surrounding drainage. 

All suspected water should be thoroughly boiled before using it to drink. Some physicians insist that the boiling should continue for one or twohours in order entirely to destroy the bacterial germs. The heaviness andinsipidity incident to boiled water may be somewhat relieved by afterwardfiltering it. Filtering, of itself, however, will do little toward riddingthe water of microbes, which are much too minute to be arrested by theordinary apparatus. --When journeying, where one must often take a hastymeal at a railway station, drink hot water in preference to cold. Aconvenient portable filter may be arranged with a bottle of powderedcharcoal, and a piece of filtering paper. A traveler by briskly stirring atablespoonful of the charcoal into a pint of water, allowing it to standfive or ten minutes, and then filtering it through the paper, may ventureto relieve his thirst in almost any part of the country. 

_Water an Absorbent of Foul Gases_. --If a pitcher of water be leftuncovered in an occupied apartment for only a few hours, it will becomefoul from the absorption of the respired and perspired gases in the room. The colder the water, the greater the capacity to contain these gases. Water kept in a room over night is therefore unfit for drinking, andshould not be used even to brush the teeth or to gargle in the throat. 

_Impure Ice, a Breeder of Disease_. --We generally take the purity ofour ice for granted, and, like the alligator in the bayou, close ourmouths and swallow it. In the country, I have seen during the ice-harvesting season, wagon after wagon passing me on the road, laden withice that had been collected from canals, rivers, and streams receivingsewerage, and from ponds that are in the summer time reeking with slime, and often offensive from the quantity of decomposed vegetable and animalmatter brought in by the washing from the meadow. These streams would beshunned as a source of water supply. 

Should you interview a native regarding the slimy mud puddle before you, called Mr. So-and-so's private "ice pond, " he would say that "in winter itis much better, and when frozen, you know, it makes fine ice, " presentingthat popular though ignorant belief that while in the act ofcrystallizing, water rids itself of all its injurious qualities, howeveroffensive it may be in its liquid state. Unfortunately, there is enoughtruth in the current idea of the elimination of noxious and foreign matterduring the process of freezing to give color to the popular belief, butnot enough to make it a safe reliance; therefore all means should be usedto enlighten the public regarding this subject. Experiment has shown thatfreezing produces little change or effect in overcoming the poisonousinfluences, and ice has often served as a vehicle to convey the germs oftyphoid and other low forms of fever. Pure ice can be procured only fromwater free from impurities, and ice for domestic or surgical purposesshould never be collected from ponds or streams which contain animal orvegetable refuse, or stagnant and muddy material. --_Journal ofReconstructives, Oct. , 1887_. 

THE GLANDULAR COAT OF THE STOMACH, AND HOW IT WEEPS (p. L62). --While thefood is thus being continually moved about, it is at the same timesubjected to the action of the chemical sac. This is, as we have said, aglandular sac. It is of some thickness, and is made of little glands boundup together with that stringy fibrous packing material which anatomistscall _connective tissue_. 

If we were to imagine many gross of small India-rubber vials all placedside by side, and bound together with hay or straw into a great mat, andthe mat rolled up into a sac, with all the mouths of the vials turnedinward, we should have a large and coarse, but tolerably fair image of theglandular coat of the stomach. Each vial would then represent one of theglands of this coat, one of the gastric or peptic glands, as they arecalled. Each gland, however, is not always a simple tube, but is oftenbranched at the bottom end, and all of them are lined, except just attheir mouths, with large rounded bodies, which not unfrequently almostchoke up their cavity. 

FIG. 72. 

[Illustration: BRANCHED GASTRIC GLAND a. _The peptic cells. _ b. _The inert cells. _]

The rounded masses, or cells, as they are called, in the interior of eachgland, form the really active part of the apparatus. Each cell is a littlelaboratory, which concocts out of the material brought to it or near it bythe blood a certain potent, biting fluid, and is hence called a peptic ordigestive cell. Each cell is born at the bottom of the tube, and inprocess of time travels upward toward the mouth. When it reaches themouth, it bursts, and pours into the stomach the fluid it has elaborated, or perhaps may give it out without bursting, while it is still within itstube. 

In those cases in which it has been possible to look in upon the stomachwhile at work (as in the famous case of Alexis St. Martin), and where theorifices of the tiny glands (for though we have compared them to bottles, they are exceedingly small) appear like little dots, tears were seen tostart at the mouths of the glands, gather into drops, and finally trickledown into the lowest part of the stomach. The stomach, as it were, weeps, and indeed the weeping of tears is just such another effect of glandularactivity--only ordinary tears form a mild and, chemically speaking, impotent fluid; while the fluid which the tears of the stomach weep--the_gastric juice_--is a sharp, piercing water of excessive chemicalpower. --Hinton. 

POISONOUS MILK, CHEESE, AND ICE CREAM (p. L69). --In late years there havebeen many cases of poisoning by ice cream, cheese, and milk. The poisonousprinciple sometimes developed in these articles of food has been made asubject of special investigation, and it has been found to be due tonatural causes. Dr. Vaughan, of Michigan, after spending several months inexperimenting upon samples of twelve different cheeses, which had causedthree hundred cases of poisoning, finally succeeded in isolating certainpoison crystals, which he calls _Tyrotoxicon_. He says: "A few dropsof an aqueous solution of these crystals placed upon the tongue producesall the symptoms observed in those who had been made sick by eating of thecheese. This was tried repeatedly upon myself, and upon some of mystudents who kindly offered themselves for experimentation. " Dr. Vaughanafterward procured the poison crystals from milk which had stood somemonths in a closed bottle, and also from a sample of ice cream by whicheighteen persons had been made ill. It was learned in the latter case thatthe custard, of which the ice cream was made, had been allowed to stand ina foul atmosphere for two hours before it was frozen. By placing smallbits of this poisonous cream in good milk, and allowing it to standtwenty-four hours, the whole became vitiated. This proved that the poisonis due to the growth of some ferment. In the autumn of 1886, many personsin different hotels at Long Branch were poisoned by milk obtained from acertain milkman. In this case it was found that the cows were milked atnoon, the warm milk being immediately placed in cans and carted eightmiles during the warmest part of the day, in a very hot month. In June, 1887, nineteen persons in New York city were similarly poisoned by milkwhich also came from one dairy. Many of these persons had narrow escapesfrom death. These, and many other like instances, teach us the importanceof the greatest care in every detail of milk handling. A little dried milkformed along the seam of a tin pail, or any similar lodging place, may bethe starting point of poison generation. A month after his firstexperiments with the ice cream mentioned above, Dr. Vaughan put smallpieces of the dried custard in pans of milk, and afterward made custardfrom this milk. This yielded tyrotoxicon as before, showing the tenaciousvitality of the poison, and also explaining the fact that the precisecause of poisoning is in many cases so difficult to trace. 

FISH AS FOOD (p. 169). --It is not desirable that fish should be the solekind of nitrogenous food eaten by any nation; and even if milk and eggs beadded thereto, the vigor of such a people will not be equal to that offlesh-eating nations. At the same time, the value of fish as a part of adietary is indicated by the larger proportion of phosphorus which itcontains, and which renders it especially fitted for the use of those whoperform much brain work, or who are the victims of much anxiety anddistress. --EDWARD SMITH, _in "Foods_. "

For the mentally exhausted, the worried, the "nervous, " and the distressedin mind, fish is not simply a food; it acts as physic. The brain isnourished by it, the "nerves"--to use the term in its popular sense--are"quieted"; the mind grows stronger, the temper less irritable, and thewhole being healthier and happier when fish is substituted for butcher'smeat. . . . I find persons who are greatly excited, even to the extent ofseeking to do violence to themselves or to those around them, who can notsleep, and who are in an agony of irritability, become composed andcontented when fed almost exclusively on fish. In such cases I havewithdrawn butter, milk, eggs, and all the varieties of warm-blooded animalfood; and, carefully noting the weight and strength, I find no diminutionof either, while fish is supplied in such quantities as fully to satisfythe appetite. --J. MORTIMER GRANVILLE, M. D. , "_Fish as Food andPhysic_. "

COFFEE AND TEA (p. 170). --Besides the alkaloid _Caffeine_ whichcoffee contains, it also develops, in roasting, a volatile oil calledCaffeone, to which is due its characteristic aroma. The main effects ofcoffee are due to both the caffeine and the caffeone, which areantagonistic, though not contemporaneous, in action. The volatile oilreduces arterial tension, allows a brisker flow of blood, and so increasesthe rapidity of the heart's action. It also acts upon the brain, andintellectual faculties in general; keeps one awake, and his mind clear. Caffeine, on the other hand, like digitalis, produces a high arterialtension, and slows the heart beat. It exerts its chief effect upon thespinal cord, to which, like strychnia, it is an excitant. The shaking handof the inveterate coffee drinker is caused by caffeine. Thus a cup ofcoffee produces on the drinker a double effect, --of the oil and thealkaloid; the former sooner and transient, the latter later andlasting. . . . Coffee is not in itself nutritious to any marked degree; but itsaves food, and also maintains life, by its exhilarating effect upon thenervous system. It is an excellent antidote to opium, producing thewakefulness that antagonizes the narcotic sleep of the drug; is now andthen curative of sick headache, and is one of the standard remedies forcertain forms of nausea. 

To the chemist, _Tea_ is much the same thing as coffee. It containsconsiderably more tannin, a volatile oil, and an alkaloid (theine)indistinguishable from caffeine. That the injurious effects of overdosesare due as much to the volatile oil as to the alkaloid, is shown by thefact that tea packers are made ill by long breathing of air filled withit, and that tea tasters in China, who avoid swallowing the infusion, canendure their trade but a few years, and leave the country with shatterednerves. 

Probably every one numbers among his friends women who are actual slavesof the tea habit, and who would find tea as hard to forsake as men findtobacco. It is not unlikely that the functional cardiac disorder, oftenspoken of as the "tobacco heart, " due to nervous derangement, andaccompanied by palpitation and pain in the cardiac region, is more oftendue to tea than tobacco. In fact, the disorders induced by excessive teadrinking have been grasped as a special disease, to which has been giventhe name of _Theism_. This includes a train of symptoms, usuallyprogressive, loss of appetite, pain after meals, headache, constipation, palpitation, cardiac distress, hysterical manifestations, dizziness, andparesis. --DR. MAURICE D. CLARKE, _Popular Science News_. 

Tea drinkers, as a rule, express doubts as regards the correctness ofalleged poisonous properties of tea. Numerous instances of individuals ofthis class have been noticed who were themselves suffering from teapoisoning. Their nerves were in a deplorably abnormal condition, the heartand brain were functionally disturbed, and the sleep less in quantity andless refreshing than it should be. . . . One's opinion of the physicaldisturbances which may be caused by rum, tobacco, or tea, are not worthmuch, when the opinion comes from a victim of the excessive use of theseagents. 

The tannin found in tea does not differ from that found in oak and otherbarks which the tanners use to convert the raw hides of animals intoleather. It is a powerful astringent, which accounts for some of thepeculiar physical evils to which confirmed tea drinkers are subject. 

_Theine_ does not differ essentially from _Cocaine_ (see p. 223). They both produce exaltation of the nervous system and increasedpowers of physical endurance. The brain is largely influenced in itsfunctions, and long periods of wakefulness are induced. Continued use ofstrong infusions of either coca or tea result in great disturbance ofnervous centers and functional offices, and either will produce fatalresults by persistent use of inordinate quantities. 

A cup of tea as served at tea tables contains usually only a trace of thealkaloidal principle, but infinitesimal quantities are capable of exertingbaneful effects upon some tea drinkers. . . . Poisons act in a variety ofways, some slowly, and without producing pain; others act violently, andwith speedy, fatal results. Inasmuch as we do not observe a very largenumber of clearly proved cases of acute poisoning by tea, we must concludethat it is characteristically a slow poison, and also that its influenceis unlike in different individuals. . . . Four or six cups of tea, however, taken during each twenty-four hours, will in time produce tea poisoning, and greater or less evil effects. 

Tea is well enough, when its use is kept under absolute, intelligentcontrol; but if it becomes master in any case, then it must be promptlyabandoned, for danger attends the intemperate tea drinker every hour ofhis life. Those advanced in life crave its stimulating effects, and it iswell for them to use it in moderation; but the young should abstain fromit entirely. --_Abridged from "Tea Poisoning, " by_ DR. NICHOLS, _inPopular Science News, December, 1887_. 

CAUSES AND EFFECTS OF INDIGESTION (p. L72). --When a light breakfast iseaten, a solid meal is requisite in the middle of the day. If thedigestive organs are left too long unemployed, they secrete an excess ofmucus, which greatly interferes with their normal functions. One meal hasa direct influence on the next; and a poor breakfast leaves the stomachover-active for dinner. This is the secret of much excess in eating. Thepoint to bear in mind is that not to eat a sufficiency at one meal makesyou too hungry for the next; and that when you are too hungry, you are aptto overload the stomach, and to give the gastric juices more to do thanthey have the power to perform. 

To eat too often, and to eat irregularly, are other sources ofindigestion. People who dine at uncertain hours, and eat one meal tooquickly on the last, must expect the stomach to retaliate in the long run. A very fruitful cause of dyspepsia is imperfect mastication. We rememberone old gentleman who used always to warn young people on this point bysaying: "Remember you have no teeth in your stomach. " Nervous peoplenearly always eat fast, and as nearly always are the victims of nervousirritability, produced by dyspepsia. . . . To sit much in a stooping postureinterferes with the stomach's action. Well-marked dyspepsia has beentraced to sitting immediately after dinner in a low armchair, so that thebody was curved forward, and the stomach compressed. . . . 

The skin, core, and kernels of fruit should be avoided. Some people arenot able to digest raw apples; and dyspepsia has been sometimes greatlyaggravated by eating pears. The latter fruit, in its ripest state, contains an abundance of gritty material, which, as it can not beseparated in the mouth, on being swallowed irritates the mucousmembrane. . . . 

Of food itself, bear in mind that hot meat is more digestible than cold;the flesh of full-grown animals than that of young ones; that land birdsare more digestible than waterfowl; wild animals than domestic ones; andthat in game, newly killed birds are easier of digestion than those whichhave been kept a long time. --_Hints to Dyspeptics, Chambers'sJournal_. 

HOW FOOD DEVELOPS ENERGY (p. 173). --It may appear strange that the smallamount of food we eat should suffice to carry our large and bulky bodiesthrough all the varied movement of the day. But this difficulty disappearsat once, when we recollect how large an amount of dormant energy can belaid by in a very small piece of matter. A lump of coal no bigger thanone's fist, if judiciously employed, will suffice to keep a small toyengine at work for a considerable time. Now, our food is matter containinglarge amounts of dormant energy, and our bodies are engines so constructedas to utilize all the energy to the best advantage. A single gramme ofbeef fat if completely burned (that is, if every atom unites with oxygen), is capable of developing more than 9, 000 heat units; and each heat unit, if employed to perform mechanical work, is capable of lifting a weight ofone gramme to a height of 424 meters; or, what comes to the same thing, 424 grammes to a height of one meter. Accordingly, the energy contained inone gramme of beef, and the oxygen with which it unites, would besufficient to raise the little bit of fat itself to a height of 3, 816kilometers, or almost as high as the distance from London to New York. --GRANT ALLEN _in "Why do we Eat our Dinner_?"

_Danger of Too High Pressure_. --A prudent fire engineer, when hiswater hose is old and weak, would not try to force as much water as hecould into it. No; to prevent a rupture he would work it at a lowpressure. But men seldom think of carrying out the same simple mechanicalprinciple when there is reason to believe that the vessels of the brainare getting weak and brittle. They eat and drink just as much as they feelinclined to, and sometimes a little more. With a good digestion, nearlyall they consume is converted into blood, to the yet further distention ofvessels already over-distended. This high-pressure style of livingproduces high-pressure results. Its effects were painfully illustrated bythe death of Charles Dickens. The brain work he performed was immense; helived generously, taking his wine as he did his meat, with a liberal hand. He disregarded the signs of structural decay, forcing his reluctant brainto do what it had once done with spontaneous ease, until all at once, under a greater tension than ordinary, a weak vessel gave way, floodingthe brain with blood. --J. R. BLACK, M. D. , _in "Apoplexy, " PopularScience Monthly, April, 1875_. 

_Evils of Gluttony_. --"Is it not strange, " says Dr. Hunt, "howpeople, even the most considerate, will trifle with their stomachs? Many aperson seems to prefer taking medicine to avoiding it by a properregulation of the appetite. You may stuff the stomach to the full, yearafter year, but as sure as effects follow causes, so sure will you reapthe accumulating penalty. " A physician of extensive practice declares thathe has never lived through a Christmas or Thanksgiving without frequentlybeing consulted for ailments produced by excessive eating. He says: "Itwould seem as if multitudes thought they had a gluttonous license once ayear, and that the most appropriate method of expressing gratitude, was bystuffing the stomach. Excessive eating produces scrofula. Surfeitingamong children results in mental stupidity and unmanageable temper. . . . I amacquainted with a family, in which about the average amount of stuffing isindulged. To my expostulations, the mother has replied: "I may not be ableto give my children as much education as some folks, and I may not be ableto give them any property, but as long as we can get it, they shall havewhat they want to eat. I have spoken of their black teeth, bad breath, eruptions, and frequent sickness. "Yes, " she has replied, "I know allthat, but would you have me stop them before their appetites are halfsatisfied, and tell them, 'there, that is all you can have'? No; as longas I can get it, my children shall have enough to eat; it never shall besaid that I have starved them. " This indulgence of children to the fullextent of their undiscriminating appetites is extreme folly and genuineunkindness. Pampered with a variety of dishes, they eat enormously, whichengenders a craving for another large meal, and so on--their youthful andelastic constitutions enabling them to bear the excess without immediateserious injury. Let them be confined to one or two plain dishes at a meal, and the quantity be determined for them; it will then be found that agrowing child does not need to be stuffed, and that his appetite will soonbecome reasonable; and if the food be plain, and mostly or entirelyvegetable, it will soon be observed that the child's teeth are whiter, itsbreath sweeter, its skin clearer, its tongue cleaner, its eyes brighter, its sleep quieter, its brains sharper, and its temper more amiable. Thereare few changes in the management of children which would prove sobeneficial as that from the present mode of cramming with a multitude ofrich foods, to a plain vegetable diet, eaten in regular and moderatequantities. --DIO LEWIS, _in Weak Lungs, and How to Make them Strong_. 

REGULAR PHYSICAL HABITS (p. 177). --Constipation lies at the root of a hostof chronic ailments, which seem especially to beset American women. Impaired blood, nervous excitability, sick headaches, mental depression, sleeplessness, and a long train of untold sufferings may be directlytraced to this physical sin. We say _sin_, for in the large majorityof instances this habit may be prevented; or, if already formed, may, byproper attention, be cured. The principal causes which lead to thisdeplorable state of the system are:

1. Errors in Food. 

2. Errors in Exercise. 

3. Inattention to Nature's laws. 

_Errors in Food_ have much to do with the evil in question. Our dietis, in general, too concentrated. We indulge ourselves with animal foodtwo or three times a day, accompanying it with spices, condiments, greasygravies, fine wheat bread, and a sparse amount of vegetables. We wind upour dinners with rich and heavy pastry, and our luncheons or our supperswith sugared sweetmeats and that indigestible compound often offered underthe name of cake. A few cups of strong tea intensify the error. Coffee hasa less astringent effect, and therefore can not be so severely arraignedfor this particular consequence. When we think what delicious meals can beenjoyed from any of the cereals, well cooked, and taken with milk orcream, bread from unbolted flour, plenty of unsugared fruit, and pure rainor spring water, filtered and cooled or taken hot, with or without milk, we wonder that so many people consent day after day to use greasy pork, fried steaks, fried potatoes, hot biscuit, and in many cases poorly madecoffee and tea. These are the people who make up the grand army of sallow-faced sufferers upon which the venders of patent pills and nauseouscompounds thrive. 

A wise mother will not allow mere culinary convenience to take precedenceof the requirements of health. She will study the peculiar physical needsof each one of her children, that she may provide for each the food bestsuited to his or her constitution. This is not a difficult matter. "Water, not only by itself, but in some of its combinations, " says Dr. Oswald, "isan effective aperient; in watermelons, and whey, for instance, but stillmore in conjunction with a dish of peas, or beans. No constipation canlong withstand the suasion of a dose of pea soup, or baked beans, flavoredwith a modicum of brown butter, and glorified with a cup of cold springwater. Moreover, the aperient effect thus produced is not followed by anastringent reaction, as in the case of drugs, --the cure, once effected, ispermanent. "

_Errors in Exercise_ may lie in two directions, and overexertion, viz. , exercise carried to the point of nervous exhaustion, is asmischievous in its effect as is the other extreme. A too long walk, forinstance, may cause the very evil it is intended to cure. 

As a rule, however, sedentary habits are chargeable with the greater shareof influence in this unhappy state of the system. Light gymnastics withindoors, a brisk walk or horseback ride without, both taken in garmentssuspended from the shoulders, and devoid of all constriction so that theabdominal viscera can partake in the general movement of the body, areadvisable. For invalids or those incapacitated for active exercise, friction or massage treatment daily, including a vigorous kneading of theabdomen, or a relaxation of the entire muscles of the body with especialthought directed to the desired result, are often of great service. 

_Inattention to Physical Laws_ is perhaps the prime culprit. Naturealways inclines to regularity, and when we do not respect her dictates, weinvite the retribution which, sooner or later, she invariably inflicts. The elimination of waste from the system is an imperative necessity, andwhenever it is thwarted, evil must and will follow. Aside from theavoidance of positive discomforts, suffering, and disease, there is thenot unimportant consideration of bodily elasticity and a fine complexion. Let every young woman who would possess and retain a fair, delicatecomplexion, remember that the most important factor in its formation andretention is a clean system. 

Proper diet, plenty of fruits, plenty of wholesome drink, enough exerciseto send the blood pleasurably bounding through the veins, followed up andenforced by prompt recognition of the immutable laws of Health in this aswell as all other organic functions, will soon work a reform that couldnot be so successfully effected by all the drugs in Christendom. --E. B. S. 

THE NERVOUS SYSTEM. 

EFFECT OF VIOLENT PASSIONS UPON HEALTH (p. 202). --The man who is given tooutbursts of anger is sure to experience a rapid change of the physicalorgans, in case he does not die in a fit of rage. 

Death under such circumstances is of frequent occurrence. Sylla, Valentinian, Nerva, Wenceslas, and Isabeau of Bavaria, all died inconsequence of an access of passion. The medical annals of our own timerecount many instances of fatal effects following the violent braindisturbance caused by anger. The symptoms usually are pulmonary andcerebral congestions. Still such fatal accidents as these are exceptional;as a rule, the passions of hate and anger deteriorate the constitution byslow, but sure degrees. 

How, then, do we explain those morbid phenomena which have their origin inmisplaced affection, in disappointed ambition, in hatred, or in anger, andwhich culminate either in serious chronic maladies, or in death orsuicide? They all seem to start from an impairment of the cerebro-spinalcenters. The continual excitation of these by ever-present emotionsdetermines a paralysis of the central nerve substance, and thus affectsits connections with the nerves extending out to the various organs. Thesenerves next degenerate by degrees, and soon the great functions arecompromised. The heart and the lungs cease to act with their normalrhythm, the circulation grows irregular and languishing. Appetitedisappears, the amount of carbonic acid exhaled decreases, and the hairgrows white, owing to the interruption of the pigmentary secretion. Thisgeneral disturbance in nutrition and secretion is attended with a fall ofthe body's temperature and anæmia. The flesh dries up and the organismbecomes less and less capable of resisting morbific influences. At thesame time, in consequence of the reaction of all these disturbances on thebrain, the psychic faculties become dull or perverted, and the patientfalls into a decline more or less complicated and aggravated by gravesymptoms. Under these conditions he dies or makes away with himself. 

Two organs, the stomach and the liver, are often affected in a peculiarand characteristic way in the course of this pathological evolution. Themodifications produced in the innervation, under the influence of cephalicexcitement, cause a disturbance of the blood circulation in the liver. This disturbance is of such a nature that the bile, now secreted in largerquantity, is resorbed into the blood instead of passing into the biliaryvesicle. Then appears what we call jaundice. The skin becomes pale, thenyellow, owing to the presence in the blood of the coloring matter of thebile. This change in the liver is usually developed slowly: sometimes, however, jaundice makes its appearance suddenly. Villeneuve mentions thecase of two youths who brought a discussion to an end by grasping theirswords; suddenly one of them turned yellow, and the other, alarmed at thistransformation, dropped his weapon. The same author speaks of a priest whobecame jaundiced on seeing a mad dog jump at him. Whatever may be said ofthese cases, we must reckon painful affections of the soul among theefficient causes of chronic diseases of the liver. 

The digestion, says the author of a work published some years ago, iscompletely subjected to the influence of the moral and intellectual state. When the brain is wearied by the passions, appetite and digestion arealmost gone. . . . There is nowhere perfect health, save when the passions arewell regulated, harmonized, and equipoised. Moral temperance is asindispensable to a calm and tranquil life as physiologicaltemperance. . . . If it is your desire that your circulatory, respiratory, anddigestive functions should be discharged properly, normally, if you wantyour appetite to be good, your sleep sound, your humor equable, avoid allemotions that are overstrong, all pleasures that are too intense, and meetthe inevitable sorrows and the cruel agonies of life with a firm andresigned soul. Ever have some occupation to employ and divert your mind, and to make it proof against the temptations of want or of desire. Thuswill you attain the term of life without overmuch disquiet andaffliction. --FERNAND PAPILLON, _in the Revue des Deux Mondes_. 

BRAIN WORK, OVERWORK, AND WORRY (p. 205). --_Overstimulation of the Brainin Childhood_. --Most civilized communities have enacted laws againstthe employment of children in severe physical labor. This is well enough, for the muscles of young persons are tender and weak, and not, therefore, adapted to the work to which cupidity or ignorance would otherwise subjectthem. But no such fostering care does the State take of the brains of theyoung. There are no laws to prevent the undeveloped nervous system beingovertasked and brought to disease, or even absolute destruction. Everyphysician sees cases of the kind, and wonders how parents of intelligencecan be so blind to the welfare of their offspring as to force, or even toallow, their brains to be worked to a degree that, in many cases, resultsin idiocy or death. Only a few months ago I saw for the first time a boyof five years of age, with a large head, a prominent forehead, and all theother signs of mental precocity. He had read the first volume of Bryant's"History of the United States, " and was preparing to tackle the othervolumes! He read the magazines of the day with as much interest as did hisfather, and conversed with equal facility on the politics of the period. But a few weeks before I saw him he had begun to walk in his sleep, thenchorea had made its appearance, and on the day before he was brought to mehe had had a well-marked epileptic paroxysm. Already his mind is weakened--perhaps permanently so. Such cases are not isolated ones. They arecontinually occurring. 

The period of early childhood--say up to seven or eight years of age--isthat during which the brain and other parts of the nervous system are mostactively developing, in order to fit them for the great work before them. It is safe to say that the only instruction given during this time shouldbe that which consists in teaching children how to observe. The perceptivefaculties alone should be made the subjects of systematic attempts atdevelopment. The child should be taught how to use his senses, andespecially how to see, hear, and touch. In this manner, knowledge would beacquired in the way that is preeminently the natural way, and ample foodwould be furnished for the child's reflective powers. --DK. WM. A. HAMMOND, _Popular Science Monthly, November, 1884_. 

_Reserve Force_. --The part which "a stock of energy" plays in brainwork can scarcely be exaggerated. Reserves are of high moment everywherein the animal economy, and the reserve of mental force is in a practicalsense more important than any other. . . . Without this reserve, healthy brainwork is impossible. Pain, hunger, anxiety, and a sense of mind weariness, are warning tokens of exhaustion. When the laborious worker, overcome withfatigue, "rouses" himself with alcohol, coffee, tea, or any other agentwhich may chance to suit him, he does not add a unit of force to his stockof energy; he simply narcotizes the sense of weariness, and, the guardbeing drugged, he appropriates the reserve. . . . Meanwhile, the effort towork becomes daily more laborious, the task of fixing the attention growsincreasingly difficult, thoughts wander, memory fails, the reasoning poweris enfeebled; physical nerve or brain disturbance may supervene, and thecrash will then come suddenly, unexpected by on-lookers, perhapsunperceived by the sufferer himself. 

_Overwork and Worry_. --The miseries of "overwork, " pure and simple, are few and comparatively insignificant. . . . The natural safeguards are sowell fitted for their task that neither body nor mind is exposed to theperil of serious exhaustion so long as their functions are duly performed. Overwork is _impossible_ so long as the effort made is natural. . . . Thereis then no excuse for idleness in the pretense of possible injury. Ifinsane asylums were searched for the victims of "overwork, " they wouldnearly all be found to have fallen a prey to "worry, " or to the degeneracywhich results from lack of purpose in life, and of steady employment. . . . The cause or condition which most commonly exposes the reserve ofmental energy to loss and injury is worry. When a strong and active mindbreaks down suddenly in the midst of business, it is usually worn out bythis cause rather than by the other. . . . Work in the teeth of worry isfraught with peril. The unhappy victim is ever on the verge of acatastrophe; if he escape, the marvel is not at his strength of intellectso much as at his good fortune. Worry is disorder, however induced, anddisorderly work is abhorred by the laws of nature, which leave it whollywithout remedy. 

The pernicious system of _Cram_ slays its thousands, becauseuneducated, undeveloped, inelastic intellects are burdened and strainedwith information adroitly deposited in the memory, --as an expert valetpacks a portmanteau, with the articles likely to be first wanted on thetop. _Desultory occupation_, mere play with objects of which the trueinterest is not appreciated, ruins a still larger number. But_worry_, that bane of brain work and mental energy, counts itsvictims by tens of thousands. --DR. J. MORTIMER GRANVILLE, _in "Worry, "Nineteenth Century_. 

SLEEP (p. 206). --_Some Curiosities of Sleep_. --One of the mostrefined and exquisite methods of torture is long continued deprivation ofsleep. The demand for unconscious rest is so imperious that nature willaccommodate itself to the most unfavorable surrounding conditions. Thus, in forced marches, regiments have been known to sleep while walking; menhave slept soundly in the saddle; and persons will sometimes sleep duringthe din of battle. It is remarkable how noises to which we have beenaccustomed will fail to disturb our natural rest. Those who have been longhabituated to the endless noise of a crowded city frequently finddifficulty in sleeping in the oppressive stillness of the country. Prolonged exposure to intense cold induces excessive somnolence, and ifthis be induced, the sleep passes into stupor, the power of resistance tocold becomes rapidly diminished, and death is the inevitable result. Intense heat often produces drowsiness, but, as is well known, is notfavorable to natural sleep. . . . It is difficult to determine with exactnessthe phenomena of sleep that are absolutely physiological, and to separatethose that are slightly abnormal. We can not assert, for example, that adreamless sleep is the only normal condition of repose of the system; norcan we determine what dreams are due to previous trains of thought, or tosuch impressions from the external world received during sleep as arepurely physiological, and what are due to abnormal nervous influence, disordered digestion, etc. 

The most remarkable experiments upon the production of dreams of adefinite character, by subjecting a person during sleep to peculiarinfluences, are those of Maury. The hallucinations produced in this wayare called hypnagogic (from its derivation this term is properly appliedonly to phenomena observed at the instant when we fall asleep, or when weare imperfectly awakened, and not to the period of most perfect repose), and they occur when the subject is not in a condition favorable to soundsleep. 

The experiments made by Maury upon himself are so curious and interestingthat we quote the most striking of them in full. 

_First Observation_. --I am tickled with a feather successively on thelips and inside of the nostrils. I dream that I am subjected to a horriblepunishment, that a mask of pitch is applied to my face, and then roughlytorn off, tearing the skin of the lip, the nose, and the face. 

_Second Observation_. --A pair of pincers is held at a little distancefrom my ear, and rubbed with steel scissors. I dream that I hear theringing of bells; this soon becomes a tocsin, and I imagine myself in thedays of June, 1848. (The time of the French Revolution. )

_Third Observation_. --I am caused to inhale Cologne water. I dream Iam in a perfumer's shop; the idea of perfumes doubtless awakens the ideaof the East; I am in Cairo, in the shop of Jean Farina. . . . 

_Fifth Observation_. --I am slightly pinched on the nape of the neck. I dream that a blister is applied, which recalls to my mind a physicianwho had treated me in infancy. 

_Seventh Observation_. . . . The words Azar, Castor, Leonore, werepronounced in my ear; on awaking I recollected that I had heard the lasttwo words, which I attributed to one of the persons who had conversed withme in my dream. --FLINT'S _Physiology of Man_. 

The transition stage between the dream simple and the dream acted iswitnessed in the spasmodic movements which a vivid dream produces in thelimbs or person of the sleeper. The dreamer engages in a fierce struggle, and twitchings of his legs and arms indicate the feeble response of bodyto the promptings of mind removed from its wonted power over the frame. Even the dog, as he sleeps, apparently dreams of the chase, and gives ventto his sensations by the short, sharp bark, or sniffs the air, and startsin his slumber as if in response to the activity with which, in hisdreaming, he is hurrying along after the object of pursuit. . . . Persons havebeen known to swim for a considerable time in the somnambulistic statewithout waking at the termination of their journey; others have safelydescended the shaft of a mine, while some have ascended steep cliffs, andhave returned home in safety during a prolonged sleep vigil. (See p. 204. )--DR. ANDREW WILSON, F. R. S. E. , _What Dreams are Made of_. 

_Sleep and Conscience_. --Edward Everett Hale says: Never go to bed inany danger of being hungry. People are kept awake by hunger quite as muchas by a bad conscience. Remembering that sleep is the essential forcewhich starts the whole system, decline tea or coffee within the last sixhours before going to bed. Avoid all mathematics or intricate study of anysort in the last six hours. This is the stuff dreams are made of, and hotheads, and the nuisances of waking hours. Keep your conscience clear. Remember that because the work of life is infinite, you can not do thewhole of it in any limited period of time, and that therefore you may justas well leave off in one place as another. 

_The Art of Rising Early_. --The proper time to rise is when sleepends. Dozing should not be allowed. True sleep is the aggregate of sleeps, or is a state consisting in the sleeping or rest of all the several partsof the organism. Sometimes one and at other times another part of thebody, as a whole, may be the least fatigued, and so the first to awake; orthe most exhausted, and therefore the most difficult to arouse. The secretof good sleep is, the physiological conditions of rest being established, so to work and weary the several parts of the organism as to give them aproportionately equal need of rest at the same moment. To wake early, andfeel ready to rise, a fair and equal start of the sleepers should besecured; and the wise self-manager should not allow a drowsy feeling ofunconsciousness, or weary senses, or an exhausted muscular system, tobeguile him into the folly of going to sleep again when once he has beenaroused. After a few days of self-discipline, the man who resolves not todoze, that is, not to allow some sleepy part of his body to keep him inbed after his brain has once awakened, will find himself, without knowingwhy, an early riser. 

INFLUENCE OF SUNLIGHT (p. 207). --Light is an essential element inproducing the grand phenomena of life, though its action is illunderstood. Where there is light there is life, and any deprivation ofthis principle is rapidly followed by disease of the animal frame, and thedestruction of the mental faculties. We have proof of this in the squalorof those whose necessities compel them to labor in places to which theblessings of sunshine never penetrate, as in our coal mines, where menhaving everything necessary for health, except light, exhibit a singularlyunhealthy appearance. The state of fatuity and wretchedness to which thoseindividuals have been reduced, who have been subjected for years toincarceration in dark dungeons, may be referred to the same deprivation. --ROBERT HUNT, _Poetry of Science_. 

_Effect of Dungeon Life_. --"You can not imagine, Mr. Kennan, " said acondemned revolutionist to me in Siberia, "the misery of prolongedconfinement in a casemate of the fortress under what are known as dungeonconditions. My casemate was sometimes cold, generally damp, and alwaysgloomy. Day after day, week after week, month after month, I lay there insolitude, hearing no sound save that of the high-pitched, melancholy bellsof the fortress cathedral, which slowly chimed the quarter hours, andwhich always seemed to say: 'Here thou liest--lie here still. ' I hadabsolutely nothing to do except to pace my cell from corner to corner, andthink. For a long time I used to talk to myself in a whisper; to repeatsoftly everything in the shape of literature that I could remember, and tocompose speeches which, under certain imagined conditions, I woulddeliver; but I finally ceased to have energy enough to do even this, andused to sit for hours in a sort of stupor, in which, so far as I can nowremember, I was not conscious of thinking at all. Before the end of thefirst year, I grew so weak, mentally and physically, that I began toforget words. I knew what ideas I desired to express, but some of thewords that I needed had gone from me, and it was with the greatestdifficulty that I could recover them. It seemed sometimes as if my ownlanguage were a strange one to me, or one which, from long disuse, I hadforgotten. I greatly feared insanity, and my apprehension was increased bythe fact that two or three of my comrades in cells on the same corridorwere either insane or subject to hallucinations; and I was often roused atnight and thrown into a violent chill of nervous excitement by theirhysterical weeping, their cries to the guard to come and take awaysomebody, or something which they imagined they saw, or their groans andentreaties when, in cases of violent delirium, they were strapped to theirbeds by the _gendarmes_. "--GEORGE KENNAN, _in Russian StatePrisoners, The Century, March, 1888_. 

THE GROWTH AND POWER OF POISON HABITS (p. 218). --In order to distinguish apoison stimulant from a harmless and nutritive substance, Nature hasfurnished us three infallible tests:

1. The first taste of every poison is either insipid or repulsive. 

2. The persistent obtrusion of the noxious substance changes that aversioninto a specific craving. 

3. The more or less pleasurable excitement produced by a gratification ofthat craving is always followed by a depressing reaction. . . . 

One radical fallacy identifies the stimulant habit in all its disguises:its victims mistake a process of irritation for one of invigoration. . . . Sooner or later the tonic is sure to pall while the morbid cravingremains, and forces its victims either to increase the quantity ofthe wonted stimulant, or else to resort to a stronger poison. A boy beginswith ginger beer and ends in ginger rum; the medical "tonic" delusionprogresses from malt extract to Mumford's Elixir; and the nicotine habitonce introduced, the alcohol habit often follows. The tendency of everystimulant habit is toward a stronger tonic. . . . We have found that the roadto the rum shop is paved with "mild stimulants, " and that every bottle ofmedical bitters is apt to get the vender a permanent customer. We havefound that cider and mild ale lead to strong ale, to lager beer, andfinally to rum, and the truth at last dawns upon us that the only safe, consistent, and effective plan is Total Abstinence from all Poisons. 

. . . More than the hunger after bread, more than the frenzy of love orhatred, the poison hunger overpowers every other instinct, even the fearof death. Dr. Isaac Jennings has illustrated this by the followingexample: A clergyman of his acquaintance attempted to dissuade a young manof great promise from habits of intemperance. "Hear me first a few words, "said the young man, "and then you may proceed. I am sensible that anindulgence in this habit will lead to the loss of property, the loss ofreputation and domestic happiness, to premature death, and to theirretrievable loss of my immortal soul; and now, with all this convictionresting firmly on my mind and flashing over my conscience like lightning, if I still continue to drink, do you suppose anything you can say willdeter me from the practice?"

. . . Ignorance is a chief cause of intemperance. The seductions of vicewould not mislead so many of our young men if they could realize thesignificance of their mistake. There is still a lingering belief that, with due precaution against excess and adulteration, a dram drinker might"get ahead" of Nature, and, as it were, trick her out of some extraenjoyment. There is no hope of a radical reform till intelligent peoplehave realized the fact that this "trick" is in every instance a losinggame, entailing penalties which far outweigh the pleasures that the novicemay mistake for enjoyments. For the depression of the vital energyincreases with every repetition of the stimulating process, and in a yearafter the first dose all the "grateful and exhilarating tonics" of ourprofessional poison venders can not restore the vigor, the courage, andthe cheerfulness which the mere consciousness of perfect health imparts tothe total abstainer. A great plurality of all beginners underrate thedifficulty of controlling the cravings of a morbid appetite. They rememberthat their natural inclinations at first opposed, rather than encouraged, the indulgence; and they feel that at the present stage of its developmentthey could abjure the passion without difficulty. But they overlook thefact that the moral power of resistance decreases with each repetition ofthe dose, and that the time will come when only the practicalimpossibility of procuring their wonted tipple will enable them to keeptheir pledge of total abstinence. It is true that, by the exercise of aconstant self-restraint, a person of great will force may resist theprogressive tendency of the poison habit and confine himself for years toa single cigar or a single bottle of wine per day. . . . But the attempt toresist that bias will overtask the strength of most individuals. Accordingto the allegory of the Grecian myth, the car of Bacchus was drawn bytigers; and it is a significant circumstance that war, famine, andpestilence have so often been the forerunners of veritable alcoholepidemics. . . . The explanation is that, after the stimulant habit has oncebeen initiated, every unusual depression of mental or physical vigor callsfor an increased application of the accustomed method of relief. . . . Nationswho are addicted to the worship of a poison god will use his temple as aplace of refuge from every calamity; and children whose petty ailmentshave been palliated with narcotics, wine, and cordials, will afterward betempted to drown their greater sorrows in deeper draughts of the samenepenthe. --FELIX L. OSWALD, M. D. , _Remedies of Nature, Popular ScienceMonthly, October and November, 1883_. 

DANGERS FROM THE USE OF NARCOTICS. --It may seem a paradox, it is a truism, to say that in the value of narcotics lies their peril. Because they havesuch power for good, because the suffering which they alleviate is in itslighter forms so common, because neuralgia and sleeplessness are ailmentsas familiar to the present generation as gout, rheumatism, and catarrhwere to our grandfathers, therefore the medicines which immediatelyrelieve sleeplessness and neuralgic pain are among the most dangerouspossessions, the most subtle temptations of civilized life. Every one ofthese drugs has, besides its instant and beneficial effect, other andinjurious tendencies. The relief which it gives is purchased at a certainprice; for, at each repetition of the dose, the immediate relief islessened or rendered uncertain, while the mischievous influence isenhanced and aggravated; till, when the drug has become a necessity oflife it has lost the greater part, if not the whole, of its value, andserves only to satisfy the need which itself alone has created. . . . We readweekly of men and women poisoned by an overdose of some favorite sedative, burned to death or otherwise fatally injured, while insensible from self-administered ether or chloroform. . . . The narcotist keeps chloroform orchloral always at hand, forgetful or ignorant that one sure effect of thefirst dose is to produce a semistupor more dangerous than actualsomnolence. In that semistupor the patient is aware, or fancies, that thedose has failed. The pain that has induced a lady to hold a chloroformedhandkerchief under her nostrils returns while her will and her judgmentare half paralyzed. She takes the bottle from the table beside her bed, intending to pour an additional supply upon her handkerchief. The unsteadyhand perhaps spills a quantity on the sheet, perhaps sinks with theunstoppered bottle under her nostrils, and in a few moments she hasinhaled enough utterly to stupefy, if not to kill. The sleepless brainworker also feels that his usual dose of chloral has failed to bringsleep; he is not aware how completely it has stupefied the brain, to whichit has not given rest. His judgment is gone, so is his steadiness of hand;and he pours out a second and too often a fatal dose. . . . But the cases thatend in a death terrible to the family, though probably involving little orno suffering to the victim himself, are by no means the worst. A lifepoisoned, paralyzed, rendered worthless for all the uses of intellectual, rational, we might almost say of human existence, is worse for thesufferer himself and for all around him than a quick and painless death;and for one such death there must be twenty, if not a hundred, instancesof this worst death in life. . . . The demoralization of the narcotist is not, like that of the drunkard, rapid, violent, and palpable; but gradual, insidious, perceptible at first only to close observers and intimatefriends. Here and there we find a constitution upon which opium exerts fewor none of its characteristic effects. Such cases are, of course, whollyexceptional; but their very existence is a danger to others, misleadingthem into the idea that they may dally with the tempter without fallingunder its yoke, or may fall under that yoke and find it a light one. Idoubt, however, whether the most fortunate of its victims would encouragethe latter idea; whether there be an opium eater who would not give a limbnever to have known what opium slavery means. . . . Besides, no one can besure, or indeed reasonably hope, that the mischief will be confined to theindividual victim. That the children of drunkards are often predisposed toinsanity is notorious; that the children of habitual opium eaters inheritan unmistakable taint, whether in a diseased brain, in morbid cravings, orsimply in a will too weak to resist temptation, is less notorious, butequally certain. --PERCY GREG, _Narcotics and Stimulants, ContemporaryReview_. 

Thus also in America scarcely a week passes but we see announced in thepublic prints deaths or suicides resulting from the use of narcotics. Now, it is from tobacco: A Yale College student dies from excessive smoking;another student in the same college, and as a result of the same habit, commits suicide; a third young man is found dead in his bed in New York, from heart disease induced by cigarettes; and so, month by month, and yearby year, grows in rapid increase the list of tobacco deaths. --Or, again, it is from opium. A Harvard student with two of his college companions insearch of a new sensation, tries opium smoking one fatal night and diesbefore morning; a woman in Ohio, belonging to a prominent family, dies atthe age of thirty-three years, from an overdose of morphine, her bodycovered with hypodermic scars; another, once the respected wife of aBaptist clergyman, becomes a morphine drunkard, drifts, step by step, intoa Central New York Almshouse, and there hangs herself; a third, young, accomplished, and wealthy, falls first a victim to the morphine habit, then to opium smoking, finally becomes the frequenter of a New York opiumjoint, and so is lost forever to home, friends, and respectability. --Occasionally it is cocaine, as in the case of the Chicago physician, who, for the purposes of investigation, experiments with this new drug uponhimself, his wife, and finally upon his innocent children; the entirefamily being found unconscious from the effects of the subtle narcotic. These are but solitary instances in an appallingly long list of similarcases, most of which have occurred within the last two years (1887-'88). 

_Cigarette Smoking_ is chargeable with a growing demoralization andmortality among boys and young men. It is no uncommon sight to see lads often years old and under, with the irresponsibility of ignorant childhood, puffing the dangerous cigarette, and thus undermining health and intellectat the very outset of useful existence. Even when told of the near andremote perils thus incurred, they scarcely listen, for do not they seetheir elders smoke and prosper?--Most of them do not understand that thereis more danger to the young than to the old in the tobacco habit, moredanger to some constitutions than to others, and more danger in thecigarette than even in the pipe or the cigar. Pause a moment to considerit, boys, when you are tempted to light the clean-looking, paper-coveredroll and place it in your mouth. Think of the heated smoke irritating thedelicate membrane in your throat, dulling your brain, and vitiating theblood which should be bounding fresh and pure through your veins. Think ofthe many filthy and diseased mouths from which have been cast away thetobacco refuse, picked up in streets and public places to reappear in the"Cheap and Popular Brand" which looks to you so innocent and soattractive. It is astonishing, indeed, how an otherwise cleanly boy willconsent to defile himself with these vile abominations. And yet, I haveknown lads who--not always with perfect politeness--would fastidiouslyrefuse "hash" at their mother's breakfast table, but who would shortlyafterward serenely place one of these unknowable compounds between theirlips and walk away with the air of superior manhood!

_Of Chloral Hydrate_, Dr. Fothergill remarks: "When this wasannounced with a flourish of trumpets as a perfectly innocuous narcotic, the sleepless folk hailed its advent with eager acclamation. But a littleexperience soon demonstrated that the innocuous, harmless drug was farfrom the boon it was proclaimed. In fact, the impression of itsharmlessness was the outcome of ignorance of its properties. Death afterdeath, even among medical men themselves, as well as nonprofessionalpersons, have already resulted from the use, or rather misuse, of thisnarcotic agent. "

_The Bromides_ (of Soda or Potash), also, should be used withcaution, and only on the prescription of a conscientious physician. "Thebromide of potash, " says Percy Greg, "is claimed not to produce sleep bystupefaction, like chloral or opium, but, at least in small doses, toallay the nervous irritability which is often the sole cause ofsleeplessness. But in larger quantities and in its ultimate effects, it isscarcely less to be dreaded than chloral. " Overdoses of the bromides willproduce among other evil effects a peculiar eruption upon the face, which, though generally temporary, is liable to reappear from time to time undercertain conditions of the system, and especially upon a subsequent dose, however dilute. 

_Absinthe_ is a compound of absinthium (the essence of wormwood), various aromatic oils, and alcohol. Absinthium, taken in small doses, induces trembling, stupor, and insensibility; in larger doses, epilepsy. When, therefore, this dangerous essence is added to alcohol, itstrengthens its influence to specific disease. Absinthe drinking isrecognized in France as such a serious vice that it has been officiallyprohibited in the army and navy. 

_Hasheesh_ is a syrup prepared from the leaves and flowers of IndianHemp. Though its use in this country is comparatively small, instances arenot unknown in which reckless or curious persons have fatally experimentedwith it. As a medicine, it is in limited use, and with results not alwayssatisfactory. It acts in a peculiar manner upon the nervous centers, occasioning that strange condition of the nervous system called catalepsy, in which the limbs of the unconscious patient remain stationary inwhatever position they may be placed. After an average dose of hasheesh, the subject becomes the helpless victim of rapidly shifting ideas, aprominent characteristic of which is an entire loss of judgment as to timeand place. A larger dose produces hallucinations and delirium, with thatdistressing sensation of falling through endless space which is induced insome people by opium. [Footnote: In an article entitled "An Overdose ofHasheesh" (_Popular Science Monthly_, February, 1884), Miss MARY A. HUNGERFORD gives a vivid description of a painful experience with thisdrug, some portion of which is as follows:

"Being one of the grand army of sufferers from headache, I took, lastsummer, by order of my physician, three small daily doses of hasheesh inthe hope of holding my intimate enemy in check. . . . I grew to regard thedrug as a harmless medicine, and one day, when I was assured by somefamiliar symptoms that my headache was about to assume an aggravated form, I took a larger quantity than had been prescribed. Twenty minutes later Iwas seized with a strange sinking or faintness which gave my family somuch alarm that they telephoned at once for the doctor. 

". . . One terrible reality--I can hardly term it a fancy even now--that cameto me again and again, was so painful that it must, I fear, always be avividly remembered agony. . . . I died, as I believed, although by a strangedouble consciousness I knew that I should again reanimate the body I hadleft. In leaving it I did not soar away, as one delights to think of thefreed spirits soaring. . . . I sank, an intangible, impalpable shape, throughthe bed, the floors, the cellar, the earth, down, down, down! Like afragment of glass dropping through the ocean, I dropped uninterruptedlythrough the earth and its atmosphere, and then fell on and onforever. . . . As time went on, and my dropping through space continued, Ibecame filled with the most profound loneliness, and a desperate fear tookhold of me that I should be thus alone for evermore, and fall and falleternally. . . . There was, it seemed to me, a forgotten text which, ifremembered, would be the spell to stop my fatal falling. I sought in mymemory for it, I prayed to recall it, I fought for it madly, wrestlingagainst the terrible fate which seemed to withhold it. Single words of itcame to me in disconnected mockery, but erased themselves instantaneously. Mentally, I writhed in such hopeless agony that, in thinking of it, Iwonder I could have borne such excess of emotion and lived. . . . I began, then, without having reached any goal, to ascend. As I rose, a great andterrible voice from a vast distance pronounced my doom: 'Fall, fall, fall, to rise again in hopeless misery, and sink again in lonely agony forever. '. . . Then ensued a wild and terrible commingling of unsyllabled sounds, sounearthly that it is not in the power of language to fitly describe them. It was something like a mighty Niagara of shrieks and groans, combinedwith the fearful din and crash of thousands of battles and the thunderousroar of a stormy sea. . . . I fought my upward way in an agony which resemblednothing so much as the terrible moment when, from strangling orsuffocation, all the forces of life struggle against death, and wrestlemadly for another breath. In place of the woeful sounds now reigned adeadly stillness, broken only at long but regular intervals by a loudreport, as if a cannon, louder than any I ever heard on earth, weredischarged at my side, almost shot into me, I might say, for the soundappeared to rend me from head to foot, and then to die away into the darkchaos about me in strange, shuddering reverberations. Even in the miseryof my ascending I was filled with a dread expectancy of the cruel sound. It gave me a feeling of acute physical torture, with a lingering intensitythat bodily suffering could not have. It was repeated an incredible numberof times, and always with the same suffering and shock to me. At last thesound came oftener, but with less force, and I seemed again nearing theshores of time. Dimly in the far distance I saw the room I had left, myself lying still and deathlike upon the bed, and the friends watchingme. . . . Then, silently and invisibly I floated into the room, and was onewith myself again. 

". . . 'She is conscious now, ' I heard one of the doctors say, and he gentlylifted the lids of my eyes and looked into them. I tried my best to throwall the intelligence I could into them, and returned his look with one ofrecognition. But, even with my eyes fixed on his, I felt myself goingagain in spite of my craving to stay. I longed to implore the doctor tosave me, to keep me from the unutterable anguish of falling into thevastness and vagueness of that shadowy sea of nothingness again. I claspedmy hands in wild entreaty; I was shaken by horrible convulsions--so, atleast, it seemed to me at the time--but, beyond a slight quivering of thefingers, no movement was discernible by the others. . . . For five hours Iremained in the same condition--short intervals of half-consciousness andthen long lapses into the agonizing experiences I have described. . . . Comingout of the last trance, I discovered that the measured rending report likethe discharge of a cannon, which attended my upward way, was the throbbingof my own heart. "]

Concerning all these and other narcotics, it should never be forgottenthat they are true poisons, sold with the mark of skull and crossbones, useful, like strychnine and henbane, in the hands of a skillful physician, but fraught with deadly danger when otherwise employed. Their private useis never safe. The weak and nervous invalid, who can not by hygienic meansbuild up new strength, need never hope to gain it by surreptitiouslyindulging in popular narcotics. Instead, he will soon discover that he hasbut added to his list of ills a new and fatal one. --E. B. S. 

THE SPECIAL SENSES. 

AN EDUCATED SENSE OF TOUCH (p. 230). --Laura Dewey Bridgman, teacher in thePerkins Institute for the Blind, South Boston, lost her sight, hearing, and sense of smell, when she was two years of age. At the age of eightyears she was taken to the institution where she yet remains. At thistime, by following her mother around the house she had become familiarwith home appointments, and by feeling her mother's hands and arms hadalso learned to sew and knit. When she first became an inmate of thePerkins Institute, she was bewildered by her strange surroundings, butafter she had become used to place and people, through her one and onlysense, her education was carefully begun. Through indomitable effort onthe part of her preceptor, she was taught to write, read, and spell, bymeans of her fingers, and thus to exchange sentiments with her teachersand with others skilled in the mysterious language of the blind and themute. She is now as proficient in the ordinary branches of learning as isthe average person, possessed of all the senses. Her studies includegeography, arithmetic, algebra, geometry, history, and philosophy. Shemakes her own clothing, can run a sewing machine, and observes greatneatness in her dress and the arrangements of her room. Her character isreligious, and she has great success as a teacher. Not long since, shecelebrated, on the same day, her fifty-eighth birthday and the fiftiethanniversary of her entrance to the Perkins Institute. During her earlieryears, it was her practice to keep a journal, and she now has about fortymanuscript books of her own making. She has also written threeautobiographical sketches, several poems, and is an accomplishedcorrespondent. When Miss Bridgman expresses pleasure, she clasps her handsand smiles. So keen and refined are her sensibilities, that it is said shecan, in a small way, appreciate the beauty of music by means of the soundvibrations on the floor. --MRS. GEORGE ARCHIBALD. (Laura D. Bridgman diedin 1889. )

THE NOSE (p. 232). --_The Anatomy of the Nose_. --Probably most of uslook upon the nose as a double hole in the head, by which we get, withmore or less acuteness, a sense of smell, and through which weoccasionally breathe. The intricate mechanism, and the skillful adaptationof means to end, which, in common with the other organs of special sense, it exhibits, naturally do not reveal themselves to any but the students ofanatomy and physiology. Its fourteen bones are probably better hidden thanany other fourteen bones of the body, and assist in converting what wouldotherwise be a mere channel of communication, into a series of cavitiesdesigned and adapted for particular purposes. The arch of four bones whichforms the bridge of the nose, and which is of such strength as to enablethe gymnast of the circus to perform the feat of supporting with it a manon a ladder, is pieced on with cartilage to form the nostrils, throughwhich the nose communicates with the outer air. Similar openings behindconnect it with the upper and posterior parts of the mouth. The spacebetween these anterior and posterior openings makes a large chamber, divided by a vertical wall into halves, each of which is still furtherseparated into three irregular cavities by three bones, called spongy, from the porosity and delicacy of their texture. The ceiling of thesechambers is formed by a bone of the thinness of paper, upon which lies thefront part of the brain, --a fact the Egyptians made use of in embalmingtheir corpses, easily crushing this bone, and extracting the brain throughthe nostrils. This bone is called cribriform (sieve-like), because it isperforated by many minute holes, through which, from the olfactory bulbs(specialized parts of the brain in which is resident the capacity ofsmell) that rest on its upper surface, issue the delicate filaments of theolfactory nerves, to spread themselves over the lining membrane of the twoupper spongy bones. It is in the upper chambers of the nose, therefore, that the function of smell is performed; the nerves that supply the lowerspongy bone being entirely unconnected with the organs of smell. Overthese latter, however, sweep in and out the currents of air when the actof respiration is properly carried out, and it is these that areespecially concerned in its abnormal performance. Usually but a verylittle of the volume of air that traverses the lower chamber of the nosehas any influence upon its upper regions; and therefore, when ourattention is attracted by an odor, we sniff, in order to bring a largerquantity of air into contact with the higher parts of the nose, orolfactory cavities, where odors are perceived. 

But the half has not been told of the anatomical and physiologicalarrangements of the nose. By minute openings its chambers havecommunication with many other parts of the head, --with the hollow thatforms the greater part of the cheek bone; with the eye by a minute spoutthat carries off the lachrymal secretion, unless the tears are so abundantas to roll down the cheeks; with the front of the roof of the mouth; withthe abundant cells of the bone that makes the forehead, and the congestionof whose lining membrane probably accounts for the severe headache that sooften accompanies and aggravates a "cold in the head. " The gateway to theinner air passages, its abundant surfaces raise the air inspired to thetemperature of the body, supply it with the moisture it lacks, and siftfrom it more or less of the mechanical impurities with which theatmosphere of our houses and shops is laden. --MAURICE D. CLARKE, M. D. , _Popular Science News, April, 1888_. 

_Smell Necessary to Taste_. --What we are in the habit of calling a"taste, " is in most cases a compound of smell, taste, temperature, andtouch--these four sensations ranking in gastronomic importance in theorder in which they are here named. . . . Amusing experiments may be made, showing that without the sense of smell it is commonly quite impossible todistinguish between different articles of food and drink. Blindfold aperson and make him clasp his nose tightly, then put successively into hismouth small pieces of beef, mutton, veal, and pork, and it is safe topredict that he will not be able to tell one morsel from another. The sameresult will be obtained with chicken, turkey, and duck; with pieces ofalmond, walnut, and hazel-nut; with slices of apple, peach, and pear; orwith different kinds of cheese, if care be taken that such kinds arechosen as do not, by their peculiar composition, betray their identitythrough the nerves of touch in the mouth. To hold an article of food underthe nose at table would be justly considered a breach of etiquette. Butthere is a second way of smelling, of which most people are quiteunconscious, viz. , by _exhaling through the nose_ while eating anddrinking. . . . It is well known that only a small portion of the mucousmembrane which lines the nostrils is the seat of the endings of the nervesof smell. In ordinary expiration, the air does not touch this olfactoryregion, but by a special effort it can be turned into thatdirection. . . . Instinct teaches most persons while eating to guide the air, impregnated with the fragrance of the food, to a part of the nostrilsdifferent from that used during ordinary exhalation; but, beingunaccustomed to psychologic analysis of their sensations, they remainquite unconscious of this proceeding, and are, indeed, in the habit ofconfusing their sensations of taste, smell, touch, and temperature in amost absurd manner. . . . 

In trying to ascertain by experiment how far smell, touch, and temperatureenter into this compound sensation, popularly known as "taste, " it is bestto make use of the pungent condiments. Mustard and horse-radish, forexample, have little or no taste, but reserve their pungent effect for themucous membrane of the nose during expiration. It is an advantage to knowthis, for if care is taken to breathe only through the mouth, we need nolonger prepare to shed tears every time we help ourselves to the mustard. The pungent quality of mustard, the fiery quality of ginger, and the coolsensation in the mouth after eating peppermint, are due to the nerves oftouch and temperature, which are commonly classed as one sense, thoughthey are quite as distinct sensations as sight and hearing, or taste andsmell. . . . 

There are two ways in which the effort to extract all its fragrance from amorsel of food confers a benefit. 

(1. ) It is necessary to keep the morsel in the mouth as long as possible. Now the habit thus formed of eating very slowly is of the utmostimportance, for if farinaceous articles of food are swallowed before thesaliva has had time to act on them, they are little better than so muchwaste material taken into the system; and if meat is not thoroughlymasticated, the stomach is overloaded with work which should have beendone by the teeth; the result, in either case, is dyspepsia. It has beensuggested that Mr. Gladstone owes his remarkable physical vigor to certainrules for chewing food, which he adopted in 1848, and to which he hasadhered ever since. "He had always, " we are told, "paid great attention tothe requirements of Nature, but he then laid down as a rule for hischildren that thirty-two bites should be given to each mouthful of meat, and a somewhat lesser number to bread, fish, etc. "

(2. ) Besides this indirect advantage resulting from the effort to get atthe fragrant odors of food, there is a still more remarkable directadvantage. It is one of the most curious psychologic facts that odorsexert a strong influence on our system, either exhilarating or depressing. While an unpleasant odor may cause a person to faint, the fumes of thesmelling bottle will restore him to consciousness. The magic and value ofgastronomic odors lies in this, that they stimulate the flow of saliva andother alimentary juices, thus making sure that the food eaten will bethoroughly utilized in renovating the system. --HENRY T. FINCK, _in "TheGastronomic Value of Odors_. " HYGIENE OF THE EAR (p. 236). --_NeverBox a Child's Ear_. --Children and grown persons alike may be entirelydeafened by falls or heavy blows upon the head. Boxing the ears produces asimilar effect, though more slowly and in less degree, and tends to dullthe sensibility of the nerve, even if it does not hurt the membrane. Iknew a youth who died from a terrible disease of the ear. There had been adischarge from it since he was a child. Of course his hearing had beendull; and _his father had often boxed his ear for inattention!_ Mostlikely that boxing on the ear, diseased as it was, had much to do with hisdeath. And this brings me to the second point. Children should never beblamed for being inattentive, until it has been found out whether they arenot a little deaf. This is easily done by placing them at a few yards'distance, and trying whether they can understand what is said to them in arather low tone of voice. Each ear should be tried, while the other isstopped by the finger. Three things should be remembered here: 1. Thatslight degrees of deafness, often lasting only for a time, are very commonamong children, especially during or after colds. 2. That a slightdeafness, which does not prevent a person from hearing when he isexpecting to be spoken to, will make him very dull to what he is notexpecting. 3. That there is a kind of deafness in which a person can hearpretty well while listening, but is really very hard of hearing when notlistening. 

_Avoid Direct Draughts in the Ear_. --There are some exposuresespecially to be guarded against. One is sitting or driving with the earexposed to a side wind. Deafness has also been known to come from lettingrain or sleet drive into the ear. 

_Do not Remove the Earwax_. --It ought to be understood that thepassage of the ear does not require cleaning by us. Nature undertakes thattask, and, in the healthy state, fulfills it perfectly. Her means forcleansing the ear is _the wax_. Perhaps the reader has never wonderedwhat becomes of the earwax. I will tell him. It dries up into thin finescales, and these peel off, one by one, from the surface of the passage, and fall out imperceptibly, leaving behind them a perfectly clean, smoothsurface. In health the passage of the ear is never dirty; but, if weattempt to clean it, we infallibly make it so. Washing the ear outfrequently with soap and water keeps the wax moist when it ought to becomedry and scaly, increases its quantity unduly, and makes it absorb the dustwith which the air always abounds. But the most hurtful thing isintroducing the corner of the towel, screwed up, and twisting it round. This does more harm to ears than all other mistakes together. It drivesdown the wax upon the membrane, much more than it gets it out. But thisplan does much more mischief than merely pressing down the wax. Itirritates the passage, and makes it cast off small flakes of skin, whichdry up, and become extremely hard, and these also are pressed down uponthe membrane. Often it is not only deafness which ensues, but pain andinflammation, and then matter is formed which the hard mass prevents fromescaping, and the membrane becomes permanently diseased. 

_The Eustachian Tube_. --The use of this tube is twofold. First, itsupplies the drum with air, and keeps the membrane exactly balanced, andfree to move, with equal air pressure on each side; and, secondly, itcarries off any fluid which may be in the drum, and prevents it from beingchoked by its own moisture. It is not always open, however, but is openedduring the act of swallowing, by a little muscle which is attached to itjust as it reaches the throat. Most persons can distinctly feel that thisis the case, by gently closing the nose and swallowing, when a distinctsensation is felt in the ears. This sensation is due to a little air beingdrawn out of the ears through the open tube during swallowing; and itlasts for a few minutes, unless the air is again restored by swallowingwith the nose unclosed, which allows for the moment a free communicationbetween the ear and the throat. We thus see a reason for the tube beingclosed. If it were always open, all the sounds produced in the throatwould pass directly into the drum of the ear, and totally confuse us. Weshould hear every breath, and live in a constant bewilderment of internalsounds. At the same time the closure, being but a light contact of thewalls of the tube, easily allows a slight escape of air _from_ thedrum, and thus not only facilitates and regulates the oscillations of theair before the vibrating membrane, but provides a safety valve, to acertain extent, against the injurious influence of loud sounds. 

The chief use of the Eustachian tube is to allow a free interchange of airbetween the ear and the throat, and it is very important that its use inthis respect should be understood. Persons who go down in diving bellssoon begin to feel a great pressure in the ears, and, if the depth isgreat, the feeling becomes extremely painful. This arises from the factthat in the diving bell the pressure of the air is very much increased, inorder to balance the weight of the water above; and thus it presses withgreat force upon the membrane of the drum, which, if the Eustachian tubehas been kept closed, has only the ordinary uncompressed air on the innerside to sustain it. It is therefore forced inward and put upon thestretch, and might be even broken. Many cases, indeed, have occurred ofinjury to the ear, producing permanent deafness, from descents in divingbells, undertaken by persons ignorant of the way in which the ear is made;though the simple precaution of frequent swallowing suffices to ward offall mischief. For, if the Eustachian tube is thus opened, again and again, as the pressure of the outside air increases, the same compressed air thatexists outside passes also into the inside of the drum, and the membraneis equally pressed upon from both sides by the air, and so is free fromstrain. The same precaution is necessary in ascending lofty mountains. --DR. JAMES HINTON. 

THE COLORED CURTAIN IN THE EYE (p. 238). --This ring-like curtain in theeye, of gray, green, bluish-green, brown, and other colors, is one amongthe very many remarkable contrivances of the organic world. The eye cannot bear the entrance of too much light, and the colored curtain soregulates its own movements as to serve this requirement. The darkcircular aperture in the center, known as the pupil, is consequentlyforever altering in size; on a bright, sunshiny day, out in the open, itmay be only the size of a pin's head, but at night, when there is no lightstronger than starlight, it is even bigger than a pea. The eye curtain isfixed at its outer edge, leaving the inner edge to contract or expand, which it does automatically and quite independent of the will, everpreserving its circular outline. Its movements may be watched in a varietyof ways, some of which we shall describe. 

The common way of watching the movements of the iris is to regard itclosely in a looking-glass while the amount of light entering the eyes isvaried. Place yourself before a looking-glass and with your face to thewindow. Probably the iris will be expanded, and there will only be a verysmall opening or pupil in the center. Now shut one eye suddenly, whilenarrowly watching the other in the glass all the time. At the moment thelight is cut off from one eye, the iris of the other contracts or is drawnup so as to enlarge the pupil. This shows that there is a remarkableinterdependence between the curtains of the two eyes, as well as that theyare affected by variations in the quantity of light falling on them. 

Perhaps one of the most interesting ways of watching the movements ofthese sympathetic eye curtains is one which may be followed while you areout walking on the street some dark winter night. A gas lamp seen at adistance is, comparatively speaking, a point of light, with bars of lightemanating from it in many directions. These bars, which give the peculiarspoked appearance to a star, are probably formed by optical defects of thelens within the eye, or by the tear fluid on the exterior surface of theeye, or by a combination of all these causes. Be that as it may, thelengths of the spokes of light are limited by the inner margin of the eyecurtain; if the curtain be drawn up, then the spokes are long; if thecurtain be let down, or, in other words, if the pupil be very small andcontracted, then one can not see any spokes at all. Hence, as I look at adistant gaslight, with its radiating golden spokes, I am looking atsomething which will give me a sure indication of any movements of the eyecurtains. I strike a match and allow its light to fall into the eyes; thespokes of the distant gas lamp have retreated into the point of flame asif by magic; as I take the burning match away from before my eyes, thespokes of the gas-lamp venture forth again. The experiment may be utilizedto see how much light is required to move the window curtains of the eyes. Suppose you are walking toward two gas lamps, A and B; B about fifty yardsbehind A. If you steadfastly look at B and at the golden spokes apparentlyissuing from it, you may make these spokes a test of how soon the light ofA will move your iris. As you gradually approach A, you come at last to aposition where its light is strong enough to make the spokes of B begin toshorten; a little nearer still and they vanish altogether. I have foundthat about a third of the light which is competent to contract the pupilvery markedly will serve to commence its movement. --WILLIAM ACKROYD. 

PURKINJE'S FIGURES (p. 222). --Stand in a dark room with a lighted candlein hand. Shutting the left, hold the candle very near the right eye, within three or four inches, obliquely outward and forward, so that thelight shall strongly illuminate the retina. Now move the light aboutgently, upward, downward, back and forth, while you gaze intently on thewall opposite. Presently the field of view becomes dark from the intenseimpression of the light, and then, as you move the light about, thereappears projected on the wall and covering its whole surface, a shadowy, ghost-like image, like a branching, leafless tree, or like a greatbodiless spider with many branching legs. What is it? It is an exact butenlarged image of the _blood vessels of the retina_. These come in atthe entrance of the optic nerve, ramify in the middle layer, and thereforein the strong light cast their shadows on the bacillary layer of theretina. The impression of these shadows is projected outward into thefield of view, and seen there as an enlarged shadowy image. These havebeen called Purkinje's Figures, from the discoverer. --PROF. JOSEPH LECONTE, _in Sight_. 

XI. 

APPENDIX. 

QUESTIONS FOR CLASS USE. 

_The questions include the Notes and the Selected Readings. The figuresrefer to the pages_. 

INTRODUCTION. 

Illustrate the value of physiological knowledge. Why should physiology bestudied in youth? When are our habits formed? How do habits help us? Whyshould children prize the lessons of experience? How does Nature punish aviolation of her laws? Name some of Nature's laws. What is the penalty oftheir violation? Name some bad habits and their punishments. Some goodhabits and their rewards. How do the young ruin their health? Compareone's constitution with a deposit in the bank. Can one in youth lay uphealth as he can money for middle or old age? Is not the preservation ofone's health a moral duty? What is suicide?

THE SKELETON. 

3. How many bones are there in the body? Is the number fixed? Is thelength of the different bones proportional? What is an organ? A function?Name the three uses of the bones. Why do the bones have such differentshapes?

4. Why are certain bones hollow? Round? Illustrate. Compare the resistingproperty of bone with that of solid oak. What is the composition of bone?How does it vary? How can you remove the mineral matter? The animalmatter? Why is a burned bone white and porous? What food do dogs find inbones?

5. What is the use of each of the constituents of a bone? What is"boneblack"? What is ossification? Why are not the bones of children aseasily broken as those of aged persons? Why do they unite so much quicker?What are the fontanelles?

6. Describe the structure of a bone. What is the object of the filling?Why does the amount vary in different parts of a bone? What is theappearance of a bone seen through a microscope?

7. What is the periosteum? Is a bone once removed ever restored? What arethe lacunæ? The Haversian canals? Why so called? _Ans_. From theirdiscoverer, Havers. Define a bone. [Footnote: Bone structure may besummarized as follows: A bone is a collection of _Haversianelements_, or rods. An Haversian element consists of a tube surroundedby _lamellæ_, which contain _lacunæ_, connected by _canaliculi_. --DR. T. B. STOWELL. ] What occupies the lacunæ? _Ans_. The bone cells(osteoblasts). How do bones grow?

8. Illustrate. How does a broken bone heal? How rapidly is bone produced?Illustrate. Objects of "splints"? Describe how a joint is packed. Lubricated. 

9. How are the bones tied together? What is a tissue? Illustrate. Name thethree general divisions of the bones. What is the object of the skull?Which bone is movable? How is the lower jaw hinged? Describe theconstruction of the skull. What is a suture?

10. Tell how the peculiar form and structure of the skull adapt it for itsuse. Illustrate the impenetrability of the skull. 

11. Describe the experiment of the balls. What does it show? What twocavities are in the trunk? Name its principal bones. Describe the spine. 

12. What is the object of the processes? Of the pads? Why is a man shorterat night than in the morning? Describe the perfection of the spine. 

13. Describe the articulation of the skull with the spine. Why is theatlas so called?

14. Describe the ribs. What is the natural form of the chest? Why is itmade in separate pieces? How does the oblique position of the ribs aid inrespiration? (See note, p. 80. )

15. How do the hipbones give solidity? What two sets of limbs branch fromthe trunk? State their mutual resemblance. Name the bones of the shoulder. Describe the collar bone. 

16. Describe the shoulder blade. Can you describe the indirectarticulation of the shoulder blade with the trunk? Name the bones of thearm. Describe the shoulder joint. The elbow-joint. 

17. Describe the wrist. Name the bones of the hand. How many bones in thefingers? The thumb? What gives the thumb its freedom of motion?

18, 19. Name and describe the fingers. In what lies the perfection of thehand? How do the gestures of the hand enforce our ideas and feelings?Describe the hip joint. What gives the upper limbs more freedom of motionthan the lower? How does the pressure of the air aid us in walking?Illustrate. 

20. Name the bones of the lower limbs. Describe the knee joint. Thepatella. What is the use of the fibula? Can you show how the lowerextremity of the fibula, below its juncture with the tibia, is prolongedto form a part of the ankle joint? Name the bones of the foot. What is theuse of the arch of the foot? What makes the step elastic? Describe theaction of the foot as we step. 

21. In graceful walking, should the toes or the heel touch the groundfirst? What are the causes of deformed feet? What is the natural positionof the big toe? Did you ever see a big toe lying in a straight line withthe foot, as shown in statuary and paintings? How should we have our bootsand shoes made? What are the effects of high heels? Of narrow heels? Ofnarrow toes? Of tight-laced boots? Of thin soles? What are the rickets?Cause of this disease? Cure? Is there any provision for remedying defectsin the body? Name one. 

22, 23. What is a felon? Cure? Cause of bowlegs? How can they beprevented? Causes of spinal curvature? Cure? What is the correct positionin sitting at one's desk? Is there any necessity for walking and sittingerect? Any advantage aside from health? Describe the bad effects of astooping position. What is a sprain? Why does it need special care? Whatis a dislocation? How is it generally caused? How soon should it betreated?

269. What relation does man, in his general structure, bear to othervertebrates? Mention some marked physical peculiarities which distinguishhim from the lower mammals. 

270, 271. Describe the state of a fracture a week after its occurrence. What is this new formation called? What marks the termination of the firststage of curative progress? How do the broken ends of the bone now appear?What is the state of the fracture at the end of the second stage? What isthe condition of the callus at this time? Describe the third and lastseries of changes. Is the process of union completed sooner in old peopleor in young? In the upper or lower extremities? In smaller animals or man?What length of time is required to heal a broken arm? A broken leg?

272. What gives the human hand its peculiar prehensile power? Whatadvantage has the human thumb over that of the ape? Compare the foot ofman with that of the ape. What peculiarity of the foot is particularlynoticeable in man? Contrast the function of the great toe in man and inthe ape. 

273. Are the toes naturally flexible? How are their powers crippled? Givean instance in which the toes were trained to do the work of the fingers. 

274. Why are an elastic step and a graceful carriage such rareaccomplishments? What is the natural shape of the foot? Which is thelonger, the great toe or the second toe? Is an even-sided symmetrynecessary to the beauty of a boot?

THE MUSCLES. 29. What relations do the skeleton and the muscles bear toeach other? How is the skeleton concealed? Why is it the image of death?What are the muscles? How many are there? What peculiar property havethey? Name other properties of muscles. _Ans_. Tonicity, elasticity. 

30. How are they arranged? Where is the biceps? The triceps? How do themuscles move the limbs? Illustrate. What is the cause of squinting? Cure?(See p. 244. )

31. Name and define the two kinds of muscles. Illustrate each. What is thestructure of a muscle? Of what is a fibril itself composed? How does thepeculiar construction of the muscle confer strength?

32. Describe the tendons. What is their use? Illustrate the advantages ofthis mode of attachment. 

33. What two special arrangements of the tendons in the hand? Their use?How is the rotary motion of the eye obtained?

34, 35. What is a lever? Describe the three classes of levers. Illustrateeach. Describe the head as a lever. What parts of the body illustrate thethree kinds of levers? Give an illustration of the second class of levers. The third class. Why is the Tendon of Achilles so named? What is theadvantage of the third class of levers? Why desirable in the hand? Whatclass of lever is the lower jaw?

36. What advantages are gained by the enlargement of the bones at thejoints? Illustrate. How do we stand erect? Is it an involuntary act?

37. Why can not a child walk at once, as many young animals do? Why can wenot hold up the head easily when we walk on "all fours"? Why can not ananimal stand erect as man does?

38. Describe the process of walking. Show that walking is a process offalling. Describe the process of running. What causes the swinging of thehand in walking? Why are we shorter when walking? [Footnote: Stand a boyerect against a wall. Mark his height with a stick. Now have him step offa part of a pace, and then several whole paces. Next, let him close hiseyes, and walk to the wall again. He will be perceptibly lower than thestick, until he straightens up once more from a walking position. ] Whydoes a person when lost often go in a circle? In which direction does onealways turn in that case? [Footnote: Take several boys into a smooth grasslot. Set up a stick at a distance for them to walk toward. Test the boys, to find which are left-handed, or right-handed; which left-legged orright-legged. Then blindfold the boys and let them walk, as they think, toward the mark. See who varies toward the right, and who turns to theleft. ]

39. What is the muscular sense? Value of educating it? How do we gratifyit?

40. What effect has exercise upon a muscle? Is there any danger in violentexercise? For what purpose should we exercise? Should exercise be in theopen air? What is the rule for exercise? Is a young person excusable, wholeads a sedentary life, and yet takes no daily outdoor exercise? What willbe Nature's penalty for such a violation of her law? Will a postponementof the penalty show that we have escaped it?

41. Ought a scholar to study during the time of recess? Will a promenadein the vitiated air of the schoolroom furnish suitable exercise? What isthe best time for taking exercise? What class of persons can safelyexercise before breakfast?

42. What are the advantages of the different kinds of exercise? Should wenot walk more? What is the general influence upon the body of vigorousexercise?

43. State some of the wonders of the muscles. What is the St. Vitus'sDance? Cure?

44. What are convulsions? What is the locked-jaw? Causes? The gout? Cause?Cure? The rheumatism? Its two forms? Peculiarity of the acute?

45. Danger in acute rheumatism? In what does chronic rheumatism oftenresult? What is lumbago? Give instances. What is a ganglion? Its cure? Abursa?

275. What is meant by the origin of a muscle? The attachment? Is a musclealways extended between two contiguous bones? Give an illustration. Canthe points of origin and of attachment change offices? Illustrate. What isan important consequence of the attachment of the muscles to the bones?If, in the limb of a dead body, one end of a muscle is separated from itspoint of attachment, what occurs? Would the result be the same duringlife? To what is this phenomenon due?

276. Why are the muscles continually striving to shorten? Describe theeffect when several opposing muscles are attached to one bone. When is thebalanced position of the limbs best observed? Are the muscles alwaysattached to bones? Give example. How does the flesh of man differ fromthat of an ox? How may the structure of muscular fibers be rudelyillustrated? Describe smooth muscle fibers. How do they differ fromstriated muscle fibers?

277. In what form do smooth muscle fibers frequently occur? In such cases, how are they usually arranged? What is the effect of their contraction? Ofwhat especial use is this power in case of the smaller arteries? In caseof the intestine?

278. In the latter instance, how does the contraction take place? Are thestriated muscle fibers voluntary or involuntary? Name an exception to thisrule. Give other peculiarities of the muscle fibers of the heart. Whatcauses the contraction of smooth muscle fibers? Of striated muscle fibers?Why do little children seldom injure themselves by overexertion? How isthe danger increased in youth?

279. What class of people are in most peril from violent or excessiveexercise? Why? At what age should one cease from haste of all kinds? Giveinstances of valuable lives lost from personal imprudence. 

280. What are the effects of insufficient exercise upon the young? Howdoes it predispose to disease? What makes the children of the laboringclasses so hardy? Is a regulation step desirable in walking? Why not? Whyis it more fatiguing to walk uphill than on level ground?

281. How does the management of the breath affect this fatigue? How shoulda belt be worn, if used during exercise? Can other forms of exercise besuccessfully substituted for walking? Why not? What is the difference inmovement between walking and skating? Which is the better exercise? Whatare the dangers from skating? What precaution should be used by those whohave weak ankles?

282. Name the different action of the muscles in the forward and backwardmovements in rowing. What is the comparative value of rowing as anexercise? Why is it especially desirable for women? How should women dresswhen rowing, horseback riding, tennis playing, etc. ? What rules should beobserved by rowers? Why should the breath be allowed to escape while theoar is in the water?

283. What sanitary measures should be observed after a row? What effecthas too frequent and too prolonged immersion on young swimmers? Doesswimming require much muscular exertion? Why? Why does an occasionalswimmer become exhausted sooner than an experienced one? On what do easeand speed in swimming depend? Is the habit of diving desirable? Shoulddiving ever be practiced in shallow water?

284. Why is lawn tennis the most desirable of outdoor games? _Ans_. Not only because nearly every muscle of the body is brought into exercise, but because it is one of the few field sports in which women cangracefully join. In this it shares the honor with croquet. What are thedangers attendant on lawn tennis? From what do many of them arise? Whyshould tennis shoes have heels? To what class of people is horsebackriding particularly suited? What class of invalids should not indulge inbicycling and tricycling? To what class is it peculiarly beneficial?

285. What are the dangers attendant on baseball games? Football? When maylight and heavy gymnastics be profitably employed? Name a sufficientapparatus. What are the objections to gymnasium exercise? Its advantages?

THE SKIN. 

49. What are the uses of the skin? Describe its adaptation to its place. What is its function as an organ? Describe the structure of the skin. Thesensitiveness of the cutis. The insensitiveness of the cuticle. 

50. How is the skin constantly changing? The shape and number of thecells? Value of the cuticle? How is the cuticle formed? _Ans_. Bysecretion from the cutis. 

51. What is the complexion? Its cause? Why is a scar white? What is thecause of "tanning"? What are freckles? Albinos? Describe the action of thesun on the skin. 

52. Why are the hairs and the nails spoken of under the title of the skin?Uses of the hair? Its structure? How can it be examined? What is the hairbulb? What is it called? How does a hair grow? At what rate? When can itbe restored, if destroyed? Does hair grow after death?

53. When hair has become gray, can its original color be naturallyrestored? What is the danger of hair dyes? Are they of any real value? Howcan the hair stand on end? How do horses move their skin? Is there anyfeeling in a hair?

54. Illustrate the indestructibility of the hair. What are the uses of thenails? How do the nails grow? What is the mucous membrane?

55. Its composition? The connective tissue? Why so called? What uses doesit subserve?

56. What is its character? How does the fat exist in the body? Its uses?State the various uses of membrane in the body. Where is there no fat?Where is there always fat?

57. Why are the teeth spoken of in connection with the mucous membrane?Name and describe the four kinds of teeth. What are the milk teeth?Describe them. What teeth appear first?

58. Give the order and age at which they appear. When do the permanentteeth appear? Describe their growth. Which one comes first? Last?

59. Describe the structure of the teeth. How are the teeth fitted in thejaw?

60. Why do the teeth decay? What care should be taken of the teeth? Whatcaution should be observed? What are the oil glands?

61. Use of this secretion? What are the perspiratory glands? State theirnumber. Their total length. What are the "pores" of the skin?

62, 63. What is the perspiration? What is the constitution of theperspiration? Illustrate its value. Name the three uses of the skin. Illustrate the absorbing power of the skin. What precaution should beobserved in handling a dead body? Why are cosmetics and hair dyesinjurious? What relation exists between the skin and the lungs? Whatlesson does this teach? When is the best time for a bath? Why?

64, 65. What is the value of friction? Why should not a bath be taken justbefore or after a meal? Is an excess of soap beneficial? What is the"reaction"? Explain its invigorating influence. How is it secured? Generaleffect of a cold bath? Of a warm bath? If we feel chilly and depressedafter a bath, what is the teaching? Describe the Russian vapor bath. Whyis the sea bath so stimulating?

66. How long should one remain in any bath? How does clothing keep uswarm? Explain the use of linen as an article of clothing. Cotton. Wool. Flannel. How can we best protect ourselves against the changes of ourclimate?

67. What colored clothing is best adapted for all seasons? Value of thenap? Furs? Thick _vs_. Thin clothing? Should we wear thick clothingduring the day, and in the evening put on thin clothing? Can childrenendure exposure better than grown persons? What is the erysipelas? Howrelieved?

68, 69. Eczema? What do its various forms denote? Corns? Cause? Cure?Ingrowing nails? Cure? Warts? Cure? Chilblain? Cause? Preventive?

286. Name some causes of baldness. Give Dr. Nichols's opinion. Why isfrequent shampooing inadvisable? One probable reason why women are lessfrequently bald than men? What is the best general treatment for the hairand scalp? Upon what does the color of the hair mainly depend?

287. In cases of sudden blanching of the hair what is the effect upon thepigment? Give an illustration. How do the extra air bubbles find their wayinto the hair? Does air naturally exist in the hair? What relation do thenails bear to the scarfskin?

288. What causes the horny appearance of the nails? Describe the root ofthe nail in its relation to the sensitive and the scarfskin. Upon whatdoes the nail rest? What is its appearance? What is the lunula? Why is itlighter than the rest of the nail? How does the nail increase in length?In thickness? Where is the greatest thickness? How does the growth of thenail during disease compare with its growth in health?

289. How long does it take the thumb nail to grow from its root to itsfree extremity? The great toe? Give general rules for the care of thenails. How does physical cleanliness promote moral purity? What does itsneglect indicate?

290. What especial care should be taken in regard to the feet? Why? Arebaths a modern refinement? What can you say about the ancient Greek andRoman baths? What constitutes the value of the Turkish bath?

291. What class of people should never use this bath? To what class ofinvalids is it particularly beneficial? Is sea bathing advisable forpersons of all ages? How should an inexperienced sea bather begin? Whenshould the sea bath be taken?

292. How long should a delicate person remain in the water? State thedanger of bathing when overheated. Under what conditions of body and oftemperature should sea or river bathing be avoided? Why? Give illustrationof the English soldier. How should the temperature of the water, inbathing, compare with that of the air? Of the body?

293. Describe the bathers' cramp. What are its causes? What precautionshould be used by bathers in regard to the mouth and ears? Why?

294. How can a person who does not know how to swim, save himself fromdrowning?

295. What are the advantages of woolen clothing? Why is it particularlydesirable in malarial countries? What double purpose does woolen clothingserve in semitropical climates?

296. Does the warmth of clothing depend on its weight? What errors areoften made and with what effect? State what is said in regard to poisonousdyes in wearing apparel. Give illustration. 

297. What effect has uncleanly attire on the health? Does this apply toouter as well as under garments?

RESPIRATION AND THE VOICE. 

73. Name the organs of respiration and the voice. Describe the larynx. Theepiglottis. The œsophagus. What is meant by food "going the wrong way"?

74. Describe the vocal cords. Their use. How is sound produced?

75. How are the higher tones of the voice produced? The lower? Upon whatdoes loudness depend? A falsetto voice? What is the cause of the voice"changing"? What is speech? Is the tongue necessary to speech? Illustrate. (See also page 298. )

76. What is vocalization? How are talking machines made?

77. How is _a_ formed by the voice? What is _h_? Differencebetween a sigh and a groan? What vowel sounds are made in laughing? Doeswhistling depend on the voice? Tell how the various consonants are formed. What are the labials? The dentals? The linguals? What vowels does a childpronounce first?

78. Describe the windpipe. The bronchi. The bronchial tubes. Why is thetrachea so called? Describe the structure of the lungs. What are the lungsof slaughtered animals called? Why will a piece of the lungs float onwater?

79. Name the wrappings of the lungs. Describe the pleura. How is frictionprevented? What are the cilia? Their use?

80. What two acts constitute respiration? In what two ways may theposition of the ribs change the capacity of the chest? Describe theprocess of inspiration. Describe the diaphragm. 

81. What is the process of expiration? How often do we breathe? What issighing? Coughing? Sneezing? Snoring? Laughing? Crying?

82. Describe hiccough. Yawning. Its value? What is meant by the breathingcapacity? How does it vary? How much, in addition, can the lungs expelforcibly? How much of the breathing capacity is available only throughpractice? Value of this extra supply? Can we expel all the air from ourlungs? Value of this constant supply?

83. How constant is the need of air? What is the vital element of the air?Describe the action of the oxygen in our lungs. What does the blood giveup? Gain? What are the constituents of the air? What are the peculiarproperties and uses of each?

84. How can we test the air we exhale? What does its analysis reveal?Which is the most dangerous constituent? What occurs when we rebreatheexhaled air?

85. Describe its evil effects. What is denoted by the "Black Hole ofCalcutta"? Give other illustrations of the dangers of bad air. Describethe need of ventilation. Will a single breath pollute the air?

86-95. How can we detect the floating impurities in the air? What is theinfluence of a fire or a light? Of a hot stove? When is the ventilationperfect? What diseases are largely owing to bad air? Should the windowsand doors be tightly closed, if we have no other means of ventilation? Isnot a draught of air dangerous? How can we prevent this, and yet securefresh air? What is the general principle of ventilation? Must pure airnecessarily be cold air? Are schoolrooms always properly ventilated? Whatis the effect? Are churches? Are our bedrooms? Should children or delicatepeople sleep in cold rooms? Can we, at night, breathe anything but nightair? Is the night air out of doors ever injurious? _Ans_. In timesand places of malaria, and also in very damp weather, it should beavoided, even at the risk of bad air in doors. Describe some of thewonders of respiration. 

96. How is constriction of the lungs produced? When may clothing beconsidered tight? What are the dangers of tight lacing? Which would makethe stronger, more vigorous, and longer-lived person, the form shown in_A_ or _B_, Fig. 33? Is it safe to run any risk in thisdangerous direction?

97. What is Bronchitis? Pleurisy? Pneumonia? Consumption? What is onegreat cause of Consumption? How may a constitutional tendency to thisdisease be warded off in youth? _Ans_. Besides plenty of fresh airand exercise, care should be taken in the diet. Rich pastry, unripe fruit, salted meat, and acid drinks should be avoided, and a certain quantity offat should be eaten at each meal. --BENNETT. What is asphyxia? Describe theprocess for restoring such a person. (See p. 264. )

98. What is diphtheria? Its peculiarities? Danger? The croup? Itscharacteristics? Remedy? (See p. 260. ) Causes of stammering? How cured?

297. How does the singing voice differ from the speaking voice? How canyou prove the effect of duration of sound in speaking and singing? How dothe intonations of the voice affect the meaning of words?

298. Give illustrations of speech in persons without a tongue. What is theeffect of alcohol and tobacco on the throat? Do they have an influence onthe voice? Does the excessive use of tea and coffee ever affect the voice?How? To what is the hoarse tone of an inebriate due?

299, 300. What was Adelina Patti's advice with regard to stimulants andlate hours? Does the respiration of woman differ from that of man? Giveexperiments with Indian women. What lessons do we draw from these facts?What rule should be observed in regard to the size of a bodice? What arebacteria or microbes? How is their existence revealed? What does the GermTheory of Disease teach in regard to microbes?

301. What can you say about the microbe of putrefaction? How can youobtain it for examination? What office in Nature do bacteria seem toserve? Give the theory in regard to propagation of special disease germs. Do they always cause disease when taken into the body? [Footnote: Of theimmense number and variety of microorganisms found in Nature, only veryfew are disease producing. Dr. Austin Flint says in _The Forum_, forDecember, 1888: "It is probable that future investigations into thephysiology of digestion, will show that bacteria play an important part inthis function. Pasteur has recently isolated no less than seventeendifferent microorganisms in the mouth, which were not destroyed by thegastric juice. Some of these dissolved albumen, gluten, and caseine, andsome transformed starch into sugar. Bacteria normally exist in greatnumber and variety in the intestines, although the part which they take inintestinal digestion has not been accurately determined. "--The number ofspores introduced into the human system by respiration, when the health isperfectly sound, has been estimated at three hundred thousand a day. ]

302. State some conditions which favor the growth of disease germs. Whichprevent or retard their growth. Relate the effect of vaccination, according to the germ theory. 

303. 304. If a drop of an infusion charged with bacteria be put in theextract of beef or mutton, what is the result? What would be the effectupon an open wound? Give Dr. Tyndall's personal experience. Name someefficient antidote against the bacteria of putrefaction. _Ans_. Carbolic acid solution is extensively used for this purpose. How aredisease germs often disseminated? State the necessity of disinfection inregard to soiled clothing. 

305. Illustrate how disease has been communicated by clothing. What is thefirst necessary condition to a sanitary home? What is the meaning of theword malaria? What are three active agents in the production of malaria? Afourth? Describe a typical malarious locality. How does newly brokenground induce malaria?

306. State the different ways in which running water can be contaminated. What care should be taken in regard to the level of building site?

307. Give some of the results of a wet foundation. What rules should beobserved in regard to shade? What is the effect of too dense foliage abouta dwelling? In building a house, what precautions should be taken againstdampness? What about the cellar? Sewerage? Plumbing? Ventilation?Fireplaces? Piazzas and balconies? Sleeping rooms?

308. What general purpose does a house serve? What care should be taken inregard to the dust or ash heap? What is the effect if liquids or tablerefuse be thrown upon it? Where should it be situated? How often shouldrefuse be carted away? If its frequent removal be inexpedient, whatprecaution should be used? What are the best of all deodorizers? Howshould the back premises be cared for? What is the best way to dispose ofhousehold garbage?

309. How can this be done? With what additional advantage? Give Dr. Derby's remarks in regard to sewers, their condition, and the results. Howshould traps and drains be cared for? How should bad smells be treated? Isa foul smell always the most dangerous? How do poisonous gases often findentrance to a house? What rule should be observed in regard to ventilatingand soil pipes?

310. What precautions should be observed in digging about a dwelling? Howdo waste pipes often become closed? How may they be cleared? What dangersarise from unventilated waste pipes? How are washbasin pipes contaminated?Tell what came from a neighbor's cesspool. Can you name similar instanceswhich have come under your own observation?

311, 312. Describe the condition and effects of a neglected cellar. Tellwhat came from a crack in a cellar wall. 

313. What effect have brick and mortar in keeping out gases? How do bedcoverings take the place of day garments? What kind of bed covering isdesirable? Is a comfortable bed necessary to perfect health? How often andfor how long time should a bed be ventilated?

THE CIRCULATION. 

105. Name the organs of the circulation. Does the blood permeate all partsof the body? What is the average amount in each person? Its composition?The plasma? The red corpuscles? The white?

106. What is the size of a red cell? Are the shape and size uniform? Valueof this? Illustrate. Are the disks permanent? What substances arecontained in the plasma? What is fibrin?

107. In what sense is the blood "liquid flesh"? What is the use of the reddisks? What is the office of the oxygen in the body? Where is the bloodpurified?

108. What is transfusion? Is it of value?

109. Give some illustrations. What is the cause of coagulation of theblood? Value of this property? Has the fibrin any other use?

110. What organ propels the blood? What is the location of the heart? Howlarge is it? Put your hand over it. What is the pericardium? Describe thesystole. 

111. The diastole. How many chambers in the heart? What is their averagesize? What is meant by the right and left heart? What are the auricles?Why so called? The ventricles?

112. What is the use of the auricles? The ventricles? Which are made thestronger? Show the need of valves in the ventricles. Why are there novalves in the auricles? Draw on the board the form of the valves. Namethem. 

113. Describe the tricuspid valve. The bicuspid. How are these valvesstrengthened?

114. What peculiarity in the attachment of these cords? Describe thesemilunar valves. What are the arteries? Why so named? What is their use?Their structure? How does their elasticity act? What is meant by a"collateral circulation"?

115. How are the arteries protected? Where are they located? Give ageneral description of the arterial system. What is the aorta? What is thepulse? On which arteries can we best feel it? What is the average numberof beats per minute? How and why does this vary?

116. Why does a physician feel a patient's pulse? What are the veins? Whatblood do they carry? Describe the venous system. What vein does not leadtoward the heart? Describe the valves of the veins. What valves of theheart do they resemble? What are varicose veins?

117. Where and how can we see the operation of these valves? What are thecapillaries? What is the function of the capillaries? [Footnote: Thedistinctive function of the capillaries is to offer peripheral resistanceto the circulation of the blood. This insures "blood pressure, " acondition indispensable to the "heart beat, " and also causes leakage(transudation). This leakage brings the nutriment in contact with thetissue cells, whereby they are renewed. In the same way the air passesfrom the blood to the cells. ] What changes take place in this system?

118. Describe the circulation of the blood as seen in the web of a frog'sfoot. 

119. Who discovered the circulation of the blood? How was the discoveryreceived? What remark did Harvey make? What does that show? Name the twodivisions of the circulation. Describe the route of the blood by thediagram. 1. The lesser circulation. 2. The greater circulation. 

120. What is the velocity of the blood? How long does it require for allthe blood to pass through the heart? How long does it take the blood tomake the tour of the body? What is the average temperature of the body?How much does this vary in health? _Ans_. Not more than 2°, even inthe greatest extremes of temperature. --FLINT. 

121. How and where is the heat of the body generated? How is itdistributed? In what diseases is the variation of temperature marked? Howis the temperature of the body regulated?

122. In what way does life exist through death? Is not this as true in themoral as in the physical world? What does it teach? How rapidly do ourbodies change? What are the three vital organs?

123. Name some of the wonders of the heart. 

124-126. What is the lymphatic circulation? What is the thoracic duct? Thelymph? The glands? What is the office of the lymphatics? What are thelacteals? Give some illustrations of the action of the lymphatics of thedifferent organs. Should we use care in selecting wall paper? What ismeant by the subcutaneous insertion of morphine? How do hibernatinganimals live during the winter? What is a congestion? Its cause?

127. What is blushing? Why does terror cause one to grow cold and pale?How is an inflammation caused? Name its four characteristics. 

128. How may severe bleeding be stopped? How can you tell whether theblood comes from an artery or a vein? Why should you know this? What isthe scrofula? What are "kernels"?

129, 130. How may a scrofulous tendency of the system be counteracted?What kinds of food stimulate this disease? What is the cause of a "cold"?Why does exposure sometimes cause a cold in the head, sometimes on thelungs, and at others bring on a rheumatic attack? Why is a cold dangerous?_Ans_. It weakens the system and paves the way for other diseases. What is the theory of treating a cold? Describe the method. What iscatarrh? Cause?

131, 132. How is alcohol produced? Is alcohol present in domestic winesand home-brewed ales? Are they, then, harmless drinks? What is a ferment?(See also pp. 300, 301. ) What is the difference between ferments, bacteria, microbes, and fungi? _Ans_. A few investigators still lookupon the microorganisms known as bacteria and microbes as animalexistences, but the larger part now concede them to be vegetable. 

133. What is the effect of fermentation? What can you say concerningyeast?

134. Explain the process of making beer. Wine. What is distillation?

135, 136. Is there more than one kind of alcohol? What can you say ofmethyl alcohol? Amyl? Ethyl? Which is the ordinary alcohol of commerce?What is the peculiar effect of fusel oil? Is it often found in wines andspirits? Has alcohol any beneficial properties?

137, 138. Describe one of the striking effects of alcohol. What is theeffect of alcohol on plant and animal life?

139, 140. What is the difference between the alcohol present in beer andcider, and that in gin and whiskey? Name another dangerous effect ofalcoholic drinks. What business consideration should deter young men fromliquor drinking?

141-143. Illustrate the general effect of alcohol upon the circulation. Upon the heart. Is alcohol a stimulant or a narcotic? Describe how alcoholbecomes the "Genius of Degeneration. " Explain what is meant by "VascularEnlargement. "

144, 145. Describe the effect of alcohol upon the membranes. Upon theblood. Does it render the blood thin or heavy? What is the differencebetween pure and alcoholized blood?

145-147. Describe the effect of alcohol upon the lungs. What form ofconsumption does it induce? Are liquor drinkers more or less liable toepidemic diseases?

314. How does the pulse felt by the finger correspond with the beat of theheart? Name some agencies that influence the pulse beat? Which part of thebody has the most varied form of pulsation?

315. Compare the pulses of the wrist and brain in the sleeping and thewaking states. How do catarrhal colds generally arise? How are they bestcured?

316. What is said of the vitality of catarrh germs? What is a popularfallacy with regard to the care of sick rooms? Give Dr. Austin Flint'sremarks in this connection. 

DIGESTION AND FOOD. 

151. Why do we need food? Why will a person starve without food? Are thecurrent stories of people who live without food to be relied upon? Howmuch food is needed per day by an adult in active exercise?

152. How much in a year? How does this amount vary? Describe the body as amold. As an eddy. What does food do for us? What does food contain?

153. How is this force set free? What force is this? How can it be turnedinto muscular motion, mental vigor, etc. ? Do we then draw all our powerfrom nature? What becomes of these forces when we are done with them? Dowe destroy the force we use? _Ans_. No matter has been destroyed, sofar as we know, since the creation, and force is equally indestructible. Compare our food to a tense spring. 

154. What three kinds of food do we need? What is nitrogenous food? Namethe common forms. What is the characteristic of nitrogenous food? Whycalled albuminous? What is carbonaceous food? Its two kinds? Constituentsof sugar? Where are starch and gum ranked? Why? Use of carbonaceous food?What becomes of this heat? Composition of fat? How does fat compare withsugar in producing heat?

155. Name the other uses of carbonaceous food. From what kind of food doesthe body derive the greatest strength? Name the mineral matters whichshould be contained in our food. What can you say of the abundance andnecessity of water? Ought we not to exercise great care in selecting thewater we drink? [Footnote: Water which has passed through lead pipes isapt to contain salts of that metal, and is therefore open to suspicion. Metallic lined ice pitchers, galvanized-iron reservoirs, and many soda-water fountains, are liable to the same objection. (See pp. 317, 318. )]Does the character of our food influence the quantity of water we need?

156. What are the uses of the different minerals contained in food?Illustrate the importance of salt. Could a person live on one kind of foodalone? Illustrate. 

157. Describe the effect of living on lean meat. Show the necessity of amixed diet. Illustrate. Show the need of digestion. Illustrate. 

158. What is assimilation? Describe the general plan of digestion. Whatdid Berzelius call digestion? Why? What amount of liquid is daily secretedby the alimentary canal? What is the alimentary canal? How is it lined?How does the amœba digest its food?

159. The hydra? Define secretion. Describe the saliva. How is it secreted?What is the amount? Its organic principle? Its use? How soon does it act?How long? What tends to check or increase the flow of saliva?

160. Describe the process of swallowing. The stomach. Its size. Itsconstruction. What is the peristaltic movement?

162. What is the pylorus? For what does this open? What is the gastricjuice? How abundant is it? To what is its acidity due? What organicprinciple does it contain? How is pepsin prepared? How is the flow ofgastric juice influenced?

163. What is its use? Appearance of the food as it passes through thepylorus? Why is not the stomach itself digested? What is the constructionof the intestines? How are the intestines divided? What is the duodenum?Why so called? What juices are secreted here?

164. What is the bile? Describe the liver. What is its weight? Itsconstruction? _Ans_. It consists of a mass of polyhedral cells only1/100 to 1/2000 of an inch in diameter, filling a mesh of capillaries. Thecapillaries carry the blood to and fro, and the cells secrete the bile. What is the cyst? What does the liver secrete from the blood besides thebile? Is the bile necessary to life? Illustrate. What is its use?

165. What is the pancreatic juice? Its organic principle? Its use?Appearance of the food when it leaves the duodenum? Describe the smallintestine. What is absorption? In what two ways is the food absorbed?

166. Where does the process commence? How long does it last? Describe thelacteals. Of what general system do they form a part? What do the veinsabsorb? Where do they carry the food? How is it modified?

167. What is glycogen? Describe the complexity of the process ofdigestion. What length of time is required for digestion in the stomach?

168. May not food which requires little time in the stomach need more inthe other organs, and _vice versa_? Tell the story of Alexis St. Martin. What time was required to digest an ordinary meal? Apples? Eggs, raw and cooked? Roast beef? Pork? Which is the king of the meats? What isthe nutritive value of mutton? Lamb? How should it be cooked? Objection topork? What is the trichina?

169. Should ham ever be eaten raw? Value of fish? Oysters? Milk? Cheese?Eggs? Bread? Brown bread? Are warm biscuit and bread healthful? Nutritivevalue of corn?

170. Of the potato? Of ripe fruits? Of coffee? To what is its stimulatingproperty due? Its influence on the system? When should it be discarded?Should children use any stimulants?

171. Effects of tea? Influence of strong tea? What is the active principleof tea? Nutritive value of chocolate? What is its active principle? Storyof Linnæus? How should tea be made? What is the effect of cooking food?What precaution in boiling meat? In roasting? Object of this hightemperature? What precaution in making soup? Why is frying an unhealthfulmode of cooking?

172. State the five evil results of rapid eating. What disease grows outof it? If one is compelled to eat a meal rapidly, as at a railroadstation, what should he take? Why? Why does a child need more foodproportionately than an old person? State the relation of waste to repairin youth, in middle, and in old age. What kind and quantity of food does asedentary occupation require? What caution should students who have beenaccustomed to manual labor observe? Must a student starve himself?

173. Is there not danger of overeating? Would not an occasional abstinencefrom a meal be beneficial? Do not most people eat more than is for theirgood? How should the season regulate our diet? The climate? Illustrate. What does a natural appetite indicate? How are we to judge between anatural and an artificial longing? What does the craving of childhood forsugar indicate? [Footnote: It does not follow from this, however, that thefree use of sugar in its separate form is desirable. The ordinary articlesof vegetable food contain sugar (or starch, which in the body is convertedinto sugar), in large proportion; and there is good reason to believe thatin its naturally combined form it is both more easily digested, and moreavailable for the purposes of nutrition, than when crystallized. Theordinary sugar of commerce, moreover, derived from the sugar cane, is notcapable of being directly applied to physiological purposes. Cane sugar isconverted within the body into another kind of sugar, identical with thatderived from the grape, before it can enter into the circuit of the vitalchanges. ]

174. What is the effect upon the circulation of taking food? Should welabor or study just before or after a meal? Why not? What time shouldintervene between our meals? Is "lunching" a healthful practice? Eatingheartily just before retiring? Is it never wise to eat at this time? (Seep. 337. ) Why should care be banished from the table? Will a regularroutine of food be beneficial?

175, 176. Describe some of the wonders of digestion. What are theprincipal causes of dyspepsia? How may we avoid that disease?

177. What are the mumps? What care should be taken? Is alcohol a food?Illustrate. 

178-187. Compare the action of alcohol with that of water. Is the alcoholtaken into the stomach eliminated unchanged? Does alcohol contain anyelement needed by the body? What is the effect of alcohol upon thedigestion? Will pepsin act in the presence of alcohol? What is the effectof alcohol upon the liver? What is "Fatty Degeneration"? What is theeffect of alcohol upon the kidneys? Does alcohol impart heat to the body?Does it confer strength? What does Dr. Kane say? Describe Richardson'sexperiments. Tell what peculiar influence alcohol exerts. What isalcoholism? What is heredity?

317. What characteristics should good drinking water possess? Are thesealways proof of its purity? Will filters remove all danger ofcontamination? How may a river infect the entire population of a town?State how well water may become a dangerous drink. 

318. Relate how cases of fever have been caused by carelessness indairies. How should suspected water be treated? Describe a convenientportable filter. Tell how water is affected by foul air. 

319. Tell how ice may breed disease. What caution should be observed inengaging ice for our summer supply? Illustrate the structure of theglandular coat of the stomach. 

320. What is the office of the cells? Describe the life history of a cell. How does the stomach weep, and what is the character of its tears?

321. What is tyrotoxicon? Give Dr. Vaughan's experiments with cheese, milk, and ice cream. Tell how milk may be poisoned. 

322. Compare the vigor of exclusively fish-eating with flesh-eatingpeople. What is the peculiar value of fish as a diet? To what class ofpeople is it best suited? Name examples. Describe the principles containedin coffee. What is the effect of caffeone? Of caffeine? Give some of thespecific effects of coffee. How does tea differ from coffee? Describe theinjurious effects of excessive tea drinking. 

324. Compare theine and cocaine. Should children drink tea and coffee?

325. Give some causes of indigestion. Why are nervous people prone todyspepsia? Give the comparative digestibility of various meats. 

326. Describe how our food sustains our bodies. Illustrate the energycontained in one gramme of beef fat. Why is there danger in a "high-pressure" style of living? Illustrate. 

327. State the effects of gluttony. Why is it unkindness to indulgeinordinate appetites in children? What should be the rule in regard totheir food? What effects would follow its observance?

THE NERVOUS SYSTEM. 

191. What are the organs of the nervous system? What is the general use ofthis system? How does it distinguish animals from plants? What are thevegetative functions? What is the gray matter? Its use? The white matter?Its use?

193. Describe the brain. What is its office? Its size? How does it vary?Illustrate. Name its two divisions. 

194, 195. Describe the cerebrum. The convolutions. The membranes whichbind the brain together. What can you say of the quantity of blood whichgoes to the brain? What does it show? What do the convolutions indicate?What is the use of the two halves of the brain? What theories have beenadvanced concerning it? Is every injury to the brain fatal? Illustrate. Compare the human brain with the brains of some animals. 

196. What is the effect of removing the cerebrum? Describe the cerebellum. What is the arbor vitæ? What does this part of the brain control? What arethe peculiar functions of the cerebellum? Give Dr. Bastian's remarks. 

197. What is the effect of an injury to the cerebellum? Describe thespinal cord. What is the medulla oblongata? Describe the nerves. Is eachpart of the body supplied with its own nerve? Prove it. 

198. What are the motory nerves? The sensory? When will motion be lost andfeeling remain, and _vice versa?_ What is meant by a transfer ofpain? Illustrate. 

199. Name the three classes of nerves. What are the spinal nerves?Describe the origin of the spinal nerve. 

199-201. What are the cranial nerves? How many pairs are there? Describethem. 

201, 202. Describe the sympathetic system. What is its use? How does thebrain control all the vital processes? What is meant by the crossing ofthe cords? What is the effect? What exception in the seventh pair ofcranial nerves?

203, 204. What is reflex action? Give illustrations. Give instances of theunconscious action of the brain. [Footnote: The cerebellum has itsunconscious action in the processes of respiration and in the involuntarymovements which are made in response to the senses, as in winking, starting back at a sound, etc. The cerebrum acts automatically in oasesfamiliar to all. A large part of our mental activity consists of thisunconscious brain work. There are many cases in which the mind hasobviously reasoned more clearly and more successfully in this automaticcondition, when left entirely to itself, than when we have been cudgelingour brains, so to speak, to get the solution. Oliver Wendell Holmes hasaptly expressed this fact. "We wish, " he says, "to remember something inthe course of conversation. No effort of the will can reach it; but wesay, 'Wait a minute, and it will come to me, ' and we go on talking. Someminutes later, the idea we are in search of comes all at once into themind, delivered like a prepaid parcel, or like a foundling in a basket, laid at the door of consciousness. How it came there, we know not. Themind must have been at work, groping and feeling for it in the dark; itcan not have come of itself. Yet, all the while, our consciousness, _sofar as we are conscious of our consciousness_, was busy with otherthoughts. "

Some interesting personal experiences upon this point are given in anarticle entitled "The Antechamber of Consciousness, " by Francis Speir, Jr. , in the _Popular Science Monthly_ for March, 1888. ] Can there befeeling or motion in the lower limbs when the spinal cord is destroyed?What does the story told by Dr. John Hunter show? Give illustrations ofthe independent action of the spinal cord in animals. What are the uses ofreflex action?

205. State its value in the formation of habits. How does the brain grow?What laws govern it? What must be the effect of constant light reading? Ofoverstudy or mental labor?

206. State the relation of sleep to repair and waste. How many hours doeseach person need? What kind of work requires most sleep?

206-208. What is the influence of sunlight on the body? Illustrate. Namesome of the wonders of the brain. 

208-213. What four stages are there in the effect of alcohol on thenervous system? Describe each. Does alcohol confer any permanent strength?What is the physiological effect of alcohol on the brain? On the mentaland moral powers? What is the Delirium Tremens? Should a man be punishedfor a crime he commits while drunk?

214-218. What are the principal constituents of tobacco? What are itsphysiological effects? Who are most likely to escape injury? Is tobacco afood? What is its influence upon youth? Why are cigarettes speciallyinjurious? What effect does tobacco have on the sensibilities? Nameillustrations of the injurious effect of tobacco on young men. 

219-221. How is opium obtained? What is its physiological effect? Whichform of using it is most injurious? Can one give up the use of opium whenhe pleases? How do people sometimes take opium without knowing it?

221. What is the harmful influence of chloral hydrate? Describe itsdifferent physiological effects. 

222. Compare its influence with that of alcohol. How is chloroformobtained? Does its use require great caution? Illustrate its effects. 

223, 224. What is cocaine? What is its value? Its physiological effect?Its dangers?

331-333. What is the effect of extreme anger? Give the physiologicalexplanation of this deterioration. What two organs particularly suffer?Illustrate. To what cause are many suicides referable? How can one securea calm and tranquil life? What is the effect of forcing the brain inchildhood?

334. Illustrate. How should a child be taught?

334, 335. Why should we not exhaust our energies to the last degree? Whatwarnings does Nature give us? Do stimulants supply force? What is theeffect of mental exhaustion? Which is the most common, overwork or worry?Most dangerous? What is worry? Its effect? What other causes often induceinsanity?

336-338. State some curiosities of sleep. Some conditions necessary tosound and healthful slumber. How may we acquire the habit of early rising?

338, 339. Give some of the results of dungeon life. 

339-347. What can you say of the growth and power of poison habits?Illustrate. How does physiological ignorance often cause intemperance?What is the usual result of a stimulant habit? In what virtue lies theperil of narcotics? Balance the good and the evil in their use. Illustratehow death often results from chloroform and chloral. What common result isworse than death? Compare the demoralization in the cases of the opiumuser and the alcohol drinker. What principle of heredity attaches to theuse of opium? Give instances of deaths from tobacco, opium, etc. What canyou say of cigarette smoking? Chloral hydrate? The bromides? Absinthe?Hasheesh?

THE SPECIAL SENSES. 

229, 230. What is a sense? Name the five senses. To what organ do all thesenses minister? If the nerve leading to any organ of sense be cut, whatwould be the effect? [Footnote: Each, organ is adapted to receive apeculiar kind of impression. Hence we can not smell with, the eyes nor seewith the nose. Thus, if the nerve communicating between the brain and anyorgan be destroyed, that means of knowledge is cut off. ] Sometimes personslose feeling in a limb, but retain motion; why is this? What is the senseof touch sometimes called? Describe the organ of touch. What are thepapillæ? Where are they most abundant? [Footnote: If we apply the pointsof a compass blunted with cork to different parts of the body, we candistinguish the two points at one twenty-fourth of an inch apart on thetongue, one sixteenth, of an inch on the lips, one twelfth of an inch onthe tips of the fingers, and one half inch on the great toe; while, ifthey are one inch on the cheek, and two inches on the back, they willscarcely produce a separate sensation. --HUXLEY. ] What are the uses of thissense? What special knowledge do we obtain by it? Why do we always desireto handle any curious object? Can the sense of touch always be reliedupon? Illustrate. What is the _tactus eruditus_? Tell how one sensecan take the place of another. Give illustrations of the delicacy of touchpossessed by the blind. 

230-232. Describe the sense of taste. How can you see the papillæ oftaste? What causes the velvety look of the tongue? Why do salt and bitterflavors induce vomiting? Why does an acid "pucker" the face? Whatsubstances are tasteless? Illustrate. Has sulphur any taste? Chalk? Sand?What is the use of this sense? Does it not also add to the pleasures oflife? Why are the acts of eating, drinking, etc. , thus made sources ofhappiness?

232, 233. Describe the organ of smell. State the intimate relation whichexists between the senses of smell and taste. Name some common mistakeswhich occur in consequence. Must the object to be smelled touch the nose?What is the theory of smell? How do you account for the statement made inthe note concerning musk and ambergris? What are the uses of this sense?Are agreeable odors healthful, and disagreeable ones unhealthful?

234-236. Describe the organ of hearing. Describe the external ear. What isthe tympanum or drum of the ear? Describe the middle ear. Name the bonesof the ear. Describe their structure. Describe the internal ear. By whatother name is it known? What substances float in the liquid which fillsthe labyrinth? What is their use? Describe the fibers of Corti. What dothey form? Use of this microscopic harp? Give the theory of sound. Whereis the sound, in the external object or in the mind? Can there be anysound, then, where there is no mind? What advice is given concerning thecare of the ear? How can insects be removed? Which sense would you ratherlose, hearing or sight? Does not a blind person always excite moresympathy than a deaf one? How does the sight assist the hearing?[Footnote: In _hearing_, the attention is more or less characteristic. If we wish to distinguish a distant noise, or perceive a sound, thehead inclines and turns in such a manner as to present the externalear in the direction of the sound, at the same time the eyes arefixed and partially closed. The movement of the lips of his interlocutoris the usual means by which the deaf man supplies the want of hearing; theeyes and the entire head, from its position, having a peculiar and painfulexpression of attention. In looking at the portrait of La Condamine, itwas easily recognized as that of a deaf person. Even when hearing isperfect, the eyes act sometimes as auxiliaries to it. In order tounderstand an orator perfectly, it seems necessary to see him--thegestures and the expression of the face seeming to add to the clearness ofthe words. The lesson of a teacher can not be well understood if anyobstacle is interposed between him and the eyes of the listening pupil. Sothat if a pupil's eyes wander, we know that he is not attentive. --_Wonders of the Human Body_. ]

236, 237. Describe the eye. Name the three coats of which it is composed. Is it a perfect sphere? _Ans_. The cornea projects in front, and theoptic nerve at the back sticks out like a handle, while the ball itselfhas its longest diameter from side to side. How is the interior divided?Object of the crystalline lens? How is the crystalline lens kept in place?Describe the liquids which fill the eye. 

238. What is the pupil? Describe the eyelids. Why is the inner side of theeyelid so sensitive? What is the cause of a black eye? Use of theeyelashes? Where are the oil glands located? What is their use? Describethe lachrymal gland. The lachrymal lake. What causes the overflow in oldage?

239. Explain the structure of the retina. Use of the rods and cones. Whatis the blind spot?

240. Illustrate. What is the theory of sight? Illustrate. 

241, 242. State the action of the crystalline lens. Its power ofadaptation. Do children ever need spectacles?

243. What is the cataract? How cured? What is color blindness? Illustrate. What care should be taken of the eyes? Should one constantly lean forwardover his book or work? What special care should nearsighted children take?By what carelessness may we impair our sight?

244. How is squinting caused? Cured? What care should be used after anillness? Should we ever read or write at twilight? Danger of reading uponthe ears? What course should we take when objects get into the eye? Howmay they be removed?

245. Are "eyestones" useful? Why should we never use eyewashes except uponthe advice of a competent physician? What rule should be observed withregard to the direction of the light when we are at work? Name some causesof near-sightedness. Remedies. 

346. Give the account of Laura Bridgman. 

347-350. Describe the anatomy of the nose. In what part of the nose is thefunction of smell performed? Why do we "sniff" when our attention isattracted by an odor? Give some experiments which illustrate theconnection between smell, taste, and touch. Why should we retain our foodin the mouth as long as possible? Of what use are gastronomic odors?

350. Why should a child's ear never be boxed? Illustrate. How can wedetect inattention from deafness in a child? What should we consider inthis respect?

351. Why should we avoid direct draughts in the ear? Explain the use ofearwax. What common habit is very injurious? Why?

352, 353. What is the office of the Eustachian tube? Illustrate. 

353, 354. Describe the action of the "eye curtain. " Give experiments. Whatare "Purkinje's Figures"? Describe experiment. 

HEALTH AND DISEASE. 

251-254. State some of the benefits of health. Contrast it with sickness. How were diseases formerly supposed to be caused? What remedies were used?What does modern science teach us to be the nature of disease? Give someillustrations showing how diseases may be prevented. Is it probable thatthe body was intended to give out in any one of its organs? What is thefirst step to be taken in the cure of a disease? What should be the objectof medicine? What is now the chief dependence of the best physicians? Whatdo you think concerning the common use of patent nostrums? Ought we not touse the greatest care in the selection of our physician?

GLOSSARY. 

Ab do' men (_abdo_, I conceal). The largest cavity in the body, inwhich are hidden the intestines, stomach, etc. 

Ab sorb' ent (_ab_, from _sorbeo_, I suck up). 

Ac' e tab' u lum (_acetum_, vinegar). The socket for holding the headof the thigh bone, shaped like an ancient vinegar vessel. 

A ce' tic (_acetum_, vinegar). 

Ad' i pose. Fatty. 

Al bu' men (_albus_, white). A substance resembling the white of egg. 

Al bu' mi nous substances contain much albumen. 

Al' i men' ta ry. Pertaining to food. 

Al' ka line (-lin) substances neutralize acids. 

An' æs thet' ic. A substance that destroys the feeling of pain. 

A or' ta. The largest artery of the body. 

Ap' o plex y (pleks y). A disease marked by loss of sensation andvoluntary motion. 

A' que ous (a'-kwe-us). Watery. 

A rach' noid (_arachne_, a spider; _eidos_, form). A membranelike a spider's web covering the brain. 

Ar' bor vi'tæ means "the tree of life. "

Ar' tery (_aer_, air; _tereo_, I contain). So named becauseafter death the arteries contain air only, and hence the ancients supposedthem to be air tubes leading through the body. 

Ar tic' u late (_articulo_, I form a joint). 

Ar tic' u la tion. A joint. 

As phyx' ia (-fix-i-a). Literally, no pulse; apparent death. 

As sim' i la' tion is the process of changing food into flesh, etc. 

At' las. So called because, as in ancient fable the god Atlas supportedthe globe on his shoulders, so in the body this bone bears the head. 

Au' di to ry Nerve. The nerve of hearing. 

Au' ri cle (-kl) (_auris_, ear) of the heart. So named from itsshape. 

Bi' ceps. A muscle with two heads, or origins. 

Bi cus' pid. Tooth with two points; also a valve of the heart. 

Bron' chi (-ki). The two branches of the windpipe. 

Bron' chi al Tubes. Subdivisions of bronchi. 

Bur sa (a purse). Small sac containing fluid near a joint. 

Ca nine' (_canis_, a dog) teeth are like dog's teeth. 

Cap' il la ries (_capillus_, a hair). A system of tiny blood vessels. 

Car' bon. Pure charcoal. 

Car bon' ic Acid. A deadly gas given off by the lungs and by fires. 

Ca rot' ids (_karos_, lethargy). Arteries of the neck, so namedbecause the ancients supposed them to be the seat of sleep. 

Car' pus. The wrist. 

Car' ti lage. Gristle. 

Cell. A minute sac, usually with soft walls and fluid contents. 

Cel' lu lar (_cellula_, a little cell). Full of cells. 

Cer' e bel' lum. The little brain. 

Cer' e brum. A Latin word meaning brain. 

Cer' vi cal. Relating to the neck. 

Chlo' ral (klo) Hy' drate. A drug used to induce sleep. 

Cho' roid. The second coat of the eye. 

Chyle (kile). A milky juice formed in digestion. 

Chyme (kime). From _chumos_, juice. 

Cir' cu la' tion. The course of the blood through the body. 

Cil' i a (the plural of _cilium_, an eyelash). Hair-like projectionsin the air passages. 

Clav' i cle (klav'-i-kl). From _clavis_, a key. 

Co ag' u la'tion. A clotting of blood. 

Coc' cyx (a cuckoo). A bony mass below the sacrum. 

Coch' le a. A Latin word meaning snail shell. See Ear

Com' pound. A substance composed of two or more elements. 

Con ta' gious diseases are those caught by contact, the breath, etc. 

Con' trac til' i ty (_con_, together; _traho_, I draw). 

Con' vo lu' tion (_con_, together; _volvo_, I roll). 

Cor' ne a (_cornu_, a horn). A transparent, horn-like window in theeye. 

Cor' pus cle (kor'-pus-l). From a Latin word meaning a little body. It isapplied to the disks of the blood. 

Cra' ni al. Relating to the skull. 

Crys'tal line (_crystallum_, a crystal). 

Cu ta' ne ous (_cutis_, skin). Pertaining to the skin. 

Cu' ti cle (ku'-ti-kl). From a Latin word meaning little skin. 

Cu' tis, the true skin. 

Den' tal (_dens, dentis_, a tooth). 

Di' a phragm (-fram). The muscle dividing the abdomen from the chest. 

Di as' to le (_diastello_, I put asunder). Dilation of the heart. 

Dis' lo ca' tion. A putting out of joint. 

Dor' sal (_dorsum_, the back). 

Duct. A small tube. 

Du o de' num (_duodeni_, twelve each). 

Du' ra Ma' ter (_durus_, hard; _mater_, mother). The outermembrane of the brain. 

Dys pep' si a is a difficulty of digestion

E lim' i nate. To expel. 

Ep' idem' ic. A disease affecting a great number of persons at once. 

Ep' i der' mis. The cuticle. 

Ep' i glot' tis (_epi_, upon; _glottis_, the tongue). The lid ofthe windpipe. 

Ep' i the' li um. The outer surface of mucous or serous membranes. 

Eu sta' chi an (u-sta'-ki-an) Tube. So named from its discoverer, anItalian physician. 

Ex cre' tion. Waste particles thrown off by the excretory organs. 

Fer' men ta' tion. The process by which sugar is turned into alcohol. 

Fi' brin (_fibra_, a fiber). 

Fil' a ment (_filum_, a thread). 

Func' tion. See Organ. 

Gan' gli on (gang'-gli-on). From _ganglion_, a knot; plu. Ganglia. 

Gas' tric (_gaster_, stomach). 

Glands (_glandz_). From _glans_, a Latin word meaning acorn. Their object, is to secrete in their cells some liquid from the blood. 

Glot' tis. The opening at the top of the larynx. 

Hu' me rus. The arm bone. 

Hu' mor. A Latin word meaning moisture. 

Hy' dro gen. The lightest gas known, and one of the elements of water. 

Hy' gi ene. From a Greek word meaning health. 

Hyp' o glos' sal. Literally "under the tongue"; a nerve of the tongue. 

In ci' sor (_incido_, I cut) teeth are cutting teeth. 

In' spi ra' tion (_in_ and _spiro_, I breathe in). 

In tes' tine (-tin). From _intus_, within. 

Lach' ry mal (_lachryma_, a tear). Pertaining to tears. 

Lac' te al (_lac_, _lactis_, milk). So called from the milkylook of the chyle during digestion. 

La cu' na, plu. Lacunæ (_lakos_, a hole). Cavities in the bonestructure. 

Lar' ynx (lar'-inx). The upper part of the windpipe. 

Lig' a ments (_ligo_, I bind) tie bones together. 

Lu' bri cate. To oil in order to prevent friction. 

Lum' bar (_lumbus_, a loin). Pertaining to the loins. 

Lymph (limf). From _lympha_, pure water. 

Lym phat' ic (lim-fat-ik). 

Mas' ti ca' tion. The act of chewing. 

Me dul' la Ob lon ga' ta. The upper part of the spinal cord. 

Mam' brane. A thin skin, or tissue. 

Mes' en tery. The membrane by which the intestines are fastened to thespine. 

Met' a car' pal (_meta_, after; _karpos_, wrist). 

Met' a tar' sal (_meta_, after; _tarsos_, the instep). 

Mi' cro scope (_mikros_, small; _skopeo_, I see). 

Mo'lar (_mola_, a mill) teeth are the grinders. 

Morp' hine (_Morpheus_, the Greek god of sleep). 

Mo' tor. Giving motion. 

Mu' cous (-kus) Membrane. A thin tissue, or skin, covering the opencavities of the body. See Serous. 

Mu' cous. A fluid secreted by a membrane and serving to lubricate it. 

Mus' cle (mus-l). A bundle of fibers covered by a membrane. 

My o' pi a (_muo_, I contract; _ops_, the eye). 

Nar cot' ic. A drug producing sleep. 

Na' sal (na'-zal). From _nasus_, the nose. 

Nerve (neuron, a cord). 

Ni' tro gen Gas is the passive element of the air. 

Ni trog' e nous. Containing nitrogen. 

Nu tri' tion. The process by which the body is nourished. 

Πsoph' agus (e-sof'-a-gus). The gullet; literally, a "food-carrier. "

Ol fac' to ry. Pertaining to the smell. 

Or' gan. An organ is a portion of the body designed for a particular use, which is called its _function_; thus the heart circulates the blood. 

Os' se ous. Bone-like. 

Os' si fy (_ossa_, bones; _facio_, I make). 

Ox i da' tion. The process of combining with oxygen. 

Ox' y gen. The active element of the air. 

Pal' ate (_palatum_, the palate). Roof of the mouth. 

Pan' cre as (_pas_, all; _kreas_, flesh). An organ of digestion. 

Pa pil' la, plu. Papillæ. Tiny cone-like projections. 

Pa ral' y sis. A disease in which one loses sensation, or the power ofmotion, or both. 

Pa rot' id (_para_, near; _ous_, _otos_, ear). One of thesalivary glands. 

Pa tel' la (a little dish). The kneepan. 

Pec' to ral. Pertaining to the chest. 

Pep' sin (_pepto_, I digest). The chief constituent of the gastricjuice. 

Per' i car' di um (_peri_, around; _kardia_, the heart). Themembrane wrapping the heart. 

Per' i os' te um (_peri_, around; _osteon_, bone). The membranearound the bone. 

Per' i stal' tic (_peri_, round; _stallein_, to arrange). Applied to the worm-like movement of the alimentary canal. 

Phar' ynx (far'-inx). From _pharugx_, the throat. 

Pi' a Ma' ter (tender mother). See Brain. 

Pig' ment. A paint. 

Plas' ma (plaz'-ma). The nutritious fluid of the blood. 

Pleu' ra (plu'-ra). From _pleuar_, a rib. The membrane that lines thechest and wraps the lungs. 

Pres by o' pi a (_presbus_, old; _ops_, the eye). A defect inthe eye common to old age. 

Proc' ess. A projection. Sometimes it retains its ordinary meaning of"operation. "

Py lo' rus (a gate). The doorway through which the food passes from thestomach. 

Pul' mo na ry (_pulmo_, the lungs). Pertaining to the lungs. 

Ra' di us. A Latin word meaning the spoke of a wheel, a ray, etc. 

Ram' i fy. To spread like the branches of a tree. 

Res' pi ra´ tion (_re_, again; _spiro_, I breathe). Act ofbreathing. 

Ret' i na (_rete_, a net). The expansion of the optic nerve in theeye. 

Sa' crum (sacred). So named, it is said, because this bone of the pelviswas anciently offered in sacrifice. 

Sa li' va. A Latin word meaning spittle; the fluid secreted by thesalivary glands. 

Scap' u la. The shoulder blade. 

Scav' en ger. A street sweeper. 

Sele rot' ic (skie-rot'-ic). The outer coat of the eye. 

Se cre' tion (_secretum_, to separate). 

Sed' en ta ry persons are those who sit much. 

Sen' so ry Nerves. The nerves of feeling. 

Se' rous Membrane. A thin tissue, or skin, covering the cavities of thebody that are not open to the external air. 

Se' rum. The thin part of the blood. 

Sub cla' vi an. Located under the clavicle. 

Sub lin' gual (_sub_, under: _lingua_, the tongue). The salivarygland located under the tongue. 

Sub max' il la ry (_sub_, under; _maxilla_, jawbone). Thesalivary gland located under the jaw. 

Syn o' vi a (_sun_, with; _oon_, egg). A fluid that lubricatesthe joints. 

Syn o' vi al Membrane packs the joints. 

Sys' to le (_sustello_, I contract). Contraction of the heart. 

Tem' po ral. An artery on the temple (_tempus_, time), so calledbecause, as is said, the hair whitens first at that point. 

Ten' dons (_tendo_, I stretch). The cords conveying motion from themuscle to the bone. 

Tho' rax (a breastplate). The cavity containing the lungs, etc. 

Tib' ia. The shin-bone. 

Tis' sue. A general term applied to the textures of which the differentorgans are composed; osseous tissue forms bones. 

Tra' che a (tra'-ke-a). Means rough, alluding to the roughened surface ofthe windpipe. 

Tri' ceps. A muscle with three heads, or origins. 

Tri' cus' pid (_tres_, three; _cuspis_, point). A valve of theheart. 

Tym' pa num (a drum) of the ear. 

Vas' cu lar (_vasculum_, little vessel). Full of small blood vessels. 

Ven' tri cle (-kl). A cavity of the heart. 

Ver' te bra, plu. Vertebræ (_verto_, I turn). A term applied to eachone of the bones of the spine. 

Vil' lus (_villus_, tuft of hair), plu. Villi. 

Vi' ti ate. To taint. To spoil. 

Vit' re ous (_vitrium_, glass). Glassy. 

Vo' mer (plowshare). A bone of the nose.