[Illustration: FLORA attired by the ELEMENTS] THE BOTANIC GARDEN; _A Poem, in Two Parts. _ PART I. CONTAINING THE ECONOMY OF VEGETATION. PART II. THE LOVES OF THE PLANTS. WITH Philosophical Notes. ADVERTISEMENT. The general design of the following sheets is to inlist Imaginationunder the banner of Science; and to lead her votaries from the looseranalogies, which dress out the imagery of poetry, to the stricter, oneswhich form the ratiocination of philosophy. While their particulardesign is to induce the ingenious to cultivate the knowledge of Botany, by introducing them to the vestibule of that delightful science, andrecommending to their attention the immortal works of the celebratedSwedish Naturalist, LINNEUS. In the first Poem, or Economy of Vegetation, the physiology of Plants isdelivered; and the operation of the Elements, as far as they may besupposed to affect the growth of Vegetables. In the second Poem, orLoves of the Plants, the Sexual System of Linneus is explained, with theremarkable properties of many particular plants. APOLOGY. It may be proper here to apologize for many of the subsequentconjectures on some articles of natural philosophy, as not beingsupported by accurate investigation or conclusive experiments. Extravagant theories however in those parts of philosophy, where ourknowledge is yet imperfect, are not without their use; as they encouragethe execution of laborious experiments, or the investigation ofingenious deductions, to confirm or refute them. And since naturalobjects are allied to each other by many affinities, every kind oftheoretic distribution of them adds to our knowledge by developing someof their analogies. The Rosicrucian doctrine of Gnomes, Sylphs, Nymphs, and Salamanders, wasthought to afford a proper machinery for a Botanic poem; as it isprobable, that they were originally the names of hieroglyphic figuresrepresenting the elements. Many of the important operations of Nature were shadowed or allegorizedin the heathen mythology, as the first Cupid springing from the Egg ofNight, the marriage of Cupid and Psyche, the Rape of Proserpine, theCongress of Jupiter and Juno, Death and Resuscitation of Adonis, &c. Many of which are ingeniously explained in the works of Bacon, Vol. V. P. 47. 4th Edit. London, 1778. The Egyptians were possessed of manydiscoveries in philosophy and chemistry before the invention of letters;these were then expressed in hieroglyphic paintings of men and animals;which after the discovery of the alphabet were described and animated bythe poets, and became first the deities of Egypt, and afterwards ofGreece and Rome. Allusions to those fables were therefore thought properornaments to a philosophical poem, and are occasionally introducedeither as represented by the poets, or preserved on the numerous gemsand medallions of antiquity. TO THE AUTHOR OF THE POEM ON THE LOVES OF THE PLANTS. BY THE REV. W. B. STEPHENS. Oft tho' thy genius, D----! amply fraughtWith native wealth, explore new worlds of mind;Whence the bright ores of drossless wisdom brought, Stampt by the Muse's hand, enrich mankind; Tho' willing Nature to thy curious eye, Involved in night, her mazy depths betray;Till at their source thy piercing search descryThe streams, that bathe with Life our mortal clay; Tho', boldly soaring in sublimer moodThrough trackless skies on metaphysic wings, Thou darest to scan the approachless Cause of Good, And weigh with steadfast hand the Sum of Things; Yet wilt thou, charm'd amid his whispering bowersOft with lone step by glittering Derwent stray, Mark his green foliage, count his musky flowers, That blush or tremble to the rising ray; While FANCY, seated in her rock-roof'd dell, Listening the secrets of the vernal grove, Breathes sweetest strains to thy symphonious shell, And gives new echoes to the throne of Love. _Repton, Nov. 28, 1788. _ _Argument of the First Canto. _ The Genius of the place invites the Goddess of Botany. 1. She descends, is received by Spring, and the Elements, 59. Addresses the Nymphs ofFire. Star-light Night seen in the Camera Obscura, 81. I. Love createdthe Universe. Chaos explodes. All the Stars revolve. God. 97. II. Shooting Stars. Lightning. Rainbow. Colours of the Morning and EveningSkies. Exterior Atmosphere of inflammable Air. Twilight. Fire-balls. Aurora Borealis. Planets. Comets. Fixed Stars. Sun's Orb, 115. III. 1. Fires at the Earth's Centre. Animal Incubation, 137. 2. VolcanicMountains. Venus visits the Cyclops, 149. IV. Heat confined on the Earthby the Air. Phosphoric lights in the Evening. Bolognian Stone. CalcinedShells. Memnon's Harp, 173. Ignis fatuus. Luminous Flowers. Glow-worm. Fire-fly. Luminous Sea-insects. Electric Eel. Eagle armed withLightning, 189. V. 1. Discovery of Fire. Medusa, 209. 2. The chemicalProperties of Fire. Phosphorus. Lady in Love, 223. 3. Gunpowder, 237. VI. Steam-engine applied to Pumps, Bellows, Water-engines, Corn-mills, Coining, Barges, Waggons, Flying-chariots, 253. Labours of Hercules. Abyla and Calpe, 297. VII. 1. Electric Machine. Hesperian Dragon. Electric kiss. Halo round the heads of Saints. Electric Shock. Fairy-rings, 335. 2. Death of Professor Richman, 371. 3. Franklin drawsLightning from the Clouds. Cupid snatches the Thunder-bolt from Jupiter, 383. VIII. Phosphoric Acid and Vital Heat produced in the Blood. Thegreat Egg of Night, 399. IX. Western Wind unfettered. Naiad released. Frost assailed. Whale attacked, 421. X. Buds and Flowers expanded byWarmth, Electricity, and Light. Drawings with colourless sympatheticInks; which appear when warmed by the Fire, 457. XI. Sirius. Jupiter andSemele. Northern Constellations. Ice-islands navigated into the TropicSeas. Rainy Monsoons, 497. XII. Points erected to procure Rain. Elijahon Mount-Carmel, 549. Departure of the Nymphs of Fire like sparks fromartificial Fireworks, 587. THE ECONOMY OF VEGETATION. CANTO I. STAY YOUR RUDE STEPS! whose throbbing breasts infold The legion-fiends of Glory, or of Gold! Stay! whose false lips seductive simpers part, While Cunning nestles in the harlot-heart!-- 5 For you no Dryads dress the roseate bower, For you no Nymphs their sparkling vases pour; Unmark'd by you, light Graces swim the green, And hovering Cupids aim their shafts, unseen. "But THOU! whose mind the well-attemper'd ray 10 Of Taste and Virtue lights with purer day; Whose finer sense each soft vibration owns With sweet responsive sympathy of tones; So the fair flower expands it's lucid form To meet the sun, and shuts it to the storm;-- 15 For thee my borders nurse the fragrant wreath, My fountains murmur, and my zephyrs breathe; Slow slides the painted snail, the gilded fly Smooths his fine down, to charm thy curious eye; On twinkling fins my pearly nations play, 20 Or win with sinuous train their trackless way; My plumy pairs in gay embroidery dress'd Form with ingenious bill the pensile nest, To Love's sweet notes attune the listening dell, And Echo sounds her soft symphonious shell. [ _So the fair flower_. L. 13. It seems to have been the original designof the philosophy of Epicurus to render the mind exquisitely sensible toagreeable sensations, and equally insensible to disagreeable ones. ] 25 "And, if with Thee some hapless Maid should stray, Disasterous Love companion of her way, Oh, lead her timid steps to yonder glade, Whose arching cliffs depending alders shade; There, as meek Evening wakes her temperate breeze, 30 And moon-beams glimmer through the trembling trees, The rills, that gurgle round, shall soothe her ear, The weeping rocks shall number tear for tear; There as sad Philomel, alike forlorn, Sings to the Night from her accustomed thorn; 35 While at sweet intervals each falling note Sighs in the gale, and whispers round the grot; The sister-woe shall calm her aching breast, And softer slumbers steal her cares to rest. -- [_Disasterous Love_. L. 26. The scenery is taken from a botanic gardenabout a mile from Lichfield, where a cold bath was erected by Sir JohnFloyer. There is a grotto surrounded by projecting rocks, from the edgesof which trickles a perpetual shower of water; and it is hererepresented as adapted to love-scenes, as being thence a properresidence for the modern goddess of Botany, and the easier to introducethe next poem on the Loves of the Plants according to the system ofLinneus. ] "Winds of the North! restrain your icy gales, 40 Nor chill the bosom of these happy vales! Hence in dark heaps, ye gathering Clouds, revolve! Disperse, ye Lightnings! and, ye Mists, dissolve! --Hither, emerging from yon orient skies, BOTANIC GODDESS! bend thy radiant eyes; 45 O'er these soft scenes assume thy gentle reign, Pomona, Ceres, Flora in thy train; O'er the still dawn thy placid smile effuse, And with thy silver sandals print the dews; In noon's bright blaze thy vermil vest unfold, 50 And wave thy emerald banner star'd with gold. " Thus spoke the GENIUS, as He stept along, And bade these lawns to Peace and Truth belong; Down the steep slopes He led with modest skill The willing pathway, and the truant rill, 55 Stretch'd o'er the marshy vale yon willowy mound, Where shines the lake amid the tufted ground, Raised the young woodland, smooth'd the wavy green, And gave to Beauty all the quiet scene. -- She comes!--the GODDESS!--through the whispering air, 60 Bright as the morn, descends her blushing car; Each circling wheel a wreath of flowers intwines, And gem'd with flowers the silken harness shines; The golden bits with flowery studs are deck'd, And knots of flowers the crimson reins connect. -- 65 And now on earth the silver axle rings, And the shell sinks upon its slender springs; Light from her airy seat the Goddess bounds, And steps celestial press the pansied grounds. Fair Spring advancing calls her feather'd quire, 70 And tunes to softer notes her laughing lyre; Bids her gay hours on purple pinions move, And arms her Zephyrs with the shafts of Love, Pleased GNOMES, ascending from their earthy beds, Play round her graceful footsteps, as she treads; 75 Gay SYLPHS attendant beat the fragrant air On winnowing wings, and waft her golden hair; Blue NYMPHS emerging leave their sparkling streams, And FIERY FORMS alight from orient beams; Musk'd in the rose's lap fresh dews they shed, 80 Or breathe celestial lustres round her head. [_Pleased Gnomes_. L. 73. The Rosicrucian doctrine of Gnomes, Sylphs, Nymphs, and Salamanders affords proper machinery for a philosophic poem;as it is probable that they were originally the names of hieroglyphicfigures of the Elements, or of Genii presiding over their operations. The Fairies of more modern days seem to have been derived from them, andto have inherited their powers. The Gnomes and Sylphs, as being morenearly allied to modern Fairies are represented as either male orfemale, which distinguishes the latter from the Aurae of the LatinPoets, which were only female; except the winds, as Zephyrus and Auster, may be supposed to have been their husbands. ] First the fine Forms her dulcet voice requires, Which bathe or bask in elemental fires; From each bright gem of Day's refulgent car, From the pale sphere of every twinkling star, 85 From each nice pore of ocean, earth, and air, With eye of flame the sparkling hosts repair, Mix their gay hues, in changeful circles play, Like motes, that tenant the meridian ray. -- So the clear Lens collects with magic power 90 The countless glories of the midnight hour; Stars after stars with quivering lustre fall, And twinkling glide along the whiten'd wall. -- Pleased, as they pass, she counts the glittering bands, And stills their murmur with her waving hands; 95 Each listening tribe with fond expectance burns, And now to these, and now to those, she turns. I. "NYMPHS OF PRIMEVAL FIRE! YOUR vestal train Hung with gold-tresses o'er the vast inane, Pierced with your silver shafts the throne of Night, 100 And charm'd young Nature's opening eyes with light; When LOVE DIVINE, with brooding wings unfurl'd, Call'd from the rude abyss the living world. "--LET THERE BE LIGHT!" proclaim'd the ALMIGHTY LORD, Astonish'd Chaos heard the potent word;--105 Through all his realms the kindling Ether runs, And the mass starts into a million suns; Earths round each sun with quick explosions burst, And second planets issue from the first; Bend, as they journey with projectile force, 110 In bright ellipses their reluctant course; Orbs wheel in orbs, round centres centres roll, And form, self-balanced, one revolving Whole. --Onward they move amid their bright abode, Space without bound, THE BOSOM OF THEIR GOD! [_Nymphs of primeval fire_. L. 97. The fluid matter of heat is perhapsthe most extensive element in nature; all other bodies are immersed init, and are preserved in their present state of solidity or fluidity bythe attraction of their particles to the matter of heat. Since all knownbodies are contractible into less space by depriving them of someportion of their heat, and as there is no part of nature totallydeprived of heat, there is reason to believe that the particles ofbodies do not touch, but are held towards each other by their self-attraction, and recede from each other by their attraction to the massof heat which surrounds them; and thus exist in an equilibrium betweenthese two powers. If more of the matter of heat be applied to them, theyrecede further from each other, and become fluid; if still more beapplied, they take an aerial form, and are termed Gasses by the modernchemists. Thus when water is heated to a certain degree, it wouldinstantly assume the form of steam, but for the pressure of theatmosphere, which prevents this change from taking place so easily; thesame is true of quicksilver, diamonds, and of perhaps all other bodiesin Nature; they would first become fluid, and then aeriform byappropriated degrees of heat. On the contrary, this elastic matter ofheat, termed Calorique in the new nomenclature of the FrenchAcademicians, is liable to become consolidated itself in itscombinations with some bodies, as perhaps in nitre, and probably incombustible bodies as sulphur and charcoal. See note on l. 232, of thisCanto. Modern philosophers have not yet been able to decide whetherlight and heat be different fluids, or modifications of the same fluid, as they have many properties in common. See note on l. 462 of thisCanto. ] [_When Love Divine_. L. 101. From having observed the gradual evolutionof the young animal or plant from its egg or seed; and afterwards itssuccessive advances to its more perfect state, or maturity; philosophersof all ages seem to have imagined, that the great world itself hadlikewise its infancy and its gradual progress to maturity; this seems tohave given origin to the very antient and sublime allegory of Eros, orDivine Love, producing the world from the egg of Night, as it floated inChaos. See l. 419. Of this Canto. The external crust of the earth, as far as it has been exposed to ourview in mines or mountains, countenances this opinion; since these haveevidently for the most part had their origin from the shells of fishes, the decomposition of vegetables, and the recrements of other animalmaterials, and must therefore have been formed progressively from smallbeginnings. There are likewise some apparently useless or incompleteappendages to plants and animals, which seem to shew they have graduallyundergone changes from their original state; such as the stamens withoutanthers, and styles without stigmas of several plants, as mentioned inthe note on Curcuma, Vol. II. Of this work. Such is the halteres, orrudiments of wings of some two-winged insects; and the paps of maleanimals; thus swine have four toes, but two of them are imperfectlyformed, and not long enough for use. The allantoide in some animalsseems to have become extinct; in others is above tenfold the size, whichwould seem necessary for its purpose. Buffon du Cochon. T. 6. P. 257. Perhaps all the supposed monstrous births of Nature are remains of theirhabits of production in their former less perfect state, or attemptstowards greater perfection. ] [_Through all his realms_. L. 105. Mr. Herschel has given a very sublimeand curious account of the construction of the heavens with hisdiscovery of some thousand nebulae, or clouds of stars; many of whichare much larger collections of stars, than all those put together, whichare visible to our naked eyes, added to those which form the galaxy, ormilky zone, which surrounds us. He observes that in the vicinity ofthese clusters of stars there are proportionally fewer stars than inother parts of the heavens; and hence he concludes, that they haveattracted each other, on the supposition that infinite space was atfirst equally sprinkled with them; as if it had at the beginning beenfilled with a fluid mass, which had coagulated. Mr. Herschel has furthershewn, that the whole sidereal system is gradually moving round somecentre, which may be an opake mass of matter, Philos. Trans. V. LXXIV. If all these Suns are moving round some great central body; they musthave had a projectile force, as well as a centripetal one; and maythence be supposed to have emerged or been projected from the material, where they were produced. We can have no idea of a natural power, whichcould project a Sun out of Chaos, except by comparing it to theexplosions or earthquakes owing to the sudden evolution of aqueous or ofother more elastic vapours; of the power of which under immeasurabledegrees of heat, and compression, we are yet ignorant. It may be objected, that if the stars had been projected from a Chaos byexplosions, that they must have returned again into it from the knownlaws of gravitation; this however would not happen, if the whole ofChaos, like grains of gunpowder, was exploded at the same time, anddispersed through infinite space at once, or in quick succession, inevery possible direction. The same objection may be stated against thepossibility of the planets having been thrown from the sun byexplosions; and the secondary planets from the primary ones; which willbe spoken of more at large in the second Canto, but if the planets aresupposed to have been projected from their suns, and the secondary fromthe primary ones, at the beginning of their course; they might be soinfluenced or diverted by the attractions of the suns, or sun, in theirvicinity, as to prevent their tendency to return into the body, fromwhich they were projected. If these innumerable and immense suns thus rising out of Chaos aresupposed to have thrown out their attendant planets by new explosions, as they ascended; and those their respective satellites, filling in amoment the immensity of space with light and motion, a grander ideacannot be conceived by the mind of man. ] 115 II. "ETHEREAL POWERS! YOU chase the shooting stars, Or yoke the vollied lightenings to your cars, Cling round the aërial bow with prisms bright, And pleased untwist the sevenfold threads of light; Eve's silken couch with gorgeous tints adorn, 120 And fire the arrowy throne of rising Morn. --OR, plum'd with flame, in gay battalion's spring To brighter regions borne on broader wing; Where lighter gases, circumfused on high, Form the vast concave of exterior sky;125 With airy lens the scatter'd rays assault, And bend the twilight round the dusky vault; Ride, with broad eye and scintillating hair, The rapid Fire-ball through the midnight air; Dart from the North on pale electric streams, 130 Fringing Night's sable robe with transient beams. --OR rein the Planets in their swift careers, Gilding with borrow'd light their twinkling spheres; Alarm with comet-blaze the sapphire plain, The wan stars glimmering through its silver train;135 Gem the bright Zodiac, stud the glowing pole, Or give the Sun's phlogistic orb to roll. [_Chase the shooting stars_. L. 115. The meteors called shooting stars, the lightening, the rainbow, and the clouds, are phenomena of the lowerregions of the atmosphere. The twilight, the meteors call'd fire-balls, or flying dragons, and the northern lights, inhabit the higher regionsof the atmosphere. See additional notes, No. I. ] [_Cling round the aerial bow_. L. 117. See additional notes, No. II] [_Eve's silken couch_. L. 119. See additional notes, No. III. ] [_Where lighter gases_. L. 123. Mr. Cavendish has shewn that the gascalled inflammable air, is at least ten times lighter than common air;Mr. Lavoisier contends, that it is one of the component parts of water, and is by him called hydrogene. It is supposed to afford their principalnourishment to vegetables and thence to animals, and is perpetuallyrising from their decomposition; this source of it in hot climates, andin summer months, is so great as to exceed estimation. Now if this lightgas passes through the atmosphere, without combining with it, it mustcompose another atmosphere over the aerial one; which must expand, whenthe pressure above it is thus taken away, to inconceivable tenuity. If this supernatural gasseous atmosphere floats upon the aerial one, like ether upon water, what must happen? 1. It will flow from the line, where it will be produced in the greatest quantities, and become muchaccumulated over the poles of the earth; 2. The common air, or lowerstratum of the atmosphere, will be much thinner over the poles than atthe line; because if a glass globe be filled with oil and water, andwhirled upon its axis, the centrifugal power will carry the heavierfluid to the circumference, and the lighter will in consequence be foundround the axis. 3. There may be a place at some certain latitude betweenthe poles and the line on each side the equator, where the inflammablesupernatant atmosphere may end, owing to the greater centrifugal forceof the heavier aerial atmosphere. 4. Between the termination of theaerial and the beginning of the gasseous atmosphere, the airs willoccasionally be intermixed, and thus become inflammable by the electricspark; these circumstances will assist in explaining the phenomena offire-balls, northern lights, and of some variable winds, and longcontinued rains. Since the above note was first written, Mr. Volta I am informed hasapplied the supposition of a supernatant atmosphere of inflammable air, to explain some phenomena in meteorology. And Mr. Lavoisier hasannounced his design to write on this subject. Traité de Chimie, Tom. I. I am happy to find these opinions supported by such respectableauthority. ] [_And bend the twilight_. L. 126. The crepuscular atmosphere, or theregion where the light of the sun ceases to be refracted to us, isestimated by philosophers to be between 40 and 50 miles high, at whichtime the sun is about 18 degrees below the horizon; and the rarity ofthe air is supposed to be from 4, 000 to 10, 000 times greater than at thesurface of the earth. Cotes's Hydrost. P. 123. The duration of twilightdiffers in different seasons and in different latitudes; in England theshortest twilight is about the beginning of October and of March; inmore northern latitudes, where the sun never sinks more than 18 degrees, below the horizon, the twilight continues the whole night. The time ofits duration may also be occasionally affected by the varying height ofthe atmosphere. A number of observations on the duration of twilight indifferent latitudes might afford considerable information concerning theaerial strata in the higher regions of the atmosphere, and might assistin determining whether an exterior atmosphere of inflammable gas, orHydrogene, exists over the aerial one. ] [_Alarm with Comet-blaze_. L. 133. See additional notes, No. IV. ] [_The Sun's phlogistic orb_. L. 136. See additional notes, No. V. ] III. NYMPHS! YOUR fine forms with steps impassive mock Earth's vaulted roofs of adamantine rock; Round her still centre tread the burning soil, 140 And watch the billowy Lavas, as they boil; Where, in basaltic caves imprison'd deep, Reluctant fires in dread suspension sleep; Or sphere on sphere in widening waves expand, And glad with genial warmth the incumbent land. 145 So when the Mother-bird selects their food With curious bill, and feeds her callow brood; Warmth from her tender heart eternal springs, And pleased she clasps them with extended wings. [_Round the still centre_. L. 139. Many philosophers have believed thatthe central parts of the earth consist of a fluid mass of burning lava, which they have called a subterraneous sun; and have supposed, that itcontributes to the production of metals, and to the growth ofvegetables. See additional notes, No. VI. ] [_Or sphere on sphere_. L. 143. See additional notes, No. VII. ] "YOU from deep cauldrons and unmeasured caves150 Blow flaming airs, or pour vitrescent waves; O'er shining oceans ray volcanic light, Or hurl innocuous embers to the night. -- While with loud shouts to Etna Heccla calls, And Andes answers from his beacon'd walls;155 Sea-wilder'd crews the mountain-stars admire, And Beauty beams amid tremendous fire. [_Hurl innocuous embers_. L. 152. The immediate cause of volcaniceruptions is believed to be owing to the water of the sea, or fromlakes, or inundations, finding itself a passage into the subterraneousfires, which may lie at great depths. This must first produce by itscoldness a condensation of the vapour there existing, or a vacuum, andthus occasion parts of the earth's crust or shell to be forced down bythe pressure of the incumbent atmosphere. Afterwards the water beingsuddenly raised into steam produces all the explosive effects ofearthquakes. And by new accessions of water during the intervals of theexplosions the repetition of the shocks is caused. These circumstanceswere hourly illustrated by the fountains of boiling water in Iceland, inwhich the surface of the water in the boiling wells sunk down low beforeevery new ebullition. Besides these eruptions occasioned by the steam of water, there seems tobe a perpetual effusion of other vapours, more noxious and (as far as itis yet known) perhaps greatly more expansile than water from theVolcanos in various parts of the world. As these Volcanos are supposedto be spiracula or breathing holes to the great subterraneous fires, itis probable that the escape of elastic vapours from them is the cause, that the earthquakes of modern days are of such small extent compared tothose of antient times, of which vestiges remain in every part of theworld, and on this account may be said not only to be innocuous, butuseful. ] "Thus when of old, as mystic bards presume, Huge CYCLOPS dwelt in Etna's rocky womb, On thundering anvils rung their loud alarms, 160 And leagued with VULCAN forged immortal arms; Descending VENUS sought the dark abode, And sooth'd the labours of the grisly God. -- While frowning Loves the threatening falchion wield, And tittering Graces peep behind the shield, 165 With jointed mail their fairy limbs o'erwhelm, Or nod with pausing step the plumed helm; With radiant eye She view'd the boiling ore, Heard undismay'd the breathing bellows roar, Admired their sinewy arms, and shoulders bare, 170 And ponderous hammers lifted high in air, With smiles celestial bless'd their dazzled sight, And Beauty blazed amid infernal night. IV. "EFFULGENT MAIDS! YOU round deciduous day, Tressed with soft beams, your glittering bands array;175 On Earth's cold bosom, as the Sun retires, Confine with folds of air the lingering fires; O'er Eve's pale forms diffuse phosphoric light, And deck with lambent flames the shrine of Night. So, warm'd and kindled by meridian skies, 180 And view'd in darkness with dilated eyes, BOLOGNA'S chalks with faint ignition blaze, BECCARI'S shells emit prismatic rays. So to the sacred Sun in MEMNON's fane, Spontaneous concords quired the matin strain;185 --Touch'd by his orient beam, responsive rings The living lyre, and vibrates all it's strings; Accordant ailes the tender tones prolong, And holy echoes swell the adoring song. [_Confine with folds of air_. L. 176. The air, like all other badconductors of electricity, is known to be a bad conductor of heat; andthence prevents the heat acquired from the sun's rays by the earth'ssurface from being so soon dissipated, in the same manner as a blanket, which may be considered as a sponge filled with air, prevents the escapeof heat from the person wrapped in it. This seems to be one cause of thegreat degree of cold on the tops of mountains, where the rarity of theair is greater, and it therefore becomes a better conductor both of heatand electricity. See note on Barometz, Vol. II. Of this work. There is however another cause to which the great coldness of mountainsand of the higher regions of the atmosphere is more immediately to beascribed, explained by Dr. Darwin in the Philos. Trans. Vol. LXXVIII. Who has there proved by experiments with the air-gun and air-pump, thatwhen any portion of the atmosphere becomes mechanically expanded, itabsorbs heat from the bodies in its vicinity. And as the air whichcreeps along the plains, expands itself by a part of the pressure beingtaken off when it ascends the sides of mountains; it at the same timeattracts heat from the summits of those mountains, or other bodies whichhappen to be immersed in it, and thus produces cold. Hence he concludesthat the hot air at the bottom of the Andes becomes temperate by its ownrarefaction when it ascends to the city of Quito; and by its furtherrarefaction becomes cooled to the freezing point when it ascends to thesnowy regions on the summits of those mountains. To this also heattributes the great degree of cold experienced by the aeronauts intheir balloons; and which produces hail in summer at the height of onlytwo or three miles in the atmosphere. ] [_Diffuse phosphoric light_. L. 177. I have often been induced tobelieve from observation, that the twilight of the evenings is lighterthan that of the mornings at the same distance from noon. Some mayascribe this to the greater height of the atmosphere in the eveningshaving been rarefied by the sun during the day; but as its density mustat the same time be diminished, its power of refraction would continuethe same. I should rather suppose that it may be owing to thephosphorescent quality (as it is called) of almost all bodies; that is, when they have been exposed to the sun they continue to emit light for aconsiderable time afterwards. This is generally believed to arise eitherfrom such bodies giving out the light which they had previouslyabsorbed; or to the continuance of a slow combustion which the lightthey had been previously exposed to had excited. See the next note. ] [_Beccari's shells_. L. 182. Beccari made many curious experiments onthe phosphoric light, as it is called, which becomes visible on bodiesbrought into a dark room, after having been previously exposed to thesunshine. It appears from these experiments, that almost all inflammablebodies possess this quality in a greater or less degree; white paper orlinen thus examined after having been exposed to the sunshine, isluminous to an extraordinary degree; and if a person shut up in a darkroom, puts one of his hands out into the sun's light for a short timeand then retracts it, he will be able to see that hand distinctly andnot the other. These experiments seem to countenance the idea of lightbeing absorbed and again emitted from bodies when they are removed intodarkness. But Beccari further pretended, that some calcareouscompositions when exposed to red, yellow, or blue light, throughcoloured glasses, would on their being brought into a dark room emitcoloured lights. This mistaken fact of Beccari's, Mr. Wilson decidedlyrefutes; and among many other curious experiments discovered, that ifoyster-shells were thrown into a common fire and calcined for about halfan hour, and then brought to a person who had previously been someminutes in a dark room, that many of them would exhibit beautiful irisesof prismatic colours, from whence probably arose Beccari's mistake. Mr. Wilson from hence contends, that these kinds of phosphori do not emitthe light they had previously received, but that they are set on fire bythe sun's rays, and continue for some time a slow combustion after theyare withdrawn from the light. Wilson's Experiments on Phosphori. Dodsley, 1775. The Bolognian stone is a selenite, or gypsum, and has been longcelebrated for its phosphorescent quality after having been burnt in asulphurous fire; and exposed when cold to the sun's light. It may bethus well imitated: Calcine oyster-shells half an hour, pulverize themwhen cold, and add one third part of flowers of sulphur, press themclose into a small crucible, and calcine them for an hour or longer, andkeep the powder in a phial close stopped. A part of this powder is to beexposed for a minute or two to the sunbeams, and then brought into adark room. The calcined Bolognian stone becomes a calcareous hepar ofsulphur; but the calcined shells, as they contain the animal acid, mayalso contain some of the phosphorus of Kunkel. ] [_In Memnon's fane_. L. 183. See additional notes. No. VIII. ] "YOU with light Gas the lamps nocturnal feed, 190 Which dance and glimmer o'er the marshy mead; Shine round Calendula at twilight hours, And tip with silver all her saffron flowers; Warm on her mossy couch the radiant Worm, Guard from cold dews her love-illumin'd form, 195 From leaf to leaf conduct the virgin light, Star of the earth, and diamond of the night. You bid in air the tropic Beetle burn, And fill with golden flame his winged urn; Or gild the surge with insect-sparks, that swarm200 Round the bright oar, the kindling prow alarm; Or arm in waves, electric in his ire, The dread Gymnotus with ethereal fire. -- Onward his course with waving tail he helms, And mimic lightenings scare the watery realms, 205 So, when with bristling plumes the Bird of JOVE Vindictive leaves the argent fields above, Borne on broad wings the guilty world he awes, And grasps the lightening in his shining claws. [_The lamps nocturnal_. L. 189. The ignis fatuus or Jack a lantern, frequently alluded to by poets, is supposed to originate from theinflammable air, or Hydrogene, given up from morasses; which being of aheavier kind from its impurity than that obtained from iron and water, hovers near the surface of the earth, and uniting with common air givesout light by its slow ignition. Perhaps such lights have no existence, and the reflection of a star on watery ground may have deceived thetravellers, who have been said to be bewildered by them? if the fact wasestablished it would much contribute to explain the phenomena ofnorthern lights. I have travelled much in the night, in all seasons ofthe year, and over all kinds of soil, but never saw one of these Willo'wisps. ] [_Shine round Calendula_. L. 191. See note on Tropaeolum in Vol. II. ] [_The radiant Worm_. L. 193. See additional notes, No. IX. ] [_The dread Gymnotus_. L. 202. The Gymnotus electricus is a native ofthe river of Surinam in South America; those which were brought over toEngland about eight years ago were about three or four feet long, andgave an electric shock (as I experienced) by putting one finger on theback near its head, and another of the opposite hand into the water nearits tail. In their native country they are said to exceed twenty feet inlength, and kill any man who approaches them in an hostile manner. It isnot only to escape its enemies that this surprizing power of the fish isused, but also to take its prey; which it does by benumbing them andthen devouring them before they have time to recover, or by perfectlykilling them; for the quantity of the power seemed to be determined bythe will or anger of the animal; as it sometimes struck a fish twicebefore it was sufficiently benumbed to be easily swallowed. The organs productive of this wonderful accumulation of electric matterhave been accurately dissected and described by Mr. J. Hunter. Philos. Trans. Vol. LXV. And are so divided by membranes as to compose a veryextensive surface, and are supplied with many pairs of nerves largerthan any other nerves of the body; but how so large a quantity is soquickly accumulated as to produce such amazing effects in a fluid illadapted for the purpose is not yet satisfactorily explained. The Torpedopossesses a similar power in a less degree, as was shewn by Mr. Walch, and another fish lately described by Mr. Paterson. Philo. Trans. Vol. LXXVI. In the construction of the Leyden-Phial, (as it is called) which iscoated on both sides, it is known, that above one hundred times thequantity of positive electricity can be condensed on every square inchof the coating on one side, than could have been accumulated on the samesurface if there had been no opposite coating communicating with theearth; because the negative electricity, or that part of it which causedits expansion, is now drawn off through the glass. It is also wellknown, that the thinner the glass is (which is thus coated on both sidesso as to make a Leyden-phial, or plate) the more electricity can becondensed on one of its surfaces, till it becomes so thin as to break, and thence discharge itself. Now it is possible, that the quantity of electricity condensible on oneside of a coated phial may increase in some high ratio in respect to thethinness of the glass, since the power of attraction is known todecrease as the squares of the distances, to which this circumstance ofelectricity seems to bear some analogy. Hence if an animal membrane, asthin as the silk-worm spins its silk, could be so situated as to becharged like the Leyden bottle, without bursting, (as such thin glasswould be liable to do, ) it would be difficult to calculate the immensequantity of electric fluid, which might be accumulated on its surface. No land animals are yet discovered which possess this power, though theair would have been a much better medium for producing its effects;perhaps the size of the necessary apparatus would have been inconvenientto land animals. ] [_In his shining claws_. L. 208. Alluding to an antique gem in thecollection of the Grand Duke of Florence. Spence. ] V. 1. "NYMPHS! Your soft smiles uncultur'd man subdued, 210 And charm'd the Savage from his native wood; You, while amazed his hurrying Hords retire From the fell havoc of devouring FIRE, Taught, the first Art! with piny rods to raise By quick attrition the domestic blaze, 215 Fan with soft breath, with kindling leaves provide, And lift the dread Destroyer on his side. So, with bright wreath of serpent-tresses crown'd, Severe in beauty, young MEDUSA frown'd; Erewhile subdued, round WISDOM'S Aegis roll'd220 Hiss'd the dread snakes, and flam'd in burnish'd gold; Flash'd on her brandish'd arm the immortal shield, And Terror lighten'd o'er the dazzled field. [_Of devouring fire_. L. 212. The first and most important discovery ofmankind seems to have been that of fire. For many ages it is probablefire was esteemed a dangerous enemy, known only by its dreadfuldevastations; and that many lives must have been lost, and manydangerous burns and wounds must have afflicted those who first dared tosubject it to the uses of life. It is said that the tall monkies ofBorneo and Sumatra lie down with pleasure round any accidental fire intheir woods; and are arrived to that degree of reason, that knowledge ofcausation, that they thrust into the remaining fire the half-burnt endsof the branches to prevent its going out. One of the nobles of thecultivated people of Otaheita, when Captain Cook treated them with tea, catched the boiling water in his hand from the cock of the tea-urn, andbellowed with pain, not conceiving that water could become hot, like redfire. Tools of steel constitute another important discovery in consequence offire; and contributed perhaps principally to give the European nationsso great superiority over the American world. By these two agents, fireand tools of steel, mankind became able to cope with the vegetablekingdom, and conquer provinces of forests, which in uncultivatedcountries almost exclude the growth of other vegetables, and of thoseanimals which are necessary to our existence. Add to this, that thequantity of our food is also increased by the use of fire, for somevegetables become salutary food by means of the heat used in cookery, which are naturally either noxious or difficult of digestion; aspotatoes, kidney-beans, onions, cabbages. The cassava when made intobread, is perhaps rendered mild by the heat it undergoes, more than byexpressing its superfluous juice. The roots of white bryony and of arum, I am informed lose much of their acrimony by boiling. ] [_Young Medusa frowned_. L. 218. The Egyptian Medusa is represented onantient gems with wings on her head, snaky hair, and a beautifulcountenance, which appears intensely thinking; and was supposed torepresent divine wisdom. The Grecian Medusa, on Minerva's shield, asappears on other gems, has a countenance distorted with rage or pain, and is supposed to represent divine vengeance. This Medusa was one ofthe Gorgons, at first very beautiful and terrible to her enemies;Minerva turned her hair into snakes, and Perseus having cut off her headfixed it on the shield of that goddess; the sight of which thenpetrified the beholders. Dannet Dict. ] 2. NYMPHS! YOU disjoin, unite, condense, expand, And give new wonders to the Chemist's hand;225 On tepid clouds of rising steam aspire, Or fix in sulphur all it's solid fire; With boundless spring elastic airs unfold, Or fill the fine vacuities of gold; With sudden flash vitrescent sparks reveal, 230 By fierce collision from the flint and steel; Or mark with shining letter KUNKEL's name In the pale Phosphor's self-consuming flame. So the chaste heart of some enchanted Maid Shines with insidious light, by Love betray'd;235 Round her pale bosom plays the young Desire, And slow she wastes by self-consuming fire. [_Or fix in sulphur_. L. 226. The phenomena of chemical explosionscannot be accounted for without the supposition, that some of the bodiesemployed contain concentrated or solid heat combined with them, to whichthe French Chemists have given the name of Calorique. When air isexpanded in the air-pump, or water evaporated into steam, they drink upor absorb a great quantity of heat; from this analogy, when gunpowder isexploded it ought to absorb much heat, that is, in popular language, itought to produce a great quantity of cold. When vital air is united withphlogistic matter in respiration, which seems to be a slow combustion, its volume is lessened; the carbonic acid, and perhaps phosphoric acidare produced; and heat is given out; which according to the experimentsof Dr. Crawford would seem to be deposited from the vital air. But asthe vital air in nitrous acid is condensed from a light elastic gas tothat of a heavy fluid, it must possess less heat than before. And hencea great part of the heat, which is given out in firing gunpowder, Ishould suppose, must reside in the sulphur or charcoal. Mr. Lavoisier has shewn, that vital air, or Oxygene, looses less of itsheat when it becomes one of the component parts of nitrous acid, than inany other of its combinations; and is hence capable of giving out agreat quantity of heat in the explosion of gunpowder; but as there seemsto be great analogy between the matter of heat, or Calorique, and theelectric matter; and as the worst conductors of electricity are believedto contain the greatest quantity of that fluid; there is reason tosuspect that the worst conductors of heat may contain the most of thatfluid; as sulphur, wax, silk, air, glass. See note on l. 174 of thisCanto. ] [_Vitrescent sparks_. L. 229. When flints are struck against otherflints they have the property of giving sparks of light; but it seems tobe an internal light, perhaps of electric origin, very different fromthe ignited sparks which are struck from flint and steel. The sparksproduced by the collision of steel with flint appear to be globularparticles of iron, which have been fused, and imperfectly scorified orvitrified. They are kindled by the heat produced by the collision; buttheir vivid light, and their fusion and vitrification are the effects ofa combustion continued in these particles during their passage throughthe air. This opinion is confirmed by an experiment of Mr. Hawksbee, whofound that these sparks could not be produced in the exhausted receiver. See Keir's Chemical Dict. Art. Iron, and art. Earth vitrifiable. ] [_The pale Phosphor_. L. 232. See additionable notes, No. X. ] 3. "YOU taught mysterious BACON to explore Metallic veins, and part the dross from ore; With sylvan coal in whirling mills combine240 The crystal'd nitre, and the sulphurous mine; Through wiry nets the black diffusion strain, And close an airy ocean in a grain. -- Pent in dark chambers of cylindric brass Slumbers in grim repose the sooty mass;245 Lit by the brilliant spark, from grain to grain Runs the quick fire along the kindling train; On the pain'd ear-drum bursts the sudden crash, Starts the red flame, and Death pursues the flash. -- Fear's feeble hand directs the fiery darts, 250 And Strength and Courage yield to chemic arts; Guilt with pale brow the mimic thunder owns, And Tyrants tremble on their blood-stain'd thrones. [_And close an airy ocean_. L. 242. Gunpowder is plainly described inthe works of Roger Bacon before the year 1267. He describes it in acurious manner, mentioning the sulphur and nitre, but conceals thecharcoal in an anagram. The words are, sed tamen salis petrae _lure mopecan ubre_, et sulphuris; et sic facies tonitrum, et corruscationem, siscias, artificium. The words lure mope can ubre are an anagram ofcarbonum pulvere. Biograph. Britan. Vol. I. Bacon de Secretis Operibus, Cap. XI. He adds, that he thinks by an artifice of this kind Gideondefeated the Midianites with only three hundred men. Judges, Chap. VII. Chamb. Dict. Art. Gunpowder. As Bacon does not claim this as his owninvention, it is thought by many to have been of much more antientdiscovery. The permanently elastic fluid generated in the firing of gunpowder iscalculated by Mr. Robins to be about 244 if the bulk of the powder be 1. And that the heat generated at the time of the explosion occasions therarefied air thus produced to occupy about 1000 times the space of thegunpowder. This pressure may therefore be called equal to 1000atmospheres or six tons upon a square inch. As the suddenness of thisexplosion must contribute much to its power, it would seem that thechamber of powder, to produce its greatest effect, should be lighted inthe centre of it; which I believe is not attended to in the manufactureof muskets or pistols. From the cheapness with which a very powerful gunpowder is likely soonto be manufactured from aerated marine acid, or from a new method offorming nitrous acid by means of mangonese or other calciform ores, itmay probably in time be applied to move machinery, and supersede the useof steam. There is a bitter invective in Don Quixot against the inventors of gun-powder, as it levels the strong with the weak, the knight cased in steelwith the naked shepherd, those who have been trained to the sword, withthose who are totally unskilful in the use of it; and throws down allthe splendid distinctions of mankind. These very reasons ought to havebeen urged to shew that the discovery of gunpowder has been of publicutility by weakening the tyranny of the few over the many. ] VI. NYMPHS! You erewhile on simmering cauldrons play'd, And call'd delighted SAVERY to your aid;255 Bade round the youth explosive STEAM aspire In gathering clouds, and wing'd the wave with fire; Bade with cold streams the quick expansion stop, And sunk the immense of vapour to a drop. -- Press'd by the ponderous air the Piston falls260 Resistless, sliding through it's iron walls; Quick moves the balanced beam, of giant-birth, Wields his large limbs, and nodding shakes the earth. [_Delighted Savery_. L. 254. The invention of the steam-engine forraising water by the pressure of the air in consequence of thecondensation of steam, is properly ascribed to Capt. Savery; a plate anddescription of this machine is given in Harris's Lexicon Technicum, art. Engine. Though the Marquis of Worcester in his Century of Inventionsprinted in the year 1663 had described an engine for raising water bythe explosive power of steam long before Savery's. Mr. Desegulieraffirms, that Savery bought up all he could procure of the books of theMarquis of Worcester, and destroyed them, professing himself then tohave discovered the power of steam by accident, which seems to have beenan unfounded slander. Savery applied it to the raising of water tosupply houses and gardens, but could not accomplish the draining ofmines by it. Which was afterwards done by Mr. Newcomen and Mr. JohnCowley at Dartmouth, in the year 1712, who added the piston. A few years ago Mr. Watt of Glasgow much improved this machine, and withMr. Boulton of Birmingham has applied it to variety of purposes, such asraising water from mines, blowing bellows to fuse the ore, supplyingtowns with water, grinding corn and many other purposes. There is reasonto believe it may in time be applied to the rowing of barges, and themoving of carriages along the road. As the specific levity of air is toogreat for the support of great burthens by balloons, there seems noprobable method of flying conveniently but by the power of steam, orsome other explosive material; which another half century may probablediscover. See additional notes, No. XI. ] "The Giant-Power from earth's remotest caves Lifts with strong arm her dark reluctant waves;265 Each cavern'd rock, and hidden den explores, Drags her dark coals, and digs her shining ores. -- Next, in close cells of ribbed oak confined, Gale after gale, He crowds the struggling wind; The imprison'd storms through brazen nostrils roar, 270 Fan the white flame, and fuse the sparkling ore. Here high in air the rising stream He pours To clay-built cisterns, or to lead-lined towers; Fresh through a thousand pipes the wave distils, And thirsty cities drink the exuberant rills. --275 There the vast mill-stone with inebriate whirl On trembling floors his forceful fingers twirl. Whose flinty teeth the golden harvests grind, Feast without blood! and nourish human-kind. [_Feast without blood!_ l. 278. The benevolence of the great Author ofall things is greatly manifest in the sum of his works, as Dr. Balguyhas well evinced in his pamphlet on Divine Benevolence asserted, printedfor Davis, 1781. Yet if we may compare the parts of nature with eachother, there are some circumstances of her economy which seem tocontribute more to the general scale of happiness than others. Thus thenourishment of animal bodies is derived from three sources: 1. The milkgiven from the mother to the offspring; in this excellent contrivancethe mother has pleasure in affording the sustenance to the child, andthe child has pleasure in receiving it. 2. Another source of the food ofanimals includes seeds or eggs; in these the embryon is in a torpid orinsensible state, and there is along with it laid up for its earlynourishment a store of provision, as the fruit belonging to some seeds, and the oil and starch belonging to others; when these are consumed byanimals the unfeeling seed or egg receives no pain, but the animalreceives pleasure which consumes it. Under this article may be includedthe bodies of animals which die naturally. 3. But the last method ofsupporting animal bodies by the destruction of other living animals, aslions preying upon lambs, these upon living vegetables, and mankind uponthem all, would appear to be a less perfect part of the economy ofnature than those before mentioned, as contributing less to the sum ofgeneral happiness. ] "Now his hard hands on Mona's rifted crest, 280 Bosom'd in rock, her azure ores arrest; With iron lips his rapid rollers seize The lengthening bars, in thin expansion squeeze; Descending screws with ponderous fly-wheels wound The tawny plates, the new medallions round;285 Hard dyes of steel the cupreous circles cramp, And with quick fall his massy hammers stamp. The Harp, the Lily and the Lion join, And GEORGE and BRITAIN guard the sterling coin. [_Mona's rifted crest_. L. 279. Alluding to the very valuable copper-mines in the isle of Anglesey, the property of the Earl of Uxbridge. ] [_With iron-lips_. L. 281. Mr. Boulton has lately constructed at Sohonear Birmingham, a most magnificent apparatus for Coining, which hascost him some thousand pounds; the whole machinery is moved by animproved steam-engine, which rolls the copper for half-pence finer thancopper has before been rolled for the purpose of making money; it worksthe coupoirs or screw-presses for cutting out the circular pieces ofcopper; and coins both the faces and edges of the money at the sametime, with such superior excellence and cheapness of workmanship, aswell as with marks of such powerful machinery as must totally preventclandestine imitation, and in consequence save many lives from the handof the executioner; a circumstance worthy the attention of a greatminister. If a civic crown was given in Rome for preserving the life ofone citizen, Mr. Boulton should be covered with garlands of oak! By thismachinery four boys of ten or twelve years old are capable of strikingthirty thousand guineas in an hour, and the machine itself keeps anunerring account of the pieces struck. ] "Soon shall thy arm, UNCONQUER'D STEAM! afar290 Drag the slow barge, or drive the rapid car; Or on wide-waving wings expanded bear The flying-chariot through the fields of air. --Fair crews triumphant, leaning from above, Shall wave their fluttering kerchiefs as they move;295 Or warrior-bands alarm the gaping crowd, And armies shrink beneath the shadowy cloud. "So mighty HERCULES o'er many a clime Waved his vast mace in Virtue's cause sublime, Unmeasured strength with early art combined, 300 Awed, served, protected, and amazed mankind. -- First two dread Snakes at JUNO'S vengeful nod Climb'd round the cradle of the sleeping God; Waked by the shrilling hiss, and rustling sound, And shrieks of fair attendants trembling round, 305 Their gasping throats with clenching hands he holds; And Death untwists their convoluted folds. Next in red torrents from her sevenfold heads Fell HYDRA'S blood on Lerna's lake he sheds; Grasps ACHELOUS with resistless force, 310 And drags the roaring River to his course; Binds with loud bellowing and with hideous yell The monster Bull, and threefold Dog of Hell. [_So mighty Hercules_. L. 297. The story of Hercules seems of greatantiquity, as appears from the simplicity of his dress and armour, alion's skin and a club; and from the nature of many of his exploits, thedestruction of wild beasts and robbers. This part of the history ofHercules seems to have related to times before the invention of the bowand arrow, or of spinning flax. Other stories of Hercules are perhaps oflater date, and appear to be allegorical, as his conquering the river-god Achilous, and bringing Cerberus up to day light; the former mightrefer to his turning the course of a river, and draining a morass, andthe latter to his exposing a part of the superstition of the times. Thestrangling the lion and tearing his jaws asunder, are described from astatue in the Museum Florentinum, and from an antique gem; and thegrasping Anteus to death in his arms as he lifts him from the earth, isdescribed from another antient cameo. The famous pillars of Herculeshave been variously explained. Pliny asserts that the natives of Spainand of Africa believed that the mountains of Abyla and Calpè on eachside of the straits of Gibraltar were the pillars of Hercules; and thatthey were reared by the hands of that god, and the sea admitted betweenthem. Plin. Hist. Nat. P. 46. Edit. Manut. Venet. 1609. If the passage between the two continents was opened by an earthquake inantient times, as this allegorical story would seem to countenance, there must have been an immense current of water at first run into theMediterranean from the Atlantic; since there is at present a strongstream sets always from thence into the Mediterranean. Whatever may bethe cause, which now constantly operates, so as to make the surface ofthe Mediterranean lower than that of the Atlantic, it must have kept itvery much lower before a passage for the water through the streights wasopened. It is probable before such an event took place, the coasts andislands of the Mediterranean extended much further into that sea, andwere then for a great extent of country, destroyed by the floodsoccasioned by the new rise of water, and have since remained beneath thesea. Might not this give rise to the flood of Deucalion? See noteCassia, V. II. Of this work. ] "Then, where Nemea's howling forests wave, He drives the Lion to his dusky cave;315 Seized by the throat the growling fiend disarms, And tears his gaping jaws with sinewy arms; Lifts proud ANTEUS from his mother-plains, And with strong grasp the struggling Giant strains; Back falls his fainting head, and clammy hair, 320 Writhe his weak limbs, and flits his life in air;-- By steps reverted o'er the blood-dropp'd fen He tracks huge CACUS to his murderous den; Where breathing flames through brazen lips he fled, And shakes the rock-roof'd cavern o'er his head. 325 "Last with wide arms the solid earth He tears, Piles rock on rock, on mountain mountain rears; Heaves up huge ABYLA on Afric's sand, Crowns with high CALPÈ Europe's saliant strand, Crests with opposing towers the splendid scene, 330 And pours from urns immense the sea between. -- --Loud o'er her whirling flood Charybdis roars, Affrighted Scylla bellows round his shores, Vesuvio groans through all his echoing caves, And Etna thunders o'er the insurgent waves. 335 VII. 1. NYMPHS! YOUR fine hands ethereal floods amass From the warm cushion, and the whirling glass; Beard the bright cylinder with golden wire, And circumfuse the gravitating fire. Cold from each point cerulean lustres gleam, 340 Or shoot in air the scintillating stream. So, borne on brazen talons, watch'd of old The sleepless dragon o'er his fruits of gold; Bright beam'd his scales, his eye-balls blazed with ire, And his wide nostrils breath'd inchanted fire. [_Ethereal floods amass_. L. 335. The theory of the accumulation of theelectric fluid by means of the glass-globe and cushion is difficult tocomprehend. Dr. Franklin's idea of the pores of the glass being openedby the friction, and thence rendered capable of attracting more electricfluid, which it again parts with, as the pores contract again, seemsanalogous in some measure to the heat produced by the vibration, orcondensation of bodies, as when a nail is hammered or filed till itbecomes hot, as mentioned in additional Notes, No. VII. Somephilosophers have endeavoured to account for this phenomenon bysupposing the existence of two electric fluids which may be called thevitreous and resinous ones, instead of the plus and minus of the sameether. But its accumulation on the rubbed glass bears great analogy toits accumulation on the surface of the Leyden bottle, and can notperhaps be explained from any known mechanical or chemical principle. See note on Gymnotus. L. 202, of this Canto. ] [_Cold from each point_. L. 339. See additional note, No. XIII. ] 345 "YOU bid gold-leaves, in crystal lantherns held, Approach attracted, and recede repel'd; While paper-nymphs instinct with motion rife, And dancing fauns the admiring Sage surprize. OR, if on wax some fearless Beauty stand, 350 And touch the sparkling rod with graceful hand; Through her fine limbs the mimic lightnings dart, And flames innocuous eddy round her heart; O'er her fair brow the kindling lustres glare, Blue rays diverging from her bristling hair;355 While some fond Youth the kiss ethereal sips. And soft fires issue from their meeting lips. So round the virgin Saint in silver streams The holy Halo shoots it's arrowy beams. [_You bid gold leaves_. L. 345. Alluding to the very sensibleelectrometer improved by Mr. Bennett, it consists of two slips of gold-leaf suspended from a tin cap in a glass cylinder, which has a partialcoating without, communicating with the wooden pedestal. If a stick ofsealing wax be rubbed for a moment on a dry cloth, and then held in theair _at the distance of two or three feet_ from the cap of thisinstrument, the gold leaves seperate, such is its astonishingsensibility to electric influence! (See Bennet on electricity, Johnson, Lond. ) The nerves of sense of animal bodies do not seem to be affectedby less quantities of light or heat!] [_The holy Halo_. L. 358. I believe it is not known with certainty atwhat time the painters first introduced the luminous circle round thehead to import a Saint or holy person. It is now become a part of thesymbolic language of painting, and it is much to be wished that thiskind of hieroglyphic character was more frequent in that art; as it ismuch wanted to render historic pictures both more intelligible, and moresublime; and why should not painting as well as poetry express itself inmetaphor, or in indistinct allegory? A truly great modern painter latelyendeavoured to enlarge the sphere of pictorial language, by putting ademon behind the pillow of a wicked man on his death bed. Whichunfortunately for the scientific part of painting, the cold criticism ofthe present day has depreciated; and thus barred perhaps the only roadto the further improvement in this science. ] "YOU crowd in coated jars the denser fire, 360 Pierce the thin glass, and fuse the blazing wire; Or dart the red flash through the circling band Of youths and timorous damsels, hand in hand. --Starts the quick Ether through the fibre-trains Of dancing arteries, and of tingling veins, 365 Goads each fine nerve, with new sensation thrill'd, Bends the reluctant limbs with power unwill'd; Palsy's cold hands the fierce concussion own, And Life clings trembling on her tottering throne. -- So from dark clouds the playful lightning springs, 370 Rives the firm oak, or prints the Fairy-rings. [_With new sensation thrill'd_. L. 365. There is probably a system ofnerves in animal bodies for the purpose of perceiving heat; since thedegree of this fluid is so necessary to health that we become presentlyinjured either by its access or defect; and because almost every part ofour bodies is supplied with branches from different pairs of nerves, which would not seem necessary for their motion alone: It is thereforeprobable, that our sensation of electricity is only of its violence inpassing through our system by its suddenly distending the muscles, likeany other mechanical violence; and that it is general pain alone that wefeel, and not any sensation analogous to the specific quality of theobject. Nature may seem to have been niggardly to mankind in bestowingupon them so few senses; since a sense to have perceived electricity, and another to have perceived magnetism might have been of great serviceto them, many ages before these fluids were discovered by accidentalexperiment, but it is possible an increased number of senses might haveincommoded us by adding to the size of our bodies. ] [_Palsy's cold hands_. L. 367. Paralytic limbs are in general onlyincapable of being stimulated into action by the power of the will;since the pulse continues to beat and the fluids to be absorbed in them;and it commonly happens, when paralytic people yawn and stretchthemselves, (which is not a voluntary motion, ) that the affected limbmoves at the same time. The temporary motion of a paralytic limb islikewise caused by passing the electric shock through it; which wouldseem to indicate some analogy between the electric fluid, and thenervous fluid, which is seperated from the blood by the brain, andthence diffused along the nerves for the purposes of motion andsensation. It probably destroys life by its sudden expansion of thenerves or fibres of the brain; in the same manner as it fuses metals andsplinters wood or stone, and removes the atmosphere, when it passes fromone object to another in a dense state. ] [_Prints the Fairy rings_. L. 370. See additional note No. XIII. ] 2. NYMPHS! on that day YE shed from lucid eyes. Celestial tears, and breathed ethereal sighs! When RICHMAN rear'd, by fearless haste betrayed, The wiry rod in Nieva's fatal shade;--375 Clouds o'er the Sage, with fringed skirts succeed, Flash follows flash, the warning corks recede; Near and more near He ey'd with fond amaze The silver streams, and watch'd the saphire blaze; Then burst the steel, the dart electric sped, 380 And the bold Sage lay number'd with the dead!-- NYMPHS! on that day YE shed from lucid eyes Celestial tears, and breathed ethereal sighs! [_When Richman reared_. L. 373. Dr. Richman Professor of naturalphilosophy at Petersburgh about the year 1763, elevated an insulatedmetallic rod to collect the aerial electricity, as Dr. Franklin hadpreviously done at Philadelphia; and as he was observing the repulsionof the balls of his electrometer approached too near the conductor, andreceiving the lightening in his head with a loud explosion, was struckdead amidst his family. ] 3. "YOU led your FRANKLIN to your glazed retreats, Your air-built castles, and your silken seats;385 Bade his bold arm invade the lowering sky, And seize the tiptoe lightnings, ere they fly; O'er the young Sage your mystic mantle spread, And wreath'd the crown electric round his head. -- Thus when on wanton wing intrepid LOVE390 Snatch'd the raised lightning from the arm of JOVE; Quick o'er his knee the triple bolt He bent, The cluster'd darts and forky arrows rent, Snapp'd with illumin'd hands each flaming shaft, His tingling fingers shook, and stamp'd, and laugh'd;395 Bright o'er the floor the scatter'd fragments blaz'd, And Gods retreating trembled as they gaz'd; The immortal Sire, indulgent to his child, Bow'd his ambrosial locks, and Heaven relenting smiled. [_You led your Franklin_. L. 383. Dr. Franklin was the first thatdiscovered that lightening consisted of electric matter, he elevated atall rod with a wire wrapped round it, and fixing the bottom of a rodinto a glass bottle, and preserving it from falling by means of silk-strings, he found it electrified whenever a cloud parted over it, receiving sparks by his finger from it, and charging coated phials. Thisgreat discovery taught us to defend houses and ships and temples fromlightning, and also to understand, _that people are always perfectlysafe in a room during a thunder storm if they keep themselves at threeor four feet distance from the walls_; for the matter of lightning inpassing from the clouds to the earth, or from the earth to the clouds, runs through the walls of a house, the trunk of a tree, or otherelevated object; except there be some moister body, as an animal incontact with them, or nearly so; and in that case the lightning leavesthe wall or tree, and passes through the animal; but as it can passthrough metals with still greater facility, it will leave animal bodiesto pass through metallic ones. If a person in the open air be surprized by a thunderstorm, he will knowhis danger by observing on a second watch the time which passes betweenthe flash and the crack, and reckoning a mile for every four seconds anda half, and a little more. For sound travels at the rate of 1142 feet ina second of time, and the velocity of light through such small distancesis not to be estimated. In these circumstances a person will be safer bylying down on the ground, than erect, and still safer if within a fewfeet of his horse; which being then a more elevated animal will receivethe shock, in preference as the cloud passes over. See additional notes, No. XIII. ] [_Intrepid Love_. L. 389. This allegory is uncommonly beautiful, representing Divine Justice as disarmed by Divine Love, and relenting ofhis purpose. It is expressed on an agate in the Great Duke's collectionat Florence. Spence. ] VIII. "When Air's pure essence joins the vital flood, 400 And with phosphoric Acid dyes the blood, YOUR VIRGIN TRAINS the transient HEAT dispart, And lead the soft combustion round the heart; Life's holy lamp with fires successive feed, From the crown'd forehead to the prostrate weed, 405 From Earth's proud realms to all that swim or sweep The yielding ether or tumultuous deep. You swell the bulb beneath the heaving lawn, Brood the live seed, unfold the bursting spawn; Nurse with soft lap, and warm with fragrant breath410 The embryon panting in the arms of Death; Youth's vivid eye with living light adorn, And fire the rising blush of Beauty's golden morn. [_Transient heat dispart_. L. 401. Dr. Crawford in his ingenious work onanimal heat has endeavoured to prove, that during the combination of thepure part of the atmosphere with the phlogistic part of the blood, thatmuch of the matter of the heat is given out from the air; and that thisis the great and perpetual source of the heat of animals; to which wemay add that the phosphoric acid is probably produced by thiscombination; by which acid the colour of the blood is changed in thelungs from a deep crimson to a bright scarlet. There seems to be howeveranother source of animal heat, though of a similar nature; and that isfrom the chemical combinations produced in all the glands; since bywhatever cause any glandular secretion is increased, as by friction ortopical imflammation, the heat of that part becomes increased at thesame time; thus after the hands have been for a time immersed in snow, on coming into a warm room, they become red and hot, without anyincreased pulmonary action. BESIDES THIS there would seem to be anothermaterial received from the air by respiration; which is so necessary tolife, that the embryon must learn to breathe almost within a minuteafterits birth, or it dies. The perpetual necessity of breathing shews, thatthe material thus acquired is perpetually consuming or escaping, and onthat account requires perpetual renovation. Perhaps the spirit ofanimation itself is thus acquired from the atmosphere, which if it besupposed to be finer or more subtle than the electric matter, could notlong be retained in our bodies, and must therefore require perpetualrenovation. ] "Thus when the Egg of Night, on Chaos hurl'd, Burst, and disclosed the cradle of the world;415 First from the gaping shell refulgent sprung IMMORTAL LOVE, his bow celestial strung;-- O'er the wide waste his gaudy wings unfold, Beam his soft smiles, and wave his curls of gold;-- With silver darts He pierced the kindling frame, 420 And lit with torch divine the ever-living flame. " [_Thus when the egg of Night_. L. 413. There were two Cupids belongingto the antient mythology, one much elder than the other. The eldercupid, or Eros, or divine Love, was the first that came out of the greategg of night, which floated in Chaos, and was broken by the horns of thecelestial bull, that is, was hatched by the warmth of the spring. He waswinged and armed, and by his arrows and torch pierced and vivified allthings, producing life and joy. Bacon, Vol. V. P. 197. Quarto edit. Lond. 1778. "At this time, (says Aristophanes, ) sable-winged nightproduced an egg, from whence sprung up like a blossom Eros, the lovely, the desirable, with his glossy golden wings. " Avibus. Bryant'sMythology, Vol. II. P. 350. Second edition. This interesting moment ofthis sublime allegory Mrs. Cosway has chosen for her very beautifulpainting. She has represented Eros or divine Love with large wingshaving the strength of the eagle's wings, and the splendor of thepeacocks, with his hair floating in the form of flame, and with a haloof light vapour round his head; which illuminates the painting; while heis in the act of springing forwards, and with his hands separating theelements. ] IX. The GODDESS paused, admired with conscious pride The effulgent legions marshal'd by her side, Forms sphered in fire with trembling light array'd, Ens without weight, and substance without shade;425 And, while tumultuous joy her bosom warms, Waves her white hand, and calls her hosts to arms, "Unite, ILLUSTRIOUS NYMPHS! your radiant powers, Call from their long repose the VERNAL HOURS. Wake with soft touch, with rosy hands unbind430 The struggling pinions of the WESTERN WIND; Chafe his wan cheeks, his ruffled plumes repair, And wring the rain-drops from his tangled hair. Blaze round each frosted rill, or stagnant wave, And charm the NAIAD from her silent cave;435 Where, shrined in ice, like NIOBE she mourns, And clasps with hoary arms her empty urns. Call your bright myriads, trooping from afar, With beamy helms, and glittering shafts of war; In phalanx firm the FIEND OF FROST assail, 440 Break his white towers, and pierce his crystal mail; To Zembla's moon-bright coasts the Tyrant bear, And chain him howling to the Northern Bear. [_Of the Western Wind_. L. 430. The principal frosts of this country areaccompanied or produced by a N. E. Wind, and the thaws by a S. W. Wind;the reason of which is that the N. E. Winds consist of regions of airbrought from the north, which appear to acquire an easterly direction asthey advance; and the S. W. Winds consist of regions of air brought fromthe south, which appear to acquire a westerly direction as they advance. The surface of the earth nearer the pole moves slower than it does inour latitude; whence the regions of air brought from thence, moveslower, when they arrive hither, than the earth's surface with whichthey now become in contact; that is they acquire an apparent easterlydirection, as the earth moves from west to east faster than this newpart of its atmosphere. The S. W. Winds on the contrary consist ofregions of air brought from the south, where the surface of the earthmoves faster than in our latitude; and have therefore a westerlydirection when they arrive hither by their moving faster than thesurface of the earth, with which they are in contact; and in general thenearer to the west and the greater the velocity of these winds thewarmer they should be in respect to the season of the year, since theyhave been brought more expeditiously from the south, than those windswhich have less westerly direction, and have thence been less cooled intheir passage. Sometimes I have observed the thaw to commence immediately on the changeof the wind, even within an hour, if I am not mistaken, or sooner. Atother times the S. W. Wind has continued a day, or even two, before thethaw has commenced; during which time some of the frosty air, which hadgone southwards, is driven back over us; and in consequence has taken awesterly direction, as well as a southern one. At other times I haveobserved a frost with a N. E. Wind every morning, and a thaw with a S. W. Wind every noon for several days together. See additional note, XXXIII. ] [_The Fiend of Frost_. L. 439. The principal injury done to vegetationby frost is from the expansion of the water contained in the vessels ofplants. Water converted into ice occupies a greater space than it didbefore, as appears by the bursting of bottles filled with water at thetime of their freezing. Hence frost destroys those plants of our islandfirst, which are most succulent; and the most succulent parts first ofother plants; as their leaves and last year's shoots; the vessels ofwhich are distended and burst by the expansion of their freezing fluids, while the drier or more resinous plants, as pines, yews, laurels, andother ever-greens, are less liable to injury from cold. The trees invallies are on this account more injured by the vernal frosts than thoseon eminencies, because their early succulent shoots come out sooner. Hence fruit trees covered by a six-inch coping of a wall are lessinjured by the vernal frosts because their being shielded from showersand the descending night-dews has prevented them from being moist at thetime of their being frozen: which circumstance has given occasion to avulgar error amongst gardeners, who suppose frost to descend. As the common heat of the earth in this climate is 48 degrees, thosetender trees which will bear bending down, are easily secured from thefrost by spreading them upon the ground, and covering them with straw orfern. This particularly suits fig-trees, as they easily bear bending tothe ground, and are furnished with an acrid juice, which secures themfrom the depredations of insects; but are nevertheless liable to beeaten by mice. See additional notes, No. XII. ] "So when enormous GRAMPUS, issuing forth From the pale regions of the icy North;445 Waves his broad tail, and opes his ribbed mouth, And seeks on winnowing fin the breezy South; From towns deserted rush the breathless hosts, Swarm round the hills, and darken all the coasts; Boats follow boats along the shouting tides, 450 And spears and javelins pierce his blubbery sides; Now the bold Sailor, raised on pointed toe, Whirls the wing'd harpoon on the slimy foe; Quick sinks the monster in his oozy bed, The blood-stain'd surges circling o'er his head, 455 Steers to the frozen pole his wonted track, And bears the iron tempest on his back. X. "On wings of flame, ETHEREAL VIRGINS! sweep O'er Earth's fair bosom, and complacent deep; Where dwell my vegetative realms benumb'd, 460 In buds imprison'd, or in bulbs intomb'd, Pervade, PELLUCID FORMS! their cold retreat, Ray from bright urns your viewless floods of _heat_; From earth's deep wastes _electric_ torrents pour, Or shed from heaven the scintillating shower;465 Pierce the dull root, relax its fibre-trains, Thaw the thick blood, which lingers in its veins; Melt with warm breath the fragrant gums, that bind The expanding foliage in its scaly rind; And as in air the laughing leaflets play, 470 And turn their shining bosoms to the ray, NYMPHS! with sweet smile each opening glower invite, And on its damask eyelids pour the _light_. [_In buds imprison'd_. L. 460. The buds and bulbs of plants constitutewhat is termed by Linneus the Hybernaculum, or winter cradle of theembryon vegetable. The buds arise from the bark on the branches oftrees, and the bulbs from the caudex of bulbous-rooted plants, or thepart from which the fibres of the root are produced, they are defendedfrom too much moisture, and from frosts, and from the depredations ofinsects by various contrivances, as by scales, hairs, resinousvarnishes, and by acrid rinds. The buds of trees are of two kinds, either flower-buds or leaf buds; theformer of these produce their seeds and die; the latter produce otherleaf buds or flower buds and die. So that all the buds of trees may beconsidered as annual plants, having their embryon produced during thepreceeding summer. The same seems to happen with respect to bulbs; thusa tulip produces annually one flower-bearing bulb, sometimes two, andseveral leaf-bearing bulbs; and then the old root perishes. Next yearthe flower-bearing bulb produces seeds and other bulbs and perishes;while the leaf-bearing bulb, producing other bulbs only, perisheslikewise; these circumstances establish a strict analogy between bulbsand buds. See additional notes, No. XIV. ] [_Viewless floods of heat_. L. 462. The fluid matter of heat, orCalorique, in which all bodies are immersed, is as necessary tovegetable as to animal existence. It is not yet determinable whetherheat and light be different materials, or modifications of the samematerials, as they have some properties in common. They appear to beboth of them equally necessary to vegetable health, since without lightgreen vegetables become first yellow, that is, they lose the bluecolour, which contributed to produce the green; and afterwards they alsolose the yellow and become white; as is seen in cellery blanched oretiolated for the table by excluding the light from it. The upper surface of leaves, which I suppose to be their organ ofrespiration, seems to require light as well as air; since plants whichgrow in windows on the inside of houses are equally sollicitous to turnthe upper side of their leaves to the light. Vegetables at the same timeexsude or perspire a great quantity from their leaves, as animals dofrom their lungs; this perspirable matter as it rises from their finevessels, (perhaps much finer than the pores of animal skins, ) is dividedinto inconcievable tenuity; and when acted upon by the Sun's lightappears to be decomposed; the hydrogene becomes a part of the vegetable, composing oils or resins; and the Oxygene combined with light orcalorique ascends, producing the pure part of the atmosphere or vitalair. Hence during the light of the day vegetables give up more pure airthan their respiration injures; but not so in the night, even thoughequally exposed to warmth. This single fact would seem to shew, thatlight is essentially different from heat; and it is perhaps by itscombination with bodies, that their combined or latent heat is set atliberty, and becomes sensible. See additional note, XXXIV. ] [_Electric torrents pour_. L. 463. The influence of electricity inforwarding the germination of plants and their growth seems to be prettywell established; though Mr. Ingenhouz did not succeed in hisexperiments, and thence doubts the success of those of others. Andthough M. Rouland from his new experiments believes, that neitherpositive nor negative electricity increases vegetation; both whichphilosophers had previously been supporters of the contrary doctrine;for many other naturalists have since repeated their experimentsrelative to this object, and their new results have confirmed theirformer ones. Mr. D'Ormoy and the two Roziers have found the same successin numerous experiments which they have made in the last two years; andMr. Carmoy has shewn in a convincing manner that electricity acceleratesgermination. Mr. D'Ormoy not only found various seeds to vegetate sooner, and to growtaller which were put upon his insulated table and supplied withelectricity, but also that silk-worms began to spin much sooner whichwere kept electrified than those of the same hatch which were kept inthe same place and manner, except that they were not electrified. Theseexperiments of M. D'Ormoy are detailed at length in the Journal dePhysique of Rozier, Tom. XXXV. P. 270. M. Bartholon, who had before written a tract on this subject, andproposed ingenious methods for applying electricity to agriculture andgardening, has also repeated a numerous set of experiments; and shewsboth that natural electricity, as well as the artificial, increases thegrowth of plants, and the germination of seeds; and opposes Mr. Ingenhouz by very numerous and conclusive facts. Ib. Tom. XXXV. P. 401. Since by the late discoveries or opinions of the Chemists there isreason to believe that water is decomposed in the vessels of vegetables;and that the Hydrogene or inflammable air, of which it in part consists, contributes to the nourishment of the plant, and to the production ofits oils, rosins, gums, sugar, &c. And lastly as electricity decomposeswater into these two airs termed Oxygene and Hydrogene, there is apowerful analogy to induce us to believe that it accelerates orcontributes to the growth of vegetation, and like heat may possiblyenter into combination with many bodies, or form the basis of some yetunanalised acid. ] "So shall my pines, Canadian wilds that shade, Where no bold step has pierc'd the tangled glade, 475 High-towering palms, that part the Southern flood With shadowy isles and continents of wood, Oaks, whose broad antlers crest Britannia's plain, Or bear her thunders o'er the conquer'd main, Shout, as you pass, inhale the genial skies, 480 And bask and brighten in your beamy eyes; Bow their white heads, admire the changing clime, Shake from their candied trunks the tinkling rime; With bursting buds their wrinkled barks adorn, And wed the timorous floret to her thorn;485 Deep strike their roots, their lengthening tops revive, And all my world of foliage wave, alive. "Thus with Hermetic art the ADEPT combines The royal acid with cobaltic mines; Marks with quick pen, in lines unseen portrayed, 490 The blushing mead, green dell, and dusky glade; Shades with pellucid clouds the tintless field, And all the future Group exists conceal'd; Till waked by fire the dawning tablet glows, Green springs the herb, the purple floret blows, 495 Hills vales and woods in bright succession rise, And all the living landscape charms his eyes. [_Thus with Hermetic art_. L. 487. The sympathetic inks made by Zaffredissolved in the marine and nitrous acids have this curious property, that being brought to the fire one of them becomes green, and the otherred; but what is more wonderful, they again lose these colours, (unlessthe heat has been too great, ) on their being again withdrawn from thefire. Fire-screens have been thus painted, which in the cold have shewnonly the trunk and branches of a dead tree, and sandy hills, which ontheir approach to the fire have put forth green leaves and red flowers, and grass upon the mountains. The process of making these inks is veryeasy, take Zaffre, as sold by the druggists, and digest it in aquaregia, and the calx of Cobalt will be dissolved; which solution must bediluted with a little common water to prevent it from making too strongan impression on the paper; the colour when the paper is heated becomesof a fine green-blue. If Zaffre or Regulus of Cobalt be dissolved in thesame manner in spirit of nitre, or aqua fortis, a reddish colour isproduced on exposing the paper to heat. Chemical Dictionary by Mr. Keir, Art. Ink Sympathetic. ] XI. "With crest of gold should sultry SIRIUS glare, And with his kindling tresses scorch the air; With points of flame the shafts of Summer arm, 500 And burn the beauties he designs to warm;-- --So erst when JOVE his oath extorted mourn'd, And clad in glory to the Fair return'd; While Loves at forky bolts their torches light, And resting lightnings gild the car of Night;505 His blazing form the dazzled Maid admir'd, Met with fond lips, and in his arms expir'd;-- NYMPHS! on light pinion lead your banner'd hosts High o'er the cliffs of ORKNEY'S gulphy coasts; Leave on your left the red volcanic light, 510 Which HECCLA lifts amid the dusky night; Mark on the right the DOFRINE'S snow-capt brow, Where whirling MAELSTROME roars and foams below; Watch with unmoving eye, where CEPHEUS bends His triple crown, his scepter'd hand extends;515 Where studs CASSIOPE with stars unknown Her golden chair, and gems her sapphire zone; Where with vast convolution DRACO holds The ecliptic axis in his scaly folds, O'er half the skies his neck enormous rears, 520 And with immense meanders parts the BEARS; Onward, the kindred BEARS with footstep rude Dance round the Pole, pursuing and pursued. [_With stars unknown_. L. 515. Alluding to the star which appeared inthe chair of Cassiopea in the year 1572, which at first surpassedJupiter in magnitude and brightness, diminished by degrees anddisappeared in 18 months; it alarmed all the astronomers of the age, andwas esteemed a comet by some. --Could this have been the Georgium sidus?] "There in her azure coif and starry stole, Grey TWILIGHT sits, and rules the slumbering Pole;525 Bends the pale moon-beams round the sparkling coast, And strews with livid hands eternal frost. There, NYMPHS! alight, array your dazzling powers, With sudden march alarm the torpid Hours; On ice-built isles expand a thousand sails, 530 Hinge the strong helms, and catch the frozen gales; The winged rocks to feverish climates guide, Where fainting Zephyrs pant upon the tide; Pass, where to CEUTA CALPE'S thunder roars, And answering echoes shake the kindred shores;535 Pass, where with palmy plumes CANARY smiles, And in her silver girdle binds her isles; Onward, where NIGER'S dusky Naiad laves A thousand kingdoms with prolific waves, Or leads o'er golden sands her threefold train540 In steamy channels to the fervid main, While swarthy nations croud the sultry coast, Drink the fresh breeze, and hail the floating Frost, NYMPHS! veil'd in mist, the melting treasures steer, And cool with arctic snows the tropic year. 545 So from the burning Line by Monsoons driven Clouds sail in squadrons o'er the darken'd heaven; Wide wastes of sand the gelid gales pervade, And ocean cools beneath the moving shade. [_On ice-built isles_. L. 529. There are many reasons to believe fromthe accounts of travellers and navigators, that the islands of ice inthe higher northern latitudes as well as the Glaciers on the Alpscontinue perpetually to increase in bulk. At certain times in the ice-mountains of Switzerland there happen cracks which have shewn the greatthickness of the ice, as some of these cracks have measured three orfour hundred ells deep. The great islands of ice in the northern seasnear Hudson's bay have been observed to have been immersed above onehundred fathoms beneath the surface of the sea, and to have risen afifth or sixth part above the surface, and to have measured betweenthree and four miles in circumference. Phil. Trans. No. 465. Sect. 2. Dr. Lister endeavoured to shew that the ice of sea-water contains somesalt and perhaps less air than common ice, and that it is therefore muchmore difficult of solution; whence he accounts for the perpetual andgreat increase of these floating islands of ice. Philos. Trans. No. 169. As by a famous experiment of Mr. Boyles it appears that ice evaporatesvery fast in severe frosty weather when the wind blows upon it; and asice in a thawing state is known to contain six times more cold thanwater at the same degree of sensible coldness, it is easy to understandthat winds blowing over islands and continents of ice perhaps much belownothing on Farenheit's scale, and coming from thence into our latitudemust bring great degrees of cold along with them. If we add to this thequantity of cold produced by the evaporation of the water as well as bythe solution of the ice, we cannot doubt but that the northern ice isthe principle source of the coldness of our winters, and that it isbrought hither by the regions of air blowing from the north, and whichtake an apparent easterly direction by their coming to a part of thesurface of the earth which moves faster than the latitude they comefrom. Hence the increase of the ice in the polar regions by increasingthe cold of our climate adds at the same time to the bulk of theGlaciers of Italy and Switzerland. If the nations who inhabit this hemisphere of the globe, instead ofdestroying their sea-men and exhausting their wealth in unnecessarywars, could be induced to unite their labours to navigate these immensemasses of ice into the more southern oceans, two great advantages wouldresult to mankind, the tropic countries would be much cooled by theirsolution, and our winters in this latitude would be rendered much milderfor perhaps a century or two, till the masses of ice became againenormous. Mr. Bradley describes the cold winds and wet weather which sometimeshappen in May and June to the solution of ice-islands accidentallyfloating from the north. Treatise on Husbandry and Gardening, Vol. II. P. 437. And adds, that Mr. Barham about the year 1718, in his voyagefrom Jamaica to England in the beginning of June, met with ice-islandscoming from the north, which were surrounded with so great a fog thatthe ship was in danger of striking upon them, and that one of themmeasured fifty miles in length. We have lately experienced an instance of ice-islands brought from theSouthern polar regions, on which the Guardian struck at the beginning ofher passage from the Cape of Good Hope towards Botany Bay, on December22, 1789. These islands were involved in mist, were about one hundredand fifty fathoms long, and about fifty fathoms above the surface of thewater. A part from the top of one of them broke off and fell into thesea, causing an extraordinary commotion in the water and a thick smokeall round it. ] [_Threefold train_. L. 539. The river Niger after traversing an immensetract of populous country is supposed to divide itself into three othergreat rivers. The Rio Grande, the Gambia, and the Senegal. Gold-dust isobtained from the sands of these rivers. ] [_Wide wastes of sand_. L. 547. When the sun is in the Southern tropic36 deg. Distant from the zenith, the thermometer is seldom lower than 72deg. At Gondar in Abyssinia, but it falls to 60 or 53 deg. When the sunis immediately vertical; so much does the approach of rain counteractthe heat of the sun. Bruce's Travels, Vol. 3. P. 670. ] XII. Should SOLSTICE, stalking through the sickening bowers, 550 Suck the warm dew-drops, lap the falling showers; Kneel with parch'd lip, and bending from it's brink From dripping palm the scanty river drink; NYMPHS! o'er the soil ten thousand points erect, And high in air the electric flame collect. 555 Soon shall dark mists with self-attraction shroud The blazing day, and sail in wilds of cloud; Each silvery Flower the streams aerial quaff, Bow her sweet head, and infant Harvest laugh. [_Ten thousand points erect_. L. 553. The solution of water in air or incalorique, seems to acquire electric matter at the same time, as appearsfrom an experiment of Mr. Bennet. He put some live coals into aninsulated funnel of metal, and throwing on them a little water observedthat the ascending steam was electrised plus, and the water whichdescended through the funnel was electrised minus. Hence it appears thatthough clouds by their change of form may sometimes become electrisedminus yet they have in general an accumulation of electricity. Thisaccumulation of electric matter also evidently contributes to supportthe atmospheric vapour when it is condensed into the form of clouds, because it is seen to descend rapidly after the flashes of lightninghave diminished its quantity; whence there is reason to conclude thatvery numerous metallic rods with fine points erected high in the airmight induce it at any time to part with some of its water. If we may trust the theory of Mr. Lavoisier concerning the compositionand decomposition of water, there would seem another source of thunder-showers; and that is, that the two gasses termed oxygene gas or vitalair, and hydrogene gas or inflammable air, may exist in the summeratmosphere in a state of mixture but not of combination, and that theelectric spark or flash of lightning may combine them and produce waterinstantaneously. ] "Thus when ELIJA mark'd from Carmel's brow560 In bright expanse the briny flood below; Roll'd his red eyes amid the scorching air, Smote his firm breast, and breathed his ardent prayer; High in the midst a massy altar stood, And slaughter'd offerings press'd the piles of wood;565 While ISRAEL'S chiefs the sacred hill surround, And famish'd armies crowd the dusty ground; While proud Idolatry was leagued with dearth, And wither'd famine swept the desert earth. -- "OH, MIGHTY LORD! thy woe-worn servant hear, 570 "Who calls thy name in agony of prayer; "Thy fanes dishonour'd, and thy prophets slain, "Lo! I alone survive of all thy train!-- "Oh send from heaven thy sacred fire, --and pour "O'er the parch'd land the salutary shower, --575 "So shall thy Priest thy erring flock recal, -- "And speak in thunder, "THOU ART LORD OF ALL. "-- He cried, and kneeling on the mountain-sands, Stretch'd high in air his supplicating hands. --Descending flames the dusky shrine illume;580 Fire the wet wood, the sacred bull consume; Wing'd from the sea the gathering mists arise, And floating waters darken all the skies; The King with shifted reins his chariot bends, And wide o'er earth the airy flood descends;585 With mingling cries dispersing hosts applaud, And shouting nations own THE LIVING GOD. " The GODDESS ceased, --the exulting tribes obey, Start from the soil, and win their airy way; The vaulted skies with streams of transient rays590 Shine, as they pass, and earth and ocean blaze. So from fierce wars when lawless Monarch's cease, Or Liberty returns with laurel'd Peace; Bright fly the sparks, the colour'd lustres burn, Flash follows f595 Blue serpents sweep along the dusky air, Imp'd by long trains of scintillating hair; Red rockets rise, loud cracks are heard on high, And showers of stars rush headlong from the sky, Burst, as in silver lines they hiss along, 600 And the quick flash unfolds the gazing throng. _Argument of the Second Canto. _ Address to the Gnomes. I. The Earth thrown from a volcano of the Sun;it's atmosphere and ocean; it's journey through the zodiac; vicissitudeof day-light, and of seasons, 11. II. Primeval islands. Paradise, or thegolden Age. Venus rising from the sea, 33. III. The first greatearthquakes; continents raised from the sea; the Moon thrown from avolcano, has no atmosphere, and is frozen; the earth's diurnal motionretarded; it's axis more inclined; whirls with the moon round a newcentre. 67. IV. Formation of lime-stone by aqueous solution; calcareousspar; white marble; antient statue of Hercules resting from his labours. Antinous. Apollo of Belvidere. Venus de Medici. Lady Elizabeth Foster, and Lady Melbourn by Mrs. Damer. 93. V. 1. Of morasses. Whence theproduction of Salt by elutriation. Salt-mines at Cracow, 115. 2. Production of nitre. Mars and Venus caught by Vulcan, 143. 3. Productionof iron. Mr. Michel's improvement of artificial magnets. Uses of Steelin agriculture, navigation, war, 183. 4. Production of acids, whenceFlint. Sea-sand. Selenite. Asbestus. Fluor. Onyx, Agate, Mocho, Opal, Sapphire, Ruby, Diamond. Jupiter and Europa, 215. VI. 1. Newsubterraneous fires from fermentation. Production of Clays; manufactureof Porcelain in China; in Italy; in England. Mr. Wedgwood's works atEtruria in Staffordshire. Cameo of a Slave in Chains; of Hope. Figureson the Portland or Barberini vase explained, 271. 2. Coal; Pyrite;Naphtha; Jet; Amber. Dr. Franklin's discovery of disarming the Tempestof it's lightning. Liberty of America; of Ireland; of France, 349. VII. Antient central subterraneous fires. Production of Tin, Copper, Zink, Lead, Mercury, Platina, Gold and Silver. Destruction of Mexico. Slaveryof Africa, 395. VIII. Destruction of the armies of Cambyses, 431. IX. Gnomes like stars of an Orrery. Inroads of the Sea stopped. Rockscultivated. Hannibal passes the Alps, 499. X. Matter circulates. Manuresto Vegetables like Chyle to Animals. Plants rising from the Earth. St. Peter delivered from Prison, 537. XI. Transmigration of matter, 565. Death and resuscitation of Adonis, 575. Departure of the Gnomes, 601. THE ECONOMY OF VEGETATION. CANTO II. AND NOW THE GODDESS with attention sweet Turns to the GNOMES, that circle round her feet; Orb within orb approach the marshal'd trains, And pigmy legions darken all the plains; 5 Thrice shout with silver tones the applauding bands, Bow, ere She speaks, and clap their fairy hands. So the tall grass, when noon-tide zephyr blows, Bends it's green blades in undulating rows; Wide o'er the fields the billowy tumult spreads, 10 And rustling harvests bow their golden heads. I. "GNOMES! YOUR bright forms, presiding at her birth, Clung in fond squadrons round the new-born EARTH; When high in ether, with explosion dire, From the deep craters of his realms of fire, 15 The whirling Sun this ponderous planet hurl'd, And gave the astonish'd void another world. When from it's vaporous air, condensed by cold, Descending torrents into oceans roll'd; And fierce attraction with relentless force 20 Bent the reluctant wanderer to it's course. [_From the deep craters_. L. 14. The existence of solar volcanos iscountenanced by their analogy to terrestrial, and lunar volcanos; and bythe spots on the sun's disk, which have been shewn by Dr. Wilson to beexcavations through its luminous surface, and may be supposed to be thecavities from whence the planets and comets were ejected by explosions. See additional notes, No. XV. On solar volcanos. ] [_When from its vaporous air_. L. 17. If the nucleus of the earth wasthrown out from the sun by an explosion along with as large a quantityof surrounding hot vapour as its attraction would occasion to accompanyit, the ponderous semi-fluid nucleus would take a spherical form fromthe attraction of its own parts, which would become an oblate spheroidfrom its diurnal revolution. As the vapour cooled the water would beprecipitated, and an ocean would surround the spherical nucleus with asuperincumbent atmosphere. The nucleus of solar lava would likewisebecome harder as it became cooler. To understand how the strata of theearth were afterwards formed from the sediments of this circumfluentocean the reader is referred to an ingenious Treatise on the Theory ofthe Earth by Mr. Whitehurst, who was many years a watch-maker andengineer at Derby, but whose ingenuity, integrity, and humanity, wererarely equalled in any station of life. ] "Where yet the Bull with diamond-eye adorns The Spring's fair forehead, and with golden horns; Where yet the Lion climbs the ethereal plain, And shakes the Summer from his radiant mane; 25 Where Libra lifts her airy arm, and weighs, Poised in her silver ballance, nights and days; With paler lustres where Aquarius burns, And showers the still snow from his hoary urns; YOUR ardent troops pursued the flying sphere, 30 Circling the starry girdle of the year; While sweet vicissitudes of day and clime Mark'd the new annals of enascent Time. II. "You trod with printless step Earth's tender globe, While Ocean wrap'd it in his azure robe; 35 Beneath his waves her hardening strata spread, Raised her PRIMEVAL ISLANDS from his bed, Stretch'd her wide lawns, and sunk her winding dells, And deck'd her shores with corals, pearls, and shells. [_While ocean wrap'd_. L. 34. See additional notes, No. XVI. On theproduction of calcareous earth. ] [_Her hardening srata spread_. L. 35. The granite, or moor-stone, orporphory, constitute the oldest part of the globe, since the limestone, shells, coralloids, and other sea-productions rest upon them; and uponthese sea-productions are found clay, iron, coal, salt, and siliceoussand or grit-stone. Thus there seem to be three divisions of the globedistinctly marked; the first I suppose to have been the original nucleusof the earth, or lava projected from the sun; 2. Over this lie therecrements of animal and vegetable matter produced in the ocean; and, 3. Over these the recrements of animal and vegetable matter produced uponthe land. Besides these there are bodies which owe their origin to acombination of those already mentioned, as siliceous sand, fluor, alabaster; which seem to have derived their acids originally from thevegetable kingdom, and their earthy bases from sea-productions. Seeadditional notes, No. XVI. On calcareous earth. ] [_Raised her primeval islands_. L. 36. The nucleus of the earth, stillcovered with water, received perpetual increase by the immensequantities of shells and coralloids either annually produced andrelinquishied, or left after the death of the animals. These wouldgradually by their different degrees of cohesion be some of them moreand others less removable by the influence of solar tides, and gentletropical breezes, which then must have probably extended from one poleto the other; for it is supposed the moon was not yet produced, and thatno storms or unequal winds had yet existence. Hence then the primeval islands had their gradual origin, were raisedbut a few feet above the level of the sea, and were not exposed to thegreat or sudden variations of heat and cold, as is so well explained inMr. Whitehurst's Theory of the Earth, chap. Xvi. Whence the paradise ofthe sacred writers, and the golden age of the profane ones, seems tohave had a real existence. As there can be no rainbow, when the heavensare covered with clouds, because the sun-beams are then precluded fromfalling upon the rain-drops opposite to the eye of the spectator, therainbow is a mark of gentle or partial showers. Mr. Whitehurst hasendeavoured to show that the primitive islands were only moistened bynocturnal dews and not by showers, as occurs at this day to the Delta ofEgypt; and is thence of opinion, that the rainbow had no existence tillafter the production of mountains and continents. As the salt of the seahas been gradually accumulating, being washed down into it from therecrements of animal and vegetable bodies, the sea must originally havebeen as fresh as river water; and as it is not yet saturated with salt, must become annually more saline. See note on l. 119 of this Canto. ] "O'er those blest isles no ice-crown'd mountains tower'd, 40 No lightnings darted, and no tempests lower'd; Soft fell the vesper-drops, condensed below, Or bent in air the rain-refracted bow; Sweet breathed the zephyrs, just perceiv'd and lost; And brineless billows only kiss'd the coast; 45 Round the bright zodiac danced the vernal hours, And Peace, the Cherub, dwelt in mortal bowers! "So young DIONE, nursed beneath the waves, And rock'd by Nereids in their coral caves, Charm'd the blue sisterhood with playful wiles, 50 Lisp'd her sweet tones, and tried her tender smiles. Then, on her beryl throne by Triton's borne, Bright rose the Goddess like the Star of morn; When with soft fires the milky dawn He leads, And wakes to life and love the laughing meads;-- 55 With rosy fingers, as uncurl'd they hung Round her fair brow, her golden locks she wrung; O'er the smooth surge on silver sandals flood, And look'd enchantment on the dazzled flood. -- The bright drops, rolling from her lifted arms, 60 In slow meanders wander o'er her charms, Seek round her snowy neck their lucid track, Pearl her white shoulders, gem her ivory back, Round her fine waist and swelling bosom swim, And star with glittering brine each crystal limb. -- 65 --The immortal form enamour'd Nature hail'd, And Beauty blazed to heaven and earth, unvail'd. [_So young Dione_. L. 47. There is an antient gem representing Venusrising out of the ocean supported by two Tritons. From the formality ofthe design it would appear to be of great antiquity before theintroduction of fine taste into the world. It is probable that thisbeautiful allegory was originally an hieroglyphic picture (before theinvention of letters) descriptive of the formation of the earth from theocean, which seems to have been an opinion of many of the most antientphilosophers. ] III. "You! who then, kindling after many an age, Saw with new fires the first VOLCANO rage, O'er smouldering heaps of livid sulphur swell 70 At Earth's firm centre, and distend her shell, Saw at each opening cleft the furnace glow, And seas rush headlong on the gulphs below. -- GNOMES! how you shriek'd! when through the troubled air Roar'd the fierce din of elemental war; 75 When rose the continents, and sunk the main, And Earth's huge sphere exploding burst in twain. -- GNOMES! how you gazed! when from her wounded side Where now the South-Sea heaves its waste of tide, Rose on swift wheels the MOON'S refulgent car, 80 Circling the solar orb; a sister-star, Dimpled with vales, with shining hills emboss'd, And roll'd round Earth her airless realms of frost. [_The first volcano_. L. 68. As the earth before the existence ofearthquakes was nearly level, and the greatest part of it covered withsea; when the first great fires began deep in the internal parts of it, those parts would become much expanded; this expansion would begradually extended, as the heat increased, through the whole terraqueousglobe of 7000 miles diameter; the crust would thence in many places openinto fissures, which by admitting the sea to flow in upon the fire, would produce not only a quantity of steam beyond calculation by itsexpansion, but would also by its decomposition produce inflammable airand vital air in quantities beyond conception, sufficient to effectthose violent explosions, the vestiges of which all over the worldexcite our admiration and our study; the difficulty of understanding howsubterraneous fires could exist without the presence of air hasdisappeared since Dr. Priestley's discoveries of such great quantitiesof pure air which constitute all the acids, and consequently exist inall saline bodies, as sea-salt, nitre, lime-stone, and in all calciformores, as manganese, calamy, ochre, and other mineral substances. See aningenious treatise by Mr. Michel on earthquakes in the Philos. Trans. In these first tremendous ignitions of the globe, as the continents wereheaved up, the vallies, which now hold the sea, were formed by the earthsubsiding into the cavities made by the rising mountains; as the steam, which raised them condensed; which would thence not have any caverns ofgreat extent remain beneath them, as some philosophers have imagined. The earthquakes of modern days are of very small extent indeed comparedto those of antient times, and are ingeniously compared by M. De Luc tothe operations of a mole-hill, where from a small cavity are raised fromtime to time small quantities of lava or pumice stone. Monthly Review, June, 1790. ] [_The moon's refulgent car_. L. 79. See additional notes, No. XV. Onsolar volcanos. ] [_Her airless realms of frost_. L. 82. If the moon had no atmosphere atthe time of its elevation from the earth; or if its atmosphere wasafterwards stolen from it by the earth's attraction; the water on themoon would rise quickly into vapour; and the cold produced by a certainquantity of this evaporation would congeal the remainder of it. Hence itis not probable that the moon is at present inhabited, but as it seemsto have suffered and to continue to suffer much by volcanos, asufficient quantity of air may in process of time be generated toproduce an atmosphere; which may prevent its heat from so easilyescaping, and its water from so easily evaporating, and thence becomefit for the production of vegetables and animals. That the moon possesses little or no atmosphere is deduced from theundiminished lustre of the stars, at the instant when they emerge frombehind her disk. That the ocean of the moon is frozen, is confirmed fromthere being no appearance of lunar tides; which, if they existed, wouldcover the part of her disk nearest the earth. See note on Canto III. L. 61. ] "GNOMES! how you trembled! with the dreadful force When Earth recoiling stagger'd from her course; 85 When, as her Line in slower circles spun, And her shock'd axis nodded from the sun, With dreadful march the accumulated main Swept her vast wrecks of mountain, vale, and plain; And, while new tides their shouting floods unite, 90 And hail their Queen, fair Regent of the night; Chain'd to one centre whirl'd the kindred spheres, And mark'd with lunar cycles solar years. [_When earth recoiling_. L. 84. On supposition that the moon was thrownfrom the earth by the explosion of water or the generation of othervapours of greater power, the remaining part of the globe would recedefrom its orbit in one direction as the moon receded in another, and thatin proportion to the respective momentum of each, and would afterwardsrevolve round their common centre of gravity. If the moon rose from any part of the earth except exactly at the lineor poles, the shock would tend to turn the axis of the earth out of itsprevious direction. And as a mass of matter rising from deep parts ofthe globe would have previously acquired less diurnal velocity than theearth's surface from whence it rose, it would receive during the time ofits rising additional velocity from the earth's surface, and wouldconsequently so much retard the motion of the earth round its axis. When the earth thus receded the shock would overturn all its buildingsand forests, and the water would rush with inconceivable violence overits surface towards the new satellite, from two causes, both by its notat first acquiring the velocity with which the earth receded, and by theattraction of the new moon, as it leaves the earth; on these accounts atfirst there would be but one tide till the moon receded to a greaterdistance, and the earth moving round a common centre of gravity betweenthem, the water on the side furthest from the moon would acquire acentrifugal force in respect to this common centre between itself andthe moon. ] IV. "GNOMES! you then bade dissolving SHELLS distil From the loose summits of each shatter'd hill, 95 To each fine pore and dark interstice flow, And fill with liquid chalk the mass below. Whence sparry forms in dusky caverns gleam With borrow'd light, and twice refract the beam; While in white beds congealing rocks beneath100 Court the nice chissel, and desire to breathe. -- [Footnote: _Dissolving shells distil_. L. 93. The lime-stone rocks havehad their origin from shells formed beneath the sea, the softer stratagradually dissolving and filling up the interstices of the harder ones, afterwards when these accumulations of shells were elevated above thewaters the upper strata became dissolved by the actions of the air anddews, and filled up the interstices beneath, producing solid rocks ofdifferent kinds from the coarse lime-stones to the finest marbles. Whenthose lime-stones have been in such a situation that they could formperfect crystals they are called spars, some of which possess a doublerefraction, as observed by Sir Isaac Newton. When these crystals arejumbled together or mixed with some colouring impurities it is termedmarble, if its texture be equable and firm; if its texture be coarse andporous yet hard, it is called lime-stone; if its texture be very looseand porous it is termed chalk. In some rocks the shells remain almostunchanged and only covered, or bedded with lime-stone, which seems tohave been dissolved and sunk down amongst them. In others the softershells and bones are dissolved, and only sharks teeth or harder echinihave preserved their form inveloped in the chalk or lime-stone; in somemarbles the solution has been compleat and no vestiges of shell appear, as in the white kind called statuary by the workmen. See addit. Notes, No. XVI. ] "Hence wearied HERCULES in marble rears His languid limbs, and rests a thousand years; Still, as he leans, shall young ANTINOUS please With careless grace, and unaffected ease;105 Onward with loftier step APOLLO spring, And launch the unerring arrow from the string; In Beauty's bashful form, the veil unfurl'd, Ideal VENUS win the gazing world. Hence on ROUBILIAC'S tomb shall Fame sublime110 Wave her triumphant wings, and conquer Time; Long with soft touch shall DAMER'S chissel charm, With grace delight us, and with beauty warm; FOSTER'S fine form shall hearts unborn engage, And MELBOURN's smile enchant another age. [_Hence wearied Hercules_. L. 101. Alluding to the celebrated Herculesof Glyco resting after his labours; and to the easy attitude ofAntinous; the lofty step of the Apollo of Belvidere; and the retreatingmodesty of the Venus de Medici. Many of the designs by Roubiliac inWestminster Abbey are uncommonly poetical; the allegory of Time and Famecontending for the trophy of General Wade, which is here alluded to, isbeautifully told; the wings of Fame are still expanded, and her hairstill floating in the air; which not only shews that she has that momentarrived, but also that her force is not yet expended; at the same time, that the old figure of Time with his disordered wings is rather leaningbackwards and yielding to her impulse, and must apparently in anotherinstant be driven from his attack upon the trophy. ] [_Foster's fine form_. L. 113. Alluding to the beautiful statues of LadyElizabeth Foster and of Lady Melbourn executed by the ingenious Mrs. Damer. ] 115 V. GNOMES! you then taught transuding dews to pass Through time-fall'n woods, and root-inwove morass Age after age; and with filtration fine Dispart, from earths and sulphurs, the saline. [_Root-inwove morass_. L. 116. The great mass of matter which rests uponthe lime-stone strata of the earth, or upon the granite where the lime-stone stratum has been removed by earthquakes or covered by lava, hashad its origin from the recrements of vegetables and of air-breathinganimals, as the lime-stone had its origin from sea animals. The wholehabitable world was originally covered with woods, till mankind formedthemselves into societies, and subdued them by fire and by steel. Hencewoods in uncultivated countries have grown and fallen through many ages, whence morasses of immense extent; and from these as the more solubleparts were washed away first, were produced sea-salt, nitre, iron, andvariety of acids, which combining with calcareous matter were productiveof many fossil bodies, as flint, sea-sand, selenite, with the preciousstones, and perhaps the diamond. See additional notes, No. XVII. ] 1. "HENCE with diffusive SALT old Ocean steeps120 His emerald shallows, and his sapphire deeps. Oft in wide lakes, around their warmer brim In hollow pyramids the crystals swim; Or, fused by earth-born fires, in cubic blocks Shoot their white forms, and harden into rocks. [_Hence with diffusive salt_. L. 119. Salts of various kinds areproduced from the recrements of animal and vegetable bodies, such asphosphoric, ammoniacal, marine salt, and others; these are washed fromthe earth by rains, and carried down our rivers into the sea; they seemall here to decompose each other except the marine salt, which hastherefore from the beginning of the habitable world been perpetuallyaccumulating. There is a town in the immense salt-mines of Cracow in Poland, with amarket-place, a river, a church, and a famous statue, (here supposed tobe of Lot's wife) by the moist or dry appearance of which thesubterranean inhabitants are said to know when the weather is fair aboveground. The galleries in these mines are so numerous and so intricate, that workmen have frequently lost their way, their lights having beenburnt out, and have perished before they could be found. Essais, &c. ParM. Macquart. And though the arches of these different stories ofgalleries are boldly executed, yet they are not dangerous; as they areheld together or supported by large masses of timber of a foot square;and these vast timbers remain perfectly sound for many centuries, whileall other pillars whether of brick, cement, or salt soon dissolve ormoulder away. Ibid. Could the timbers over water-mill wheels or cellars, be thus preserved by occasionally soaking them with brine? These immensemasses of rock-salt seem to have been produced by the evaporation ofsea-water in the early periods of the world by subterranean fires. Dr. Hutton's Theory of the Earth. See also Theorie des Sources Salees, parMr. Struve. Histoire de Sciences de Lausanne. Tom. II. This idea of Dr. Hutton's is confirmed by a fact mentioned in M. Macquart's Essais surMinerologie, who found a great quantity of fossil shells, principallybi-valves and madre-pores, in the salt-mines of Wialiczka near Cracow. During the evaporation of the lakes of salt-water, as in artificialsalt-works, the salt begins to crystallize near the edges where thewater is shallowest, forming hollow inverted pyramids; which, when theybecome of a certain size, subside by their gravity; if urged by astronger fire the salt fuses or forms large cubes; whence the saltshaped in hollow pyramids, called flake-salt, is better tasted andpreserves flesh better, than the basket or powder salt; because it ismade by less heat and thence contains more of the marine acid. The sea-water about our island contains from about one twenty-eighth to onethirtieth part of sea-salt, and about one eightieth of magnesian salt. See Brownrigg on Salt. See note on Ocymum, Vol. II. Of this work. ] 125 "Thus, cavern'd round in CRACOW'S mighty mines, With crystal walls a gorgeous city shines; Scoop'd in the briny rock long streets extend Their hoary course, and glittering domes ascend; Down the bright steeps, emerging into day, 130 Impetuous fountains burst their headlong way, O'er milk-white vales in ivory channels spread, And wondering seek their subterraneous bed. Form'd in pellucid salt with chissel nice, The pale lamp glimmering through the sculptured ice, 135 With wild reverted eyes fair LOTTA stands, And spreads to Heaven, in vain, her glassy hands; Cold dews condense upon her pearly breast, And the big tear rolls lucid down her vest. Far gleaming o'er the town transparent fanes140 Rear their white towers, and wave their golden vanes; Long lines of lustres pour their trembling rays, And the bright vault returns the mingled blaze. 2. "HENCE orient NITRE owes it's sparkling birth, And with prismatic crystals gems the earth, 145 O'er tottering domes in filmy foliage crawls, Or frosts with branching plumes the mouldering walls. As woos Azotic Gas the virgin Air, And veils in crimson clouds the yielding Fair, Indignant Fire the treacherous courtship flies, 150 Waves his light wing, and mingles with the skies. [_Hence orient Nitre_. L. 143. Nitre is found in Bengal naturallycrystallized, and is swept by brooms from earths and stones, and thencecalled sweepings of nitre. It has lately been found in large quantitiesin a natural bason of calcareous earth at Molfetta in Italy, both inthin strata between the calcareous beds, and in efflorescences ofvarious beautiful leafy and hairy forms. An account of this nitre-bed isgiven by Mr. Zimmerman and abridged in Rozier's Journal de PhysiqueFevrier. 1790. This acid appears to be produced in all situations whereanimal and vegetable matters are compleatly decomposed, and which areexposed to the action of the air as on the walls of stables, andslaughter-houses; the crystals are prisms furrowed by longitudinalgroves. Dr. Priestley discovered that nitrous air or gas which he obtained bydissolving metals in nitrous acid, would combine rapidly with vital air, and produce with it a true nitrous acid; forming red clouds during thecombination; the two airs occupy only the space before occupied by oneof them, and at the same time heat is given out from the newcombination. This dimunition of the bulk of a mixture of nitrous gas andvital air, Dr. Priestley ingeniously used as a test of the purity of thelatter; a discovery of the greatest importance in the analysis of airs. Mr. Cavendish has since demonstrated that two parts of vital air oroxygene, and one part of phlogistic air or azote, being long exposed toelectric shocks, unite, and produce nitrous acid. Philos. Trans. Vols. LXXV. And LXXVIII. Azote is one of the most abundant elements in nature, and combined withcalorique or heat, it forms azotic gas or phlogistic air, and composestwo thirds of the atmosphere; and is one of the principal componentparts of animal bodies, and when united to vital air or oxygene producesthe nitrous acid. Mr. Lavoisier found that 211/2 parts by weight ofazote, and 431/2 parts of oxygene produced 64 parts of nitrous gas, andby the further addition of 36 parts of oxygene nitrous acid wasproduced. Traité de Chimie. When two airs become united so as to producean unelastic liquid much calorique or heat is of necessity expelled fromthe new combination, though perhaps nitrous acid and oxygenated marineacid admit more heat into their combinations than other acids. ] "So Beauty's GODDESS, warm with new desire, Left, on her silver wheels, the GOD of Fire; Her faithless charms to fiercer MARS resign'd, Met with fond lips, with wanton arms intwin'd. 155 --Indignant VULCAN eyed the parting Fair, And watch'd with jealous step the guilty pair; O'er his broad neck a wiry net he flung, Quick as he strode, the tinkling meshes rung; Fine as the spider's flimsy thread He wove160 The immortal toil to lime illicit love; Steel were the knots, and steel the twisted thong, Ring link'd in ring, indissolubly strong; On viewless hooks along the fretted roof He hung, unseen, the inextricable woof. --165 --Quick start the springs, the webs pellucid spread, And lock the embracing Lovers on their bed; Fierce with loud taunts vindictive VULCAN springs, Tries all the bolts, and tightens all the strings, Shakes with incessant shouts the bright abodes, 170 Claps his rude hands, and calls the festive Gods. -- --With spreading palms the alarmed Goddess tries To veil her beauties from celestial eyes, Writhes her fair limbs, the slender ringlets strains, And bids her Loves untie the obdurate chains;175 Soft swells her panting bosom, as she turns, And her flush'd cheek with brighter blushes burns. Majestic grief the Queen of Heaven avows, And chaste Minerva hides her helmed brows; Attendant Nymphs with bashful eyes askance180 Steal of intangled MARS a transient glance; Surrounding Gods the circling nectar quaff, Gaze on the Fair, and envy as they laugh. 3. "HENCE dusky IRON sleeps in dark abodes, And ferny foliage nestles in the nodes;185 Till with wide lungs the panting bellows blow, And waked by fire the glittering torrents flow; --Quick whirls the wheel, the ponderous hammer falls, Loud anvils ring amid the trembling walls, Strokes follow strokes, the sparkling ingot shines, 190 Flows the red slag, the lengthening bar refines; Cold waves, immersed, the glowing mass congeal, And turn to adamant the hissing Steel. [_Hence dusky Iron_. L. 183. The production of iron from thedecomposition of vegetable bodies is perpetually presented to our view;the waters oozing from all morasses are chalybeate, and deposit theirochre on being exposed to the air, the iron acquiring a calciform statefrom its union with oxygene or vital air. Where thin morasses lie onbeds of gravel the latter are generally stained by the filtration ofsome of the chalybeate water through them. This formation of iron fromvegetable recrements is further evinced by the fern leaves and otherparts of vegetables, so frequently found in the centre of the knobs ornodules of some iron-ores. In some of these nodules there is a nucleus of whiter iron-earthsurrounded by many concentric strata of darker and lighter iron-earthalternately. In one, which now lies before me, the nucleus is a prism ofa triangular form with blunted angles, and about half an inch high, andan inch and half broad; on every side of this are concentric strata ofsimilar iron-earth alternately browner and less brown; each stratum isabout a tenth of an inch in thickness and there are ten of them innumber. To what known cause can this exactly regular distribution of somany earthy strata of different colours surrounding the nucleus beascribed? I don't know that any mineralogists have attempted anexplanation of this wonderful phenomenon. I suspect it is owing to thepolarity of the central nucleus. If iron-filings be regularly laid onpaper by means of a small sieve, and a magnet be placed underneath, thefilings will dispose themselves in concentric curves with vacantintervals between them. Now if these iron-filings are conceived to besuspended in a fluid, whose specific gravity is similar to their own, and a magnetic bar was introduced as an axis into this fluid, it is easyto foresee that the iron filings would dispose themselves intoconcentric spheres, with intervals of the circumnatant fluid betweenthem, exactly as is seen in these nodules of iron-earth. As all thelavas consist of one fourth of iron, (Kirvan's Mineral) and almost allother known bodies, whether of animal or vegetable origin, possess moreor less of this property, may not the distribution of a great portion ofthe globe of the earth into strata of greater or less regularity beowing to the polarity of the whole?] [_And turn to adamant_. L. 192. The circumstances which render iron morevaluable to mankind than any other metal are, 1. Its property of beingrendered hard to so great a degree and thus constituting such excellenttools. It was the discovery of this property of iron, Mr. Locke thinks, that gave such pre-eminence to the European world over the American one. 2. Its power of being welded; that is, when two pieces are made very hotand applied together by hammering, they unite compleatly, unless anyscale of iron intervenes; and to prevent this it is usual for smiths todip the very hot bar in sand, a little of which fuses into fluid glasswith the scale and is squeezed out from between the uniting parts by theforce of hammering. 3. Its power of acquiring magnetism. It is however to be wished that gold or silver were discovered in asgreat quantity as iron, since these metals being indestructible byexposure to air, water, fire or any common acids would supply wholesomevessels for cookery, so much to be desired, and so difficult to obtain, and would form the most light and durable coverings for houses, as wellas indestructible fire-grates, ovens, and boiling vessels. Seeadditional notes, No. XVIII. On Steel. ] "Last MICHELL'S hands with touch of potent charm The polish'd rods with powers magnetic arm;195 With points directed to the polar stars In one long line extend the temper'd bars; Then thrice and thrice with steady eye he guides, And o'er the adhesive train the magnet slides; The obedient Steel with living instinct moves, 200 And veers for ever to the pole it loves. [_Last Michell's hands_. L. 193. The discovery of the magnet seems tohave been in very early times; it is mentioned by Plato, Lucretius, Pliny, and Galen, and is said to have taken its name of magnes fromMagnesia, a sea-port of antient Lybia. As every piece of iron which was made magnetical by the touch of amagnet became itself a magnet, many attempts were made to improve theseartificial magnets, but without much success till Servingdon Savary, Esq. Made them of hardened steel bars, which were so powerful that oneof them weighing three pounds averdupois would lift another of the sameweight. Philos. Trans. After this Dr. Knight made very successful experiments on this subject, which, though he kept his method secret, seems to have excited others toturn their attention to magnetism. At this time the Rev. Mr. Michellinvented an equally efficacious and more expeditious way of makingstrong artificial magnets, which he published in the end of the year1750, in which he explained his method of what he called "the doubletouch", and which, since Mr. Knight's method has been known, appears tobe somewhat different from it. This method of rendering bars of hardened steel magnetical consists inholding vertically two or more magnetic bars nearly parallel to eachother with their opposite poles very near each other (but neverthelessseparated to a small distance), these are to be slided over a line ofbars laid horizontally a few times backward and forward. See Michell onMagnetism, also a detailed account in Chamber's Dictionary. What Mr. Michell proposed by this method was to include a very smallportion of the horizontal bars, intended to be made magnetical, betweenthe joint forces of two or more bars already magnetical, and by slidingthem from end to end every part of the line of bars became successivelyincluded, and thus bars possessed of a very small degree of magnetism tobegin with, would in a few times sliding backwards and forwards make theother ones much more magnetical than themselves, which are then to betaken up and used to touch the former, which are in succession to belaid down horizontally in a line. There is still a great field remains for future discoveries in magnetismboth in respect to experiment and theory; the latter consists of vagueconjectures the more probable of which are perhaps those of Elpinus, asthey assimulate it to electricity. One conjecture I shall add, viz. That the polarity of magnetism may beowing to the earth's rotatory motion. If heat, electricity, andmagnetism are supposed to be fluids of different gravities, heat beingthe heaviest of them, electricity the next heavy, and magnetism thelightest, it is evident that by the quick revolution of the earth theheat will be accumulated most over the line, electricity next beneaththis, and that the magnetism will be detruded to the poles and axis ofthe earth, like the atmospheres of common air and of inflammable gas, asexplained in the note on Canto I. L. 123. Electricity and heat will both of them displace magnetism, and thisshows that they may gravitate on each other; and hence when too great aquantity of the electric fluid becomes accumulated at the poles bydescending snows, or other unknown causes, it may have a tendency torise towards the tropics by its centrifugal force, and produce thenorthern lights. See additional notes, No. I. ] "Hail, adamantine STEEL! magnetic Lord! King of the prow, the plowshare, and the sword! True to the pole, by thee the pilot guides His steady helm amid the struggling tides, 205 Braves with broad sail the immeasurable sea, Cleaves the dark air, and asks no star but Thee. -- By thee the plowshare rends the matted plain, Inhumes in level rows the living grain; Intrusive forests quit the cultured ground, 210 And Ceres laughs with golden fillets crown'd. -- O'er restless realms when scowling Discord flings Her snakes, and loud the din of battle rings; Expiring Strength, and vanquish'd Courage feel Thy arm resistless, adamantine STEEL! 215 4. "HENCE in fine streams diffusive ACIDS flow, Or wing'd with fire o'er Earth's fair bosom blow; Transmute to glittering Flints her chalky lands, Or sink on Ocean's bed in countless Sands. Hence silvery Selenite her chrystal moulds, 220 And soft Asbestus smooths his silky folds; His cubic forms phosphoric Fluor prints, Or rays in spheres his amethystine tints. Soft cobweb clouds transparent Onyx spreads, And playful Agates weave their colour'd threads;225 Gay pictured Mochoes glow with landscape-dyes, And changeful Opals roll their lucid eyes; Blue lambent light around the Sapphire plays, Bright Rubies blush, and living Diamonds blaze. [_Diffusive Acids flow_. L. 215. The production of marine acid fromdecomposing vegetable and animal matters with vital air, and of nitrousacid from azote and vital air, the former of which is united to itsbasis by means of the exhalations from vegetable and animal matters, constitute an analogy which induces us to believe that many other acidshave either their bases or are united to vital air by means of some partof decomposing vegetable and animal matters. The great quantities of flint sand whether formed in mountains or in thesea would appear to derive its acid from the new world, as it is foundabove the strata of lime-stone and granite which constitute the oldworld, and as the earthy basis of flint is probably calcareous, a greatpart of it seems to be produced by a conjunction of the new and oldworld; the recrements of air-breathing animals and vegetables probablyafford the acid, and the shells of marine animals the earthy basis, while another part may have derived its calcareous part also from thedecomposition of vegetable and animal bodies. The same mode of reasoning seems applicable to the siliceous stonesunder various names, as amethyst, onyx, agate, mochoe, opal, &c. Whichdo not seem to have undergone any process from volcanic fires, and asthese stones only differ from flint by a greater or less admixture ofargillaceous and calcareous earths. The different proportions of whichin each kind of stone may be seen in Mr. Kirwan's valuable Elements ofMineralogy. See additional notes, No. XIX. ] [_Living diamonds blaze_. L. 228. Sir Isaac Newton having observed thegreat power of refracting light, which the diamond possesses above allother crystallized or vitreous matter, conjectured that it was aninflammable body in some manner congealed. Insomuch that all the lightis reflected which falls on any of its interior surfaces at a greaterangle of incidence than 241/2 degrees; whereas an artificial gem ofglass does not reflect any light from its hinder surface, unless thatsurface is inclined in an angle of 41 degrees. Hence the diamondreflects half as much more light as a factitious gem in similarcircumstances; to which must be added its great transparency, and theexcellent polish it is capable of. The diamond had nevertheless beenplaced at the head of crystals or precious stones by the mineralogists, till Bergman ranged it of late in the combustible class of bodies, because by the focus of Villette's burning mirror it was evaporated by aheat not much greater than will melt silver, and gave out light. Mr. Hoepfner however thinks the dispersion of the diamond by this great heatshould be called a phosphorescent evaporation of it, rather than acombustion; and from its other analogies of crystallization, hardness, transparency, and place of its nativity, wishes again to replace itamongst the precious stones. Observ. Sur la Physique, par Rozier, Tom. XXXV. P. 448. See new edition of the Translation of Cronsted, by DeCosta. ] "Thus, for attractive earth, inconstant JOVE230 Mask'd in new shapes forsook his realms above. -- First her sweet eyes his Eagle-form beguiles, And HEBE feeds him with ambrosial smiles; Next the chang'd God a Cygnet's down assumes, And playful LEDA smooths his glossy plumes;235 Then glides a silver Serpent, treacherous guest! And fair OLYMPIA folds him in her breast; Now lows a milk-white Bull on Afric's strand, And crops with dancing head the daisy'd land. -- With rosy wreathes EUROPA'S hand adorns240 His fringed forehead, and his pearly horns; Light on his back the sportive Damsel bounds, And pleased he moves along the flowery grounds; Bears with slow step his beauteous prize aloof, Dips in the lucid flood his ivory hoof;245 Then wets his velvet knees, and wading laves His silky sides amid the dimpling waves. While her fond train with beckoning hands deplore, Strain their blue eyes, and shriek along the shore; Beneath her robe she draws her snowy feet, 250 And, half-reclining on her ermine seat, Round his raised neck her radiant arms she throws, And rests her fair cheek on his curled brows; Her yellow tresses wave on wanton gales, And high in air her azure mantle sails. 255 --Onward He moves, applauding Cupids guide, And skim on shooting wing the shining tide; Emerging Triton's leave their coral caves, Sound their loud conchs, and smooth the circling waves, Surround the timorous Beauty, as she swims, 260 And gaze enamour'd on her silver limbs. --Now Europe's shadowy shores with loud acclaim Hail the fair fugitive, and shout her name; Soft echoes warble, whispering forests nod, And conscious Nature owns the present God. 265 --Changed from the Bull, the rapturous God assumes Immortal youth, with glow celestial blooms, With lenient words her virgin fears disarms, And clasps the yielding Beauty in his arms; Whence Kings and Heroes own illustrious birth, 270 Guards of mankind, and demigods on earth. [_Inconstant Jove_. L. 229. The purer air or ether in the antientmythology was represented by Jupiter, and the inferior air by Juno; andthe conjunction of these deities was said to produce the vernal showers, and procreate all things, as is further spoken of in Canto III. L. 204. It is now discovered that pure air, or oxygene, uniting with variety ofbases forms the various kinds of acids; as the vitriolic acid from pureair and sulphur; the nitrous acid from pure air and phlogistic air, orazote; and carbonic acid, (or fixed air, ) from pure air and charcoal. Some of these affinities were perhaps portrayed by the Magi of Egypt, who were probably learned in chemistry, in their hieroglyphic picturesbefore the invention of letters, by the loves of Jupiter withterrestrial ladies. And thus physically as well as metaphysically mightbe said "Jovis omnia plena. "] VI. "GNOMES! as you pass'd beneath the labouring soil, The guards and guides of Nature's chemic toil, YOU saw, deep-sepulchred in dusky realms, Which Earth's rock-ribbed ponderous vault o'erwhelms, 275 With self-born fires the mass fermenting glow, And flame-wing'd sulphurs quit the earths below. [_With self-born fires_. L. 275. After the accumulation of plains andmountains on the calcareous rocks or granite which had been previouslyraised by volcanic fires, a second set of volcanic fires were producedby the fermentation of this new mass, by which after the salts or acidsand iron had been washed away in part by elutriation, dissipated thesulphurous parts which were insoluble in water; whence argillaceous andsiliceous earths were left in some places; in others, bitumen becamesublimed to the upper part of the stratum, producing coals of variousdegrees of purity. ] 1. "HENCE ductile CLAYS in wide expansion spread, Soft as the Cygnet's down, their snow-white bed; With yielding flakes successive forms reveal, 280 And change obedient to the whirling wheel. --First CHINA'S sons, with early art elate, Form'd the gay tea-pot, and the pictured plate; Saw with illumin'd brow and dazzled eyes In the red stove vitrescent colours rise;285 Speck'd her tall beakers with enamel'd stars, Her monster-josses, and gigantic jars; Smear'd her huge dragons with metallic hues, With golden purples, and cobaltic blues; Bade on wide hills her porcelain castles glare, 290 And glazed Pagodas tremble in the air. [_Hence ductile clays_ l. 277. See additional notes, No. XX. ] [_Saw with illumin'd brow_. L. 283. No colour is distinguishable in thered-hot kiln but the red itself, till the workman introduces a smallpiece of dry wood, which by producing a white flame renders all theother colours visible in a moment. ] [_With golden purples_. L. 288. See additional notes, No. XXI. ] "ETRURIA! next beneath thy magic hands Glides the quick wheel, the plaistic clay expands, Nerved with fine touch, thy fingers (as it turns) Mark the nice bounds of vases, ewers, and urns;295 Round each fair form in lines immortal trace Uncopied Beauty, and ideal Grace. [_Etruria! next_. L. 291. Etruria may perhaps vie with China itself inthe antiquity of its arts. The times of its greatest splendour wereprior to the foundations of Rome, and the reign of one of its bestprinces, Janus, was the oldest epoch the Romans knew. The earliesthistorians speak of the Etruscans as being then of high antiquity, mostprobably a colony from Phoenicia, to which a Pelasgian colony acceded, and was united soon after Deucalion's flood. The peculiar character oftheir earthern vases consists in the admirable beauty, simplicity, anddiversity of forms, which continue the best models of taste to theartists of the present times; and in a species of non-vitreous encausticpainting, which was reckoned, even in the time of Pliny, among the lostarts of antiquity, but which has lately been recovered by the ingenuityand industry of Mr. Wedgwood. It is supposed that the principalmanufactories were about Nola, at the foot of Vesuvius; for it is inthat neighbourhood that the greatest quantities of antique vases havebeen found; and it is said that the general taste of the inhabitants isapparently influenced by them; insomuch that strangers coming to Naples, are commonly struck with the diversity and elegance even of the mostordinary vases for common uses. See D'Hancarville's preliminarydiscourses to the magnificent collection of Etruscan vases, published bySir William Hamilton. ] "GNOMES! as you now dissect with hammers fine The granite-rock, the nodul'd flint calcine; Grind with strong arm, the circling chertz betwixt, 300 Your pure Ka-o-lins and Pe-tun-tses mixt; O'er each red saggars burning cave preside, The keen-eyed Fire-Nymphs blazing by your side; And pleased on WEDGWOOD ray your partial smile, A new Etruria decks Britannia's isle. --305 Charm'd by your touch, the flint liquescent pours Through finer sieves, and falls in whiter showers; Charm'd by your touch, the kneaded clay refines, The biscuit hardens, the enamel shines; Each nicer mould a softer feature drinks, 310 The bold Cameo speaks, the soft Intaglio thinks. [Illustration: _H. Webber init J. Holloway sculpt Copied from Capt. Phillip's Voyage to Botany Bay, by permission of the Proprietor_] [Transcriber's note: names of painter and engraver are only guesswork. ] [Illustration: AM I NOT A MAN AND A BROTHER] "To call the pearly drops from Pity's eye, Or stay Despair's disanimating sigh, Whether, O Friend of art! the gem you mould Rich with new taste, with antient virtue bold;315 Form the poor fetter'd SLAVE on bended knee From Britain's sons imploring to be free; Or with fair HOPE the brightening scenes improve, And cheer the dreary wastes at Sydney-cove; Or bid Mortality rejoice and mourn320 O'er the fine forms on PORTLAND'S mystic urn. -- [_Form the poor fetter'd Slave_. L. 315. Alluding to two cameos of Mr. Wedgwood's manufacture; one of a Slave in chains, of which hedistributed many hundreds, to excite the humane to attend to and toassist in the abolition of the detestable traffic in human creatures;and the other a cameo of Hope attended by Peace, and Art, and Labour;which was made of clay from Botany Bay; to which place he sent many ofthem to shew the inhabitants what their materials would do, and toencourage their industry. A print of this latter medallion is prefixedto Mr. Stockdale's edition of Philip's Expedition to Botany Bay. ] [_Portland's mystic urn_. L. 320. See additional notes, No. XXII. ] "_Here_ by fall'n columns and disjoin'd arcades, On mouldering stones, beneath deciduous shades, Sits HUMANKIND in hieroglyphic state, Serious, and pondering on their changeful state;325 While with inverted torch, and swimming eyes, Sinks the fair shade of MORTAL LIFE, and dies. _There_ the pale GHOST through Death's wide portal bends His timid feet, the dusky steep descends; With smiles assuasive LOVE DIVINE invites, 330 Guides on broad wing, with torch uplifted lights; IMMORTAL LIFE, her hand extending, courts The lingering form, his tottering step supports; Leads on to Pluto's realms the dreary way, And gives him trembling to Elysian day. 335 _Beneath_ in sacred robes the PRIESTESS dress'd, The coif close-hooded, and the fluttering vest, With pointing finger guides the initiate youth, Unweaves the many-colour'd veil of Truth, Drives the profane from Mystery's bolted door, 340 And Silence guards the Eleusinian lore. -- [Illustration: _The Portland Vase_] [Illustration: _The first Compartment_, London Published Dec'r 1st 1791by J. Johnson, St. Paul's Church Yard. ] [Transcriber's note: 2nd line with date very small and nearly illegible] [Illustration: _The second Compartment_] [Illustration: _The Handles & Bottom of the Vase. _ London PublishedDec'r 1st 1791 by J. Johnson, St. Paul's Church Yard. ] "Whether, O Friend of Art! your gems derive Fine forms from Greece, and fabled Gods revive; Or bid from modern life the Portrait breathe, And bind round Honour's brow the laurel wreath;345 Buoyant shall sail, with Fame's historic page, Each fair medallion o'er the wrecks of age; Nor Time shall mar; nor steel, nor fire, nor rust Touch the hard polish of the immortal bust. [_Fine forms from Greece_. L. 342. In real stones, or in paste or softcoloured glass, many pieces of exquisite workmanship were produced bythe antients. Basso-relievos of various sizes were made in coarse brownearth of one colour; but of the improved kind of two or more colours, and of a true porcelain texture, none were made by the antients, norattempted I believe by the moderns, before those of Mr. Wedgwood'smanufactory. ] 2. "HENCE sable COAL his massy couch extends, 350 And stars of gold the sparkling Pyrite blends; Hence dull-eyed Naphtha pours his pitchy streams, And Jet uncolour'd drinks the solar beams, Bright Amber shines on his electric throne, And adds ethereal lustres to his own. 355 --Led by the phosphor-light, with daring tread Immortal FRANKLIN sought the fiery bed; Where, nursed in night, incumbent Tempest shrouds The seeds of Thunder in circumfluent clouds, Besieged with iron points his airy cell, 360 And pierced the monster slumbering in the shell. [_Hence sable Coal_. L. 349. See additional notes, No. XXIII. On coal. ] [_Bright Amber shines_. L. 353. Coal has probably all been sublimed moreor less from the clay, with which it was at first formed in decomposingmorasses; the petroleum seems to have been separated and condensed againin superior strata, and a still finer kind of oil, as naphtha, hasprobably had the same origin. Some of these liquid oils have again losttheir more volatile parts, and become cannel-coal, asphaltum, jet, andamber, according to the purity of the original fossil oil. Dr. Priestleyhas shewn, that essential oils long exposed to the atmosphere absorbboth the vital and phlogistic part of it; whence it is probable theirbecoming solid may in great measure depend, as well as by the exhalationof their more volatile parts. On distillation with volatile alcaly allthese fossil oils are shewn to contain the acid of amber, which evincesthe identity of their origin. If a piece of amber be rubbed it attractsstraws and hairs, whence the discovery of electricity, and whence itsname, from electron the Greek word for amber. ] [_Immortal Franklin_. L. 356. See note on Canto I. L. 383. ] "So, born on sounding pinions to the WEST, When Tyrant-Power had built his eagle nest; While from his eyry shriek'd the famish'd brood, Clenched their sharp claws, and champ'd their beaks for blood, 365 Immortal FRANKLIN watch'd the callow crew, And stabb'd the struggling Vampires, ere they flew. --The patriot-flame with quick contagion ran, Hill lighted hill, and man electrised man; Her heroes slain awhile COLUMBIA mourn'd, 370 And crown'd with laurels LIBERTY return'd. "The Warrior, LIBERTY, with bending sails Helm'd his bold course to fair HIBERNIA'S vales;-- Firm as he steps, along the shouting lands, Lo! Truth and Virtue range their radiant bands;375 Sad Superstition wails her empire torn, Art plies his oar, and Commerce pours her horn. "Long had the Giant-form on GALLIA'S plains Inglorious slept, unconscious of his chains; Round his large limbs were wound a thousand strings380 By the weak hands of Confessors and Kings; O'er his closed eyes a triple veil was bound, And steely rivets lock'd him to the ground; While stern Bastile with iron cage inthralls His folded limbs, and hems in marble walls. 385 --Touch'd by the patriot-flame, he rent amazed The flimsy bonds, and round and round him gazed; Starts up from earth, above the admiring throng Lifts his Colossal form, and towers along; High o'er his foes his hundred arms He rears, 390 Plowshares his swords, and pruning hooks his spears; Calls to the Good and Brave with voice, that rolls Like Heaven's own thunder round the echoing poles; Gives to the winds his banner broad unfurl'd, And gathers in its shade the living world! [_While stern Bastile_. L. 383. "We descended with great difficulty intothe dungeons, which were made too low for our standing upright; and wereso dark, that we were obliged at noon-day to visit them by the light ofa candle. We saw the hooks of those chains, by which the prisoners werefastened by their necks to the walls of their cells; many of which beingbelow the level of the water were in a constant state of humidity; fromwhich issued a noxious vapour, which more than once extinguished thecandles. Since the destruction of the building many subterraneous cellshave been discovered under a piece of ground, which seemed only a bankof solid earth before the horrid secrets of this prison-house weredisclosed. Some skeletons were found in these recesses with irons stillfastened to their decayed bones. " Letters from France, by H. M. Williams, p. 24. ] 395 VII. "GNOMES! YOU then taught volcanic airs to force Through bubbling Lavas their resistless course, O'er the broad walls of rifted Granite climb, And pierce the rent roof of incumbent Lime, Round sparry caves metallic lustres fling, 400 And bear phlogiston on their tepid wing. [_And pierce the rent roof_. L. 398. The granite rocks and the limestonerocks have been cracked to very great depths at the time they wereraised up by subterranean fires; in these cracks are found most of themetallic ores, except iron and perhaps manganese, the former of which isgenerally found in horizontal strata, and the latter generally near thesurface of the earth. Philosophers possessing so convenient a test for the discovery of ironby the magnet, have long since found it in all vegetable and animalmatters; and of late Mr. Scheele has discovered the existence ofmanganese in vegetable ashes. Scheele, 56 mem. Stock. 1774. Kirwan. Min. 353. Which accounts for the production of it near the surface of earth, and thence for its calciform appearance, or union with vital air. Bergman has likewise shewn, that the limestones which become bluish ordark coloured when calcined, possess a mixture of manganese, and arethence preferable as a cement to other kinds of lime. 2. Bergman, 229. Which impregnation with manganese has probably been received from thedecomposition of superincumbent vegetable matters. These cracks or perpendicular caverns in the granite or limestone passto unknown depths; and it is up these channels that I have endeavouredto shew that the steam rises which becomes afterwards condensed andproduces the warm springs of this island, and other parts of the world. (See note on Fucus, Vol. II. ) And up these cracks I suppose certainvapours arise, which either alone, or by meeting with somethingdescending into them from above, have produced most of the metals; andseveral of the materials in which they are bedded. Thus the ponderousearth, Barytes, of Derbyshire, is found in these cracks, and isstratified frequently with lead-ore, and frequently surrounds it. Thisponderous earth has been found by Dr. Hoepfner in a granite inSwitzerland, and may have thus been sublimed from immense depths bygreat heat, and have obtained its carbonic or vitriolic acid from above. Annales de Chimie. There is also reason to conclude that something fromabove is necessary to the formation of many of the metals: at Hawkstonein Shropshire, the seat of Sir Richard Hill, there is an elevated rockof siliceous sand which is coloured green with copper in many placeshigh in the air; and I have in my possession a specimen of lead formedin the cavity of an iron nodule, and another of lead amid spar from acrack of a coal-stratum; all which countenance the modern production ofthose metals from descending materials. To which should be added, thatthe highest mountains of granite, which have therefore probably neverbeen covered with marine productions on account of their earlyelevation, nor with vegetable or animal matters on account of theirgreat coldness, contain no metallic ores, whilst the lower ones containcopper and tin in their cracks or veins, both in Saxony, Silesia, andCornwall. Kirwan's Mineral. P. 374. The transmutation of one metal into another, though hithertoundiscovered by the alchymists, does not appear impossible; suchtransmutations have been supposed to exist in nature, thus lapiscalaminaris may have been produced from the destruction of lead-ore, asit is generally found on the top of the veins of lead, where it has beencalcined or united with air, and because masses of lead-ore are oftenfound intirely inclosed in it. So silver is found mixed in almost alllead-ores, and sometimes in seperate filaments within the cavities oflead-ore, as I am informed by Mr. Michell, and is thence probably apartial transmutation of the lead to silver, the rapid progress ofmodern chemistry having shewn the analogy between metallic calces andacids, may lead to the power of transmuting their bases: a discoverymuch to be wished. ] "HENCE glows, refulgent Tin! thy chrystal grains, And tawny Copper shoots her azure veins; Zinc lines his fretted vault with sable ore, And dull Galena tessellates the floor;405 On vermil beds in Idria's mighty caves The living Silver rolls its ponderous waves; With gay refractions bright Platina shines, And studs with squander'd stars his dusky mines; Long threads of netted gold, and silvery darts, 410 Inlay the Lazuli, and pierce the Quartz;-- --Whence roof'd with silver beam'd PERU, of old, And hapless MEXICO was paved with gold. "Heavens! on my sight what sanguine colours blaze! Spain's deathless shame! the crimes of modern days!415 When Avarice, shrouded in Religion's robe, Sail'd to the West, and slaughter'd half the globe; While Superstition, stalking by his side, Mock'd the loud groans, and lap'd the bloody tide; For sacred truths announced her frenzied dreams, 420 And turn'd to night the sun's meridian beams. -- Hear, oh, BRITANNIA! potent Queen of isles, On whom fair Art, and meek Religion smiles, Now AFRIC'S coasts thy craftier sons invade With murder, rapine, theft, --and call it Trade!425 --The SLAVE, in chains, on supplicating knee, Spreads his wide arms, and lifts his eyes to Thee; With hunger pale, with wounds and toil oppress'd, "ARE WE NOT BRETHREN?" sorrow choaks the rest;-- --AIR! bear to heaven upon thy azure flood430 Their innocent cries!--EARTH! cover not their blood! VIII. "When Heaven's dread justice smites in crimes o'ergrown The blood-nursed Tyrant on his purple throne, GNOMES! YOUR bold forms unnumber'd arms outstretch, And urge the vengeance o'er the guilty wretch. --435 Thus when CAMBYSES led his barbarous hosts From Persia's rocks to Egypt's trembling coasts, Defiled each hallowed fane, and sacred wood, And, drunk with fury, swell'd the Nile with blood; Waved his proud banner o'er the Theban states, 440 And pour'd destruction through her hundred gates; In dread divisions march'd the marshal'd bands, And swarming armies blacken'd all the lands, By Memphis these to ETHIOP'S sultry plains, And those to HAMMON'S sand-incircled fanes. --445 Slow as they pass'd, the indignant temples frown'd, Low curses muttering from the vaulted ground; Long ailes of Cypress waved their deepen'd glooms, And quivering spectres grinn'd amid the tombs; Prophetic whispers breathed from S450 And MEMNON'S lyre with hollow murmurs rung; Burst from each pyramid expiring groans, And darker shadows stretch'd their lengthen'd cones. -- Day after day their deathful rout They steer, Lust in the van, and rapine in the rear. [_Thus when Cambyses_. L. 435. Cambyses marched one army from Thebes, after having overturned the temples, ravaged the country, and deluged itwith blood, to subdue Ethiopia; this army almost perished by famine, insomuch, that they repeatedly slew every tenth man to supply theremainder with food. He sent another army to plunder the temple ofJupiter Ammon, which perished overwhelm'd with sand. ] [_Expiring groans_. L. 451. Mr. Savery or Mr. Volney in their Travelsthrough Egypt has given a curious description of one of the pyramids, with the operose method of closing them, and immuring the body, (as theysupposed) for six thousand years. And has endeavoured from thence toshew, that, when a monarch died, several of his favourite courtiers wereinclosed alive with the mummy in these great masses of stone-work; andhad food and water conveyed to them, as long as they lived, properapertures being left for this purpose, and for the admission of air, andfor the exclusion of any thing offensive. ] 455 "GNOMES! as they march'd, You hid the gathered fruits, The bladed grass, sweet grains, and mealy roots; Scared the tired quails, that journey'd o'er their heads, Retain'd the locusts in their earthy beds; Bade on your sands no night-born dews distil, 460 Stay'd with vindictive hands the scanty rill. -- Loud o'er the camp the Fiend of Famine shrieks, Calls all her brood, and champs her hundred beaks; O'er ten square leagues her pennons broad expand, And twilight swims upon the shuddering sand;465 Perch'd on her crest the Griffin Discord clings, And Giant Murder rides between her wings; Blood from each clotted hair, and horny quill, And showers of tears in blended streams distil; High-poised in air her spiry neck she bends, 470 Rolls her keen eye, her Dragon-claws extends, Darts from above, and tears at each fell swoop With iron fangs the decimated troop. "Now o'er their head the whizzing whirlwinds breathe, And the live desert pants, and heaves beneath;475 Tinged by the crimson sun, vast columns rise Of eddying sands, and war amid the skies, In red arcades the billowy plain surround, And stalking turrets dance upon the ground. --Long ranks in vain their shining blades extend, 480 To Demon-Gods their knees unhallow'd bend, Wheel in wide circle, form in hollow square, And now they front, and now they fly the war, Pierce the deaf tempest with lamenting cries, Press their parch'd lips, and close their blood-shot eyes. 485 --GNOMES! o'er the waste YOU led your myriad powers, Climb'd on the whirls, and aim'd the flinty showers!-- Onward resistless rolls the infuriate surge, Clouds follow clouds, and mountains mountains urge; Wave over wave the driving desert swims, 490 Bursts o'er their heads, inhumes their struggling limbs; Man mounts on man, on camels camels rush, Hosts march o'er hosts, and nations nations crush, -- Wheeling in air the winged islands fall, And one great earthy Ocean covers all!--495 Then ceased the storm, --NIGHT bow'd his Ethiop brow To earth, and listen'd to the groans below, -- Grim HORROR shook, --awhile the living hill Heaved with convulsive throes, --and all was still! [_And stalking turrets_. L. 478. "At one o'clock we alighted among someacacia trees at Waadi el Halboub, having gone twenty-one miles. We werehere at once surprised and terrified by a sight surely one of the mostmagnificent in the world. In that vast expanse of desert, from W. ToN. W. Of us, we saw a number of prodigious pillars of sand at differentdistances, at times moving with great celerity, at others stalking onwith a majestic slowness; at intervals we thought they were coming in avery few minutes to overwhelm us; and small quantities of sand didactually more than once reach us. Again they would retreat so as to bealmost out of sight, their tops reaching to the very clouds. There thetops often separated from the bodies; and these, once disjoined, dispersed in the air, and did not appear more. Sometimes they werebroken in the middle, as if struck with large cannon-shot. About noonthey began to advance with considerable swiftness upon us, the windbeing very strong at north. Eleven of them ranged along side of us aboutthe distance of three miles. The greatest diameter of the largestappeared to me at that distance as if it would measure ten feet. Theyretired from us with a wind at S. E. Leaving an impression upon my mindto which I can give no name, though surely one ingredient in it wasfear, with a considerable deal of wonder and astonishment. It was invain to think of flying; the swiftest horse, or fastest sailing ship, could be of no use to carry us out of this danger; and the fullpersuasion of this rivetted me as if to the spot where I stood. "The same appearance of moving pillars of sand presented themselves tous this day in form and disposition like those we had seen at WaadiHalboub, only they seemed to be more in number and less in size. Theycame several times in a direction close upon us, that is, I believe, within less than two miles. They began immediately after sun rise like athick wood and almost darkened the sun. His rays shining through themfor near an hour, gave them an appearance of pillars of fire. Our peoplenow became desperate, the Greeks shrieked out and said it was the day ofjudgment; Ismael pronounced it to be hell; and the Turcorories, that theworld was on fire. " Bruce's Travels, Vol. IV. P. 553, -555. From this account it would appear, that the eddies of wind were owing tothe long range of broken rocks, which bounded one side of the sandydesert, and bent the currents of air, which struck against their sides;and were thus like the eddies in a stream of water, which falls againstoblique obstacles. This explanation is probably the true one, as thesewhirl-winds were not attended with rain or lightening like the tornadoesof the West-Indies. ] IX. "GNOMES! whose fine forms, impassive as the air, 500 Shrink with soft sympathy for human care; Who glide unseen, on printless slippers borne, Beneath the waving grass, and nodding corn; Or lay your tiny limbs, when noon-tide warms, Where shadowy cowslips stretch their golden arms, --505 So mark'd on orreries in lucid signs, Star'd with bright points the mimic zodiac shines; Borne on fine wires amid the pictured skies With ivory orbs the planets set and rise; Round the dwarf earth the pearly moon is roll'd, 510 And the sun twinkling whirls his rays of gold. -- Call your bright myriads, march your mailed hosts, With spears and helmets glittering round the coasts; Thick as the hairs, which rear the Lion's mane, Or fringe the Boar, that bays the hunter-train;515 Watch, where proud Surges break their treacherous mounds, And sweep resistless o'er the cultured grounds; Such as erewhile, impell'd o'er Belgia's plain, Roll'd her rich ruins to the insatiate main; With piles and piers the ruffian waves engage, 520 And bid indignant Ocean stay his rage. [_So mark'd on orreries_. L. 505. The first orrery was constructed by aMr. Rowley, a mathematician born at Lichfield; and so named from hispatron the Earl of Orrery. Johnson's Dictionary. ] "Where, girt with clouds, the rifted mountain yawns, And chills with length of shade the gelid lawns, Climb the rude steeps, the granite-cliffs surround, Pierce with steel points, with wooden wedges wound;525 Break into clays the soft volcanic slaggs, Or melt with acid airs the marble craggs; Crown the green summits with adventurous flocks, And charm with novel flowers the wondering rocks. --So when proud Rome the Afric Warrior braved, 530 And high on Alps his crimson banner waved; While rocks on rocks their beetling brows oppose With piny forests, and unfathomed snows; Onward he march'd, to Latium's velvet ground With fires and acids burst the obdurate bound, 535 Wide o'er her weeping vales destruction hurl'd, And shook the rising empire of the world. [_The granite-cliffs. _ l. 523. On long exposure to air the granites orporphories of this country exhibit a ferrugenous crust, the iron beingcalcined by the air first becomes visible, and is then washed away fromthe external surface, which becomes white or grey, and thus in timeseems to decompose. The marbles seem to decompose by loosing theircarbonic acid, as the outside, which has been long exposed to the air, does not seem to effervesce so hastily with acids as the parts morerecently broken. The immense quantity of carbonic acid, which exists inthe many provinces of lime-stone, if it was extricated and decomposedwould afford charcoal enough for fuel for ages, or for the production ofnew vegetable or animal bodies. The volcanic slaggs on Mount Vesuviusare said by M. Ferber to be changed into clay by means of the sulphur-acid, and even pots made of clay and burnt or vitrified are said by himto be again reducible to ductile clay by the volcanic steams. Ferber'sTravels through Italy, p. 166. ] [_Wooden wedges wound_. L. 524. It is usual in seperating large mill-stones from the siliceous sand-rocks in some parts of Derbyshire to borehorizontal holes under them in a circle, and fill these with pegs madeof dry wood, which gradually swell by the moisture of the earth, and ina day or two lift up the mill-stone without breaking it. ] [_With fires and acids_. L. 534. Hannibal was said to erode his way overthe Alps by fire and vinegar. The latter is supposed to allude to thevinegar and water which was the beverage of his army. In respect to theformer it is not improbable, but where wood was to be had in greatabundance, that fires made round limestone precipices would calcine themto a considerable depth, the night-dews or mountain-mists wouldpenetrate these calcined parts and pulverize them by the force of thesteam which the generated heat would produce, the winds would dispersethis lime-powder, and thus by repeated fires a precipice of lime-stonemight be destroyed and a passage opened. It should be added, thataccording to Ferber's observations, these Alps consist of lime-stone. Letters from Italy. ] X. "Go, gentle GNOMES! resume your vernal toil, Seek my chill tribes, which sleep beneath the soil; On grey-moss banks, green meads, or furrow'd lands540 Spread the dark mould, white lime, and crumbling sands; Each bursting bud with healthier juices feed, Emerging scion, or awaken'd seed. So, in descending streams, the silver Chyle Streaks with white clouds the golden floods of bile;545 Through each nice valve the mingling currents glide, Join their fine rills, and swell the sanguine tide; Each countless cell, and viewless fibre seek, Nerve the strong arm, and tinge the blushing cheek. "Oh, watch, where bosom'd in the teeming earth, 550 Green swells the germ, impatient for its birth; Guard from rapacious worms its tender shoots, And drive the mining beetle from its roots; With ceaseless efforts rend the obdurate clay, And give my vegetable babes to day!555 --Thus when an Angel-form, in light array'd, Like HOWARD pierced the prison's noisome shade; Where chain'd to earth, with eyes to heaven upturn'd, The kneeling Saint in holy anguish mourn'd;-- Ray'd from his lucid vest, and halo'd brow560 O'er the dark roof celestial lustres glow, "PETER, arise!" with cheering voice He calls, And sounds seraphic echo round the walls; Locks, bolts, and chains his potent touch obey, And pleased he leads the dazzled Sage to day. 565 XI. "YOU! whose fine fingers fill the organic cells, With virgin earth, of woods and bones and shells; Mould with retractile glue their spongy beds, And stretch and strengthen all their fibre-threads. -- Late when the mass obeys its changeful doom, 570 And sinks to earth, its cradle and its tomb, GNOMES! with nice eye the slow solution watch, With fostering hand the parting atoms catch, Join in new forms, combine with life and sense, And guide and guard the transmigrating Ens. [_Mould with retractile glue_. L. 567. The constituent parts of animalfibres are believed to be earth and gluten. These do not seperate exceptby long putrefaction or by fire. The earth then effervesces with acids, and can only be converted into glass by the greatest force of fire. Thegluten has continued united with the earth of the bones above 2000 yearsin Egyptian mummies; but by long exposure to air or moisture itdiffolves and leaves only the earth. Hence bones long buried, whenexposed to the air, absorb moisture and crumble into powder. Phil. Trans. No. 475. The retractibility or elasticity of the animal fibredepends on the gluten; and of these fibres are composed the membranesmuscles and bones. Haller. Physiol. Tom. I, p. 2. For the chemical decomposition of animal and vegetable bodies see theingenious work of Lavoisier, Traité de Chimie, Tom. I. P. 132. Whoresolves all their component parts into oxygene, hydrogene, carbone, andazote, the three former of which belong principally to vegetable and thelast to animal matter. ] [_The transmigrating Ens_. L. 574, The perpetual circulation of matterin the growth and dissolution of vegetable and animal bodies seems tohave given Pythagoras his idea of the metempsycosis or transmigration ofspirit; which was afterwards dressed out or ridiculed in variety ofamusing fables. Other philosophers have supposed, that there are twodifferent materials or essences, which fill the universe. One of these, which has the power of commencing or producing motion, is called spirit;the other, which has the power of receiving and of communicating motion, but not of beginning it, is called matter. The former of these issupposed to be diffused through all space, filling up the interstices ofthe suns and planets, and constituting the gravitations of the siderealbodies, the attractions of chemistry, with the spirit of vegetation, andof animation. The latter occupies comparatively but small space, constituting the solid parts of the suns and planets, and theiratmospheres. Hence these philosophers have supposed, that both matterand spirit are equally immortal and unperishable; and that on thedissolution of vegetable or animal organization, the matter returns tothe general mass of matter; and the spirit to the general mass ofspirit, to enter again into new combinations, according to the originalidea of Pythagoras. The small apparent quantity of matter that exists in the universecompared to that of spirit, and the short time in which the recrementsof animal or vegetable bodies become again vivified in the forms ofvegetable mucor or microscopic insects, seems to have given rise toanother curious fable of antiquity. That Jupiter threw down a largehandful of souls upon the earth, and left them to scramble for the fewbodies which were to be had. ] 575 "So when on Lebanon's sequester'd hight The fair ADONIS left the realms of light, Bow'd his bright locks, and, fated from his birth To change eternal, mingled with the earth;-- With darker horror shook the conscious wood, 580 Groan'd the sad gales, and rivers blush'd with blood; On cypress-boughs the Loves their quivers hung, Their arrows scatter'd, and their bows unstrung; And BEAUTY'S GODDESS, bending o'er his bier, Breathed the soft sigh, and pour'd the tender tear. --585 Admiring PROSERPINE through dusky glades Led the fair phantom to Elysian shades, Clad with new form, with finer sense combined, And lit with purer flame the ethereal mind. --Erewhile, emerging from infernal night, 590 The bright Assurgent rises into light, Leaves the drear chambers of the insatiate tomb, And shines and charms with renovated bloom. -- While wondering Loves the bursting grave surround, And edge with meeting wings the yawning ground, 595 Stretch their fair necks, and leaning o'er the brink View the pale regions of the dead, and shrink; Long with broad eyes ecstatic BEAUTY stands, Heaves her white bosom, spreads her waxen hands; Then with loud shriek the panting Youth alarms, 600 "My Life! my Love!" and springs into his arms. " [_Adonis_. L. 576. The very antient story of the beautiful Adonispassing one half of the year with Venus, and the other with Proserpinealternately, has had variety of interpretations. Some have supposed thatit allegorized the summer and winter solstice; but this seems tooobvious a fact to have needed an hieroglyphic emblem. Others havebelieved it to represent the corn, which was supposed to sleep in theearth during the winter months, and to rise out of it in summer. Thisdoes not accord with the climate of Egypt, where the harvest soonfollows the seed-time. It seems more probably to have been a story explaining some hieroglyphicfigures representing the decomposition and resuscitation of animalmatter; a sublime and interesting subject, and which seems to have givenorigin to the doctrine of the transmigration, which had probably itsbirth also from the hieroglyphic treasures of Egypt. It is remarkablethat the cypress groves in the ancient greek writers, as in Theocritus, were dedicated to Venus; and afterwards became funereal emblems. Whichwas probably occasioned by the Cypress being an accompaniment of Venusin the annual processions, in which she was supposed to lament over thefuneral of Adonis; a ceremony which obtained over all the eastern worldfrom great antiquity, and is supposed to be referred to by Ezekiel, whoaccuses the idolatrous woman of weeping for Thammus. ] The GODDESS ceased, --the delegated throng O'er the wide plains delighted rush along; In dusky squadrons, and in shining groups, Hosts follow hosts, and troops succeed to troops;605 Scarce bears the bending grass the moving freight, And nodding florets bow beneath their weight. So when light clouds on airy pinions sail, Flit the soft shadows o'er the waving vale; Shade follows shade, as laughing Zephyrs drive, 610 And all the chequer'd landscape seems alive. [_Zephyrs drive_. L. 609. These lines were originally written thus, Shade follows shade by laughing Zephyrs drove, And all the chequer'd landscape seems to move. but were altered on account of the supposed false grammar in using theword drove for driven, according to the opinion of Dr. Lowth: at thesame time it may be observed, 1. That this is in many cases only anellipsis of the letter _n_ at the end of the word; as froze, for frozen;wove, for woven; spoke, for spoken; and that then the participleaccidentally becomes similar to the past tense: 2. That the languageseems gradually tending to omit the letter _n_ in other kind of wordsfor the sake of euphony; as housen is become houses; eyne, eyes; thine, thy, &c. And in common conversation, the words forgot, spoke, froze, rode, are frequently used for forgotten, spoken, frozen, ridden. 3. Itdoes not appear that any confusion would follow the indiscriminate useof the same word for the past tense and the participle passive, sincethe auxiliary verb _have_, or the preceding noun or pronoun alwaysclearly distinguishes them: and lastly, rhime-poetry must lose the useof many elegant words without this license. ] _Argument of the Third Canto. _ Address to the Nymphs. I. Steam rises from the ocean, floats in clouds, descends in rain and dew, or is condensed on hills, produces springs, and rivers, and returns to the sea. So the blood circulates through thebody and returns to the heart. 11. II. 1. Tides, 57. 2. Echinus, nautilus, pinna, cancer. Grotto of a mermaid. 65. 3. Oil stills thewaves. Coral rocks. Ship-worm, or Teredo. Maelstrome, a whirlpool on thecoast of Norway. 85. III. Rivers from beneath the snows on the Alps. TheTiber. 103. IV. Overflowing of the Nile from African Monsoons, 129. V. 1. Giesar, a boiling fountain in Iceland, destroyed by inundation, andconsequent earthquake, 145. 2. Warm medicinal springs. Buxton. Duke andDutchess of Devonshire. 157. VI. Combination of vital air andinflammable gas produces water. Which is another source of springs andrivers. Allegorical loves of Jupiter and Juno productive of vernalshowers. 201. VII. Aquatic Taste. Distant murmur of the sea by night. Sea-horse. Nereid singing. 261. VIII. The Nymphs of the river Derwentlament the death of Mrs. French, 297. IX. Inland navigation. Monumentfor Mr. Brindley, 341. X. Pumps explained. Child sucking. Mothersexhorted to nurse their children. Cherub sleeping. 365. XI. Engines forextinguishing fire. Story of two lovers perishing in the flames. 397. XII. Charities of Miss Jones, 447. XIII. Marshes drained. Herculesconquers Achilous. The horn of Plenty. 483. XIV. Showers. Dews. Floatinglands with water. Lacteal system in animals. Caravan drinking. 529. Departure of the Nymphs like water spiders; like northern nationsskaiting on the ice. 569. THE ECONOMY OF VEGETATION. CANTO III. AGAIN the GODDESS speaks!--glad Echo swells The tuneful tones along her shadowy dells, Her wrinkling founts with soft vibration shakes, Curls her deep wells, and rimples all her lakes, 5 Thrills each wide stream, Britannia's isle that laves, Her headlong cataracts, and circumfluent waves. --Thick as the dews, which deck the morning flowers, Or rain-drops twinkling in the sun-bright showers, Fair Nymphs, emerging in pellucid bands, 10 Rise, as she turns, and whiten all the lands. I. "YOUR buoyant troops on dimpling ocean tread, Wafting the moist air from his oozy bed, AQUATIC NYMPHS!--YOU lead with viewless march The winged vapours up the aerial arch, 15 On each broad cloud a thousand sails expand, And steer the shadowy treasure o'er the land, Through vernal skies the gathering drops diffuse, Plunge in soft rains, or sink in silver dews. -- YOUR lucid bands condense with fingers chill 20 The blue mist hovering round the gelid hill; In clay-form'd beds the trickling streams collect, Strain through white sands, through pebbly veins direct; Or point in rifted rocks their dubious way, And in each bubbling fountain rise to day. [_The winged vapours_. L. 14. See additional note No. XXV. Onevaporation. ] [_On each broad cloud_. L. 15. The clouds consist of condensed vapour, the particles of which are too small separately to overcome the tenacityof the air, and which therefore do not descend. They are in such smallspheres as to repel each other, that is, they are applied to each otherby such very small surfaces, that the attraction of the particles ofeach drop to its own centre is greater than its attraction to thesurface of the drop in its vicinity; every one has observed with whatdifficulty small spherules of quicksilver can be made to unite, owing tothe same cause; and it is common to see on riding through shallow wateron a clear day, numbers of very small spheres of water as they arethrown from the horses feet run along the surface for many yards beforethey again unite with it. In many cases these spherules of water, whichcompose clouds, are kept from uniting by a surplus of electric fluid;and fall in violent showers as soon as that is withdrawn from them, asin thunder storms. See note on Canto I. L. 553. If in this state a cloud becomes frozen, it is torn to pieces in itsdescent by the friction of the air, and falls in white flakes of snow. Or these flakes are rounded by being rubbed together by the winds, andby having their angles thawed off by the warmer air beneath as theydescend; and part of the water produced by these angles thus dissolvedis absorbed into the body of the hailstone, as may be seen by holding alump of snow over a candle, and there becomes frozen into ice by thequantity of cold which the hailstone possesses beneath the freezingpoint, or which is produced by its quick evaporation in falling; andthus hailstones are often found of greater or less density according asthey consist of a greater portion of snow or ice. If hailstonesconsisted of the large drops of showers frozen in their descent, theywould consist of pure transparent ice. As hail is only produced in summer, and is always attended with storms, some philosophers have believed that the sudden departure of electricityfrom a cloud may effect something yet unknown in this phenomenon; but itmay happen in summer independent of electricity, because the aqueousvapour is then raised higher in the atmosphere, whence it has further tofall, and there is warmer air below for it to fall through. ] [_Or sink in silver dews_. L. 18. During the coldness of the night themoisture before dissolved in the air is gradually precipitated, and asit subsides adheres to the bodies it falls upon. Where the attraction ofthe body to the particles of water is greater than the attractions ofthose particles to each other, it becomes spread upon their surface, orslides down them in actual contact; as on the broad parts of the bladesof moist grass: where the attraction of the surface to the water is lessthan the attraction of the particles of water to each other, the dewstands in drops; as on the points and edges of grass or gorse, where thesurface presented to the drop being small it attracts it so little asbut just to support it without much changing its globular form: wherethere is no attraction between the vegetable surface and the dew drops, as on cabbage leaves, the drop does not come into contact with the leaf, but hangs over it repelled, and retains it natural form, composed of theattraction and pressure of its own parts, and thence looks likequicksilver, reflecting light from both its surfaces. Nor is this owingto any oiliness of the leaf, but simply to the polish of its surface, asa light needle may be laid on water in the same manner without touchingit; for as the attractive powers of polished surfaces are greater whenin actual contact, so the repulsive power is greater before contact. ] [_The blue mist_. L. 20. Mists are clouds resting on the ground, theygenerally come on at the beginning of night, and either fill the moistvallies, or hang on the summits of hills, according to the degree ofmoisture previously dissolved, and the eduction of heat from them. Theair over rivers during the warmth of the day suspends much moisture, andas the changeful surface of rivers occasions them to cool sooner thanthe land at the approach of evening, mists are most frequently seen tobegin over rivers, and to spread themselves over moist grounds, and fillthe vallies, while the mists on the tops of mountains are more properlyclouds, condensed by the coldness of their situation. On ascending up the side of a hill from a misty valley, I have observeda beautiful coloured halo round the moon when a certain thickness ofmist was over me, which ceased to be visible as soon as I emerged out ofit; and well remember admiring with other spectators the shadow of thethree spires of the cathedral church at Lichfield, the moon risingbehind it, apparently broken off, and lying distinctly over our heads asif horizontally on the surface of the mist, which arose about as high asthe roof of the church. There are some curious remarks on shadows orreflexions seen on the surface of mists from high mountains in Ulloa'sVoyages. The dry mist of summer 1783, was probably occasioned byvolcanic eruption, as mentioned in note on Chunda, Vol. II. Andtherefore more like the atmosphere of smoke which hangs on still daysover great cities. There is a dry mist, or rather a diminished transparence of the air, which according to Mr. Saussure accompanies fair weather, while greattransparence of air indicates rain. Thus when large rivers two milesbroad, such as at Liverpool, appear narrow, it is said to prognosticaterain; and when wide, fair weather. This want of transparence of the airin dry weather, may be owing to new combinations or decompositions ofthe vapours dissolved in it, but wants further investigation. Essais surL'Hygromet, p. 357. ] [_Round the gelid hill_. L. 20. See additional notes, No. XXVI. On theorigin of springs. ] 25 "NYMPHS! YOU then guide, attendant from their source, The associate rills along their sinuous course; Float in bright squadrons by the willowy brink, Or circling slow in limpid eddies sink; Call from her crystal cave the Naiad-Nymph, 30 Who hides her fine form in the passing lymph, And, as below she braids her hyaline hair, Eyes her soft smiles reflected in the air; Or sport in groups with River-Boys, that lave Their silken limbs amid the dashing wave; 35 Pluck the pale primrose bending from its edge, Or tittering dance amid the whispering sedge. -- "Onward YOU pass, the pine-capt hills divide, Or feed the golden harvests on their side; The wide-ribb'd arch with hurrying torrents fill, 40 Shove the slow barge, or whirl the foaming mill. OR lead with beckoning hand the sparkling train Of refluent water to its parent main, And pleased revisit in their sea-moss vales Blue Nereid-forms array'd in shining scales, 45 Shapes, whose broad oar the torpid wave impels, And Tritons bellowing through their twisted shells. "So from the heart the sanguine stream distils, O'er Beauty's radiant shrine in vermil rills, Feeds each fine nerve, each slender hair pervades, 50 The skins bright snow with living purple shades, Each dimpling cheek with warmer blushes dyes, Laughs on the lips, and lightens in the eyes. --Erewhile absorb'd, the vagrant globules swim From each fair feature, and proportion'd limb, 55 Join'd in one trunk with deeper tint return To the warm concave of the vital urn. II. 1. "AQUATIC MAIDS! YOU sway the mighty realms Of scale and shell, which Ocean overwhelms; As Night's pale Queen her rising orb reveals, 60 And climbs the zenith with refulgent wheels, Car'd on the foam your glimmering legion rides, Your little tridents heave the dashing tides, Urge on the sounding shores their crystal course, Restrain their fury, or direct their force. [_Car'd on the foam_. L. 61. The phenomena of the tides have been wellinvestigated and satisfactorily explained by Sir Isaac Newton and Dr. Halley from the reciprocal gravitations of the earth, moon, and sun. Asthe earth and moon move round a centre of motion near the earth'ssurface, at the same time that they are proceeding in their annual orbitround the sun, it follows that the water on the side of the earthnearest this centre of motion between the earth and moon will be moreattracted by the moon, and the waters on the opposite side of the earthwill be less attracted by the moon, than the central parts of the earth. Add to this that the centrifugal force of the water on the side of theearth furthest from the centre of the motion, round which the earth andmoon move, (which, as was said before, is near the surface of the earth)is greater than that on the opposite side of the earth. From both thesecauses it is easy to comprehend that the water will rise on two sides ofthe earth, viz. On that nearest to the moon, and its opposite side, andthat it will be flattened in consequence at the quadratures, and thusproduce two tides in every lunar day, which consists of about twenty-four hours and forty-eight minutes. These tides will be also affected by the solar attraction when itcoincides with the lunar one, or opposes it, as at new and full moon, and will also be much influenced by the opposing shores in every part ofthe earth. Now as the moon in moving round the centre of gravity between itself andthe earth describes a much larger orbit than the earth describes roundthe same centre, it follows that the centrifugal motion on the side ofthe moon opposite to the earth must be much greater than the centrifugalmotion of the side of the earth opposite to the moon round the samecentre. And secondly, as the attraction of the earth exerted on themoon's surface next to the earth is much greater than the attraction ofthe moon exerted on the earth's surface, the tides on the lunar sea, (ifsuch there be, ) should be much greater than those of our ocean. Add tothis that as the same face of the moon always is turned to the earth, the lunar tides must be permanent, and if the solid parts of the moon bespherical, must always cover the phasis next to us. But as there areevidently hills and vales and volcanos on this side of the moon, theconsequence is that the moon has no ocean, or that it is frozen. ] 65 2. "NYMPHS! YOU adorn, in glossy volumes roll'd, The gaudy conch with azure, green, and gold. You round Echinus ray his arrowy mail, Give the keel'd Nautilus his oar and sail; Firm to his rock with silver cords suspend 70 The anchor'd Pinna, and his Cancer-friend; With worm-like beard his toothless lips array, And teach the unwieldy Sturgeon to betray. -- Ambush'd in weeds, or sepulcher'd in sands, In dread repose He waits the scaly bands, 75 Waves in red spires the living lures, and draws The unwary plunderers to his circling jaws, Eyes with grim joy the twinkling shoals beset, And clasps the quick inextricable net. You chase the warrior Shark, and cumberous Whale, 80 And guard the Mermaid in her briny vale; Feed the live petals of her insect-flowers, Her shell-wrack gardens, and her sea-fan bowers; With ores and gems adorn her coral cell, And drop a pearl in every gaping shell. [_The gaudy conch_. L. 66. The spiral form of many shells seem to haveafforded a more frugal manner of covering the long tail of the fish withcalcareous armour; since a single thin partition between the adjoiningcircles of the fish was sufficient to defend both surfaces, and thusmuch cretaceous matter is saved; and it is probable that from thisspiral form they are better enabled to feel the vibrations of theelement in which they exist. See note on Canto IV. L. 162. Thiscretaceous matter is formed by a mucous secretion from the skin of thefish, as is seen in crab-fish, and others which annually cast theirshells, and is at first a soft mucous covering, (like that of a hen'segg, when it is laid a day or two too soon, ) and which graduallyhardens. This may also be seen in common shell snails, if a part oftheir shell be broken it becomes repaired in a similar manner withmucus, which by degrees hardens into shell. It is probable the calculi or stones found in other animals may have asimilar origin, as they are formed on mucous membranes, as those of thekidney and bladder, chalk-stones in the gout, and gall-stones; and areprobably owing to the inflammation of the membrane where they areproduced, and vary according to the degree of inflammation of themembrane which forms them, and the kind of mucous which it naturallyproduces. Thus the shelly matter of different shell-fish differs, fromthe courser kinds which form the shells of crabs, to the finer kindswhich produces the mother-pearl. The beautiful colours of some shells originate from the thinness of thelaminae of which they consist, rather than to any colouring matter, asis seen in mother-pearl, which reflects different colours according tothe obliquity of the light which falls on it. The beautiful prismaticcolours seen on the Labrodore stone are owing to a similar cause, viz. The thinness of the laminae of which it consists, and has probably beenformed from mother-pearl shells. It is curious that some of the most common fossil shells are not nowknown in their recent state, as the cornua ammonis; and on the contrary, many shells which are very plentiful in their recent state, as limpets, sea-ears, volutes, cowries, are very rarely found fossil. Da Costa'sConchology, p. 163. Were all the ammoniae destroyed when the continentswere raised? Or do some genera of animals perish by the increasing powerof their enemies? Or do they still reside at inaccessible depths in thesea? Or do some animals change their forms gradually and become newgenera?] [_Echinus. Nautilus_. L. 67, 68. See additional notes, No. XXVII. ] [_Pinna. Cancer_. L. 70. See additional notes, No. XXVII. ] [_With worm-like beard_. L. 71. See additional notes, No. XXVIII. ] [_Feed the live petals_. L. 82. There is a sea-insect described by Mr. Huges whose claws or tentacles being disposed in regular circles andtinged with variety of bright lively colours represent the petals ofsome most elegantly fringed and radiated flowers as the carnation, marigold, and anemone. Philos. Trans. Abridg. Vol. IX. P. 110. The AbbeDicquemarre has further elucidated the history of the actinia; andobserved their manner of taking their prey by inclosing it in thesebeautiful rays like a net. Phil. Trans. Vol. LXIII. And LXV. And LXVII. ] [_And drop a pearl_. L. 84. Many are the opinions both of antient andmodern concerning the production of pearls. Mr. Reaumur thinks they areformed like the hard concretions in many land animals as stones of thebladder, gallstones, and bezoar, and hence concludes them to be adisease of the fish, but there seems to be a stricter analogy betweenthese and the calcareous productions found in crab-fish called crab'seyes, which are formed near the stomach of the animal, and constitute areservoir of calcareous matter against the renovation of the shell, atwhich time they are re-dissolved and deposited for that purpose. As theinternal part of the shell of the pearl oyster or muscle consists ofmother-pearl which is a similar material to the pearl and as the animalhas annually occasion to enlarge his shell there is reason to suspect theloose pearls are similar reservoirs of the pearly matter for thatpurpose. ] 85 3. "YOUR myriad trains o'er stagnant ocean's tow, Harness'd with gossamer, the loitering prow; Or with fine films, suspended o'er the deep, Of oil effusive lull the waves to sleep. You stay the flying bark, conceal'd beneath, 90 Where living rocks of worm-built coral breathe; Meet fell TEREDO, as he mines the keel With beaked head, and break his lips of steel; Turn the broad helm, the fluttering canvas urge From MAELSTROME'S fierce innavigable surge. 95 --'Mid the lorn isles of Norway's stormy main, As sweeps o'er many a league his eddying train, Vast watery walls in rapid circles spin, And deep-ingulph'd the Demon dwells within; Springs o'er the fear-froze crew with Harpy-claws, 100 Down his deep den the whirling vessel draws; Churns with his bloody mouth the dread repast, The booming waters murmuring o'er the mast. [_Or with fine films_. L. 87. See additional notes, No. XXIX. ] [_Where living rocks_. L. 90. The immense and dangerous rocks built bythe swarms of coral infects which rise almost perpendicularly in thesouthern ocean like walls are described in Cook's voyages, a point ofone of these rocks broke off and stuck in the hole which it had made inthe bottom of one of his ships, which would otherwise have perished bythe admission of water. The numerous lime-stone rocks which consist of acongeries of the cells of these animals and which constitute a greatpart of the solid earth shew their prodigious multiplication in all agesof the world. Specimens of these rocks are to be seen in the Lime-worksat Linsel near Newport in Shropshire, in Coal-brook Dale, and in manyparts of the Peak of Derbyshire. The insect has been well described byM. Peyssonnel, Ellis, and others. Phil. Trans. Vol. XLVII. L. LII. AndLVII. ] [_Meet fell Teredo_. L. 91. See additional notes, No. XXX. ] [_Turn the broad helm_. L 93. See additional notes, No. XXXI. ] III. "Where with chill frown enormous ALPS alarms A thousand realms, horizon'd in his arms;105 While cloudless suns meridian glories shed From skies of silver round his hoary head, Tall rocks of ice refract the coloured rays, And Frost sits throned amid the lambent blaze; NYMPHS! YOUR thin forms pervade his glittering piles, 110 His roofs of chrystal, and his glasy ailes; Where in cold caves imprisoned Naiads sleep, Or chain'd on mossy couches wake and weep; Where round dark crags indignant waters bend Through rifted ice, in ivory veins descend, 115 Seek through unfathom'd snows their devious track, Heave the vast spars, the ribbed granites crack, Rush into day, in foamy torrents shine, And swell the imperial Danube or the Rhine. -- Or feed the murmuring TIBER, as he laves120 His realms inglorious with diminish'd waves, Hears his lorn Forum sound with Eunuch-strains, Sees dancing slaves insult his martial plains; Parts with chill stream the dim religious bower, Time-mouldered bastion, and dismantled tower;125 By alter'd fanes and nameless villas glides, And classic domes, that tremble on his sides; Sighs o'er each broken urn, and yawning tomb, And mourns the fall of LIBERTY and ROME. [_Where round dark craggs_. L. 113. See additional notes, No. XXXII. ] [_Heave the vast spars_. L. 116. Water in descending down elevatedsituations if the outlet for it below is not sufficient for its emissionacts with a force equal to the height of the column, as is seen in anexperimental machine called the philosophical bellows, in which a fewpints of water are made to raise many hundred pounds. To this cause isto be ascribed many large promontories of ice being occasionally throwndown from the glaciers; rocks have likewise been thrown from the sidesof mountains by the same cause, and large portions of earth have beenremoved many hundred yards from their situations at the foot ofmountains. On inspecting the locomotion of about thirty acres of earthwith a small house near Bilder's Bridge in Shropshire, about twentyyears ago, from the foot of a mountain towards the river, I wellremember it bore all the marks of having been thus lifted up, pushedaway, and as it were crumpled into ridges, by a column of watercontained in the mountain. From water being thus confined in high columns between the strata ofmountainous countries it has often happened that when wells orperforations have been made into the earth, that springs have arisenmuch above the surface of the new well. When the new bridge was buildingat Dublin Mr. G. Semple found a spring in the bed of the river where hemeant to lay the foundation of a pierre, which, by fixing iron pipesinto it, he raised many feet. Treatise on Building in Water, by G. Semple. From having observed a valley north-west of St. Alkmond's wellnear Derby, at the head of which that spring of water once probablyexisted, and by its current formed the valley, (but which in after timesfound its way out in its present situation, ) I suspect that St. Alkmond's well might by building round it be raised high enough tosupply many streets in Derby with spring-water which are now onlysupplied with river-water. See an account of an artificial spring ofwater, Phil. Trans. Vol. LXXV. P. 1. In making a well at Sheerness the water rose 300 feet above its sourcein the well. Phil. Trans. Vol. LXXIV. And at Hartford in Connecticutthere is a well which was dug seventy feet deep before water was found, then in boring an augur-hole through a rock the water rose so fast as tomake it difficult to keep it dry by pumps till they could blow the holelarger by gunpowder, which was no sooner accomplished than it filled andrun over, and has been a brook for near a century. Travels throughAmerica. Lond. 1789. Lane. ] IV. "Sailing in air, when dark MONSOON inshrouds130 His tropic mountains in a night of clouds; Or drawn by whirlwinds from the Line returns, And showers o'er Afric all his thousand urns; High o'er his head the beams of SIRIUS glow, And, Dog of Nile, ANUBIS barks below. 135 NYMPHS! YOU from cliff to cliff attendant guide In headlong cataracts the impetuous tide; Or lead o'er wastes of Abyssinian sands The bright expanse to EGYPT'S shower-less lands. --Her long canals the sacred waters fill, 140 And edge with silver every peopled hill; Gigantic SPHINX in circling waves admire; And MEMNON bending o'er his broken lyre; O'er furrow'd glebes and green savannas sweep, And towns and temples laugh amid the deep. [_Dark monsoon inshrouds_. L. 129. When from any peculiar situations ofland in respect to sea the tropic becomes more heated, when the sun isvertical over it, than the line, the periodical winds called monsoonsare produced, and these are attended by rainy seasons; for as the air atthe tropic is now more heated than at the line it ascends by decrease ofits specific gravity, and floods of air rush in both from the South Westand North East, and these being one warmer than the other the rain isprecipitated by their mixture as observed by Dr. Hutton. See additionalnotes, No. XXV. All late travellers have ascribed the rise of the Nileto the monsoons which deluge Nubia and Abyssinia with rain. The whirlingof the ascending air was even seen by Mr. Bruce in Abyssinia; he says, "every morning a small cloud began to whirl round, and presently afterthe whole heavens became covered with clouds, " by this vortex ofascending air the N. E. Winds and the S. W. Winds, which flow in to supplythe place of the ascending column, became mixed more rapidly anddeposited their rain in greater abundance. Mr. Volney observes that the time of the rising of the Nile commencesabout the 19th of June, and that Abyssinia and the adjacent parts ofAfrica are deluged with rain in May, June, and July, and produce a massof water which is three months in draining off. The Abbe Le Plucheobserves that as Sirius, or the dog-star, rose at the time of thecommencement of the flood its rising was watched by the astronomers, andnotice given of the approach of inundation by hanging the figure ofAnubis, which was that of a man with a dog's head, upon all theirtemples. Histoire de Ciel. ] [Illustration: Fertilization of Egypt. ] [_Egypt's shower-less lands_. L. 138. There seem to be two situationswhich may be conceived to be exempted from rain falling upon them, onewhere the constant trade-winds meet beneath the line, for here tworegions of warm air are mixed together, and thence do not seem to haveany cause to precipitate their vapour; and the other is, where the windsare brought from colder climates and become warmer by their contact withthe earth of a warmer one. Thus Lower Egypt is a flat country warmed bythe sun more than the higher lands of one side of it, and than theMediterranean on the other; and hence the winds which blow over itacquire greater warmth, which ever way they come, than they possessedbefore, and in consequence have a tendency to acquire and not to partwith their vapour like the north-east winds of this country. There issaid to be a narrow spot upon the coast of Peru where rain seldomoccurs, at the same time according to Ulloa on the mountainous regionsof the Andes beyond there is almost perpetual rain. For the wind blowsuniformly upon this hot part of the coast of Peru, but no cause ofdevaporation occurs till it begins to ascend the mountainous Andes, andthen its own expansion produces cold sufficient to condense its vapour. ] 145 V. 1. "High in the frozen North where HECCLA glows, And melts in torrents his coeval snows; O'er isles and oceans sheds a sanguine light, Or shoots red stars amid the ebon night; When, at his base intomb'd, with bellowing sound150 Fell GIESAR roar'd, and struggling shook the ground; Pour'd from red nostrils, with her scalding breath, A boiling deluge o'er the blasted heath; And, wide in air, in misty volumes hurl'd Contagious atoms o'er the alarmed world;155 NYMPHS! YOUR bold myriads broke the infernal spell, And crush'd the Sorceress in her flinty cell. [_Fell Giesar roar'd_. L. 150. The boiling column of water at Giesar inIceland was nineteen feet in diameter, and sometimes rose to the heightof ninety-two feet. On cooling it deposited a siliceous matter orchalcedony forming a bason round its base. The heat of this water beforeit rose out of the earth could not be ascertained, as water looses allits heat above 212 (as soon as it is at liberty to expand) by theexhalation of a part, but the flinty bason which is deposited from itshews that water with great degrees of heat will dissolve siliceousmatter. Van Troil's Letters on Iceland. Since the above account in theyear 1780 this part of Iceland has been destroyed by an earthquake orcovered with lava, which was probably effected by the force of aqueoussteam, a greater quantity of water falling on the subterraneous firesthan could escape by the antient outlets and generating an increasedquantity of vapour. For the dispersion of contagious vapours fromvolcanos see an account of the Harmattan in the notes on Chunda, Vol. II. ] 2. "Where with soft fires in unextinguish'd urns, Cauldron'd in rock, innocuous Lava burns; On the bright lake YOUR gelid hands distil160 In pearly mowers the parsimonious rill; And, as aloft the curling vapours rise Through the cleft roof, ambitious for the skies, In vaulted hills condense the tepid steams, And pour to HEALTH the medicated streams. 165 --So in green vales amid her mountains bleak BUXTONIA smiles, the Goddess-Nymyh of Peak; Deep in warm waves, and pebbly baths she dwells, And calls HYGEIA to her sainted wells. [_Buxtonia smiles_. L. 166. Some arguments are mentioned in the note onFucus Vol. II. To shew that the warm springs of this country do notarise from the decomposition of pyrites near the surface of the earth, but that they are produced by steam rising up the fissures of themountains from great depths, owing to water falling on subterraneousfires, and that this steam is condensed between the strata of theincumbent mountains and collected into springs. For further proofs onthis subject the reader is referred to a Letter from Dr. Darwin in Mr. Pilkington's View of Derbyshire, Vol I. P. 256. ] "Hither in sportive bands bright DEVON leads170 Graces and Loves from Chatsworth's flowery meads. -- Charm'd round the NYMPH, they climb the rifted rocks; And steep in mountain-mist their golden locks; On venturous step her sparry caves explore, And light with radiant eyes her realms of ore;175 --Oft by her bubbling founts, and shadowy domes, In gay undress the fairy legion roams, Their dripping palms in playful malice fill, Or taste with ruby lip the sparkling rill; Croud round her baths, and, bending o'er the side, 180 Unclasp'd their sandals, and their zones untied, Dip with gay fear the shuddering foot undress'd, And quick retract it to the fringed vest; Or cleave with brandish'd arms the lucid stream, And sob, their blue eyes twinkling in the steam. 185 --High o'er the chequer'd vault with transient glow Bright lustres dart, as dash the waves below; And Echo's sweet responsive voice prolongs The dulcet tumult of their silver tongues. -- O'er their flush'd cheeks uncurling tresses flow, 190 And dew-drops glitter on their necks of snow; Round each fair Nymph her dropping mantle clings, And Loves emerging shake their showery wings. [_And sob, their blue eyes_. L. 184. The bath at Buxton being of 82degrees of heat is called a warm bath, and is so compared with commonspring-water which possesses but 48 degrees of heat, but is neverthelessa cold bath compared to the heat of the body which is 98. On going intothis bath there is therefore always a chill perceived at the firstimmersion, but after having been in it a minute the chill ceases and asensation of warmth succeeds though the body continues to be immersed inthe water. The cause of this curious phenomenon is to be looked for inthe laws of animal sensation and not from any properties of heat. When aperson goes from clear day-light into an obscure room for a while itappears gloomy, which gloom however in a little time ceases, and thedeficiency of light becomes no longer perceived. This is not solelyowing to the enlargement of the iris of the eye, since that is performedin an instant, but to this law of sensation, that when a less stimulusis applied (within certain bounds) the sensibility increases. Thus atgoing into a bath as much colder than the body as that of Buxton, thediminution of heat on the skin is at first perceived, but in about aminute the sensibility to heat increases and the nerves of the skin areequally excited by the lessened stimulus. The sensation of warmth atemerging from a cold-bath, and the pain called the hot-ach, after thehands have been immersed in snow, depend on the same principle, viz. Theincreased sensibility of the skin after having been previously exposedto a stimulus less than usual. ] "Here oft her LORD surveys the rude domain, Fair arts of Greece triumphant in his train;195 LO! as he steps, the column'd pile ascends, The blue roof closes, or the crescent bends; New woods aspiring clothe their hills with green, Smooth slope the lawns, the grey rock peeps between; Relenting Nature gives her hand to Taste, 200 And Health and Beauty crown the laughing waste. [_Here oft her Lord_. L. 193. Alluding to the magnificent and beautifulcrescent, and superb stables lately erected at Buxton for theaccomodation of the company by the Duke of Devonshire; and to theplantations with which he has decorated the surrounding mountains. ] VI. "NYMPHS! YOUR bright squadrons watch with chemic eyes The cold-elastic vapours, as they rise; With playful force arrest them as they pass, And to _pure_ AIR betroth the _flaming_ GAS. 205 Round their translucent forms at once they fling Their rapturous arms, with silver bosoms cling; In fleecy clouds their fluttering wings extend, Or from the skies in lucid showers descend; Whence rills and rivers owe their secret birth, 210 And Ocean's hundred arms infold the earth. [_And to pure air_. L. 204. Until very lately water was esteemed asimple element, nor are all the most celebrated chemists of Europe yetconverts to the new opinion of its decomposition. Mr. Lavoisier andothers of the French school have most ingeniously endeavoured to shewthat water consists of pure air, called by them oxygene, and ofinflammable air, called hydrogene, with as much of the matter of heat, or calorique, as is necessary to preserve them in the form of gas. Gasis distinguished from steam by its preserving its elasticity under thepressure of the atmosphere, and in the greatest degrees of cold yetknown. The history of the progress of this great discovery is detailedin the Memoires of the Royal Academy for 1781, and the experimentalproofs of it are delivered in Lavoisier's Elements of Chemistry. Theresults of which are that water consists of eighty-five parts by weightof oxygene, and fifteen parts by weight of hydrogene, with a sufficientquantity of Calorique. Not only numerous chemical phenomena, but manyatmospherical and vegetable facts receive clear and beautifulelucidation from this important analysis. In the atmosphere inflammableair is probably perpetually uniting with vital air and producingmoisture which descends in dews and showers, while the growth ofvegetables by the assistance of light is perpetually again decomposingthe water they imbibe from the earth, and while they retain theinflammable air for the formation of oils, wax, honey, resin, &c. Theygive up the vital air to replenish the atmosphere. ] "So, robed by Beauty's Queen, with softer charms SATURNIA woo'd the Thunderer to her arms; O'er her fair limbs a veil of light she spread, And bound a starry diadem on her head;215 Long braids of pearl her golden tresses grac'd, And the charm'd CESTUS sparkled round her waist. --Raised o'er the woof, by Beauty's hand inwrought, Breathes the soft Sigh, and glows the enamour'd Thought; Vows on light wings succeed, and quiver'd Wiles, 220 Assuasive Accents, and seductive Smiles. --Slow rolls the Cyprian car in purple pride, And, steer'd by LOVE, ascends admiring Ide; Climbs the green slopes, the nodding woods pervades, Burns round the rocks, or gleams amid the shades. 225 --Glad ZEPHYR leads the train, and waves above The barbed darts, and blazing torch of Love; Reverts his smiling face, and pausing flings Soft showers of roses from aurelian wings. Delighted Fawns, in wreathes of flowers array'd, 230 With tiptoe Wood-Boys beat the chequer'd glade; Alarmed Naiads, rising into air, Lift o'er their silver urns their leafy hair; Each to her oak the bashful Dryads shrink, And azure eyes are seen through every chink. 235 --LOVE culls a flaming shaft of broadest wing, And rests the fork upon the quivering string; Points his arch eye aloft, with fingers strong Draws to his curled ear the silken thong; Loud twangs the steel, the golden arrow flies, 240 Trails a long line of lustre through the skies; "'Tis done!" he shouts, "the mighty Monarch feels!" And with loud laughter shakes the silver wheels; Bends o'er the car, and whirling, as it moves, His loosen'd bowstring, drives the rising doves. 245 --Pierced on his throne the slarting Thunderer turns, Melts with soft sighs, with kindling rapture burns; Clasps her fair hand, and eyes in fond amaze The bright Intruder with enamour'd gaze. "And leaves my Goddess, like a blooming bride, 250 "The fanes of Argos for the rocks of Ide? "Her gorgeous palaces, and amaranth bowers, "For cliff-top'd mountains, and aerial towers?" He said; and, leading from her ivory seat The blushing Beauty to his lone retreat, 255 Curtain'd with night the couch imperial shrouds, And rests the crimson cushions upon clouds. -- Earth feels the grateful influence from above, Sighs the soft Air, and Ocean murmurs love; Etherial Warmth expands his brooding wing, 260 And in still showers descends the genial Spring. [_And steer'd by love_. L. 222. The younger love, or Cupid, the son ofVenus, owes his existence and his attributes to much later times thanthe Eros, or divine love, mentioned in Canto I. Since the former is nowhere mentioned by Homer, though so many apt opportunities ofintroducing him occur in the works of that immortal bard. Bacon. ] [_And in still showers. _ l. 260. The allegorical interpretation of thevery antient mythology which supposes Jupiter to represent the superiorpart of the atmosphere or ether, and Juno the inferior air, and that theconjunction of these two produces vernal showers, as alluded to inVirgil's Georgics, is so analogous to the present important discovery ofthe production of water from pure air, or oxygene, and inflammable air, or hydrogene, (which from its greater levity probably resides over theformer, ) that one should be tempted to believe that the very antientchemists of Egypt had discovered the composition of water, and thusrepresented it in their hieroglyphic figures before the invention ofletters. In the passage of Virgil Jupiter is called ether, and descends inprolific showers on the bosom of Juno, whence the spring succeeds andall nature rejoices. Tum pater omnipotens foecundis imbribus Aether Conjugis in gremium laetae descendit, et omnes Magnus alit, magno commixtus corpore, faetus. Virg. Georg. Lib. II. L. 325. ] VII. "NYMPHS OF AQUATIC TASTE! whose placid smile Breathes sweet enchantment o'er BRITANNIA'S isle; Whose sportive touch in showers resplendent flings Her lucid cataracts, and her bubbling springs;265 Through peopled vales the liquid silver guides, And swells in bright expanse her freighted tides. YOU with nice ear, in tiptoe trains, pervade Dim walks of morn or evening's silent shade; Join the lone Nightingale, her woods among, 270 And roll your rills symphonious to her song; Through fount-full dells, and wave-worn valleys move, And tune their echoing waterfalls to love; Or catch, attentive to the distant roar, The pausing murmurs of the dashing shore;275 Or, as aloud she pours her liquid strain, Pursue the NEREID on the twilight main. --Her playful Sea-horse woos her soft commands, Turns his quick ears, his webbed claws expands, His watery way with waving volutes wins, 280 Or listening librates on unmoving fins. The Nymph emerging mounts her scaly seat, Hangs o'er his glossy sides her silver feet, With snow-white hands her arching veil detains, Gives to his slimy lips the slacken'd reins, 285 Lifts to the star of Eve her eye serene, And chaunts the birth of Beauty's radiant Queen. -- O'er her fair brow her pearly comb unfurls Her beryl locks, and parts the waving curls, Each tangled braid with glistening teeth unbinds290 And with the floating treasure musks the winds. -- Thrill'd by the dulcet accents, as she sings, The rippling wave in widening circles rings; Night's shadowy forms along the margin gleam With pointed ears, or dance upon the stream;295 The Moon transported stays her bright career, And maddening Stars shoot headlong from the sphere. [_Her playful seahorse. _ l. 277. Described form an antique gem. ] VIII. "NYMPHS! whose fair eyes with vivid lustres glow For human weal, and melt at human woe; Late as YOU floated on your silver shells, 300 Sorrowing and slow by DERWENT'S willowy dells; Where by tall groves his foamy flood he steers Through ponderous arches o'er impetuous wears, By DERBY'S shadowy towers reflective sweeps, And gothic grandeur chills his dusky deeps;305 You pearl'd with Pity's drops his velvet sides, Sigh'd in his gales, and murmur'd in his tides, Waved o'er his fringed brink a deeper gloom, And bow'd his alders o'er MILCENA'S tomb. [_O'er Milcena's tomb_. L. 308. In memory of Mrs. French, a lady who tomany other elegant accomplishments added a proficiency in botany andnatural history. ] "Oft with sweet voice She led her infant-train, 310 Printing with graceful step his spangled plain, Explored his twinkling swarms, that swim or fly, And mark'd his florets with botanic eye. -- "Sweet bud of Spring! how frail thy transient bloom, "Fine film, " she cried, "of Nature's fairest loom!315 "Soon Beauty fades upon its damask throne!"-- --Unconscious of the worm, that mined her own!-- --Pale are those lips, where soft caresses hung, Wan the warm cheek, and mute the tender tongue, Cold rests that feeling heart on Derwent's shore, 320 And those love-lighted eye-balls roll no more! --HERE her sad Consort, stealing through the gloom Of Hangs in mute anguish o'er the scutcheon'd hearse, Or graves with trembling style the votive verse. 325 "Sexton! oh, lay beneath this sacred shrine, When Time's cold hand shall close my aching eyes, Oh, gently lay this wearied earth of mine, Where wrap'd in night my loved MILCENA lies. "So shall with purer joy my spirit move, 330 When the last trumpet thrills the caves of Death, Catch the first whispers of my waking love, And drink with holy kiss her kindling breath. "The spotless Fair, with blush ethereal warm, Shall hail with sweeter smile returning day, 335 Rise from her marble bed a brighter form, And win on buoyant step her airy way. "Shall bend approved, where beckoning hosts invite, On clouds of silver her adoring knee, Approach with Seraphim the throne of light, 340 --And BEAUTY plead with angel-tongue for Me!" IX. "YOUR virgin trains on BRINDLEY'S cradle smiled, And nursed with fairy-love the unletter'd child, Spread round his pillow all your secret spells, Pierced all your springs, and open'd all your wells. --345 As now on grass, with glossy folds reveal'd, Glides the bright serpent, now in flowers conceal'd; Far shine the scales, that gild his sinuous back, And lucid undulations mark his track; So with strong arm immortal BRINDLEY leads350 His long canals, and parts the velvet meads; Winding in lucid lines, the watery mass Mines the firm rock, or loads the deep morass, With rising locks a thousand hills alarms, Flings o'er a thousand streams its silver arms, 355 Feeds the long vale, the nodding woodland laves, And Plenty, Arts, and Commerce freight the waves. --NYMPHS! who erewhile round BRINDLEY'S early bier On show-white bosoms shower'd the incessant tear, Adorn his tomb!--oh, raise the marble bust, 360 Proclaim his honours, and protect his dust! With urns inverted, round the sacred shrine Their ozier wreaths let weeping Naiads twine; While on the top MECHANIC GENIUS stands, Counts the fleet waves, and balances the lands. [_On Brindley's cradle smiled_. L. 341. The life of Mr. Brindley, whosegreat abilities in the construction of canal navigation were calledforth by the patronage of the Duke of Bridgwater, may be read in Dr. Kippis's Biographia Britannica, the excellence of his genius is visiblein every part of this island. He died at Turnhurst in Staffordshire in1772, and ought to have a monument in the cathedral church atLichfield. ] 365 X. "NYMPHS! YOU first taught to pierce the secret caves Of humid earth, and lift her ponderous waves; Bade with quick stroke the sliding piston bear The viewless columns of incumbent air;-- Press'd by the incumbent air the floods below, 370 Through opening valves in foaming torrents flow, Foot after foot with lessen'd impulse move, And rising seek the vacancy above. -- So when the Mother, bending o'er his charms, Clasps her fair nurseling in delighted arms;375 Throws the thin kerchief from her neck of snow, And half unveils the pearly orbs below; With sparkling eye the blameless Plunderer owns Her soft embraces, and endearing tones, Seeks the salubrious fount with opening lips, 380 Spreads his inquiring hands, and smiles, and sips. [_Lift her ponderous waves_. L. 366. The invention of the pump is ofvery antient date, being ascribed to one Ctesebes an Athenian, whence itwas called by the Latins machina Ctesebiana; but it was long before itwas known that the ascent of the piston lifted the superincumbent columnof the atmosphere, and that then the pressure of the surrounding air onthe surface of the well below forced the water up into the vacuum, andthat on that account in the common lifting pump the water would riseonly about thirty-five feet, as the weight of such a column of water wasin general an equipoise to the surrounding atmosphere. The foamyappearance of water, when the pressure of the air over it is diminished, is owing to the expansion and escape of the air previously dissolved byit, or existing in its pores. When a child first sucks it only pressesor champs the teat, as observed by the great Harvey, but afterwards itlearns to make an incipient vacuum in its mouth, and acts by removingthe pressure of the atmosphere from the nipple, like a pump. ] "CONNUBIAL FAIR! whom no fond transport warms To lull your infant in maternal arms; Who, bless'd in vain with tumid bosoms, hear His tender wailings with unfeeling ear;385 The soothing kiss and milky rill deny To the sweet pouting lip, and glistening eye!-- Ah! what avails the cradle's damask roof, The eider bolster, and embroider'd woof!-- Oft hears the gilded couch unpity'd plains, 390 And many a tear the tassel'd cushion stains! No voice so sweet attunes his cares to rest, So soft no pillow, as his Mother's breast!-- --Thus charm'd to sweet repose, when twilight hours Shed their soft influence on celestial bowers, 395 The Cherub, Innocence, with smile divine Shuts his white wings, and sleeps on Beauty's shrine. [_Ah! what avails_. L. 387. From an elegant little poem of Mr. Jerningham's intitled Il Latte, exhorting ladies to nurse their ownchildren. ] XI. "From dome to dome when flames infuriate climb, Sweep the long street, invest the tower sublime; Gild the tall vanes amid the astonish'd night, 400 And reddening heaven returns the sanguine light; While with vast strides and bristling hair aloof Pale Danger glides along the falling roof; And Giant Terror howling in amaze Moves his dark limbs across the lurid blaze. 405 NYMPHS! you first taught the gelid wave to rise Hurl'd in resplendent arches to the skies; In iron cells condensed the airy spring, And imp'd the torrent with unfailing wing; --On the fierce flames the shower impetuous falls, 410 And sudden darkness shrouds the shatter'd walls; Steam, smoak, and dust in blended volumes roll, And Night and Silence repossess the Pole. -- [_Hurl'd in resplendent arches_. L. 406. The addition of an air-cell tomachines for raising water to extinguish fire was first introduced byMr. Newsham of London, and is now applied to similar engines for washingwall-trees in gardens, and to all kinds of forcing pumps, and might beapplied with advantage to lifting pumps where the water is brought froma great distance horizontally. Another kind of machine was invented byone Greyl, in which a vessel of water was every way dispersed by theexplosion of gun-powder lodging in the centre of it, and lighted by anadapted match; from this idea Mr. Godfrey proposed a water-bomb ofsimilar construction. Dr. Hales to prevent the spreading of fireproposed to cover the floors and stairs of the adjoining houses withearth; Mr. Hartley proposed to prevent houses from taking fire bycovering the cieling with thin iron-plates, and Lord Mahon by a bed ofcoarse mortar or plaister between the cieling and floor above it. Maynot this age of chemical science discover some method of injecting orsoaking timber with lime-water and afterwards with vitriolic acid, andthus fill its pores with alabaster? or of penetrating it with siliceousmatter, by processes similar to those of Bergman and Achard? SeeCronstadt's Mineral. 2d. Edit. Vol. I. P. 222. ] "Where were ye, NYMPHS! in those disasterous hours, Which wrap'd in flames AUGUSTA'S sinking towers?415 Why did ye linger in your wells and groves, When sad WOODMASON mourn'd her infant loves? When thy fair Daughters with unheeded screams, Ill-fated MOLESWORTH! call'd the loitering streams?-- The trembling Nymph on bloodless fingers hung420 Eyes from the tottering wall the distant throng, With ceaseless shrieks her sleeping friends alarms, Drops with singed hair into her lover's arms. -- The illumin'd Mother seeks with footsteps fleet, Where hangs the safe balcony o'er the street, 425 Wrap'd in her sheet her youngest hope suspends, And panting lowers it to her tiptoe friends; Again she hurries on affection's wings, And now a third, and now a fourth, she brings; Safe all her babes, she smooths her horrent brow, 430 And bursts through bickering flames, unscorch'd, below. So, by her Son arraign'd, with feet unshod O'er burning bars indignant Emma trod. [Footnote: _Woodmason, Molesworth_. L. 416. The histories of theseunfortunate families may be seen in the Annual Register, or in theGentleman's Magazine. ] "E'en on the day when Youth with Beauty wed, The flames surprized them in their nuptial bed;--435 Seen at the opening sash with bosom bare, With wringing hands, and dark dishevel'd hair, The blushing Beauty with disorder'd charms Round her fond lover winds her ivory arms; Beat, as they clasp, their throbbing hearts with fear, 440 And many a kiss is mix'd with many a tear;-- Ah me! in vain the labouring engines pour Round their pale limbs the ineffectual shower!-- --Then crash'd the floor, while shrinking crouds retire, And Love and Virtue sunk amid the fire!--445 With piercing screams afflicted strangers mourn, And their white ashes mingle in their urn. XII. "PELLUCID FORMS! whose crystal bosoms show The shine of welfare, or the shade of woe; Who with soft lips salute returning Spring, 450 And hail the Zephyr quivering on his wing; Or watch, untired, the wintery clouds, and share With streaming eyes my vegetable care; Go, shove the dim mist from the mountain's brow, Chase the white fog, which floods the vale below;455 Melt the thick snows, that linger on the lands, And catch the hailstones in your little hands; Guard the coy blossom from the pelting shower, And dash the rimy spangles from the bower; From each chill leaf the silvery drops repel, 460 And close the timorous floret's golden bell. [_Shove the dim mist_. L. 453. See note on l. 20 of this Canto. ] [_Catch the hail-stones_. L. 456. See note on l. 15 of this Canto. ] [_From each chill leaf_. L. 459. The upper side of the leaf is the organof vegetable respiration, as explained in the additional notes, No. XXXVII, hence the leaf is liable to injury from much moisture on thissurface, and is destroyed by being smeared with oil, in these respectsresembling the lungs of animals or the spiracula of insects. To preventthese injuries some leaves repel the dew-drops from their upper surfacesas those of cabbages; other vegetables close the upper surfaces of theirleaves together in the night or in wet weather, as the sensitive plant;others only hang their leaves downwards so as to shoot the wet fromthem, as kidney-beans, and many trees. See note on l. 18 of this Canto. ] [_Golden bell_. L. 460. There are muscles placed about the footstalks ofthe leaves or leaflets of many plants, for the purpose of closing theirupper surfaces together, or of bending them down so as to shoot off theshowers or dew-drops, as mentioned in the preceeding note. The claws ofthe petals or of the divisions of the calyx of many flowers arefurnished in a similar manner with muscles, which are exerted to open orclose the corol and calyx of the flower as in tragopogon, anemone. Thisaction of opening and closing the leaves or flowers does not appear tobe produced simply by _irritation_ on the muscles themselves, but by theconnection of those muscles with a _sensitive_ sensorium or brainexisting in each individual bud or flower. 1st. Because many flowersclose from the defect of stimulus, not by the excess of it, as bydarkness, which is the absence of the stimulus of light; or by cold, which is the absence of the stimulus of heat. Now the defect of heat, orthe absence of food, or of drink, affects our _sensations_, which hadbeen previously accustomed to a greater quantity of them; but a musclecannot be said to be stimulated into action by a defect of stimulus. 2. Because the muscles around the footstalks of the subdivisions of theleaves of the sensitive plant are exerted when any injury is offered tothe other extremity of the leaf, and some of the stamens of the flowersof the class Syngenesia contract themselves when others are irritated. See note on Chondrilla, Vol. II. Of this work. From this circumstance the contraction of the muscles of vegetablesseems to depend on a disagreeable _sensation_ in some distant part, andnot on the _irritation_ of the muscles themselves. Thus when a particleof dust stimulates the ball of the eye, the eye-lids are instantlyclosed, and when too much light pains the retina, the muscles of theiris contract its aperture, and this not by any connection or consent ofthe nerves of those parts, but as an effort to prevent or to remove adisagreeable sensation, which evinces that vegetables are endued withsensation, or that each bud has a common sensorium, and is furnishedwith a brain or a central place where its nerves were connected. ] "So should young SYMPATHY, in female form, Climb the tall rock, spectatress of the storm; Life's sinking wrecks with secret sighs deplore, And bleed for others' woes, Herself on shore;465 To friendless Virtue, gasping on the strand, Bare her warm heart, her virgin arms expand, Charm with kind looks, with tender accents cheer, And pour the sweet consolatory tear; Grief's cureless wounds with lenient balms asswage, 470 Or prop with firmer staff the steps of Age; The lifted arm of mute Despair arrest, And snatch the dagger pointed to his breast; Or lull to slumber Envy's haggard mien, And rob her quiver'd shafts with hand unseen. 475 --Sound, NYMPHS OF HELICON! the trump of Fame, And teach Hibernian echoes JONES'S name; Bind round her polish'd brow the civic bay, And drag the fair Philanthropist to day. -- So from secluded springs, and secret caves, 480 Her Liffy pours his bright meandering waves, Cools the parch'd vale, the sultry mead divides, And towns and temples star his shadowy sides. [_Jones's name_. L. 476. A young lady who devotes a great part of anample fortune to well chosen acts of secret charity. ] XIII. "CALL YOUR light legions, tread the swampy heath, Pierce with sharp spades the tremulous peat beneath;485 With colters bright the rushy sward bisect, And in new veins the gushing rills direct;-- So flowers shall rise in purple light array'd, And blossom'd orchards stretch their silver shade; Admiring glebes their amber ears unfold, 490 And Labour sleep amid the waving gold. "Thus when young HERCULES with firm disdain Braved the soft smiles of Pleasure's harlot train; To valiant toils his forceful limbs assign'd, And gave to Virtue all his mighty mind, 495 Fierce ACHELOUS rush'd from mountain-caves, O'er sad Etolia pour'd his wasteful waves, O'er lowing vales and bleating pastures roll'd, Swept her red vineyards, and her glebes of gold, Mined all her towns, uptore her rooted woods, 500 And Famine danced upon the shining floods. The youthful Hero seized his curled crest, And dash'd with lifted club the watery Pest; With waving arm the billowy tumult quell'd, And to his course the bellowing Fiend repell'd. [_Fierce Achelous_. L. 495. The river Achelous deluged Etolia, by one ofits branches or arms, which in the antient languages are called horns, and produced famine throughout a great tract of country, this wasrepresented in hieroglyphic emblems by the winding course of a serpentand the roaring of a bull with large horns. Hercules, or the emblem ofstrength, strangled the serpent, and tore off one horn from the bull;that is, he stopped and turned the course of one arm of the river, andrestored plenty to the country. Whence the antient emblem of the horn ofplenty. Dict. Par M. Danet. ] 505 "Then to a Snake the finny Demon turn'd His lengthen'd form, with scales of silver burn'd; Lash'd with restless sweep his dragon-train, And shot meandering o'er the affrighted plain. The Hero-God, with giant fingers clasp'd510 Firm round his neck, the hissing monster grasp'd; With starting eyes, wide throat, and gaping teeth, Curl his redundant folds, and writhe in death. "And now a Bull, amid the flying throng The grisly Demon foam'd, and roar'd along;515 With silver hoofs the flowery meadows spurn'd, Roll'd his red eye, his threatening antlers turn'd. Dragg'd down to earth, the Warrior's victor-hands Press'd his deep dewlap on the imprinted sands; Then with quick bound his bended knee he fix'd520 High on his neck, the branching horns betwixt, Strain'd his strong arms, his sinewy shoulders bent, And from his curled brow the twisted terror rent. --Pleased Fawns and Nymphs with dancing step applaud, And hang their chaplets round the resting God;525 Link their soft hands, and rear with pausing toil The golden trophy on the furrow'd soil; Fill with ripe fruits, with wreathed flowers adorn, And give to PLENTY her prolific horn. [_Dragg'd down to earth_. L. 517. Described from an antique gem. ] XIV. "On Spring's fair lap, CERULEAN SISTERS! pour530 From airy urns the sun-illumined shower, Feed with the dulcet drops my tender broods, Mellifluous flowers, and aromatic buds; Hang from each bending grass and horrent thorn The tremulous pearl, that glitters to the morn;535 Or where cold dews their secret channels lave, And Earth's dark chambers hide the stagnant wave, O, pierce, YE NYMPHS! her marble veins, and lead Her gushing fountains to the thirsty mead; Wide o'er the shining vales, and trickling hills540 Spread the bright treasure in a thousand rills. So shall my peopled realms of Leaf and Flower Exult, inebriate with the genial shower; Dip their long tresses from the mossy brink, With tufted roots the glassy currents drink;545 Shade your cool mansions from meridian beams, And view their waving honours in your streams. [_Spread the bright treasure_. L. 540. The practice of flooding landslong in use in China has been but lately introduced into this country. Besides the supplying water to the herbage in dryer seasons, it seems todefend it from frost in the early part of the year, and thus doublyadvances the vegetation. The waters which rise from springs passingthrough marl or limestone are replete with calcareous earth, and whenthrown over morasses they deposit this earth and incrust or consolidatethe morass. This kind of earth is deposited in great quantity from thesprings at Matlock bath, and supplies the soft porous limestone of whichthe houses and walls are there constructed; and has formed the wholebank for near a mile on that side of the Derwent on which they stand. The water of many springs contains much azotic gas, or phlogistic air, besides carbonic gas, or fixed air, as that of Buxton and Bath; thisbeing set at liberty may more readily contribute to the production ofnitre by means of the putrescent matters which it is exposed to by beingspread upon the surface of the land; in the same manner as frequentlyturning over heaps of manure facilitates the nitrous process byimprisoning atmospheric air in the interstices of the putrescentmaterials. Water arising by land-floods brings along with it much of themost soluble parts of the manure from the higher lands to the lowerones. River-water in its clear state and those springs which are calledsoft are less beneficial for the purpose of watering lands, as theycontain less earthy or saline matter; and water from dissolving snowfrom its slow solution brings but little earth along with it, as may beseen by the comparative clearness of the water of snow-floods. ] "Thus where the veins their confluent branches bend, And milky eddies with the purple blend; The Chyle's white trunk, diverging from its source, 550 Seeks through the vital mass its shining course; O'er each red cell, and tissued membrane spreads In living net-work all its branching threads; Maze within maze its tortuous path pursues, Winds into glands, inextricable clues;555 Steals through the stomach's velvet sides, and sips The silver surges with a thousand lips; Fills each fine pore, pervades each slender hair, And drinks salubrious dew-drops from the air. "Thus when to kneel in Mecca's awful gloom, 560 Or press with pious kiss Medina's tomb, League after league, through many a lingering day, Steer the swart Caravans their sultry way; O'er sandy wastes on gasping camels toil, Or print with pilgrim-steps the burning soil;565 If from lone rocks a sparkling rill descend, O'er the green brink the kneeling nations bend, Bathe the parch'd lip, and cool the feverish tongue, And the clear lake reflects the mingled throng. " The Goddess paused, --the listening bands awhile570 Still seem to hear, and dwell upon her smile; Then with soft murmur sweep in lucid trains Down the green slopes, and o'er the pebbly plains, To each bright stream on silver sandals glide, Reflective fountain, and tumultuous tide. 575 So shoot the Spider-broods at breezy dawn Their glittering net-work o'er the autumnal lawn; From blade to blade connect with cordage fine The unbending grass, and live along the line; Or bathe unwet their oily forms, and dwell580 With feet repulsive on the dimpling well. So when the North congeals his watery mass, Piles high his snows, and floors his seas with glass; While many a Month, unknown to warmer rays, Marks its slow chronicle by lunar days;585 Stout youths and ruddy damsels, sportive train, Leave the white soil, and rush upon the main; From isle to isle the moon-bright squadrons stray, And win in easy curves their graceful way; On step alternate borne, with balance nice590 Hang o'er the gliding steel, and hiss along the ice. _Argument of the Fourth Canto. _ Address to the Sylphs. I. Trade-winds. Monsoons. N. E. And S. W. Winds. Land and sea breezes. Irregular winds. 9. II. Production of vital airfrom oxygene and light. The marriage of Cupid and Psyche. 25. III. 1. Syroc. Simoom. Tornado. 63. 2. Fog. Contagion. Story of Thyrsis andAegle. Love and Death. 79. IV. 1. Barometer. Air-pump. 127. 2. Air-balloon of Mongulfier. Death of Rozier. Icarus. 143. V. Discoveries ofDr. Priestley. Evolutions and combinations of pure air. Rape ofProserpine. 165. VI. Sea-balloons, or houses constructed to move underthe sea. Death of Mr. Day. Of Mr. Spalding. Of Captain Pierce and hisDaughters. 195. VII. Sylphs of music. Cecelia singing. Cupid with a lyreriding upon a lion. 233. VIII. Destruction of Senacherib's army by apestilential wind. Shadow of Death. 263. IX. 1. Wish to possess thesecret of changing the course of the winds. 305. 2. Monster devouringair subdued by Mr. Kirwan. 321. X. 1. Seeds suspended in their pods. Stars discovered by Mr. Herschel. Destruction and resuscitation of allthings. 351. 2. Seeds within seeds, and bulbs within bulbs. Picture onthe retina of the eye. Concentric strata of the earth. The great seed. 381. 3. The root, pith, lobes, plume, calyx, coral, sap, blood, leavesrespire and absorb light. The crocodile in its egg. 409. XI. Opening ofthe flower. The petals, style, anthers, prolific dust. Transmutation ofthe silkworm. 441. XII. 1. Leaf-buds changed into flower-buds bywounding the bark, or strangulating a part of the branch. 461. 2. Ingrafting. Aaron's rod pullulates. 477. XIII. 1. Insects on trees. Humming-bird alarmed by the spider-like apearance of Cyprepedia. 491. 2. Diseases of vegetables. Scratch on unnealed glass. 511. XIV. 1. Tenderflowers. Amaryllis, fritillary, erythrina, mimosa, cerea. 523. 2. Vines. Oranges. Diana's trees. Kew garden. The royal family. 541. XV. Offeringto Hygeia. 587. Departure of the Goddess. 629. THE ECONOMY OF VEGETATION. CANTO IV. As when at noon in Hybla's fragrant bowers CACALIA opens all her honey'd flowers; Contending swarms on bending branches cling, And nations hover on aurelian wing; 5 So round the GODDESS, ere she speaks, on high Impatient SYLPHS in gawdy circlets fly; Quivering in air their painted plumes expand, And coloured shadows dance upon the land. [_Cacalia opens_. L. 2. The importance of the nectarium or honey-glandin the vegetable economy is seen from the very complicated apparatus, which nature has formed in some flowers for the preservation of theirhoney from insects, as in the aconites or monkshoods; in other plantsinstead of a great apparatus for its protection a greater secretion ofit is produced that thence a part may be spared to the depredation ofinsects. The cacalia suaveolens produces so much honey that on some daysit may be smelt at a great distance from the plant. I remember oncecounting on one of these plants besides bees of various kinds withoutnumber, above two hundred painted butterflies, which gave it thebeautiful appearance of being covered with additional flowers. ] I. "SYLPHS! YOUR light troops the tropic Winds confine, 10 And guide their streaming arrows to the Line; While in warm floods ecliptic breezes rise, And sink with wings benumb'd in colder skies. You bid Monsoons on Indian seas reside, And veer, as moves the sun, their airy tide; 15 While southern gales o'er western oceans roll, And Eurus steals his ice-winds from the Pole. Your playful trains, on sultry islands born, Turn on fantastic toe at eve and morn; With soft susurrant voice alternate sweep 20 Earth's green pavilions and encircling deep. OR in itinerant cohorts, borne sublime On tides of ether, float from clime to clime; O'er waving Autumn bend your airy ring, Or waft the fragrant bosom of the Spring. [_The tropic winds_. L. 9. See additional notes, No. XXXIII. ] 25 II. "When Morn, escorted by the dancing Hours, O'er the bright plains her dewy lustre showers; Till from her sable chariot Eve serene Drops the dark curtain o'er the brilliant scene; You form with chemic hands the airy surge, 30 Mix with broad vans, with shadowy tridents urge. SYLPHS! from each sun-bright leaf, that twinkling shakes O'er Earth's green lap, or shoots amid her lakes, Your playful bands with simpering lips invite, And wed the enamour'd OXYGENE to LIGHT. -- 35 Round their white necks with fingers interwove, Cling the fond Pair with unabating love; Hand link'd in hand on buoyant step they rise, And soar and glisten in unclouded skies. Whence in bright floods the VITAL AIR expands, 40 And with concentric spheres involves the lands; Pervades the swarming seas, and heaving earths, Where teeming Nature broods her myriad births; Fills the fine lungs of all that _breathe_ or _bud_, Warms the new heart, and dyes the gushing blood; 45 With Life's first spark inspires the organic frame, And, as it wastes, renews the subtile flame. [_The enamour'd oxygene_. L. 34. The common air of the atmosphereappears by the analysis of Dr. Priestley and other philosophers toconsist of about three parts of an elastic fluid unfit for respirationor combustion, called azote by the French school, and about one fourthof pure vital air fit for the support of animal life and of combustion, called oxygene. The principal source of the azote is probably from thedecomposition of all vegetable and animal matters by putrefaction andcombustion; the principal source of vital air or oxygene is perhaps fromthe decomposition of water in the organs of vegetables by means of thesun's light. The difficulty of injecting vegetable vessels seems to shewthat their perspirative pores are much less than those of animals, andthat the water which constitutes their perspiration is so divided at thetime of its exclusion that by means of the sun's light it becomesdecomposed, the inflammable air or hydrogene, which is one of itsconstituent parts, being retained to form the oil, resin, wax, honey, &c. Of the vegetable economy; and the other part, which united withlight or heat becomes vital air or oxygene gas, rises into theatmosphere and replenishes it with the food of life. Dr. Priestley has evinced by very ingenious experiments that the bloodgives out phlogiston, and receives vital air, or oxygene-gas by thelungs. And Dr. Crawford has shewn that the blood acquires heat from thisvital air in respiration. There is however still a something more subtilthan heat, which must be obtained in respiration from the vital air, asomething which life can not exist a few minutes without, which seemsnecessary to the vegetable as well as to the animal world, and which asno organized vessels can confine it, requires perpetually to be renewed. See note on Canto I. L. 401. ] "So pure, so soft, with sweet attraction shone Fair PSYCHE, kneeling at the ethereal throne; Won with coy smiles the admiring court of Jove, 50 And warm'd the bosom of unconquer'd LOVE. -- Beneath a moving shade of fruits and flowers Onward they march to HYMEN'S sacred bowers; With lifted torch he lights the festive train, Sublime, and leads them in his golden chain; 55 Joins the fond pair, indulgent to their vows, And hides with mystic veil their blushing brows. Round their fair forms their mingling arms they fling, Meet with warm lip, and clasp with rustling wing. -- --Hence plastic Nature, as Oblivion whelms 60 Her fading forms, repeoples all her realms; Soft Joys disport on purple plumes unfurl'd, And Love and Beauty rule the willing world. [_Fair Psyche_. L. 48. Described from an antient gem on a fine onyx inpossession of the Duke of Marlborough, of which there is a beautifulprint in Bryant's Mythol. Vol II. P. 392. And from another antient gemof Cupid and Psyche embracing, of which there is a print in Spence'sPolymetis. P. 82. ] [_Repeoples all her realms_. L. 60. Quae mare navigerum et terras frugiferentes Concelebras; per te quoniam genus omne animantum Concipitur, visitque exortum lumina folis. Lucret. ] III. 1. "SYLPHS! Your bold myriads on the withering heath Stay the fell SYROC'S suffocative breath; 65 Arrest SIMOOM in his realms of sand, The poisoned javelin balanced in his hand;-- Fierce on blue streams he rides the tainted air, Points his keen eye, and waves his whistling hair; While, as he turns, the undulating soil 70 Rolls in red waves, and billowy deserts boil. [_Arrest Simoom_. L. 65. "At eleven o'clock while we were with greatpleasure contemplating the rugged tops of Chiggre, where we expected tosolace ourselves with plenty of good water, Idris cried out with a loudvoice, "fall upon your faces, for here is the simoom!" I saw from theS. E. A haze come in colour like the purple part of a rainbow, but not socompressed or thick; it did not occupy twenty yards in breadth, and wasabout twelve feet high from the ground. It was a kind of a blush uponthe air, and it moved very rapidly, for I scarce could turn to fall uponthe ground with my head to the northward, when I felt the heat of itscurrent plainly upon my face. We all lay flat upon the ground, as ifdead, till Idris told us it was blown over. The meteor, or purple haze, which I saw was indeed passed; but the light air that still blew was ofheat to threaten suffocation. For my part I found distinctly in mybreast, that I had imbibed a part of it; nor was I free of an asthmaticsensation till I had been some months in Italy. " Bruce's Travels. Vol. IV. P. 557. It is difficult to account for the narrow track of this pestilentialwind, which is said not to exceed twenty yards, and for its smallelevation of twelve feet. A whirlwind will pass forwards, and throw downan avenue of trees by its quick revolution as it passes, but nothinglike a whirling is described as happening in these narrow streams ofair, and whirlwinds ascend to greater heights. There seems but one knownmanner in which this channel of air could be effected, and that is byelectricity. The volcanic origin of these winds is mentioned in the note on Chunda inVol. II. Of this work; it must here be added, that Professor Vairo atNaples found, that during the eruption of Vesuvius perpendicular ironbars were electric; and others have observed suffocating damps to attendthese eruptions. Ferber's Travels in Italy, p. 133. And lastly, that acurrent of air attends the passage of electric matter, as is seen inpresenting an electrized point to the flame of a candle. In Mr. Bruce'saccount of this simoom, it was in its course over a quite dry desert ofsand, (and which was in consequence unable to conduct an electric streaminto the earth beneath it, ) to some moist rocks at but a few milesdistance; and thence would appear to be a stream of electricity from avolcano attended with noxious air; and as the bodies of Mr. Bruce andhis attendants were insulated on the sand, they would not be sensible oftheir increased electricity, as it passed over them; to which it may beadded, that a sulphurous or suffocating sensation is said to accompanyflames of lightning, and even strong sparks of artificial electricity. In the above account of the simoom, a great redness in the air is saidto be a certain sign of its approach, which may be occasioned by theeruption of flame from a distant volcano in these extensive andimpenetrable deserts of sand. See Note on l. 294 of this Canto. ] You seize TORNADO by his locks of mist, Burst his dense clouds, his wheeling spires untwist; Wide o'er the West when borne on headlong gales, Dark as meridian night, the Monster sails, 75 Howls high in air, and shakes his curled brow, Lashing with serpent-train the waves below, Whirls his black arm, the forked lightning flings, And showers a deluge from his demon-wings. [_Tornado's_. L. 71. See additional notes, No. XXXIII. ] 2. "SYLPHS! with light shafts YOU pierce the drowsy FOG, 80 That lingering slumbers on the sedge-wove bog, With webbed feet o'er midnight meadows creeps, Or flings his hairy limbs on stagnant deeps. YOU meet CONTAGION issuing from afar, And dash the baleful conqueror from his car; 85 When, Guest of DEATH! from charnel vaults he steals, And bathes in human gore his armed wheels. [_On stagnant deeps_. L. 82. All contagious miasmata originate eitherfrom animal bodies, as those of the small pox, or from putrid morasses;these latter produce agues in the colder climates, and malignant feversin the warmer ones. The volcanic vapours which cause epidemic coughs, are to be ranked amongst poisons, rather than amongst the miasmata, which produce contagious diseases. ] "Thus when the PLAGUE, upborne on Belgian air, Look'd through the mist and shook his clotted hair, O'er shrinking nations steer'd malignant clouds, 90 And rain'd destruction on the gasping crouds. The beauteous AEGLE felt the venom'd dart, Slow roll'd her eye, and feebly throbb'd her heart; Each fervid sigh seem'd shorter than the last, And starting Friendship shunn'd her, as she pass'd. 95 --With weak unsteady step the fainting Maid Seeks the cold garden's solitary shade, Sinks on the pillowy moss her drooping head, And prints with lifeless limbs her leafy bed. --On wings of Love her plighted Swain pursues, 100 Shades her from winds, and shelters her from dews, Extends on tapering poles the canvas roof, Spreads o'er the straw-wove matt the flaxen woof, Sweet buds and blossoms on her bolster strows, And binds his kerchief round her aching brows;105 Sooths with soft kiss, with tender accents charms, And clasps the bright Infection in his arms. -- With pale and languid smiles the grateful Fair Applauds his virtues, and rewards his care; Mourns with wet cheek her fair companions fled110 On timorous step, or number'd with the dead; Calls to its bosom all its scatter'd rays, And pours on THYRSIS the collected blaze; Braves the chill night, caressing and caress'd, And folds her Hero-lover to her breast. --115 Less bold, LEANDER at the dusky hour Eyed, as he swam, the far love-lighted tower; Breasted with struggling arms the tossing wave, And sunk benighted in the watery grave. Less bold, TOBIAS claim'd the nuptial bed, 120 Where seven fond Lovers by a Fiend had bled; And drove, instructed by his Angel-Guide, The enamour'd Demon from the fatal bride. -- --SYLPHS! while your winnowing pinions fan'd the air, And shed gay visions o'er the sleeping pair;125 LOVE round their couch effused his rosy breath, And with his keener arrows conquer'd DEATH. [_The beauteous Aegle_. L. 91. When the plague raged in Holland in 1636, a young girl was seized with it, had three carbuncles, and was removedto a garden, where her lover, who was betrothed to her, attended her asa nurse, and slept with her as his wife. He remained uninfected, and sherecovered, and was married to him. The story is related by Vinc. Fabricius in the Misc. Cur. Ann. II. Obs. 188. ] IV. 1. "You charm'd, indulgent SYLPHS! their learned toil, And crown'd with fame your TORRICELL, and BOYLE; Taught with sweet smiles, responsive to their prayer, 130 The spring and pressure of the viewless air. --How up exhausted tubes bright currents flow Of liquid silver from the lake below, Weigh the long column of the incumbent skies, And with the changeful moment fall and rise. 135 --How, as in brazen pumps the pistons move, The membrane-valve sustains the weight above; Stroke follows stroke, the gelid vapour falls, And misty dew-drops dim the crystal walls; Rare and more rare expands the fluid thin, 140 And Silence dwells with Vacancy within. -- So in the mighty Void with grim delight Primeval Silence reign'd with ancient Night. [_Torricell and Boyle_. L. 128. The pressure of the atmosphere wasdiscovered by Torricelli, a disciple of Galileo, who had previouslyfound that the air had weight. Dr. Hook and M. Du Hamel ascribe theinvention of the air-pump to Mr. Boyle, who however confesses he hadsome hints concerning its construction from De Guerick. The vacancy atthe summit of the barometer is termed the Torricellian vacuum, and theexhausted receiver of an air pump the Boylean vacuum, in honour of thesetwo philosophers. The mist and descending dew which appear at first exhausting thereceiver of an air-pump, are explained in the Phil. Trans. Vol. LXXVIII. From the cold produced by the expansion of air. For a thermometer placedin the receiver sinks some degrees, and in a very little time, as soonas a sufficient quantity of heat can be acquired from the surroundingbodies, the dew becomes again taken up. See additional notes, No. VII. Mr. Saussure observed on placing his hygrometer in a receiver of an air-pump, that though on beginning to exhaust it the air became misty, andparted with its moisture, yet the hair of his hygrometer contracted, andthe instrument pointed to greater dryness. This unexpected occurrence isexplained by M. Monge (Annales de Chymie, Tom. V. ) to depend on the wantof the usual pressure of the atmosphere to force the aqueous particlesinto the pores of the hair; and M. Saussure supposes, that his vesicularvapour requires more time to be redissolved, than is necessary to drythe hair of his thermometer. Essais sur l'Hygrom. P. 226. But I suspectthere is a less hypothetical way of understanding it; when a colder bodyis brought into warm and moist air, (as a bottle of spring-water forinstance, ) a steam is quickly collected on its surface; the contraryoccurs when a warmer body is brought into cold and damp air, itcontinues free from dew so long as it continues warm; for it warms theatmosphere around it, and renders it capable of receiving instead ofparting with moisture. The moment the air becomes rarefied in thereceiver of the air-pump it becomes colder, as appears by thethermometer, and deposits its vapour; but the hair of Mr. Saussure'shygrometer is now warmer than the air in which it is immersed, and inconsequence becomes dryer than before, by warming the air whichimmediately surrounds it, a part of its moisture evaporating along withits heat. ] 2. "SYLPHS! your soft voices, whispering from the skies, Bade from low earth the bold MONGULFIER rise;145 Outstretch'd his buoyant ball with airy spring, And bore the Sage on levity of wing;-- Where were ye, SYLPHS! when on the ethereal main Young ROSIERE launch'd, and call'd your aid in vain? Fair mounts the light balloon, by Zephyr driven, 150 Parts the thin clouds, and sails along the heaven; Higher and yet higher the expanding bubble flies, Lights with quick flash, and bursts amid the skies. -- Headlong He rushes through the affrighted air With limbs distorted, and dishevel'd hair, 155 Whirls round and round, the flying croud alarms, And DEATH receives him in his sable arms!-- So erst with melting wax and loosen'd strings Sunk hapless ICARUS on unfaithful wings; His scatter'd plumage danced upon the wave, 160 And sorrowing Mermaids deck'd his watery grave; O'er his pale corse their pearly sea-flowers shed, And strew'd with crimson moss his marble bed; Struck in their coral towers the pausing bell, And wide in ocean toll'd his echoing knell. [_Young Rosiere launch'd_. L. 148. M. Pilatre du Rosiere with a M. Romain rose in a balloon from Boulogne in June 1785, and after havingbeen about a mile high for about half an hour the balloon took fire, andthe two adventurers were dashed to pieces on their fall to the ground. Mr. Rosiere was a philosopher of great talents and activity, joined withsuch urbanity and elegance of manners, as conciliated the affections ofhis acquaintance and rendered his misfortune universally lamented. Annual Register for 1784 and 1785, p. 329. ] [_And wide in ocean_. L. 164. Denser bodies propagate vibration or soundbetter than rarer ones; if two stones be struck together under thewater, they may be heard a mile or two by any one whose head is immersedat that distance, according to an experiment of Dr. Franklin. If the earbe applied to one end of a long beam of timber, the stroke of a pin atthe other end becomes sensible; if a poker be suspended in the middle ofa garter, each end of which is pressed against the ear, the leastpercussions on the poker give great sounds. And I am informed by layingthe ear on the ground the tread of a horse may be discerned at a greatdistance in the night. The organs of hearing belonging to fish are forthis reason much less complicated than of quadrupeds, as the fluid theyare immersed in so much better conveys its vibrations. And it isprobable that some shell-fish which have twisted shells like the cochleaand semicircular canals of the ears of men and quadrupeds may have noappropriated organ for perceiving the vibrations of the element theylive in, but may by their spiral form be in a manner all ear. ] 165 V. "SYLPHS! YOU, retiring to sequester'd bowers, Where oft your PRIESTLEY woos your airy powers, On noiseless step or quivering pinion glide, As sits the Sage with Science by his side; To his charm'd eye in gay undress appear, 170 Or pour your secrets on his raptured ear. How nitrous Gas from iron ingots driven Drinks with red lips the purest breath of heaven; How, while Conferva from its tender hair Gives in bright bubbles empyrean air;175 The crystal floods phlogistic ores calcine, And the pure ETHER marries with the MINE. [_Where oft your Priestley_. L. 166. The fame of Dr. Priestley is knownin every part of the earth where science has penetrated. His variousdiscoveries respecting the analysis of the atmosphere, and theproduction of variety of new airs or gasses, can only be clearlyunderstood by reading his Experiments on Airs, (3 vols. Octavo, Johnson, London. ) the following are amongst his many discoveries. 1. Thediscovery of nitrous and dephlogisticated airs. 2. The exhibition of theacids and alkalies in the form of air. 3. Ascertaining the purity ofrespirable air by nitrous air. 4. The restoration of vitiated air byvegetation. 5. The influence of light to enable vegetables to yield pureair. 6. The conversion by means of light of animal and vegetablesubstances, that would otherwise become putrid and offensive, intonourishment of vegetables. 7. The use of respiration by the bloodparting with phlogiston, and imbibing dephlogisticated air. The experiments here alluded to are, 1. Concerning the production ofnitrous gas from dissolving iron and many other metals in nitrous acid, which though first discovered by Dr. Hales (Static. Ess. Vol. I. P. 224)was fully investigated, and applied to the important purpose ofdistinguishing the purity of atmospheric air by Dr. Priestley. Whenabout two measures of common air and one of nitrous gas are mixedtogether a red effervescence takes place, and the two airs occupy aboutone fourth less space than was previously occupied by the common airalone. 2. Concerning the green substance which grows at the bottom ofreservoirs of water, which Dr. Priestley discovered to yield much pureair when the sun shone on it. His method of collecting this air is byplacing over the green substance, which he believes to be a vegetable ofthe genus conferva, an inverted bell-glass previously filled with water, which subsides as the air arises; it has since been found that allvegetables give up pure air from their leaves, when the sun shines uponthem, but not in the night, which may be owing to the sleep of theplant. 3. The third refers to the great quantity of pure air contained in thecalces of metals. The calces were long known to weigh much more than themetallic bodies before calcination, insomuch that 100 pounds of leadwill produce 112 pounds of minium; the ore of manganese, which is alwaysfound near the surface of the earth, is replete with pure air, which isnow used for the purpose of bleaching. Other metals when exposed to theatmosphere attract the pure air from it, and become calces by itscombination, as zinc, lead, iron; and increase in weight in proportionto the air, which they imbibe. ] "So in Sicilia's ever-blooming shade When playful PROSERPINE from CERES stray'd, Led with unwary step her virgin trains180 O'er Etna's steeps, and Enna's golden plains; Pluck'd with fair hand the silver-blossom'd bower, And purpled mead, --herself a fairer flower; Sudden, unseen amid the twilight glade, Rush'd gloomy DIS, and seized the trembling maid. --185 Her starting damsels sprung from mossy seats, Dropp'd from their gauzy laps the gather'd sweets, Clung round the struggling Nymph, with piercing cries, Pursued the chariot, and invoked the skies;-- Pleased as he grasps her in his iron arms, 190 Frights with soft sighs, with tender words alarms, The wheels descending roll'd in smoky rings, Infernal Cupids flapp'd their demon wings; Earth with deep yawn received the Fair, amaz'd, And far in Night celestial Beauty blaz'd. [_When playful Proserpine_. L. 178. The fable of Proserpine's beingseized by Pluto as she was gathering flowers, is explained by Lord Baconto signify the combination or marriage of etherial spirit with earthlymaterials. Bacon's Works, Vol. V. P. 470. Edit. 4to. Lond. 1778. Thisallusion is still more curiously exact, from the late discovery of pureair being given up from vegetables, and that then in its unmixed stateit more readily combines with metallic or inflammable bodies. From thesefables which were probably taken from antient hieroglyphics there isfrequently reason to believe that the Egyptians possessed much chemicalknowledge, which for want of alphabetical writing perished with theirphilosophers. ] 195 VI. "Led by the Sage, Lo! Britain's sons shall guide Huge SEA-BALLOONS beneath the tossing tide; The diving castles, roof'd with spheric glass, Ribb'd with strong oak, and barr'd with bolts of brass, Buoy'd with pure air shall endless tracks pursue, 200 And PRIESTLEY'S hand the vital flood renew. -- Then shall BRITANNIA rule the wealthy realms, Which Ocean's wide insatiate wave o'erwhelms; Confine in netted bowers his scaly flocks, Part his blue plains, and people all his rocks. 205 Deep, in warm waves beneath the Line that roll, Beneath the shadowy ice-isles of the Pole, Onward, through bright meandering vales, afar, Obedient Sharks shall trail her sceptred car, With harness'd necks the pearly flood disturb, 210 Stretch the silk rein, and champ the silver curb; Pleased round her triumph wondering Tritons play, And Seamaids hail her on the watery way. --Oft shall she weep beneath the crystal waves O'er shipwreck'd lovers weltering in their graves;215 Mingling in death the Brave and Good behold With slaves to glory, and with slaves to gold; Shrin'd in the deep shall DAY and SPALDING mourn, Each in his treacherous bell, sepulchral urn!-- Oft o'er thy lovely daughters, hapless PIERCE!220 Her sighs shall breathe, her sorrows dew their hearse. -- With brow upturn'd to Heaven, "WE WILL NOT PART!" He cried, and clasp'd them to his aching heart, -- --Dash'd in dread conflict on the rocky grounds, Crash the mock'd masts, the staggering wreck rebounds;225 Through gaping seams the rushing deluge swims, Chills their pale bosoms, bathes their shuddering limbs, Climbs their white shoulders, buoys their streaming hair, And the last sea-shriek bellows in the air. -- Each with loud sobs her tender sire caress'd, 230 And gasping strain'd him closer to her breast!-- --Stretch'd on one bier they sleep beneath the brine, And their white bones with ivory arms intwine! [_Led by the Sage_. L. 195. Dr. Priestley's discovery of the productionof pure air from such variety of substances will probably soon beapplied to the improvement of the diving bell, as the substances whichcontain vital air in immense quantities are of little value as manganeseand minium. See additional notes, No. XXXIII. In every hundred weight ofminium there is combined about twelve pounds of pure air, now as sixtypounds of water are about a cubic foot, and as air is eight hundredtimes lighter than water, five hundred weight of minium will produceeight hundred cubic feet of air or about six thousand gallons. Now, asthis is at least thrice as pure as atmospheric air, a gallon of it maybe supposed to serve for three minutes respiration for one man. Atpresent the air can not be set at liberty from minium by vitriolic acidwithout the application of some heat, this is however very likely soonto be discovered, and will then enable adventurers to journey beneaththe ocean in large inverted ships or diving balloons. Mr. Boyle relates, that Cornelius Drebelle contrived not only a vesselto be rowed under water, but also a liquor to be caried in that vessel, which would supply the want of fresh air. The vessel was made by orderof James I. And carried twelve rowers besides passengers. It was triedin the river Thames, and one of the persons who was in that submarinevoyage told the particulars of the experiments to a person who relatedthem to Mr. Boyle. Annual Register for 1774, p. 248. ] [_Day and Spalding mourn_. L. 217. Mr. Day perished in a diving bell, ordiving boat, of his own construction at Plymouth in June 1774, in whichhe was to have continued for a wager twelve hours one hundred feet deepin water, and probably perished from his not possessing all thehydrostatic knowledge that was necessary. See note on Ulva, Vol. II. Ofthis work. See Annual Register for 1774. P. 245. Mr. Spalding was professionally ingenious in the art of constructing andmanaging the diving bell, and had practised the business many years withsuccess. He went down accompanied by one of his young men twice to viewthe wreck of the Imperial East-Indiaman at the Kish bank in Ireland. Ondescending the third time in June, 1783, they remained about an hourunder water, and had two barrels of air sent down to them, but on thesignals from below not being again repeated, after a certain time, theywere drawn up by their assistants and both found dead in the bell. Annual Register for 1783, p. 206. These two unhappy events may for atime check the ardor of adventurers in traversing the bottom of theocean, but it is probable in another half century it may be safer totravel under the ocean than over it, since Dr. Priestley's discovery ofprocuring pure air in such great abundance from the calces of metals. ] [_Hapless Pierce!_ l, 219. The Haslewell East-Indiaman, outward bound, was wrecked off Seacomb in the isle of Purbec on the 6th of January, 1786; when Capt. Pierce, the commander, with two young ladies, hisdaughters, and the greatest part of the crew and passengers perished inthe sea. Some of the officers and about seventy seamen escaped withgreat difficulty on the rocks, but Capt. Pierce finding it wasimpossible to save the lives of the young ladies refused to quit theship, and perished with them. ] "VII. SYLPHS OF NICE EAR! with beating wings you guide The fine vibrations of the aerial tide;235 Join in sweet cadences the measured words, Or stretch and modulate the trembling cords. You strung to melody the Grecian lyre, Breathed the rapt song, and fan'd the thought of fire, Or brought in combinations, deep and clear, 240 Immortal harmony to HANDEL'S ear. -- YOU with soft breath attune the vernal gale, When breezy evening broods the listening vale; Or wake the loud tumultuous sounds, that dwell In Echo's many-toned diurnal shell. 245 YOU melt in dulcet chords, when Zephyr rings The Eolian Harp, and mingle all its strings; Or trill in air the soft symphonious chime, When rapt CECILIA lifts her eye sublime, Swell, as she breathes, her bosoms rising snow, 250 O'er her white teeth in tuneful accents slow, Through her fair lips on whispering pinions move, And form the tender sighs, that kindle love! "So playful LOVE on Ida's flowery sides With ribbon-rein the indignant Lion guides;255 Pleased on his brinded back the lyre he rings, And shakes delirious rapture from the strings; Slow as the pausing Monarch stalks along, Sheaths his retractile claws, and drinks the song; Soft Nymphs on timid step the triumph view, 260 And listening Fawns with beating hoofs pursue; With pointed ears the alarmed forest starts, And Love and Music soften savage hearts. [_Indignant lion guides_. L. 254. Described from an antient gem, expressive of the combined power of love and music, in the MuseumFlorent. ] VIII. "SYLPHS! YOUR bold hosts, when Heaven with justice dread Calls the red tempest round the guilty head, 265 Fierce at his nod assume vindictive forms, And launch from airy cars the vollied storms. -- From Ashur's vales when proud SENACHERIB trod, Pour'd his swoln heart, defied the living GOD, Urged with incessant shouts his glittering powers;270 And JUDAH shook through all her massy towers; Round her sad altars press'd the prostrate crowd, Hosts beat their breasts, and suppliant chieftains bow'd; Loud shrieks of matrons thrill'd the troubled air, And trembling virgins rent their scatter'd hair;275 High in the midst the kneeling King adored, Spread the blaspheming scroll before the Lord, Raised his pale hands, and breathed his pausing sighs, And fixed on Heaven his dim imploring eyes, -- "Oh! MIGHTY GOD! amidst thy Seraph-throng280 "Who sit'st sublime, the Judge of Right and Wrong; "Thine the wide earth, bright sun, and starry zone, "That twinkling journey round thy golden throne; "Thine is the crystal source of life and light, "And thine the realms of Death's eternal night. 285 "Oh, bend thine ear, thy gracious eye incline, "Lo! Ashur's King blasphemes thy holy shrine, "Insults our offerings, and derides our vows, --- "Oh! strike the diadem from his impious brows, "Tear from his murderous hand the bloody rod, 290 "And teach the trembling nations, "THOU ART GOD!"-- --SYLPHS! in what dread array with pennons broad Onward ye floated o'er the ethereal road, Call'd each dank steam the reeking marsh exhales, Contagious vapours, and volcanic gales, 295 Gave the soft South with poisonous breath to blow, And rolled the dreadful whirlwind on the foe!-- Hark! o'er the camp the venom'd tempest sings, Man falls on Man, on buckler buckler rings; Groan answers groan, to anguish anguish yields, 300 And DEATH'S loud accents shake the tented fields! --High rears the Fiend his grinning jaws, and wide Spans the pale nations with colossal stride, Waves his broad falchion with uplifted hand, And his vast shadow darkens all the land. [_Volcanic gales_. L. 294. The pestilential winds of the east aredescribed by various authors under various denominations; as harmattan, samiel, samium, syrocca, kamsin, seravansum. M. De Beauchamp describes aremarkable south wind in the deserts about Bagdad, called seravansum, orpoison-wind; it burns the face, impedes respiration, strips the trees oftheir leaves, and is said to pass on in a streight line, and often killspeople in six hours. P. Cotte sur la Meteorol. Analytical Review forFebruary, 1790. M. Volney says, the hot wind or ramsin seems to blow atthe season when the sands of the deserts are the hottest; the air isthen filled with an extreamly subtle dust. Vol. I. P. 61. These windsblow in all directions from the deserts; in Egypt the most violentproceed from the S. S. W. At Mecca from the E. At Surat from the N. AtBassora from the N. W. At Bagdad from the W. And in Syria from the S. E. On the south of Syria, he adds, where the Jordan flows is a country ofvolcanos; and it is observed that the earthquakes in Syria happen aftertheir rainy season, which is also conformable to a similar observationmade by Dr. Shaw in Barbary. Travels in Egypt, Vol. I. P. 303. These winds seem all to be of volcanic origin, as before mentioned, withthis difference, that the Simoom is attended with a stream of electricmatter; they seem to be in consequence of earthquakes caused by themonsoon floods, which fall on volcanic fires in Syria, at the same timethat they inundate the Nile. ] 305 IX. 1. "Ethereal cohorts! Essences of Air! Make the green children of the Spring your care! Oh, SYLPHS! disclose in this inquiring age One GOLDEN SECRET to some favour'd sage; Grant the charm'd talisman, the chain, that binds, 310 Or guides the changeful pinions of the winds! --No more shall hoary Boreas, issuing forth With Eurus, lead the tempests of the North; Rime the pale Dawn, or veil'd in flaky showers Chill the sweet bosoms of the smiling Hours. 315 By whispering Auster waked shall Zephyr rise, Meet with soft kiss, and mingle in the skies, Fan the gay floret, bend the yellow ear, And rock the uncurtain'd cradle of the year; Autumn and Spring in lively union blend, 320 And from the skies the Golden Age descend. [_One golden secret_. L. 308. The suddenness of the change of the windfrom N. E. To S. W. Seems to shew that it depends on some minute chemicalcause; which if it was discovered might probably, like other chemicalcauses, be governed by human agency; such as blowing up rocks bygunpowder, or extracting the lightening from the clouds. If this couldbe accomplished, it would be the most happy discovery that ever hashappened to these northern latitudes, since in this country the N. E. Winds bring frost, and the S. W. Ones are attended with warmth andmoisture; if the inferior currents of air could be kept perpetually fromthe S. W. Supplied by new productions of air at the line, or by superiorcurrents flowing in a contrary direction, the vegetation of this countrywould be doubled; as in the moist vallies of Africa, which know nofrost; the number of its inhabitants would be increased, and their livesprolonged; as great abundance of the aged and infirm of mankind, as wellas many birds and animals, are destroyed by severe continued frosts inthis climate. ] 2. "Castled on ice, beneath the circling Bear, A vast CAMELION spits and swallows air; O'er twelve degrees his ribs gigantic bend, And many a league his leathern jaws extend;325 Half-fish, beneath, his scaly volutes spread, And vegetable plumage crests his head; Huge fields of air his wrinkled skin receives, From panting gills, wide lungs, and waving leaves; Then with dread throes subsides his bloated form, 330 His shriek the thunder, and his sigh the storm. Oft high in heaven the hissing Demon wins His towering course, upborne on winnowing fins; Steers with expanded eye and gaping mouth, His mass enormous to the affrighted South;335 Spreads o'er the shuddering Line his shadowy limbs, And Frost and Famine follow as he swims. -- SYLPHS! round his cloud-built couch your bands array, And mould the Monster to your gentle sway; Charm with soft tones, with tender touches check, 340 Bend to your golden yoke his willing neck, With silver curb his yielding teeth restrain, And give to KIRWAN'S hand the silken rein. --Pleased shall the Sage, the dragon-wings between, Bend o'er discordant climes his eye serene, 345 With Lapland breezes cool Arabian vales, And call to Hindostan antarctic gales, Adorn with wreathed ears Kampschatca's brows, And scatter roses on Zealandic snows, Earth's wondering Zones the genial seasons share, 350 And nations hail him "MONARCH OF THE AIR. " [_A vast Camelion_. L. 322. See additional notes, No. XXXIII. On thedestruction and reproduction of the atmosphere. ] [_To Kirwan's hand_. L. 342. Mr. Kirwan has published a valuabletreatise on the temperature of climates, as a step towards investigatingthe theory of the winds; and has since written some ingenious papers onthis subject in the Transactions of the Royal Irish Society. ] X. 1. "SYLPHS! as you hover on ethereal wing, Brood the green children of parturient Spring!-- Where in their bursting cells my Embryons rest, I charge you guard the vegetable nest;355 Count with nice eye the myriad SEEDS, that swell Each vaulted womb of husk, or pod, or shell; Feed with sweet juices, clothe with downy hair, Or hang, inshrined, their little orbs in air. [_The myriad seeds_. L. 355. Nature would seem to have been wonderfullyprodigal in the seeds of vegetables, and the spawn of fish; almost anyone plant, if all its seeds should grow to maturity, would in a fewyears alone people the terrestrial globe. Mr. Ray asserts that 101seeds of tobacco weighed only one grain, and that from one tobacco plantthe seeds thus calculated amounted to 360, 000! The seeds of the fernsare by him supposed to exceed a million on a leaf. As the works ofnature are governed by general laws this exuberant reproduction preventsthe accidental extinction of the species, at the same time that theyserve for food for the higher orders of animation. Every seed possesses a reservoir of nutriment designed for the growth ofthe future plant, this consists of starch, mucilage, or oil, within thecoat of the seed, or of sugar and subacid pulp in the fruits, whichbelongs to it. For the preservation of the immature seed nature has used many ingeniousmethods; some are wrapped in down, as the seeds of the rose, bean, andcotton-plant; others are suspended in a large air-vessel, as those ofthe bladder-sena, staphylaea, and pea. ] "So, late descry'd by HERSCHEL'S piercing sight, 360 Hang the bright squadrons of the twinkling Night; Ten thousand marshall'd stars, a silver zone, Effuse their blended lustres round her throne; Suns call to suns, in lucid clouds conspire, And light exterior skies with golden fire;365 Resistless rolls the illimitable sphere, And one great circle forms the unmeasured year. --Roll on, YE STARS! exult in youthful prime, Mark with bright curves the printless steps of Time; Near and more near your beamy cars approach, 370 And lessening orbs on lessening orbs encroach;-- Flowers of the sky! ye too to age must yield, Frail as your silken sisters of the field! Star after star from Heaven's high arch shall rush, Suns sink on suns, and systems systems crush, 375 Headlong, extinct, to one dark centre fall, And Death and Night and Chaos mingle all! --Till o'er the wreck, emerging from the storm, Immortal NATURE lifts her changeful form, Mounts from her funeral pyre on wings of flame, 380 And soars and shines, another and the same. [_And light exterior_. L. 364. I suspect this line is from Dwight'sConquest of Canaan, a poem written by a very young man, and whichcontains much fine versification. ] [_Near and more near_. L. 369. From the vacant spaces in some parts ofthe heavens, and the correspondent clusters of stars in their vicinity, Mr. Herschel concludes that the nebulae or constellations of fixed starsare approaching each other, and must finally coalesce in one mass. Phil. Trans. Vol. LXXV. ] [_Till o'er the wreck_. L. 377. The story of the phenix rising from itsown ashes with a twinkling star upon its head, seems to have been anantient hieroglyphic emblem of the destruction and resuscitation of allthings. There is a figure of the great Platonic year with a phenix on his handon the reverse of a medal of Adrian. Spence's Polym. P. 189. ] 2. "Lo! on each SEED within its slender rind Life's golden threads in endless circles wind; Maze within maze the lucid webs are roll'd, And, as they burst, the living flame unfold. 385 The pulpy acorn, ere it swells, contains The Oak's vast branches in its milky veins; Each ravel'd bud, fine film, and fibre-line Traced with nice pencil on the small design. The young Narcissus, in it's bulb compress'd, 390 Cradles a second nestling on its breast; In whose fine arms a younger embryon lies, Folds its thin leaves, and shuts its floret-eyes; Grain within grain successive harvests dwell, And boundless forests slumber in a shell. 395 --So yon grey precipice, and ivy'd towers, Long winding meads, and intermingled bowers, Green files of poplars, o'er the lake that bow, And glimmering wheel, which rolls and foams below, In one bright point with nice distinction lie400 Plan'd on the moving tablet of the eye. --So, fold on fold, Earth's wavy plains extend, And, sphere in sphere, its hidden strata bend;-- Incumbent Spring her beamy plumes expands O'er restless oceans, and impatient lands, 405 With genial lustres warms the mighty ball, And the GREAT SEED evolves, disclosing ALL; LIFE _buds_ or _breathes_ from Indus to the Poles, And the vast surface kindles, as it rolls! [_Maze within maze_. L. 383. The elegant appearance on dissection of theyoung tulip in the bulb was first observed by Mariotte and is mentionedin the note on tulipa in Vol. II, and was afterwards noticed by Du Hamel. Acad. Scien. Lewenhook assures us that in the bud of a currant tree hecould not only discover the ligneous part but even the berriesthemselves, appearing like small grapes. Chamb. Dict. Art. Bud. Mr. Baker says he dissected a seed of trembling grass in which a perfectplant appeared with its root, sending forth two branches, from each ofwhich several leaves or blades of grass proceeded. Microsc. Vol. I. P. 252. Mr. Bonnet saw four generations of successive plants in the bulb ofa hyacinth. Bonnet Corps Organ. Vol. I. P. 103. Haller's Physiol. Vol. I. P. 91. In the terminal bud of a horse-chesnut the new flower may beseen by the naked eye covered with a mucilaginous down, and the same inthe bulb of a narcissus, as I this morning observed in several of themsent me by Miss ---- for that purpose. Sept. 16. Mr. Ferber speaks of the pleasure he received in observing in the budsof Hepatica and pedicularis hirsuta yet lying hid in the earth, and inthe gems of the shrub daphne mezereon, and at the base of osmundalunaria a perfect plant of the future year, discernable in all its partsa year before it comes forth, and in the seeds of nymphea nelumbo theleaves of the plant were seen so distinctly that the author found out bythem what plant the seeds belonged to. The same of the seeds of thetulip tree or liriodendum tulipiferum. Amaen. Aced. Vol. VI. ] [_And the great seed_. L. 406. Alluding to the [Greek: proton oon], orfirst great egg of the antient philosophy, it had a serpent wrappedround it emblematical of divine wisdom, an image of it was afterwardspreserved and worshipped in the temple of Dioscuri, and supposed torepresent the egg of Leda. See a print of it in Bryant's Mythology. Itwas said to have been broken by the horns of the celestial bull, thatis, it was hatched by the warmth of the Spring. See note on Canto I. L. 413. ] [_And the vast surface_. L. 408. L'Organization, le sentiment, lemovement spontané, la vie, n'existent qu'a la surface de la terre, etdans le lieux exposes á la lumiére. Traité de Chymie par M. Lavoisier, Tom. I. P. 202. ] 3. "Come, YE SOFT SYLPHS! who sport on Latian land, 410 Come, sweet-lip'd Zephyr, and Favonius bland! Teach the fine SEED, instinct with life, to shoot On Earth's cold bosom its descending root; With Pith elastic stretch its rising stem, Part the twin Lobes, expand the throbbing Gem;415 Clasp in your airy arms the aspiring Plume, Fan with your balmy breath its kindling bloom, Each widening scale and bursting film unfold, Swell the green cup, and tint the flower with gold; While in bright veins the silvery Sap ascends, 420 And refluent blood in milky eddies bends; While, spread in air, the leaves respiring play, Or drink the golden quintessence of day. --So from his shell on Delta's shower-less isle Bursts into life the Monster of the Nile;425 First in translucent lymph with cobweb-threads The Brain's fine floating tissue swells, and spreads; Nerve after nerve the glistening spine descends, The red Heart dances, the Aorta bends; Through each new gland the purple current glides, 430 New veins meandering drink the refluent tides; Edge over edge expands the hardening scale, And sheaths his slimy skin in silver mail. --Erewhile, emerging from the brooding sand, With Tyger-paw He prints the brineless strand, 435 High on the flood with speckled bosom swims, Helm'd with broad tail, and oar'd with giant limbs; Rolls his fierce eye-balls, clasps his iron claws, And champs with gnashing teeth his massy jaws; Old Nilus sighs along his cane-crown'd shores, 440 And swarthy Memphis trembles and adores. [_Teach the fine seed_. L. 411. The seeds in their natural state fall onthe surface of the earth, and having absorbed some moisture the rootshoots itself downwards into the earth and the plume rises in air. Thuseach endeavouring to seek its proper pabulum directed by a vegetableirritability similar to that of the lacteal system and to the lungs inanimals. The pith seems to push up or elongate the bud by its elasticity, likethe pith in the callow quills of birds. This medulla Linneus believes toconsist of a bundle of fibres, which diverging breaks through the barkyet gelatinous producing the buds. The lobes are reservoirs of prepared nutriment for the young seed, whichis absorbed by its placental vessels, and converted into sugar, till ithas penetrated with its roots far enough into the earth to extractsufficient moisture, and has acquired leaves to convert it intonourishment. In some plants these lobes rise from the earth and supplythe place of leaves, as in kidney-beans, cucumbers, and hence seem toserve both as a placenta to the foetus, and lungs to the young plant. During the process of germination the starch of the seed is convertedinto sugar, as is seen in the process of malting barley for the purposeof brewing. And is on this account very similar to the digestion of foodin the stomachs of animals, which converts all their aliment into achyle, which consists of mucilage, oil, and sugar; the placentation ofbuds will be spoken of hereafter. ] [_The silvery sap_. L. 419. See additional notes, No. XXXVI. ] [_Or drink the golden_. L. 422. Linneus having observed the greatinfluence of light on vegetation, imagined that the leaves of plantsinhaled electric matter from the light with their upper surface. (Systemof Vegetables translated, p. 8. ) The effect of light on plants occasions the actions of the vegetablemuscles of their leaf-stalks, which turn the upper side of the leaf tothe light, and which open their calyxes and chorols, according to theexperiments of Abbe Tessier, who exposed variety of plants in a cavernto different quantities of light. Hist. De L'Academie Royal. Ann. 1783. The sleep or vigilance of plants seems owing to the presence or absenceof this stimulus. See note on Nimosa, Vol. II. ] XI. "Come, YE SOFT SYLPHS! who fan the Paphian groves, And bear on sportive wings the callow Loves; Call with sweet whisper, in each gale that blows, The slumbering Snow-drop from her long repose;445 Charm the pale Primrose from her clay-cold bed, Unveil the bashful Violet's tremulous head; While from her bud the playful Tulip breaks, And young Carnations peep with blushing cheeks; Bid the closed _Petals_ from nocturnal cold450 The virgin _Style_ in silken curtains fold, Shake into viewless air the morning dews, And wave in light their iridescent hues; While from on high the bursting _Anthers_ trust To the mild breezes their prolific dust;455 Or bend in rapture o'er the central Fair, Love out their hour, and leave their lives in air. So in his silken sepulchre the Worm, Warm'd with new life, unfolds his larva-form; Erewhile aloft in wanton circles moves, 460 And woos on Hymen-wings his velvet loves. [_Love out their hour_. L. 456. The vegetable passion of love isagreeably seen in the flower of the parnassia, in which the malesalternately approach and recede from the female, and in the flower ofnigella, or devil in the bush, in which the tall females bend down totheir dwarf husbands. But I was this morning surprised to observe, amongst Sir Brooke Boothby's valuable collection of plants at Ashbourn, the manifest adultery of several females of the plant Collinsonia, whohad bent themselves into contact with the males of other flowers of thesame plant in their vicinity, neglectful of their own. Sept. 16. Seeadditional notes, No. XXXVIII. ] [_Unfolds his larva-form_. L. 458. The flower bursts forth from itslarva, the herb, naked and perfect like a butterfly from its chrysolis;winged with its corol; wing-sheathed by its calyx; consisting alone ofthe organs of reproduction. The males, or stamens, have their anthersreplete with a prolific powder containing the vivifying fovilla: in thefemales, or pistils, exists the ovary, terminated by the tubular stigma. When the anthers burst and shed their bags of dust, the male fovilla isreceived by the prolific lymph of the stigma, and produces the seed oregg, which is nourished in the ovary. System of Vegetables translatedfrom Linneus by the Lichfield Society, p. 10. ] XII. 1. "If prouder branches with exuberance rude Point their green gems, their barren shoots protrude; Wound them, ye SYLPHS! with little knives, or bind A wiry ringlet round the swelling rind;465 Bisect with chissel fine the root below, Or bend to earth the inhospitable bough. So shall each germ with new prolific power Delay the leaf-bud, and expand the flower; Closed in the _Style_ the tender pith shall end, 470 The lengthening Wood in circling _Stamens_ bend; The smoother Rind its soft embroidery spread In vaulted _Petals_ o'er their fertile bed; While the rough Bark, in circling mazes roll'd, Forms the green _Cup_ with many a wrinkled fold;475 And each small bud-scale spreads its foliage hard, Firm round the callow germ, a _Floral Guard_. [_Wound them, ye Sylphs!_ l. 463. Mr. Whitmill advised to bind some ofthe most vigorous shoots with strong wire, and even some of the largeroots; and Mr. Warner cuts, what he calls a wild worm about the body ofthe tree, or scores the bark quite to the wood like a screw with a sharpknife. Bradley on Gardening, Vol. II. P. 155. Mr. Fitzgerald producedflowers and fruit on wall trees by cutting off a part of the bark. Phil. Trans. Ann. 1761. M. Buffon produced the same effect by a straightbandage put round a branch, Act. Paris, Ann. 1738, and concludes that aningrafted branch bears better from its vessels being compressed by thecallous. A compleat cylinder of the bark about an inch in height was cut off fromthe branch of a pear tree against a wall in Mr. Howard's garden atLichfield about five years ago, the circumcised part is now not abovehalf the diameter of the branch above and below it, yet this branch hasbeen full of fruit every year since, when the other branches of the treebore only sparingly. I lately observed that the leaves of this woundedbranch were smaller and paler, and the fruit less in size, and ripenedsooner than on the other parts of the tree. Another branch has the barktaken off not quite all round with much the same effect. The theory of this curious vegetable fact has been esteemed difficult, but receives great light from the foregoing account of the individualityof buds. A flower-bud dies, when it has perfected its seed, like anannual plant, and hence requires no place on the bark for new roots topass downwards; but on the contrary leaf-buds, as they advance intoshoots, form new buds in the axilla of every leaf, which new budsrequire new roots to pass down the bark, and thus thicken as well aselongate the branch, now if a wire or string be tied round the bark, many of these new roots cannot descend, and thence more of the buds willbe converted into flower-buds. It is customary to debark oak-trees in the spring, which are intended tobe felled in the ensuing autumn; because the bark comes off easier atthis season, and the sap-wood, or alburnum, is believed to become harderand more durable, if the tree remains till the end of summer. The treesthus stripped of their bark put forth shoots as usual with acorns on the6th 7th and 8th joint, like vines; but in the branches I examined, thejoints of the debarked trees were much shorter than those of other oak-trees; the acorns were more numerous; and no new buds were producedabove the joints which bore acorns. From hence it appears that thebranches of debarked oak-trees produce fewer leaf-buds, and more flower-buds, which last circumstance I suppose must depend on their beingsooner or later debarked in the vernal months. And, secondly, that thenew buds of debarked oak-trees continue to obtain moisture from thealburnum after the season of the ascent of sap in other vegetablesceases; which in this unnatural state of the debarked tree may act ascapillary tubes, like the alburnum of the small debarked cylinder of apear-tree abovementioned; or may continue to act as placental vessels, as happens to the animal embryon in cases of superfetation; when thefetus continues a month or two in the womb beyond its usual time, ofwhich some instances have been recorded, the placenta continues tosupply perhaps the double office both of nutrition and of respiration. ] [_And bend to earth_. L. 466. Mr. Hitt in his treatise on fruit treesobserves that if a vigorous branch of a wall tree be bent to thehorizon, or beneath it, it looses its vigour and becomes a bearingbranch. The theory of this I suppose to depend on the difficulty withwhich the leaf-shoots can protrude the roots necessary for their newprogeny of buds upwards along the bended branch to the earth contrary totheir natural habits or powers, whence more flower-shoots are producedwhich do not require new roots to pass along the bark of the bendedbranch, but which let their offspring, the seeds, fall upon the earthand seek roots for themselves. ] [_With new prolific power_. L. 467. About Midsummer the new buds areformed, but it is believed by some of the Linnean school, that thesebuds may in their early state be either converted into flower-buds orleaf-buds according to the vigour of the vegetating branch. Thus if theupper part of a branch be cut away, the buds near the extremity of theremaining stem, having a greater proportional supply of nutriment, orpossessing a greater facility of shooting their roots, or absorbentvessels, down the bark, will become leaf-buds, which might otherwisehave been flower-buds. And the contrary as explained in note on l. 463. Of this Canto. ] [_Closed in the style_. L. 469. "I conceive the medulla of a plant toconsist of a bundle of nervous fibres, and that the propelling vitalpower separates their uppermost extremities. These, diverging, penetratethe bark, which is now gelatinous, and become multiplied in the new gem, or leaf-bud. The ascending vessels of the bark being thus divided by thenervous fibres, which perforate it, and the ascent of its fluids beingthus impeded, the bark is extended into a leaf. But the flower isproduced, when the protrusion of the medulla is greater than theretention of the including cortical part; whence the substance of thebark is expanded in the calyx; that of the rind, (or interior bark, ) inthe corol; that of the wood in the stamens, that of the medulla in thepistil. Vegetation thus terminates in the production of new life, theultimate medullary and cortical fibres being collected in the seeds. "Linnei Systema Veget. P. 6. Edit. 14. ] 2. "Where cruder juices swell the leafy vein, Stint the young germ, the tender blossom stain; On each lop'd shoot a softer scion bind, 480 Pith press'd to pith, and rind applied to rind, So shall the trunk with loftier crest ascend, And wide in air its happier arms extend; Nurse the new buds, admire the leaves unknown, And blushing bend with fruitage not its own. [_Nurse the new buds_. L. 483. Mr. Fairchild budded a passion-tree, whose leaves were spotted with yellow, into one which bears long fruit. The buds did not take, nevertheless in a fortnight yellow spots began toshew themselves about three feet above the inoculation, and in a shorttime afterwards yellow spots appeared on a shoot which came out of theground from another part of the plant. Bradley, Vol. II. P. 129. Thesefacts are the more curious since from experiments of ingrafting redcurrants on black (Ib. Vol. II. ) the fruit does not acquire any changeof flavour, and by many other experiments neither colour nor any otherchange is produced in the fruit ingrafted on other stocks. There is an apple described in Bradley's work which is said to have oneside of it a sweet fruit which boils soft, and the other side a sourfruit which boils hard, which Mr. Bradley so long ago as the year 1721ingeniously ascribes to the farina of one of these apples impregnatingthe other, which would seem the more probable if we consider that eachdivision of an apple is a separate womb, and may therefore have aseparate impregnation like puppies of different kinds in one litter. Thesame is said to have occurred in oranges and lemons, and grapes ofdifferent colours. ] 485 "Thus when in holy triumph Aaron trod, And offer'd on the shrine his mystic rod; First a new bark its silken tissue weaves, New buds emerging widen into leaves; Fair fruits protrude, enascent flowers expand, 490 And blush and tremble round the living wand. XIII. 1. "SYLPHS! on each Oak-bud wound the wormy galls, With pigmy spears, or crush the venom'd balls; Fright the green Locust from his foamy bed, Unweave the Caterpillar's gluey thread;495 Chase the fierce Earwig, scare the bloated Toad, Arrest the snail upon his slimy road; Arm with sharp thorns the Sweet-brier's tender wood, And dash the Cynips from her damask bud; Steep in ambrosial dews the Woodbine's bells, 500 And drive the Night-moth from her honey'd cells. So where the Humming-bird in Chili's bowers On murmuring pinions robs the pendent flowers; Seeks, where fine pores their dulcet balm distill, And sucks the treasure with proboscis-bill;505 Fair CYPREPEDIA with successful guile Knits her smooth brow, extinguishes her smile; A Spiders bloated paunch and jointed arms Hide her fine form, and mask her blushing charms; In ambush sly the mimic warrior lies, 510 And on quick wing the panting plunderer flies. [_Fair Cyprepedia_. L. 505. The cyprepedium from South America issupposed to be of larger size and brighter colours than that from NorthAmerica from which this print is taken; it has a large globular nectaryabout the size of a pidgeon's egg of a fleshy colour, and an incision ordepression on its upper part, much resembling the body of the largeAmerican spider; this globular nectary is attached to divergent slenderpetals not unlike the legs of the same animal. This spider is called byLinneus Arenea avicularia, with a convex orbicular thorax, the centertransversely excavated, he adds that it catches small birds as well asinsects, and has the venemous bite of a serpent. System Nature, Tom. I. P. 1034. M. Lonvilliers de Poincy, (Histoire Nat. Des Antilles, Cap. Xiv. Art. III. ) calls it Phalange, and describes the body to be the sizeof a pidgeon's egg, with a hollow on its back like a navel, and mentionsits catching the humming-bird in its strong nets. The similitude of this flower to this great spider seems to be avegetable contrivance to prevent the humming-bird from plundering itshoney. About Matlock in Derbyshire the fly-ophris is produced, thenectary of which so much resembles the small wall-bee, perhaps the apisichneumonea, that it may be easily mistaken for it at a small distance. It is probable that by this means it may often escape being plundered. See note on lonicera in the next poem. A bird of our own country called a willow-wren (Motacilla) runs up thestem of the crown-imperial (Frittillaria coronalis) and sips thependulous drops within its petals. This species of Motacilla is calledby Ray Regulus non cristatus. White's Hist. Of Selborne. ] [Illustration: _Cypripedium. London, Published Dec'r 1st 1791 by J. Johnson, St. Paul's Church Yard. _] 2. "Shield the young Harvest from devouring blight, The Smut's dark poison, and the Mildew white; Deep-rooted Mould, and Ergot's horn uncouth, And break the Canker's desolating tooth. 515 First in one point the festering wound confin'd Mines unperceived beneath the shrivel'd rin'd; Then climbs the branches with increasing strength, Spreads as they spread, and lengthens with their length; --Thus the slight wound ingraved on glass unneal'd520 Runs in white lines along the lucid field; Crack follows crack, to laws elastic just, And the frail fabric shivers into dust. [_Shield the young harvest_. L. 511. Linneus enumerates but fourdiseases of plants; Erysyche, the white mucor or mould, with sessiletawny heads, with which the leaves are sprinkled, as is frequent on thehop, humulus, maple, acer, &c. Rubigo, the ferrugineous powder sprinkledunder the leaves frequent in lady's mantle, alchemilla, &c. Clavus, when the seeds grow out into larger horns black without, as inrye. This is called Ergot by the french writers. Ustulago, when the fruit instead of seed produces a black powder, as inbarley, oats, &c. To which perhaps the honey-dew ought to have beenadded, and the canker, in the former of which the nourishing fluid ofthe plant seems to be exsuded by a retrograde motion of the cutaneouslymphatics, as in the sweating sickness of the last century. The latteris a phagedenic ulcer of the bark, very destructive to young apple-trees, and which in cherry-trees is attended with a deposition of gumarabic, which often terminates in the death of the tree. ] [_Ergot's horn_. L. 513. There is a disease frequently affects the ryein France, and sometimes in England in moist seasons, which is calledErgot, or horn seed; the grain becomes considerably elongated and iseither straight or crooked, containing black meal along with the white, and appears to be pierced by insects, which were probably the cause ofthe disease. Mr. Duhamel ascribes it to this cause, and compares it togalls on oak-leaves. By the use of this bad grain amongst the poordiseases have been produced attended with great debility andmortification of the extremities both in France and England. Dict. Raison. Art. Siegle. Philosop. Transact. ] [_On glass unneal'd_. L. 519. The glass makers occasionally make whatthey call _proofs_, which are cooled hastily, whereas the other glassvessels are removed from warmer ovens to cooler ones, and suffered tocool by slow degrees, which is called annealing, or nealing them. If anunnealed glass be scratched by even a grain of sand falling into it, itwill seem to consider of it for some time, or even a day, and will thencrack into a thousand pieces. The same happens to a smooth surfaced lead-ore in Derbyshire, theworkmen having cleared a large face of it scratch it with picks, and ina few hours many tons of it crack to pieces and fall, with a kind ofexplosion. Whitehurst's Theory of Earth. Glass dropped into cold water, called Prince Rupert's drops, explodewhen a small part of their tails are broken off, more suddenly indeed, but probably from the same cause. Are the internal particles of theseelastic bodies kept so far from each other by the external crust thatthey are nearly in a state of repulsion into which state they are thrownby their vibrations from any violence applied? Or, like elastic balls incertain proportions suspended in contact with each other, can motiononce began be increased by their elasticity, till the whole explodes?And can this power be applied to any mechanical purposes?] XIV. I. "SYLPHS! if with morn destructive Eurus springs, O, clasp the Harebel with your velvet wings;525 Screen with thick leaves the Jasmine as it blows, And shake the white rime from the shuddering Rose; Whilst Amaryllis turns with graceful ease Her blushing beauties, and eludes the breeze. -- SYLPHS! if at noon the Fritillary droops, 530 With drops nectareous hang her nodding cups; Thin clouds of Gossamer in air display, And hide the vale's chaste Lily from the ray; Whilst Erythrina o'er her tender flower Bends all her leaves, and braves the sultry hour;--535 Shield, when cold Hesper sheds his dewy light, Mimosa's soft sensations from the night; Fold her thin foilage, close her timid flowers, And with ambrosial slumbers guard her bowers; O'er each warm wall while Cerea flings her arms, 540 And wastes on night's dull eye a blaze of charms. [Illustration: _Erythrina Corallodendron. London Published Dec'r 1st byJ. Johnson St. Paul's Church Yard. _] [_With ambrosial slumbers_. L. 538. Many vegetables during the night donot seem to respire, but to sleep like the dormant animals and insectsin winter. This appears from the mimosa and many other plants closingthe upper sides of their leaves together in their sleep, and thusprecluding that side of them from both light and air. And from manyflowers closing up the polished or interior side of their petals, whichwe have also endeavoured to shew to be a respiratory organ. The irritability of plants is abundantly evinced by the absorption andpulmonary circulation of their juices; their sensibility is shewn by theapproaches of the males to the females, and of the females to the malesin numerous instances; and, as the essential circumstance of sleepconsists in the temporary abolition of voluntary power alone, the sleepof plants evinces that they possess voluntary power; which alsoindisputably appears in many of them by closing their petals or theirleaves during cold, or rain, or darkness, or from mechanic violence. ] 2. Round her tall Elm with dewy fingers twine The gadding tendrils of the adventurous Vine; From arm to arm in gay festoons suspend Her fragrant flowers, her graceful foliage bend;545 Swell with sweet juice her vermil orbs, and feed Shrined in transparent pulp her pearly seed; Hang round the Orange all her silver bells, And guard her fragrance with Hesperian spells; Bud after bud her polish'd leaves unfold, 550 And load her branches with successive gold. So the learn'd Alchemist exulting sees Rise in his bright matrass DIANA'S trees; Drop after drop, with just delay he pours The red-fumed acid on Potosi's ores;555 With sudden flash the fierce bullitions rise, And wide in air the gas phlogistic flies; Slow shoot, at length, in many a brilliant mass Metallic roots across the netted glass; Branch after branch extend their silver stems, 560 Bud into gold, and blossoms into gems. [_Diana's trees_, l. 552. The chemists and astronomers from the earliestantiquity have used the same characters to represent the metals and theplanets, which were most probably outlines or abstracts of the originalhieroglyphic figures of Egypt. These afterwards acquired niches in theirtemples, and represented Gods as well as metals and planets; whencesilver is called Diana, or the moon, in the books of alchemy. The process for making Diana's silver tree is thus described by Lemeri. Dissolve one ounce of pure silver in acid of nitre very pure andmoderately strong; mix this solution with about twenty ounces ofdistilled water; add to this two ounces of mercury, and let it remain atrest. In about four days there will form upon the mercury a tree ofsilver with branches imitating vegetation. 1. As the mercury has a greater affinity than silver with the nitrousacid, the silver becomes precipitated; and, being deprived of thenitrous oxygene by the mercury, sinks down in its metallic form andlustre. 2. The attraction between silver and mercury, which causes themreadily to amalgamate together, occasions the precipitated silver toadhere to the surface of the mercury in preference to any other part ofthe vessel. 3. The attraction of the particles of the precipitatedsilver to each other causes the beginning branches to thicken andelongate into trees and shrubs rooted on the mercury. For othercircumstances concerning this beautiful experiment see Mr. Keir'sChemical Dictionary, art. Arbor Dianae; a work perhaps of greaterutility to mankind than the lost Alexandrian Library; the continuationof which is so eagerly expected by all, who are occupied in the arts, orattached to the sciences. ] So sits enthron'd in vegetable pride Imperial KEW by Thames's glittering side; Obedient sails from realms unfurrow'd bring For her the unnam'd progeny of spring;565 Attendant Nymphs her dulcet mandates hear, And nurse in fostering arms the tender year, Plant the young bulb, inhume the living seed, Prop the weak stem, the erring tendril lead; Or fan in glass-built fanes the stranger flowers570 With milder gales, and steep with warmer showers. Delighted Thames through tropic umbrage glides, And flowers antarctic, bending o'er his tides; Drinks the new tints, the sweets unknown inhales, And calls the sons of science to his vales. 575 In one bright point admiring Nature eyes The fruits and foliage of discordant skies, Twines the gay floret with the fragrant bough, And bends the wreath round GEORGE'S royal brow. --Sometimes retiring, from the public weal580 One tranquil hour the ROYAL PARTNERS steal; Through glades exotic pass with step sublime, Or mark the growths of Britain's happier clime; With beauty blossom'd, and with virtue blaz'd, Mark the fair Scions, that themselves have rais'd;585 Sweet blooms the Rose, the towering Oak expands, The Grace and Guard of Britain's golden lands. XV. SYLPHS! who, round earth on purple pinions borne, Attend the radiant chariot of the morn; Lead the gay hours along the ethereal hight, 590 And on each dun meridian shower the light; SYLPHS! who from realms of equatorial day To climes, that shudder in the polar ray, From zone to zone pursue on shifting wing, The bright perennial journey of the spring;595 Bring my rich Balms from Mecca's hallow'd glades, Sweet flowers, that glitter in Arabia's shades; Fruits, whose fair forms in bright succession glow Gilding the Banks of Arno, or of Po; Each leaf, whose fragrant steam with ruby lip600 Gay China's nymphs from pictur'd vases sip; Each spicy rind, which sultry India boasts, Scenting the night-air round her breezy coasts; Roots whose bold stems in bleak Siberia blow, And gem with many a tint the eternal snow;605 Barks, whose broad umbrage high in ether waves O'er Ande's steeps, and hides his golden caves; --And, where yon oak extends his dusky shoots Wide o'er the rill, that bubbles from his roots; Beneath whose arms, protected from the storm610 A turf-built altar rears it's rustic form; SYLPHS! with religious hands fresh garlands twine, And deck with lavish pomp HYGEIA'S shrine. "Call with loud voice the Sisterhood, that dwell On floating cloud, wide wave, or bubbling well;615 Stamp with charm'd foot, convoke the alarmed Gnomes From golden beds, and adamantine domes; Each from her sphere with beckoning arm invite, Curl'd with red flame, the Vestal Forms of light. Close all your spotted wings, in lucid ranks620 Press with your bending knees the crowded banks, Cross your meek arms, incline your wreathed brows, And win the Goddess with unwearied vows. "Oh, wave, HYGEIA! o'er BRITANNIA'S throne Thy serpent-wand, and mark it for thy own;625 Lead round her breezy coasts thy guardian trains, Her nodding forests, and her waving plains; Shed o'er her peopled realms thy beamy smile, And with thy airy temple crown her isle!" The GODDESS ceased, --and calling from afar630 The wandering Zephyrs, joins them to her car; Mounts with light bound, and graceful, as she bends, Whirls the long lash, the flexile rein extends; On whispering wheels the silver axle slides, Climbs into air, and cleaves the crystal tides;635 Burst from its pearly chains, her amber hair Streams o'er her ivory shoulders, buoy'd in air; Swells her white veil, with ruby clasp confined Round her fair brow, and undulates behind; The lessening coursers rise in spiral rings, 640 Pierce the slow-sailing clouds, and stretch their shadowy wings. CONTENTS OF THE NOTES. CANTO I. Rosicrucian machinery. 73 All bodies are immersed in the matter of heat. Particles of bodies donot touch each other. 97 Gradual progress of the formation of the earth, and of plants andanimals. Monstrous births 101 Fixed stars approach towards each other, they were projected from chaosby explosion, and the planets projected from them 105 An atmosphere of inflammable air above the common atmosphere principallyabout the poles 123 Twilight fifty miles high. Wants further observations 126 Immediate cause of volcanos from steam and other vapours. They preventgreater earthquakes 152 Conductors of heat. Cold on the tops of mountains 176 Phosphorescent light in the evening from all bodies 177 Phosphoric light from calcined shells. Bolognian stone. Experiments ofBeccari and Wilson 182 Ignis fatuus doubtful 189 Electric Eel. Its electric organs. Compared to the electric Leyden phial202 Discovery of fire. Tools of steel. Forests subdued. Quantity of foodincreased by cookery 212 Medusa originally an hieroglyphic of divine wisdom 218 Cause of explosions from combined heat. Heat given out from air inrespiration. Oxygene looses less heat when converted into nitrous acidthan in any other of its combinations 226 Sparks from the collision of flints are electric. From the collision offlint and steel are from the combustion of the steel 229 Gunpowder described by Bacon. Its power. Should be lighted in thecentre. A new kind of it. Levels the weak and strong 242 Steam-engine invented by Savery. Improved by Newcomen. Perfected by Wattand Boulton 254 Divine benevolence. The parts of nature not of equal excellence 278 Mr. Boulton's steam-engine for the purpose of coining would save manylives from the executioner 281 Labours of Hercules of great antiquity. Pillars of Hercules. Surface ofthe Mediteranean lower than the Atlantic. Abyla and Calpe. Flood ofDeucalion 297 Accumulation of electricity not from friction 335 Mr. Bennet's sensible electrometer 345 Halo of saints is pictorial language 358 We have a sense adapted to perceive heat but not electricity 365 Paralytic limbs move by electric influence 367 Death of Professor Richman by electricity 373 Lightning drawn from the clouds. How to be safe in thunder storms 383 Animal heat from air in respiration. Perpetual necessity of respiration. Spirit of animation perpetually renewed 401 Cupid rises from the egg of night. Mrs. Cosway's painting of thissubject 413 Western-winds. Their origin. Warmer than south-winds. Produce a thaw430 Water expands in freezing. Destroys succulent plants, not resinous ones. Trees in valleys more liable to injury. Fig-trees bent to the ground inwinter 439 Buds and bulbs are the winter cradle of the plant. Defended from frostand from insects. Tulip produces one flower-bulb and several leaf-bulbs, and perishes. 460 Matter of heat is different from light. Vegetables blanched by exclusionof light. Turn the upper surface of their leaves to the light. Waterdecomposed as it escapes from their pores. Hence vegetables purify airin the day time only. 462 Electricity forwards the growth of plants. Silk-worms electrised spinsooner. Water decomposed in vegetables, and by electricity 463 Sympathetic inks which appear by heat, and disappear in the cold. Madefrom cobalt 487 Star in Cassiope's chair 515 Ice-islands 100 fathoms deep. Sea-ice more difficult of solution. Iceevaporates producing great cold. Ice-islands increase. Should benavigated into southern climates. Some ice-islands have floatedsouthwards 60 miles long. Steam attending them in warm climates 529 Monsoon cools the sands of Abyssinia 547 Ascending vapours are electrised plus, as appears from an experiment ofMr. Bennet. Electricity supports vapour in clouds. Thunder showers fromcombination of inflammable and vital airs 553 CANTO II. Solar volcanos analogous to terrestrial and lunar ones. Spots of the sunare excavations 14 Spherical form of the earth. Ocean from condensed vapour. Character ofMr. Whitehurst 17 Granite the oldest part of the earth. Then limestone. And lastly, clay, iron, coal, sandstone. Three great concentric divisions of the globe35 Formation of primeval islands before the production of the moon. Paradise. The Golden Age. Rain-bow. Water of the sea originally fresh36 Venus rising from the sea an hieroglyphic emblem of the production ofthe earth beneath the ocean 47 First great volcanos in the central parts of the earth. From steam, inflammable gas, and vital air. Present volcanos like mole-hills 68 Moon has little or no atmosphere. Its ocean is frozen. Is not yetinhabited, but may be in time 82 Earth's axis changed by the ascent of the moon. Its diurnal motionretarded. One great tide 84 Limestone produced from shells. Spars with double refractions. Marble. Chalk 93 Antient statues of Hercules. Antinous. Apollo. Venus. Designs ofRoubiliac. Monument of General Wade. Statues of Mrs. Damer 101 Morasses rest on limestone. Of immense extent 116 Salts from animal and vegetable bodies decompose each other, exceptmarine salt. Salt mines in Poland. Timber does not decay in them. Rock-salt produced by evaporation from sea-water. Fossil shells in saltmines. Salt in hollow pyramids. In cubes. Sea-water contains about one-thirtieth of salt 119 Nitre, native in Bengal and Italy. Nitrous gas combined with vital airproduces red clouds, and the two airs occupy less space than one of thembefore, and give out heat. Oxygene and azote produce nitrous acid 143 Iron from decomposed vegetables. Chalybeat springs. Fern-leaves innodules of iron. Concentric spheres of iron nodules owing to polarity, like iron-filings arranged by a magnet. Great strata of the earth owingto their polarity 183 Hardness of steel for tools. Gave superiority to the European nations. Welding of steel. Its magnetism. Uses of gold 192 Artificial magnets improved by Savery and Dr. Knight, perfected by Mr. Michel. How produced. Polarity owing to the earth's rotatory motion. Theelectric fluid, and the matter of heat, and magnetism gravitate on eachother. Magnetism being the lightest is found nearest the axis of themotion. Electricity produces northern lights by its centrifugal motion193 Acids from vegetable recrements. Flint has its acid from the new world. Its base in part from the old world, and in part from the new. Preciousstones 215 Diamond. Its great refraction of light. Its volatibility by heat. If aninflammable body. 228 Fires of the new world from fermentation. Whence sulphur and bitumen bysublimation, the clay, coal, and flint remaining 275 Colours not distinguishable in the enamel-kiln, till a bit of dry woodis introduced 283 Etrurian pottery prior to the foundations of Rome. Excelled in fineforms, and in a non-vitreous encaustic painting, which was lost tillrestored by Mr. Wedgwood. Still influences the taste of the inhabitants291 Mr. Wedgwood's cameo of a slave in chains, and of Hope 315 Basso-relievos of two or more colours not made by the antients. Inventedby Mr. Wedgwood 342 Petroleum and naptha have been sublimed. Whence jet and amber. Theyabsorb air. Attract straws when rubbed. Electricity from electron thegreek name for amber 353 Clefts in granite rocks in which metals are found. Iron and manganesefound in all vegetables. Manganese in limestone. Warm springs from steamrising up the clefts of granite and limestone. Ponderous earth inlimestone clefts and in granite. Copper, lead, iron, from descendingmaterials. High mountains of granite contain no ores near their summits. Transmutation of metals. Of lead into calamy. Into silver 398 Armies of Cambytes destroyed by famine, and by sand-storms 435 Whirling turrets of sand described and explained 478 Granite shews iron as it decomposes. Marble decomposes. Immense quantityof charcoal exists in limestone. Volcanic slags decompose, and becomeclay 523 Millstones raised by wooden pegs 524 Hannibal made a passage by fire over the Alps 534 Passed tense of many words twofold, as driven or drove, spoken or spoke. A poetic licence 609 CANTO III. Clouds consist of aqueous spheres, which do not easily unite, likeglobules of quicksilver, as may be seen in riding through water. Owingto electricity. Snow. Hailstones rounded by attrition and dissolution oftheir angles. Not from frozen drops of water 15 Dew on points and edges of grass, or hangs over cabbage-leaves, needlefloats on water 18 Mists over rivers and on mountains. Halo round the moon. Shadow of achurch-steeple upon a mist. Dry mist, or want of transparency of theair, a sign of fair-weather 20 Tides on both sides of the earth. Moon's tides should be much greaterthan the earth's tides. The ocean of the moon is frozen 61 Spiral form of shells saves calcareous matter. Serves them as an organof hearing. Calcareous matter produced from inflamed membranes. Coloursof shells, labradore-stone from mother-pearl. Fossil shells not nowfound recent 66 Sea-insects like flowers. Actinia 82 Production of pearls, not a disease of the fish. Crab's eyes. Reservoirsof pearly matter 84 Rocks of coral in the south-sea. Coralloid limestone at Linsel, andCoalbrook Dale 90 Rocks thrown from mountains, ice from glaciers, and portions of earth, or morasses, removed by columns of water. Earth-motion in Shropshire. Water of wells rising above the level of the ground. St. Alkmond's wellnear Derby might be raised many yards, so as to serve the town. Well atSheerness, and at Hartford in Connecticut 116 Moonsoons attended with rain Overflowing of the Nile. Vortex ofascending air. Rising of the Dogstar announces the floods of the Nile. Anubis hung out upon their temples 129 Situations exempt from rain. At the Line in Lower Egypt. On the coast ofPeru 138 Giesar, a boiling fountain in Iceland. Water with great degrees of heatdissolves siliceous matter. Earthquake from steam 150 Warm springs not from decomposed pyrites. From steam rising up fissuresfrom great depths 166 Buxton bath possesses 82 degrees of heat. Is improperly called a warmbath. A chill at immersion, and then a sensation of warmth, like the eyein an obscure room owing to increased sensibility of the skin 184 Water compounded of pure air and inflammable air with as much matter ofheat as preserves it fluid. Perpetually decomposed by vegetables in thesun's light, and recomposed in the atmosphere 204 Mythological interpretation of Jupiter and Juno designed as an emblem ofthe composition of water from two airs 260 Death of Mrs. French 308 Tomb of Mr. Brindley 341 Invention of the pump. The piston lifts the atmosphere above it. Thesurrounding atmosphere presses up the water into the vacuum. Manner inwhich a child sucks 366 Air-cell in engines for extinguishing fire. Water dispersed by theexplosion of Gunpowder. Houses preserved from fire by earth on thefloors, by a second ceiling of iron-plates or coarse mortar. Woodimpregnated with alabaster or flint 406 Muscular actions and sensations of plants 460 River Achelous. Horn of Plenty 495 Flooding lands defends them from vernal frosts. Some springs depositcalcareous earth. Some contain azotic gas, which contributes to producenitre. Snow water less serviceable 540 CANTO IV. Cacalia produces much honey, that a part may be taken by insects withoutinjury 2 Analysis of common air. Source of azote. Of Oxygene. Water decomposed byvegetable pores and the sun's light. Blood gives out phlogiston andreceives vital air. Acquires heat and the vivifying principle 34 Cupid and Psyche 48 Simoom, a pestilential wind. Described. Owing to volcanic electricity. Not a whirlwind 65 Contagion either animal or vegetable 82 Thyrsis escapes the Plague 91 Barometer and air-pump, Dew on exhausting the receiver though thehygrometer points to dryness. Rare air will dissolve or acquire moreheat, and more moisture, and more electricity 128 Sound propagated best by dense bodies, as wood, and water, and earth. Fish in spiral shells all ear 164 Discoveries of Dr. Priestley. Green vegetable matter. Pure air containedin the calces of metals, as minium, manganese, calamy, ochre 166 Fable of Proserpine an antient chemical emblem 178 Diving balloons supplied with pure air from minium. Account of one byMr. Boyle 195 Mr. Day. Mr. Spalding 217 Captain Pierce and his daughters 219 Pestilential winds of volcanic origin. Jordan flows through a country ofvolcanos 294 Change of wind owing to small causes. If the wind could be governed, theproducts of the earth would be doubled, and its number of inhabitantsincreased 308 Mr. Kirwan's treatise on temperature of climates 342 Seeds of plants. Spawn of fish. Nutriment lodged in seeds. Theirpreservation in their seed-vessels 355 Fixed stars approach each other 369 Fable of the Phoenix 377 Plants visible within bulbs, and buds, and seeds 383 Great Egg of Night 406 Seeds shoot into the ground. Pith. Seed-lobes. Starch converted intosugar. Like animal chyle 411 Light occasions the actions of vegetable muscles. Keeps them awake422 Vegetable love in Parnassia, Nigella. Vegetable adultery in Collinsonia456 Strong vegetable shoots and roots bound with wire, in part debarked, whence leaf-buds converted into flower-buds. Theory of this curious fact463 Branches bent to the horizon bear more fruit 466 Engrafting of a spotted passion-flower produced spots upon the stock. Apple soft on one side and hard on the other 483 Cyprepedium assumes the form of a large spider to affright the humming-bird. Fly-ophris. Willow-wren sucks the honey of the crown-imperial505 Diseases of plants four kinds. Honey-dew 511 Ergot a disease of rye 513 Glass unannealed. Its cracks owing to elasticity. One kind of lead-orecracks into pieces. Prince Rupert's drops. Elastic balls 519 Sleep of plants. Their irritability, sensibility, and voluntary motions538 ADDITIONAL NOTES. NOTE I. --METEORS. _Etherial Forms! you chase the shooting stars, Or yoke the vollied lightnings to your cars. _ CANTO I. L. 115. There seem to be three concentric strata of our incumbent atmosphere; inwhich, or between them, are produced four kinds of meteors; lightning, shooting stars, fire-balls, and northern lights. First, the lower regionof air, or that which is dense enough to resist by the adhesion of itsparticles the descent of condensed vapour, or clouds, which may extendfrom one to three or four miles high. In this region the commonlightning is produced from the accumulation or defect of electric matterin those floating fields of vapour either in respect to each other, orin respect to the earth beneath them, or the dissolved vapour abovethem, which is constantly varying both with the change of the form ofthe clouds, which thus evolve a greater or less surface; and also withtheir ever-changing degree of condensation. As the lightning is thusproduced in dense air, it proceeds but a short course on account of thegreater resistance which it encounters, is attended with a loudexplosion, and appears with a red light. 2. The second region of the atmosphere I suppose to be that which hastoo little tenacity to support condensed vapour or clouds; but which yetcontains invisible vapour, or water in aerial solution. This aerialsolution of water differs from that dissolved in the matter of heat, asit is supported by its adhesion to the particles of air, and is notprecipitated by cold. In this stratum it seems probable that the meteorscalled shooting stars are produced; and that they consist of electricsparks, or lightning, passing from one region to another of theseinvisible fields of aero-aqueous solution. The height of these shootingstars has not yet been ascertained by sufficient observation; Dr. Blagden thinks their situation is lower down in the atmosphere than thatof fireballs, which he conjectures from their swift apparent motion, andascribes their smallness to the more minute division of the electricmatter of which they are supposed to consist, owing to the greaterresistance of the denser medium through which they pass, than that inwhich the fire-balls exist. Mr. Brydone observed that the shooting starsappeared to him to be as high in the atmosphere, when he was near thesummit of mount Etna, as they do when observed from the plain. Phil. Tran. Vol. LXIII. As the stratum of air, in which shooting stars are supposed to exist ismuch rarer than that in which lightning resides, and yet much denserthan that in which fire-balls are produced, they will be attracted at agreater distance than the former, and at a less than the latter. Fromthis rarity of the air so small a sound will be produced by theirexplosion, as not to reach the lower parts of the atmosphere; theirquantity of light from their greater distance being small, is never seenthrough dense air at all, and thence does not appear red, like lightningor fire balls. There are no apparent clouds to emit or to attract them, because the constituent parts of these aero-aqueous regions may possessan abundance or deficiency of electric matter and yet be in perfectreciprocal solution. And lastly their apparent train of light isprobably owing only to a continuance of their impression on the eye; aswhen a fire-stick is whirled in the dark it gives the appearance of acompleat circle of fire: for these white trains of shooting starsquickly vanish, and do not seem to set any thing on fire in theirpassage, as seems to happen in the transit of fire-balls. 3. The second region or stratum of air terminates I suppose where thetwilight ceases to be refracted, that is, where the air is 3000 timesrarer than at the surface of the earth; and where it seems probable thatthe common air ends, and is surrounded by an atmosphere of inflammablegas tenfold rarer than itself. In this region I believe fire-ballssometimes to pass, and at other times the northern lights to exist. Oneof these fire-balls or draco volans, was observed by Dr. Pringle andmany others on Nov. 26, 1758, which was afterwards estimated to havebeen a mile and a half in circumference, to have been about one hundredmiles high, and to have moved towards the north with a velocity of nearthirty miles in a second of time. This meteor had a real tail many mileslong, which threw off sparks in its course, and the whole exploded witha sound like distant thunder. Philos. Trans. Vol. LI. Dr. Blagden has related the history of another large meteor, or fire-ball, which was seen the 18th of August, 1783, with many ingeniousobservations and conjectures. This was estimated to be between 60 and 70miles high, and to travel 1000 miles at the rate of about twenty milesin a second. This fire-ball had likewise a real train of light leftbehind it in its passage, which varied in colour; and in some part ofits course gave off sparks or explosions where it had been brightest;and a dusky red streak remained visible perhaps a minute. Philos. Trans. Vol. LXXIV. These fire-balls differ from lightning, and from shooting stars in manyremarkable circumstances; as their very great bulk, being a mile and ahalf in diameter; their travelling 1000 miles nearly horizontally; theirthrowing off sparks in their passage; and changing colours from brightblue to dusky red; and leaving a train of fire behind them, continuingabout a minute. They differ from the northern lights in not beingdiffused, but passing from one point of the heavens to another in adefined line; and this in a region above the crepuscular atmosphere, where the air is 3000 tines rarer than at the surface of the earth. There has not yet been even a conjecture which can account for theseappearances!--One I shall therefore hazard; which, if it does notinform, may amuse the reader. In the note on l. 123, it was shewn that there is probably a supernatantstratum of inflammable gas or hydrogene, over the common atmosphere; andwhose density at the surface where they meet, must be at least ten timesless than that upon which it swims; like chemical ether floating uponwater, and perhaps without any real contact. 1. In this region, wherethe aerial atmosphere terminates and the inflammable one begins, thequantity of tenacity or resistance must be almost inconceivable; inwhich a ball of electricity might pass 1000 miles with greater ease thanthrough a thousandth part of an inch of glass. 2. Such a ball ofelectricity passing between inflammable and common air would set fire tothem in a line as it patted along; which would differ in colouraccording to the greater proportionate commixture of the two airs; andfrom the same cause there might occur greater degrees of inflammation, or branches of fire, in some parts of its course. As these fire-balls travel in a defined line, it is pretty evident fromthe known laws of electricity, that they must be attracted; and as theyare a mile or more in diameter, they must be emitted from a largesurface of electric matter; because large nobs give larger sparks, lessdiffused, and more brightly luminous, than less ones or points, andresist more forceably the emission of the electric matter. What is therein nature can attract them at so great a distance as 1000 miles, and soforceably as to detach an electric spark of a mile diameter? Canvolcanos at the time of their eruptions have this effect, as they aregenerally attended with lightning? Future observations must discoverthese secret operations of nature! As a stream of common air is carriedalong with the passage of electric aura from one body to another; it iseasy to conceive, that the common air and the inflammable air betweenwhich the fire-ball is supposed to pass, will be partially intermixed bybeing thus agitated, and so far as it becomes intermixed it will takefire, and produce the linear flame and branching sparks above described. In this circumstance of their being attracted, and thence passing in adefined line, the fire-balls seem to differ from the coruscations of theaurora borealis, or northern lights, which probably take place in thesame region of the atmosphere; where the common air exists in extremetenuity, and is covered by a still rarer sphere of inflammable gas, tentimes lighter than itself. As the electric streams, which constitute these northern lights, seem tobe repelled or radiated from an accumulation of that fluid in the north, and not attracted like the fireballs; this accounts for the diffusion oftheir light, as well as the silence of their passage; while theirvariety of colours, and the permanency of them, and even the breadth ofthem in different places, may depend on their setting on fire themixture of inflammable and common air through which they pass; as seemsto happen in the transit of the fire-balls. It was observed by Dr. Priestley that the electric shock taken throughinflammable air was red, in common air it is blueish; to thesecircumstances perhaps some of the colours of the northern lights maybear analogy; though the density of the medium through which light isseen must principally vary its colour, as is well explained by Mr. Morgan. Phil. Trans. Vol. LXXV. Hence lightning is red when seen througha dark cloud, or near the horizon; because the more refrangible rayscannot permeate so dense a medium. But the shooting stars consist ofwhite light, as they are generally seen on clear nights, and nearlyvertical: in other situations their light is probably too faint to cometo us. But as in some remarkable appearances of the northern lights, asin March, 1716, all the prismatic colours were seen quickly to succeedeach other, these appear to have been owing to real combustion; as thedensity of the interposed medium could not be supposed to change sofrequently; and therefore these colours must have been owing todifferent degrees of heat according to Mr. Morgan's theory ofcombustion. In Smith's Optics, p. 69. The prismatic colours, and opticaldeceptions of the northern lights are described by Mr. Cotes. The Torricellian vacuum, if perfectly free from air, is said by Mr. Morgan and others to be a perfect non-conductor. This circumstancetherefore would preclude the electric streams from rising above theatmosphere. But as Mr. Morgan did not try to pass an electric shockthrough a vacuum, and as air, or something containing air, surroundingthe transit of electricity may be necessary to the production of light, the conclusion may perhaps still be dubious. If however the streams ofthe northern lights were supposed to rise above our atmosphere, theywould only be visible at each extremity of their course; where theyemerge from, or are again immerged into the atmosphere; but not in theirjourney through the vacuum; for the absence of electric light in avacuum is sufficiently proved by the common experiment of shaking abarometer in the dark; the electricity, produced by the friction of themercury in the glass at its top, is luminous if the barometer has alittle air in it; but there is no light if the vacuum be complete. The aurora borealis, or northern dawn, is very ingeniously accounted forby Dr. Franklin on principles of electricity. He premises the followingelectric phenomena: 1. That all new fallen snow has much positiveelectricity standing on its surface. 2. That about twelve degrees oflatitude round the poles are covered with a crust of eternal ice, whichis impervious to the electric fluid. 3. That the dense part of theatmosphere rises but a few miles high; and that in the rarer parts of itthe electric fluid will pass to almost any distance. Hence he supposes there must be a great accumulation of positiveelectric matter on the fresh fallen snow in the polar regions; which, not being able to pass through the crust of ice into the earth, mustrise into the rare air of the upper parts of our atmosphere, which willthe least resist its passage; and passing towards the equator descendagain into the denser atmosphere, and thence into the earth in silentstreams. And that many of the appearances attending these lights areoptical deceptions, owing to the situation of the eye that beholds them;which makes all ascending parallel lines appear to converge to a point. The idea, above explained in note on l. 123, of the existence of asphere of inflammable gas over the aerial atmosphere would much favourthis theory of Dr. Franklin; because in that case the dense aerialatmosphere would rise a much less height in the polar regions, diminishing almost to nothing at the pole itself; and thus give aneasier passage to the ascent of the electric fluid. And from the greatdifference in the specific gravity of the two airs, and the velocity ofthe earth's rotation, there must be a place between the poles and theequator, where the superior atmosphere of inflammable gas wouldterminate; which would account for these streams of the aurora borealisnot appearing near the equator; add to this that it is probable theelectric fluid may be heavier than the magnetic one; and will thence bythe rotation of the earth's surface ascend over the magnetic one by itscentrifugal force; and may thus be induced to rise through the thinstratum of aerial atmosphere over the poles. See note on Canto II. L. 193. I shall have occasion again to mention this great accumulation ofinflammable air over the poles; and to conjecture that these northernlights may be produced by the union of inflammable with common air, without the assistance of the electric spark to throw them intocombustion. The antiquity of the appearance of northern lights has been doubted; asnone were recorded in our annals since the remarkable one on Nov. 14, 1574, till another remarkable one on March 6, 1716, and the threefollowing nights, which were seen at the same time in Ireland, Russia, and Poland, extending near 30 degrees of longitude and from about the50th degree of latitude over almost all the north of Europe. There ishowever reason to believe them of remote antiquity though inaccuratelydescribed; thus the following curious passage from the Book ofMaccabees, (B. II. C. V. ) is such a description of them, as mightprobably be given by an ignorant and alarmed people. "Through all thecity, for the space of almost forty days, there were seen horsemenrunning in the air, in cloth of gold, and armed with lances, like a bandof soldiers; and troops of horsemen in array encountering and runningone against another, with shaking of shields and multitude of pikes, anddrawing of swords, and casting of darts, and glittering of goldenornaments and harness. " NOTE II. --PRIMARY COLOURS. _Cling round the aerial bow with prisms bright, And pleased untwist the sevenfold threads of light. _ CANTO I. L. 117. The manner in which the rainbow is produced was in some measureunderstood before Sir Isaac Newton had discovered his theory of colours. The first person who expressly shewed the rainbow to be formed by thereflection of the sunbeams from drops of falling rain was Antonio deDominis. This was afterwards more fully and distinctly explained by DesCartes. But what caused the diversity of its colours was not thenunderstood; it was reserved for the immortal Newton to discover that therays of light consisted of seven combined colours of differentrefrangibility, which could be seperated at pleasure by a wedge ofglass. Pemberton's View of Newton. Sir Isaac Newton discovered that the prismatic spectrum was composed ofseven colours in the following proportions, violet 80, indigo 40, blue60, green 60, yellow 48, orange 27, red 45. If all these colours bepainted on a circular card in the proportions above mentioned, and thecard be rapidly whirled on its center, they produce in the eye thesensation of white. And any one of these colours may be imitated bypainting a card with the two colours which are contiguous to it, in thesame proportions as in the spectrum, and whirling them in the samemanner. My ingenious friend, Mr. Galton of Birmingham, ascertained inthis manner by a set of experiments the following propositions; thetruth of which he had preconceived from the above data. 1. Any colour in the prismatic spectrum may be imitated by a mixture ofthe two colours contiguous to it. 2. If any three successive colours in the prismatic spectrum are mixed, they compose only the second or middlemost colour. 3. If any four succesive colours in the prismatic spectrum be mixed, atint similar to a mixture of the second and third colours will beproduced, but not precisely the same, because they are not in the sameproportion. 4. If beginning with any colour in the circular spectrum, you take ofthe second colour a quantity equal to the first, second, and third; andadd to that the fifth colour, equal in quantity to the fourth, fifth, and sixth; and with these combine the seventh colour in the proportionit exists in the spectrum, white will be produced. Because the first, second, and third, compose only the second; and the fourth, fifth, andsixth, compose only the fifth; therefore if the seventh be added, thesame effect is produced, as if all the seven were employed. 5. Beginning with any colour in the circular spectrum, if you take atint composed of a certain proportion of the second and third, (equal inquantity to the first, second, third, and fourth, ) and add to this thesixth colour equal in quantity to the fifth, sixth, and seventh, whitewill be produced. From these curious experiments of Mr. Galton many phenomena in thechemical changes of colours may probably become better understood;especially if, as I suppose, the same theory must apply to transmittedcolours, as to reflected ones. Thus it is well known, that if the glassof mangonese, which is a tint probably composed of violet and indigo, bemixed in a certain proportion with the glass of lead, which is yellow;that the mixture becomes transparent. Now from Mr. Galton's experimentsit appears, that in reflected colours such a mixture would producewhite, that is, the same as if all the colours were reflected. Andtherefore in transmitted colours the same circumstances must producetransparency, that is, the same as if all the colours were transmitted. For the particles, which constitute the glass of mangonese will transmitred, violet, indigo, and blue; and those of the glass of lead willtransmit orange, yellow, and green; hence all the primary colours by amixture of these glasses become transmitted, that is, the glass becomestransparent. Mr. Galton has further observed that five successive prismatic coloursmay be combined in such proportions as to produce but one colour, acircumstance which might be of consequence in the art of painting. Forif you begin at any part of the circular spectrum above described, andtake the first, second, and third colours in the proportions in whichthey exist in the spectrum; these will compose only the second colourequal in quantity to the first, second, and third; add to these thethird, fourth, and fifth in the proportion they exist in the spectrum, and these will produce the fourth colour equal in quantity to the third, fourth, and fifth. Consequently this is precisely the same thing, asmixing the second and fourth colours only; which mixture would onlyproduce the third colour. Therefore if you combine the first, second, fourth, and fifth in the proportions in which they exist in thespectrum, with double the quantity of the third colour, this thirdcolour will be produced. It is probable that many of the unexpectedchanges in mixing colours on a painter's easle, as well as in more fluidchemical mixtures, may depend on these principles rather than on a newarrangement or combination of their minute particles. Mr. Galton further observes, that white may universally be produced bythe combination of one prismatic colour, and a tint intermediate to twoothers. Which tint may be distinguished by a name compounded of the twocolours, to which it is intermediate. Thus white is produced by amixture of red with blue-green. Of orange with indigo-blue. Of Yellowwith violet-indigo. Of green with red-violet. Of blue with Orange-red. Of indigo with yellow-orange. Of violet with green-yellow. Which hefurther remarks exactly coincides with the theory and facts mentioned byDr. Robert Darwin of Shrewsbury in his account of ocular spectra; whohas shewn that when one of these contrasted colours has been longviewed, a spectrum or appearance of the other becomes visible in thefatigued eye. Philos. Trans. Vol. LXXVI. For the year 1786. These experiments of Mr. Galton might much assist the copper-plateprinters of callicoes and papers in colours; as three colours or moremight be produced by two copper-plates. Thus suppose some yellow figureswere put on by the first plate, and upon some parts of these yellowfigures and on other parts of the ground blue was laid on by anothercopper-plate. The three colours of yellow, blue, and green might beproduced; as green leaves with yellow and blue flowers. NOTE III. --COLOURED CLOUDS. _Eve's silken couch with gorgeous tints adorn, Or fire the arrowy throne of rising morn. _ CANTO I. L. 119. The rays from the rising and setting sun are refracted by our sphericalatmosphere, hence the most refrangible rays, as the violet, indigo, andblue are reflected in greater quantities from the morning and eveningskies; and the least refrangible ones, as red and orange, are last seenabout the setting sun. Hence Mr. Beguelin observed that the shadow ofhis finger on his pocket-book was much bluer in the morning and evening, when the shadow was about eight times as long as the body from which itwas projected. Mr. Melville observes, that the blue rays being morerefrangible are bent down in the evenings by our atmosphere, while thered and orange being less refrangible continue to pass on and tinge themorning and evening clouds with their colours. See Priestley's Historyof Light and Colours, p. 440. But as the particles of air, like those ofwater, are themselves blue, a blue shadow may be seen at all times ofthe day, though much more beautifully in the mornings and evenings, orby means of a candle in the middle of the day. For if a shadow on apiece of white paper is produced by placing your finger between thepaper and a candle in the day light, the shadow will appear very blue;the yellow light of the candle upon the other parts of the paperapparently deepens the blue by its contrast; these colours beingopposite to each other, as explained in note II. Colours are produced from clouds or mists by refraction, as well as byreflection. In riding in the night over an unequal country I observed avery beautiful coloured halo round the moon, whenever I was covered witha few feet of mist, as I ascended from the vallies; which ceased toappear when I rose above the mist. This I suppose was owing to thethinness of the stratum of mist, in which I was immersed; had it beenthicker, the colours refracted by the small drops, of which a fogconsists, would not have passed through it down to my eye. There is a bright spot seen on the cornea of the eye, when we face awindow, which is much attended to by portrait painters; this is thelight reflected from the spherical surface of the polished cornea, andbrought to a focus; if the observer is placed in this focus, he sees theimage of the window; if he is placed before or behind the focus, he onlysees a luminous spot, which is more luminous and of less extent, thenearer he approaches to the focus. The luminous appearance of the eyesof animals in the dusky corners of a room, or in holes in the earth, mayarise in some instances from the same principle; viz. The reflection ofthe light from the spherical cornea; which will be coloured red or bluein some degree by the morning, evening, or meridian light; or by theobjects from which that light is previously reflected. In the cavern atColebrook Dale, where the mineral tar exsudes, the eyes of the horse, which was drawing a cart from within towards the mouth of it, appearedlike two balls of phosphorus, when he was above 100 yards off, and for along time before any other part of the animal was visible. In this caseI suspect the luminous appearance to have been owing to the light, whichhad entered the eye, being reflected from the back surface of thevitreous humour, and thence emerging again in parallel rays from theanimals eye, as it does from the back surface of the drops of therainbow, and from the water-drops which lie, perhaps without contact, oncabbage-leaves, and have the brilliancy of quicksilver. This accountsfor this luminous appearance being best seen in those animals which havelarge apertures in their iris, as in cats and horses, and is the onlypart visible in obscure places, because this is a better reflectingsurface than any other part of the animal. If any of these emergent raysfrom the animals eye can be supposed to have been reflected from thechoroid coat through the semi-transparent retina, this would account forthe coloured glare of the eyes of dogs or cats and rabits in darkcorners. NOTE IV. --COMETS. _Alarm with comet-blaze the sapphire plain, The wan stars glimmering through its silver train. _ CANTO I. L. 133. There have been many theories invented to account for the tails ofcomets. Sir Isaac Newton thinks that they consist of rare vapours raisedfrom the nucleus of the comet, and so rarefied by the sun's heat as tohave their general gravitation diminished, and that they in consequenceascend opposite to the sun, and from thence reflect the rays of light. Dr. Halley compares the light of the tails of comets to the streams ofthe aurora borealis, and other electric effluvia. Philos. Trans. No. 347. Dr. Hamilton observes that the light of small stars are seenundiminished through both the light of the tails of comets, and of theaurora borealis, and has further illustrated their electric analogy, andadds that the tails of comets consist of a lucid self-shining substancewhich has not the power of refracting or reflecting the rays of light. Essays. The tail of the comet of 1744 at one time appeared to extend above 16degrees from its body, and must have thence been above twenty threemillions of miles long. And the comet of 1680, according to thecalculations of Dr. Halley on November the 11th, was not above one semi-diameter of the earth, or less than 4000 miles to the northward of theway of the earth; at which time had the earth been in that part of itsorbit, what might have been the consequence! no one would probably havesurvived to have registered the tremendous effects. The comet of 1531, 1607, and 1682 having returned in the year 1759, according to Dr. Halley's prediction in the Philos. Trans. For 1705, there seems no reason to doubt that all the other comets will returnafter their proper periods. Astronomers have in general acquiesced inthe conjecture of Dr. Halley, that the comets of 1532, and 1661 are oneand the same comet, from the similarity of the elements of their orbits, and were therefore induced to expect its return to its perihelium 1789. As this comet is liable to be disturbed in its ascent from the sun bythe planets Jupiter and Saturn, Dr. Maskelyne expected its return to itsperihelium in the beginning of the year 1789, or the latter end of theyear 1788, and certainly sometime before the 27th of April, 1789, whichprediction has not been fulfilled. Phil. Trans. Vol. LXXVI. NOTE V. --SUN'S RAYS. _Or give the sun's phlogistic orb to roll. _ CANTO I. L. 136. The dispute among philosophers about phlogiston is not concerning theexistence of an inflammable principle, but rather whether there be oneor more inflammable principles. The disciples of Stahl, which tilllately included the whole chemical world, believed in the identity ofphlogiston in all bodies which would flame or calcine. The disciples ofLavoisier pay homage to a plurality of phlogistons under the variousnames of charcoal, sulphur, metals, &c. Whatever will unite with _pure_air, and thence compose an acid, is esteemed in this ingenious theory tobe a different kind of phlogistic or inflammable body. At the same timethere remains a doubt whether these inflammable bodies, as metals, sulphur, charcoal, &c. May not be compounded of the same phlogistonalong with some other material yet undiscovered, and thus an unity ofphlogiston exist, as in the theory of Stahl, though very differentlyapplied in the explication of chemical phenomena. Some modern philosophers are of opinion that the sun is the greatfountain from which the earth and other planets derive all thephlogiston which they possess; and that this is formed by thecombination of the solar rays with all opake bodies, but particularlywith the leaves of vegetables, which they suppose to be organs adaptedto absorb them. And that as animals receive their nourishment fromvegetables they also obtain in a secondary manner their phlogiston fromthe sun. And lastly as great masses of the mineral kingdom, which havebeen found in the thin crust of the earth which human labour haspenetrated, have evidently been formed from the recrements of animal andvegetable bodies, these also are supposed thus to have derived theirphlogiston from the sun. Another opinion concerning the sun's rays is, that they are not luminoustill they arrive at our atmosphere; and that there uniting with somepart of the air they produce combustion, and light is emitted, and thatan etherial acid, yet undiscovered, is formed from this combustion. The more probable opinion is perhaps, that the sun is a phlogistic massof matter, whose surface is in a state of combustion, which like otherburning bodies emits light with immense velocity in all directions; thatthese rays of light act upon all opake bodies, and combining with themeither displace or produce their elementary heat, and become chemicallycombined with the phlogistic part of them; for light is given out whenphlogistic bodies unite with the oxygenous principle of the air, as incombustion, or in the reduction of metallic calxes; thus in presentingto the flame of a candle a letter-wafer, (if it be coloured with red-lead, ) at the time the red-lead becomes a metallic drop, a flash oflight is perceived. Dr. Alexander Wilson very ingeniously endeavours toprove that the sun is only in a state of combustion on its surface, andthat the dark spots seen on the disk are excavations or caverns throughthe luminous crust, some of which are 4000 miles in diameter. Phil. Trans. 1774. Of this I shall have occasion to speak again. NOTE VI. --CENTRAL FIRES. _Round her still centre tread the burning soil, And watch the billowy Lavas, as they boil. _ CANTO I. L. 139. M. De Mairan in a paper published in the Histoire de l'Academie deSciences, 1765, has endeavoured to shew that the earth receives but asmall part of the heat which it possesses, from the sun's rays, but isprincipally heated by fires within itself. He thinks the sun is thecause of the vicissitudes of our seasons of summer and winter by a verysmall quantity of heat in addition to that already residing in theearth, which by emanations from the centre to the circumference rendersthe surface habitable, and without which, though the sun was constantlyto illuminate two thirds of the globe at once, with a heat equal to thatat the equator, it would soon become a mass of solid ice. His reasoningsand calculations on this subject are too long and too intricate to beinserted here, but are equally curious and ingenious and carry muchconviction along with them. The opinion that the center of the earth consists of a large mass ofburning lava, has been espoused by Boyle, Boerhave, and many otherphilosophers. Some of whom considering its supposed effects onvegetation and the formation of minerals have called it a second sun. There are many arguments in support of this opinion, 1. Because thepower of the sun does not extend much beyond ten feet deep into theearth, all below being in winter and summer always of the same degree ofheat, viz. 48, which being much warmer than the mildest frost, issupposed to be sustained by some internal distant fire. Add to thishowever that from experiments made some years ago by Dr. Franklin thespring-water at Philadelphia appeared to be of 52° of heat, which seemsfurther to confirm this opinion, since the climates in North America aresupposed to be colder than those of Europe under similar degrees oflatitude. 2. Mr. De Luc in going 1359 feet perpendicular into the minesof Hartz on July the 5th, 1778, on a very fine day found the air at thebottom a little warmer than at the top of the shaft. Phil. Trans. Vol. LXIX. P. 488. In the mines in Hungary, which are 500 cubits deep, theheat becomes very troublesome when the miners get below 480 feet depth. _Morinus de Locis subter_. P. 131. But as some other deep mines asmentioned by Mr. Kirwan are said to possess but the common heat of theearth; and as the crust of the globe thus penetrated by human labour isso thin compared with the whole, no certain deduction can be made fromthese facts on either side of the question. 3. The warm-springs in manyparts of the earth at great distance from any Volcanos seem to originatefrom the condensation of vapours arising from water which is boiled bysubterraneous fires, and cooled again in their passage through a certainlength of the colder soil; for the theory of chemical solution will notexplain the equality of their heat at all seasons and through so manycenturies. See note on Fucus in Vol. II. See a letter on this subject inMr. Pilkinton's View of Derbyshire from Dr. Darwin. 4. From thesituations of volcanos which are always found upon the summit of thehighest mountains. For as these mountains have been lifted up and loseseveral of their uppermost strata as they rise, the lowest strata of theearth yet known appear at the tops of the highest hills; and the beds ofthe Volcanos upon these hills must in consequence belong to the loweststrata of the earth, consisting perhaps of granite or basaltes, whichwere produced before the existance of animal or vegetable bodies, andmight constitute the original nucleus of the earth, which I havesupposed to have been projected from the sun, hence the volcanosthemselves appear to be spiracula or chimneys belonging to great centralfires. It is probably owing to the escape of the elastic vapours fromthese spiracula that the modern earthquakes are of such small extentcompared with those of remote antiquity, of which the vestiges remainall over the globe. 5. The great size and height of the continents, andthe great size and depth of the South-sea, Atlantic, and other oceans, evince that the first earthquakes, which produced these immense changesin the globe, must have been occasioned by central fires. 6. The verydistant and expeditious communication of the shocks of some greatearthquakes. The earthquake at Lisbon in 1755 was perceived in Scotland, in the Peak of Derbyshire, and in many other distant parts of Europe. The percussions of it travelled with about the velocity of sound, viz. About thirteen miles in a minute. The earthquake in 1693 extended 2600leagues. (Goldsmith's History. ) These phenomena are easily explained ifthe central parts of the earth consist of a fluid lava, as a percussionon one part of such a fluid mass would be felt on other parts of itsconfining vault, like a stroke on a fluid contained in a bladder, whichhowever gentle on one side is perceptible to the hand placed on theother; and the velocity with which such a concussion would travel wouldbe that of sound, or thirteen miles in a minute. For further informationon this part of the subject the reader is referred to Mr. Michell'sexcellent Treatise on Earthquakes in the Philos. Trans. Vol. LI. 7. Thatthere is a cavity at the center of the earth is made probable by thelate experiments on the attraction of mountains by Mr. Maskerlyne, whosupposed from other considerations that the density of the earth nearthe surface should be five times less than its mean density. Phil. Trans. Vol. LXV. P. 498. But found from the attraction of the mountainSchehallien, that it is probable, the mean density of the earth is butdouble that of the hill. Ibid. P. 532. Hence if the first supposition bewell founded there would appear to be a cavity at the centre ofconsiderable magnitude, from whence the immense beds and mountains oflava, toadstone, basaltes, granite, &c. Have been protruded. 8. Thevariation of the compass can only be accounted for by supposing thecentral parts of the earth to consist of a fluid mass, and that part ofthis fluid is iron, which requiring a greater degree of heat to bring itinto fusion than glass or other metals, remains a solid, and the visinertiae of this fluid mass with the iron in it, occasions it to performfewer revolutions than the crust of solid earth over it, and thus it isgradually left behind, and the place where the floating iron resides ispointed to by the direct or retrograde motions of the magnetic needle. This seems to have been nearly the opinion of Dr. Halley and Mr. Euler. NOTE VII. --ELEMENTARY HEAT. _Or sphere on sphere in widening waves expand, And glad with genial warmth the incumbent land. _ CANTO I. L. 143. A certain quantity of heat seems to be combined with all bodies besidesthe sensible quantity which gravitates like the electric fluid amongstthem. This combined heat or latent heat of Dr. Black, when set atliberty by fermentation, inflammation, crystallization, freezing, orother chemical attractions producing new _combinations_, passes as afluid element into the surrounding bodies. And by thawing, diffusion ofneutral salts in water, melting, and other chemical _solutions_, aportion of heat is attracted from the bodies in vicinity and enters intoor becomes combined with the new solutions. Hence a _combination_ of metals with acids, of essential oils and acids, of alcohol and water, of acids and water, give out heat; whilst a_solution_ of snow in water or in acids, and of neutral salts in water, attract heat from the surrounding bodies. So the acid of nitre mixedwith oil of cloves unites with it and produces a most violent flame; thesame acid of nitre poured on snow instantly dissolves it and producesthe greatest degree of cold yet known, by which at Petersburghquicksilver was first frozen in 1760. Water may be cooled below 32º without being frozen, if it be placed on asolid floor and secured from agitation, but when thus cooled below thefreezing point the least agitation turns part of it suddenly into ice, and when this sudden freezing takes place a thermometer placed in itinstantly rises as some heat is given out in the act of congelation, andthe ice is thus left with the same _sensible_ degree of cold as thewater had possessed before it was agitated, but is nevertheless nowcombined with less _latent_ heat. A cubic inch of water thus cooled down to 32° mixed with an equalquantity of boiling water at 212° will cool it to the middle numberbetween these two, or to 122. But a cubic inch of ice whose sensiblecold also is but 32, mixed with an equal quantity of boiling water, willcool it six times as much as the cubic inch of cold waterabove-mentioned, as the ice not only gains its share of the sensible orgravitating heat of the boiling water but attracts to itself also andcombines with the quantity of latent heat which it had lost at the timeof its congelation. So boiling water will acquire but 212° of heat under the common pressureof the atmosphere, but the steam raised from it by its expansion or byits solution in the atmosphere combines with and carries away aprodigious quantity of heat which it again parts with on itscondensation; as is seen in common distillation where the large quantityof water in the worm-tub is so soon heated. Hence the evaporation ofether on a thermometer soon sinks the mercury below freezing, and hencea warmth of the air in winter frequently succeeds a shower. When the matter of heat or calorique is set at liberty from itscombinations, as by inflammation, it passes into the surrounding bodies, which possess different capacities of acquiring their share of the looseor sensible heat; thus a pint measure of cold water at 48° mixed with apint of boiling water at 212° will cool it to the degree between thesetwo numbers, or to 154°, but it requires two pint measures ofquicksilver at 48° of heat to cool one pint of water as above. These andother curious experiments are adduced by Dr. Black to evince theexistance of combined or latent heat in bodies, as has been explained bysome of his pupils, and well illustrated by Dr. Crawford. The world haslong been in expectation of an account of his discoveries on thissubject by the celebrated author himself. As this doctrine of elementary heat in its fluid and combined state isnot yet universally received, I shall here add two arguments in supportof it drawn from different sources, viz. From the heat given out orabsorbed by the mechanical condensation or expansion of the air, andperhaps of other bodies, and from the analogy of the various phenomenaof heat with those of electricity. I. If a thermometer be placed in the receiver of an air-pump, and theair hastily exhausted, the thermometer will sink some degrees, and theglass become steamy; the same occurs in hastily admitting a part of theair again. This I suppose to be produced by the expansion of part of theair, both during the exhaustion and re-admission of it; and that the airso expanded becomes capable of attracting from the bodies in itsvicinity a part of their heat, hence the vapours contained in it and theglass receiver are for a time colder and the steam is precipitated. Thatthe air thus parts with its moisture from the cold occasioned by itsrarefaction and not simply by the rarefaction itself is evident, becausein a minute or two the same rarefied air will again take up the dewdeposited on the receiver; and because water will evaporate sooner inrare than in dense air. There is a curious phenomenon similar to this observed in the fountainof Hiero constructed on a large scale at the Chemnicensian mines inHungary. In this machine the air in a large vessel is compressed by acolumn of water 260 feet high, a stop-cock is then opened, and as theair issues out with great vehemence, and thus becomes immediatelygreatly expanded, so much cold is produced that the moisture from thisstream of air is precipitated in the form of snow, and ice is formedadhering to the nosel of the cock. This remarkable circumstance isdescribed at large with a plate of the machine in Philos. Trans. Vol. LII. For 1761. The following experiment is related by Dr. Darwin in the Philos. Trans. Vol. LXXVIII. Having charged an air-gun as forcibly as he well could theair-cell and syringe became exceedingly hot, much more so than could beascribed to the friction in working it; it was then left about half anhour to cool down to the temperature of the air, and a thermometerhaving been previously fixed against a wall, the air was discharged in acontinual stream on its bulb, and it sunk many degrees. From these threeexperiments of the steam in the exhausted receiver being deposited andre-absorbed, when a part of the air is exhausted or re-admitted, and thesnow produced by the fountain of Hiero, and the extraordinary heat givenout in charging, and the cold produced in discharging an air-gun, thereis reason to conclude that when air is mechanically compressed theelementary fluid heat is pressed out of it, and that when it ismechanically expanded the same fluid heat is re-absorbed from the commonmass. It is probable all other bodies as well as air attract heat from theirneighbours when they are mechanically expanded, and give it out whenthey are mechanically condensed. Thus when a vibration of the particlesof hard bodies is excited by friction or by percussion, these particlesmutually recede from and approach each other reciprocally; at the timesof their recession from each other, the body becomes enlarged in bulk, and is then in a condition to attract heat from those in its vicinitywith great and sudden power; at the times of their approach to eachother this heat is again given out, but the bodies in contact having inthe mean while received the heat they had thus lost, from other bodiesbehind them, do not so suddenly or so forcibly re-absorb the heat againfrom the body in vibration; hence it remains on its surface like theelectric fluid on a rubbed glass globe, and for the same reason, becausethere is no good conductor to take it up again. Hence at every vibrationmore and more heat is acquired and stands loose upon the surface; as infiling metals or rubbing glass tubes; and thus a smith with a fewstrokes on a nail on his anvil can make it hot enough to light abrimstone-match; and hence in striking flint and steel together heatenough is produced to vitrify the parts thus strucken off, the quantityof which heat is again probably increased by the new chemicalcombination. II. The analogy between the phenomena of the electric fluid and of heatfurnishes another argument in support of the existence of heat as agravitating fluid. 1. They are both accumulated by friction on theexcited body. 2. They are propagated easily or with difficalty along thesame classes of bodies; with ease by metals, with less ease by water;and with difficulty by resins, bees-wax, silk, air, and glass. Thusglass canes or canes of sealing-wax may be melted by a blow-pipe or acandle within a quarter of an inch of the fingers which hold them, without any inconvenient heat, while a pin or other metallic substanceapplyed to the flame of a candle so readily conducts the heat asimmediately to burn the fingers. Hence clothes of silk keep the bodywarmer than clothes of linen of equal thickness, by confining the heatupon the body. And hence plains are so much warmer than the summits ofmountains by the greater density of the air confining the acquired heatupon them. 3. They both give out light in their passage through air, perhaps not in their passage through a vacuum. 4. They both of them fuseor vitrify metals. 5. Bodies after being electrized if they aremechanically extended will receive a greater quantity of electricity, asin Dr. Franklin's experiment of the chain in the tankard; the same seemstrue in respect to heat as explained above. 6. Both heat and electricitycontribute to suspend steam in the atmosphere by producing or increasingthe repulsion of its particles. 7. They both gravitate, when they havebeen accumulated, till they find their equilibrium. If we add to the above the many chemical experiments which receive aneasy and elegant explanation from the supposed matter of heat, asemployed in the works of Bergman and Lavoisier, I think we mayreasonably allow of its existence as an element, occasionally combinedwith other bodies, and occasionally existing as a fluid, like theelectric fluid gravitating amongst them, and that hence it may bepropagated from the central fires of the earth to the whole mass, andcontribute to preserve the mean heat of the earth, which in this countryis about 48 degrees but variable from the greater or less effect of thesun's heat in different climates, so well explained in Mr. Kirwan'sTreatise on the Temperature of different Latitudes. 1787, Elmsly. London. NOTE VIII. --MEMNON'S LYRE. _So to the sacred Sun in Memnon's fane Spontaneous concords quired the matin strain. _ CANTO I. L. 183. The gigantic statue of Memnon in his temple at Thebes had a lyre in hishands, which many credible writers assure us, sounded when the risingsun shone upon it. Some philosophers have supposed that the sun's lightpossesses a mechanical impulse, and that the sounds abovementioned mightbe thence produced. Mr. Michell constructed a very tender horizontalbalance, as related by Dr. Priestley in his history of light andcolours, for this purpose, but some experiments with this balance whichI saw made by the late Dr. Powel, who threw the focus of a largereflector on one extremity of it, were not conclusive either way, as thecopper leaf of the balance approached in one experiment and receded inanother. There are however methods by which either a rotative or alternatingmotion may be produced by very moderate degrees of heat. If a straightglass tube, such as are used for barometers, be suspended horizontallybefore a fire, like a roasting spit, it will revolve by intervals; foras glass is a bad conductor of heat the side next the fire becomesheated sooner than the opposite side, and the tube becomes bent into abow with the external part of the curve towards the fire, this curvethen falls down and produces a fourth part of a revolution of the glasstube, which thus revolves with intermediate pauses. Another alternating motion I have seen produced by suspending a glasstube about eight inches long with bulbs at each end on a centre like ascale beam. This curious machine is filled about one third part withpurest spirit of wine, the other two thirds being a vacuum, and iscalled a pulse-glass, if it be placed in a box before the fire, so thateither bulb, as it rises, may become shaded from the fire, and exposedto it when it descends, an alternate libration of it is produced. Forspirit of wine in vacuo emits steam by a very small degree of heat, andthis steam forces the spirit beneath it up into the upper bulb, whichtherefore descends. It is probable such a machine on a larger scalemight be of use to open the doors or windows of hot-houses or mellon-frames, when the air within them should become too much heated, or mightbe employed in more important mechanical purposes. On travelling through a hot summer's day in a chaise with a box coveredwith leather on the fore-axle-tree, I observed, as the sun shone uponthe black leather, the box began to open its lid, which at noon roseabove a foot, and could not without great force be pressed down; andwhich gradually closed again as the sun declined in the evening. This Isuppose might with still greater facility be applied to the purpose ofopening melon-frames or the sashes of hot-houses. The statue of Memnon was overthrown and sawed in two by Cambyses todiscover its internal structure, and is said still to exist. SeeSavary's Letters on Egypt. The truncated statue is said for manycenturies to have saluted the rising sun with chearful tones, and thesetting sun with melancholy ones. NOTE IX. --LUMINOUS INSECTS. _Star of the earth, and diamond of the night. _ CANTO I. L. 196. There are eighteen species of Lampyris or glow-worm, according toLinneus, some of which are found in almost every part of the world. Inmany of the species the females have no wings, and are supposed to bediscovered by the winged males by their shining in the night. Theybecome much more lucid when they put themselves in motion, which wouldseem to indicate that their light is owing to their respiration; inwhich process it is probable phosphoric acid is produced by thecombination of vital air with some part of the blood, and that light isgiven out through their transparent bodies by this slow internalcombustion. There is a fire-fly of the beetle-kind described in the Dict. Raisonnéunder the name of Acudia, which is said to be two inches long, andinhabits the West-Indies and South America; the natives use them insteadof candles, putting from one to three of them under a glass. MadamMerian says, that at Surinam the light of this fly is so great, that shesaw sufficiently well by one of them to paint and finish one of thefigures of them in her work on insects. The largest and oldest of themare said to become four inches long, and to shine like a shooting staras they fly, and are thence called Lantern-bearers. The use of thislight to the insect itself seems to be that it may not fly againstobjects in the night; by which contrivance these insects are enabled toprocure their sustenance either by night or day, as their wants mayrequire, or their numerous enemies permit them; whereas some of ourbeetles have eyes adapted only to the night, and if they happen to comeabroad too soon in the evening are so dazzled that they fly againstevery thing in their way. See note on Phosphorus, No. X. In some seas, as particularly about the coast of Malabar, as a shipfloats along, it seems during the night to be surrounded with fire, andto leave a long tract of light behind it. Whenever the sea is gentlyagitated it seems converted into little stars, every drop as it breaksemits light, like bodies electrified in the dark. Mr. Bomare says, thatwhen he was at the port of Cettes in Languedoc, and bathing with acompanion in the sea after a very hot day, they both appeared coveredwith fire after every immersion, and that laying his wet hand on the armof his companion, who had not then dipped himself, the exact mark of hishand and fingers was seen in characters of fire. As numerous microscopicinsects are found in this shining water, its light has been generallyascribed to them, though it seems probable that fish-slime in hotcountries may become in such a state of incipient putrefaction as togive light, especially when by agitation it is more exposed to the air;otherwise it is not easy to explain why agitation should be necessary toproduce this marine light. See note on Phosphorus No. X. NOTE X. --PHOSPHORUS. _Or mark in shining letters Kunckel's name In the pale phosphor's self-consuming flame. _ CANTO I. L. 231. Kunckel, a native of Hamburgh, was the first who discovered to the worldthe process for producing phosphorus; though Brandt and Boyle werelikewise said to have previously had the art of making it. It wasobtained from sal microcosmicum by evaporation in the form of an acid, but has since been found in other animal substances, as in the ashes ofbones, and even in some vegetables, as in wheat flour. Keir's chemicalDict. This phosphoric acid is like all other acids united with vitalair, and requires to be treated with charcoal or phlogiston to depriveit of this air, it then becomes a kind of animal sulphur, but of soinflammable a nature, that on the access of air it takes firespontaneously, and as it burns becomes again united with vital air, andre-assumes its form of phosphoric acid. As animal respiration seems to be a kind of slow combustion, in which itis probable that phosphoric acid is produced by the union of phosphoruswith the vital air, so it is also probable that phosphoric acid isproduced in the excretory or respiratory vessels of luminous insects, asthe glow-worm and fire-fly, and some marine insects. From the sameprinciple I suppose the light from putrid fish, as from the heads ofhadocks, and from putrid veal, and from rotten wood in a certain stateof their putrefaction, is produced, and phosphorus thus slowly combinedwith air is changed into phosphoric acid. The light from the Bolognianstone, and from calcined shells, and from white paper, and linen afterhaving been exposed for a time to the sun's light, seem to produceeither the phosphoric or some other kind of acid from the sulphurous orphlogistic matter which they contain. See note on Beccari's shells. L. 180. There is another process seems similar to this slow combustion, and thatis _bleaching_. By the warmth and light of the sun the water sprinkledupon linen or cotton cloth seems to be decomposed, (if we credit thetheory of M. Lavoisier, ) and a part of the vital air thus set at libertyand uncombined and not being in its elastic form, more easily dissolvesthe colouring or phlogistic matter of the cloth, and produces a newacid, which is itself colourless, or is washed out of the cloth bywater. The new process of bleaching confirms a part of this theory, forby uniting much vital air to marine acid by distilling it frommanganese, on dipping the cloth to be bleached in water repleat withthis super-aerated marine acid, the colouring matter disappearsimmediately, sooner indeed in cotton than in linen. See note XXXIV. There is another process which I suspect bears analogy to these above-mentioned, and that is the rancidity of animal fat, as of bacon; ifbacon be hung up in a warm kitchen, with much salt adhering on theoutside of it, the fat part of it soon becomes yellow and rancid; if itbe washed with much cold water after it has imbibed the salt, and justbefore it is hung up, I am well informed, that it will not becomerancid, or in very slight degrees. In the former case I imagine the salton the surface of the bacon attracts water during the cold of the night, which is evaporated during the day, and that in this evaporation a partof the water becomes decomposed, as in bleaching, and its vital airuniting with greater facility in its unelastic state with the animalfat, produces an acid, perhaps of the phosphoric kind, which being of afixed nature lies upon the bacon, giving it the yellow colour and rancidtaste. It is remarkable that the super-aerated marine acid does notbleach living animal substances, at least it did not whiten a part of myhand which I for some minutes exposed to it. NOTE XI. --STEAM-ENGINE. _Quick moves the balanced beam, of giant-birth, Wields his large limbs, and nodding shakes the earth. _ CANTO I. L. 261. The expansive force of steam was known in some degree to the antients, Hero of Alexandria describes an application of it to produce a rotativemotion by the re-action of steam issuing from a sphere mounted upon anaxis, through two small tubes bent into tangents, and issuing from theopposite sides of the equatorial diameter of the sphere, the sphere wassupplied with steam by a pipe communicating with a pan of boiling water, and entering the sphere at one of its poles. A french writer about the year 1630 describes a method of raising waterto the upper part of a house by filling a chamber with steam, andsuffering it to condense of itself, but it seems to have been meretheory, as his method was scarcely practicable as he describes it. In1655 the Marquis of Worcester mentions a method of raising water by firein his Century of Inventions, but he seems only to have availed himselfof the expansive force and not to have known the advantages arising fromcondensing the steam by an injection of cold water. This latter and mostimportant improvement seems to have been made by Capt. Savery sometimeprior to 1698, for in that year his patent for the use of that inventionwas confirmed by act of parliament. This gentleman appears to have beenthe first who reduced the machine to practice and exhibited it in anuseful form. This method consisted only in expelling the air from avessel by steam and condensing the steam by an injection of cold water, which making a vacuum, the pressure of the atmosphere forced the waterto ascend into the steam-vessel through a pipe of 24 to 26 feet high, and by the admission of dense steam from the boiler, forcing the waterin the steam-vessel to ascend to the height desired. This constructionwas defective because it required very strong vessels to resist theforce of the steam, and because an enormous quantity of steam wascondensed by coming in contact with the cold water in the steam-vessel. About or soon after that time M. Papin attempted a steam-engine onsimilar principles but rather more defective in its construction. The next improvement was made very soon afterwards by Messrs. Newcomenand Cawley of Dartmouth, it consisted in employing for the steam-vessela hollow cylinder, shut at bottom and open at top, furnished with apiston sliding easily up and down in it, and made tight by oakum orhemp, and covered with water. This piston is suspended by chains fromone end of a beam, moveable upon an axis in the middle of its length, tothe other end of this beam are suspended the pump-rods. The danger of bursting the vessels was avoided in this machine, ashowever high the water was to be raised it was not necessary to increasethe density of the steam but only to enlarge the diameter of thecylinder. Another advantage was, that the cylinder not being made so cold as inSavary's method, much less steam was lost in filling it after eachcondensation. The machine however still remained imperfect, for the cold water throwninto the cylinder acquired heat from the steam it condensed, and beingin a vessel exhausted of air it produced steam itself, which in partresisted the action of the atmosphere on the piston; were this remediedby throwing in more cold water the destruction of steam in the nextfilling of the cylinder would be proportionally increased. It hastherefore in practice been found adviseable not to load these engineswith columns of water weighing more than seven pounds for each squareinch of the area of the piston. The bulk of water when converted intosteam remained unknown until Mr. J. Watt, then of Glasgow, in 1764, determined it to be about 1800 times more rare than water. It soonoccurred to Mr. Watt that a perfect engine would be that in which nosteam should be condensed in filling the cylinder, and in which thesteam should be so perfectly cooled as to produce nearly a perfectvacuum. Mr. Watt having ascertained the degree of heat in which water boiled invacuo, and under progressive degrees of pressure, and instructed by Dr. Black's discovery of latent heat, having calculated the quantity of coldwater necessary to condense certain quantities of steam so far as toproduce the exhaustion required, he made a communication from thecylinder to a cold vessel previously exhausted of air and water, intowhich the steam rushed by its elasticity, and became immediatelycondensed. He then adapted a cover to the cylinder and admitted steamabove the piston to press it down instead of air, and instead ofapplying water he used oil or grease to fill the pores of the oakum andto lubricate the cylinder. He next applied a pump to extract the injection water, the condensedsteam, and the air, from the condensing vessel, every stroke of theengine. To prevent the cooling of the cylinder by the contact of the externalair, he surrounded it with a case containing steam, which he againprotected by a covering of matters which conduct heat slowly. This construction presented an easy means of regulating the power of theengine, for the steam being the acting power, as the pipe which admitsit from the boiler is more or less opened, a greater or smaller quantitycan enter during the time of a stroke, and consequently the engine canact with exactly the necessary degree of energy. Mr. Watt gained a patent for his engine in 1768, but the furtherpersecution of his designs were delayed by other avocations till 1775, when in conjunction with Mr. Boulton of Soho near Birmingham, numerousexperiments were made on a large scale by their united ingenuity, andgreat improvements added to the machinery, and an act of parliamentobtained for the prolongation of their patent for twenty-five years, they have since that time drained many of the deep mines in Cornwall, which but for the happy union of such genius must immediately haveceased to work. One of these engines works a pump of eighteen inchesdiameter, and upwards of 100 fathom or 600 feet high, at the rate of tento twelve strokes of seven feet long each, in a minute, and that withone fifth part of the coals which a common engine would have taken to dothe same work. The power of this engine may be easier comprehended bysaying that it raised a weight equal to 81000 pounds 80 feet high in aminute, which is equal to the combined action of 200 good horses. InNewcomen's engine this would have required a cylinder of the enormousdiameter of 120 inches or ten feet, but as in this engine of Mr. Wattand Mr. Boulton the steam acts, and a vacuum is made, alternately aboveand below the piston, the power exerted is double to what the samecylinder would otherways produce, and is further augmented by aninequality in the length of the two ends of the lever. These gentlemen have also by other contrivances applied their engines tothe turning of mills for almost every purpose, of which that great pileof machinery the Albion Mill is a well known instance. Forges, slittingmills, and other great works are erected where nature has furnished norunning water, and future times may boast that this grand and usefulengine was invented and perfected in our own country. Since the above article went to the press the Albion Mill is no more; itis supposed to have been set on fire by interested or maliciousincendaries, and is burnt to the ground. Whence London has lost thecredit and the advantage of possessing the most powerful machine in theworld! NOTE XII. --FROST. _In phalanx firm the fiend of Frost assail. _ CANTO I. L. 439. The cause of the expansion of water during its conversion into ice isnot yet well ascertained, it was supposed to have been owing to the airbeing set at liberty in the act of congelation which was beforedissolved in the water, and the many air bubbles in ice were thought tocountenance this opinion. But the great force with which ice expandsduring its congelation, so as to burst iron bombs and coehorns, according to the experiments of Major Williams at Quebec, invalidatesthis idea of the cause of it, and may sometime be brought into use as ameans of breaking rocks in mining, or projecting cannon-balls, or forother mechanical purposes, if the means of producing congelation shouldever be discovered to be as easy as the means of producing combustion. Mr. De Mairan attributes the increase of bulk of frozen water to thedifferent arrangement of the particles of it in crystallization, as theyare constantly joined at an angle of 60 degrees; and must by thisdisposition he thinks occupy a greater volume than if they wereparallel. He found the augmentation of the water during freezing toamount to one-fourteenth, one-eighteenth, one-nineteenth, and when thewater was previously purged of air to only one-twenty-second part. Headds that a piece of ice, which was at first only one-fourteenth partspecifically lighter than water, on being exposed some days to the frostbecame one-twelfth lighter than water. Hence he thinks ice by beingexposed to greater cold still increases in volume, and to thisattributes the bursting of ice in ponds and on the glaciers. See Lewis'sCommerce of Arts, p. 257. And the note on Muschus in the other volume ofthis work. This expansion of ice well accounts for the greater mischief done byvernal frosts attended with moisture, (as by hoar-frosts, ) than by thedry frosts called black frosts. Mr. Lawrence in a letter to Mr. Bradleycomplains that the dale-mist attended with a frost on may-day haddestroyed all his tender fruits; though there was a sharper frost thenight before without a mist, that did him no injury; and adds, that agarden not a stone's throw from his own on a higher situation, beingabove the dale-mist, had received no damage. Bradley, Vol. II. P. 232. Mr. Hunter by very curious experiments discovered that the livingprinciple in fish, in vegetables, and even in eggs and seeds, possessesa power of resisting congelation. Phil. Trans. There can be no doubt butthat the exertions of animals to avoid the pain of cold may produce inthem a greater quantity of heat, at least for a time, but thatvegetables, eggs, or seeds, should possess such a quality is trulywonderful. Others have imagined that animals possess a power ofpreventing themselves from becoming much warmer than 98 degrees of heat, when immersed in an atmosphere above that degree of heat. It is truethat the increased exhalation from their bodies will in some measurecool them, as much heat is carried off by the evaporation of fluids, butthis is a chemical not an animal process. The experiments made by thosewho continued many minutes in the air of a room heated so much above anynatural atmospheric heat, do not seem conclusive, as they remained in ita less time than would have been necessary to have heated a mass of beefof the same magnitude, and the circulation of the blood in livinganimals, by perpetually bringing new supplies of fluid to the skin, would prevent the external surface from becoming hot much sooner thanthe whole mass. And thirdly, there appears no power of animal bodies toproduce cold in diseases, as in scarlet fever, in which the increasedaction of the vessels of the skin produces heat and contributes toexhaust the animal power already too much weakened. It has been thought by many that frosts meliorate the ground, and thatthey are in general salubrious to mankind. In respect to the former itis now well known that ice or snow contain no nitrous particles, andthough frost by enlarging the bulk of moist clay leaves it softer for atime after the thaw, yet as soon as the water exhales, the clay becomesas hard as before, being pressed together by the incumbent atmosphere, and by its self-attraction, called _setting_ by the potters. Add to thisthat on the coasts of Africa, where frost is unknown, the fertility ofthe soil is almost beyond our conceptions of it. In respect to thegeneral salubrity of frosty seasons the bills of mortality are anevidence in the negative, as in long frosts many weakly and old peopleperish from debility occasioned by the cold, and many classes of birdsand other wild animals are benumbed by the cold or destroyed by theconsequent scarcity of food, and many tender vegetables perish from thedegree of cold. I do not think it should be objected to this doctrine that there aremoist days attended with a brisk cold wind when no visible ice appears, and which are yet more disagreeable and destructive than frosty weather. For on these days the cold moisture, which is deposited on the skin isthere evaporated and thus produces a degree of cold perhaps greater thanthe milder frosts. Whence even in such days both the disagreeablesensations and insalubrious effects belong to the cause abovementioned, viz. The intensity of the cold. Add to this that in these cold moistdays as we pass along or as the wind blows upon us, a new sheet of coldwater is as it were perpetually applied to us and hangs upon our bodies, now as water is 800 times denser than air and is a much better conductorof heat, we are starved with cold like those who go into a cold bath, both by the great number of particles in contact with the skin and theirgreater facility of receiving our heat. It may nevertheless be true that snows of long duration in our wintersmay be less injurious to vegetation than great rains and shorter frosts, for two reasons. 1. Because great rains carry down many thousand poundsworth of the best part of the manure off the lands into the sea, whereassnow dissolves more gradually and thence carries away less from theland; any one may distinguish a snow-flood from a rain-flood by thetransparency of the water. Hence hills or fields with considerableinclination of surface should be ploughed horizontally that the furrowsmay stay the water from showers till it deposits its mud. 2. Snowprotects vegetables from the severity of the frost, since it is alwaysin a state of thaw where it is in contact with the earth; as the earth'sheat is about 48° and the heat of thawing snow is 32° the vegetablesbetween them are kept in a degree of heat about 40, by which many ofthem are preserved. See note on Muschus, Vol. II. Of this work. NOTE XIII. --ELECTRICITY _Cold from each point cerulean lustres gleam. _ CANTO I. L. 339. ELECTRIC POINTS. There was an idle dispute whether knobs or points were preferable on thetop of conductors for the defence of houses. The design of theseconductors is to permit the electric matter accumulated in the clouds topass through them into the earth in a smaller continued stream as thecloud approaches, before it comes to what is termed striking distance;now as it is well known that accumulated electricity will pass to pointsat a much greater distance than it will to knobs there can be no doubtof their preference; and it would seem that the finer the point and theless liable to become rusty the better, as it would take off thelightening while it was still at a greater distance, and by that meanspreserve a greater extent of building; the very extremity of the pointshould be of pure silver or gold, and might be branched into a kind ofbrush, since one small point can not be supposed to receive so great aquantity as a thicker bar might conduct into the earth. If an insulated metallic ball is armed with a point, like a needle, projecting from one part of it, the electric fluid will be seen in thedark to pass off from this point, so long as the ball is kept suppliedwith electricity. The reason of this is not difficult to comprehend, every part of the electric atmosphere which surrounds the insulated ballis attracted to that ball by a large surface of it, whereas the electricatmosphere which is near the extremity of the needle is attracted to itby only a single point, in consequence the particles of electric matternear the surface of the ball approach towards it and push off by theirgreater gravitation the particles of electric matter over the point ofthe needle in a continued stream. Something like this happens in respect to the diffusion of oil on waterfrom a pointed cork, an experiment which was many years ago shewn me byDr. Franklin; he cut a piece of cork about the size of a letter-waferand left on one edge of it a point about a sixth of an inch in lengthprojecting as a tangent to the circumference. This was dipped in oil andthrown on a pond of water and continued to revolve as the oil left thepoint for a great many minutes. The oil descends from the floating corkupon the water being diffused upon it without friction and perhapswithout contact; but its going off at the point so forcibly as to makethe cork revolve in a contrary direction seems analogous to thedeparture of the electric fluid from points. Can any thing similar to either of these happen in respect to theearth's atmosphere and give occasion to the breezes on the tops ofmountains, which may be considered as points on the earthscircumference? FAIRY-RINGS. There is a phenomenon supposed to be electric which is yet unaccountedfor, I mean the Fairy-rings, as they are called, so often seen on thegrass. The numerous flashes of lightning which occur every summer are, Ibelieve, generally discharged on the earth, and but seldom (if ever)from one cloud to another. Moist trees are the most frequent conductorsof these flashes of lightning, and I am informed by purchasers of woodthat innumerable trees are thus cracked and injured. At other timeslarger parts or prominences of clouds gradually sinking as they movealong, are discharged on the moisture parts of grassy plains. Now thisknob or corner of a cloud in being attracted by the earth will becomenearly cylindrical, as loose wool would do when drawn out into a thread, and will strike the earth with a stream of electricity perhaps two orten yards in diameter. Now as a stream of electricity displaces the airit passes through, it is plain no part of the grass can be burnt by it, but just the external ring of this cylinder where the grass can haveaccess to the air, since without air nothing can be calcined. This earthafter having been so calcined becomes a richer soil, and either fungusesor a bluer grass for many years mark the place. That lightning displacesthe air in its passage is evinced by the loud crack that succeeds it, which is owing to the sides of the aerial vacuum clapping together whenthe lightning is withdrawn. That nothing will calcine without air is nowwell understood from the acids produced in the burning of phlogisticsubstances, and may be agreeably seen by suspending a paper on an ironprong and putting it into the centre of the blaze of an iron-furnace; itmay be held there some seconds and may be again withdrawn without itsbeing burnt, if it be passed quickly into the flame and out againthrough the external part of it which is in contact with the air. I knowsome circles of many yards diameter of this kind near Foremark inDerbyshire which annually produce large white funguses and strongergrass, and have done so, I am informed, above thirty years. Thisincreased fertility of the ground by calcination or charring, and itscontinuing to operate so many years is well worth the attention of thefarmer, and shews the use of paring and burning new turf in agriculture, which produces its effect not so much by the ashes of the vegetablefibres as by charring the soil which adheres to them. These situations, whether from eminence or from moisture, which wereproper once to attract and discharge a thunder-cloud, are more liableagain to experience the same. Hence many fairy-rings are often seen neareach other either without intersecting each other, as I saw this summerin a garden in Nottinghamshire, or intersecting each other as describedon Arthur's seat near Edinburgh in the Edinb. Trans. Vol. II. P. 3. NOTE XIV. --BUDS AND BULBS. _Where dwell my vegetative realms benumb'd In buds imprison'd, or in bulbs intomb'd. _ CANTO I. L. 459. A tree is properly speaking a family or swarm of buds, each bud being anindividual plant, for if one of these buds be torn or cut out andplanted in the earth with a glass cup inverted over it to prevent itsexhalation from being at first greater than its power of absorption, itwill produce a tree similar to its parent; each bud has a leaf, which isits lungs, appropriated to it, and the bark of the tree is a congeriesof the roots of these individual buds, whence old hollow trees are oftenseen to have some branches flourish with vigour after the internal woodis almost intirely decayed and vanished. According to this idea Linneushas observed that trees and shrubs are roots above ground, for if a treebe inverted leaves will grow from the root-part and roots from thetrunk-part. Phil. Bot p. 39. Hence it appears that vegetables have twomethods of propagating themselves, the oviparous as by seeds, and theviviparous as by their buds and bulbs, and that the individual plants, whether from seeds or buds or bulbs, are all annual productions likemany kinds of insects as the silk-worm, the parent perishing in theautumn after having produced an embryon, which lies in a torpid stateduring the winter, and is matured in the succeeding summer. HenceLinneus names buds and bulbs the winter-cradles of the plant orhybernacula, and might have given the same term to seeds. In warmclimates few plants produce buds, as the vegetable life can becompleated in one summer, and hence the hybernacle is not wanted; incold climates also some plants do not produce buds, as philadelphus, frangula, viburnum, ivy, heath, wood-nightshade, rue, geranium. The bulbs of plants are another kind of winter-cradle, or hybernacle, adhering to the descending trunk, and are found in the perennialherbaceous plants which are too tender to bear the cold of the winter. The production of these subterraneous winter lodges, is not yet perhapsclearly understood, they have been distributed by Linneus according totheir forms into scaly, solid, coated, and jointed bulbs, which howeverdoes not elucidate their manner of production. As the buds of trees maybe truly esteemed individual annual plants, their roots constituting thebark of the tree, it follows that these roots (viz. Of each individualbud) spread themselves over the last years bark, making a new bark overthe old one, and thence descending cover with a new bark the old rootsalso in the same manner. A similar circumstance I suppose to happen insome herbaceous plants, that is, a new bark is annually produced overthe old root, and thus for some years at least the old root or caudexincreases in size and puts up new stems. As these roots increase in sizethe central part I suppose changes like the internal wood of a tree anddoes not possess any vegetable life, and therefore gives out no fibresor rootlets, and hence appears bitten off, as in valerian, plantain, anddevil's-bit. And this decay of the central part of the root I supposehas given occasion to the belief of the root-fibres drawing down thebulb so much insisted on by Mr. Milne in his Botanical Dictionary, Art. Bulb. From the observations and drawings of various kinds of bulbous roots atdifferent times of their growth, sent me by a young lady of niceobservation, it appears probable that all bulbous roots properly socalled perish annually in this climate: Bradley, Miller, and the Authorof Spectacle de la Nature, observe that the tulip annually renews itsbulb, for the stalk of the old flower is found under the old dry coatbut on the outside of the new bulb. This large new bulb is the floweringbulb, but besides this there are other small new bulbs produced betweenthe coats of this large one but from the same caudex, (or circle fromwhich the root-fibres spring;) these small bulbs are leaf-bearing bulbs, and renew themselves annually with increasing size till they bearflowers. Miss ---- favoured me with the following curious experiment: She took asmall tulip-root out of the earth when the green leaves weresufficiently high to show the flower, and placed it in a glass of water;the leaves and flower soon withered and the bulb became wrinkled andsoft, but put out one small side bulb and three bulbs beneath descendingan inch into the water by long processes from the caudex, the old bulbin some weeks intirely decayed; on dissecting this monster, the middledescending bulb was found by its process to adhere to the caudex and tothe old flower-stem, and the side ones were separated from the flower-stem by a few shrivelled coats but adhered to the caudex. Whence sheconcludes that these last were off-sets or leaf-bulbs which should havebeen seen between the coats of the new flower-bulb if it had been leftto grow in the earth, and that the middle one would have been the newflower-bulb. In some years (perhaps in wet seasons) the florists aresaid to lose many of their tulip-roots by a similar process, the newleaf-bulbs being produced beneath the old ones by an elongation of thecaudex without any new flower-bulbs. By repeated dissections she observes that the leaf-bulbs or off-sets oftulip, crocus, gladiolus, fritillary, are renewed in the same manner asthe flowering-bulbs, contrary to the opinion of many writers; this newleaf-bulb is formed on the inside of the coats from whence the leavesgrow, and is more or less advanced in size as the outer coats and leavesare more or less shrivelled. In examining tulip, iris, hyacinth, hare-bell, the new bulb was invariably found _between_ the flower-stem andthe base of the innermost leaf of those roots which had flowered, and_inclosed_ by the base of the innermost leaf in those roots which hadnot flowered, in both cases adhering to the caudex or fleshy circle fromwhich the root-fibres spring. Hence it is probable that the bulbs of hyacinths are renewed annually, but that this is performed from the caudex within the old bulb, theouter coat of which does not so shrivel as in crocus and fritillary andhence this change is not so apparent. But I believe as soon as theflower is advanced the new bulbs may be seen on dissection, nor does theannual increase of the size of the root of cyclamen and of aletriscapensis militate against this annual renewal of them, since the leaf-bulbs or off-sets, as described above, are increased in size as they areannually renewed. See note on orchis, and on anthoxanthum, in Vol. II. Of this work. NOTE XV. --SOLAR VOLCANOS. _From the deep craters of his realms of fire The whirling sun this ponderous planet hurld_. CANTO II. L. 14. Dr. Alexander Wilson, Professor of Astronomy at Glasgow, published apaper in the Philosophical Transactions for 1774, demonstrating that thespots in the sun's disk are real cavities, excavations through theluminous material, which covers the other parts of the sun's surface. One of these cavities he found to be about 4000 miles deep and manytimes as wide. Some objections were made to this doctrine by M. De laLaude in the Memoirs of the French Academy for the year 1776, whichhowever have been ably answered by Professor Wilson in reply in thePhilos. Trans. For 1783. Keil observes, in his Astronomical Lectures, p. 44, "We frequently see spots in the sun which are larger and broader notonly than Europe or Africa, but which even equal, if they do not exceed, the surface of the whole terraqueous globe. " Now that these cavities aremade in the sun's body by a process of nature similar to our earthquakesdoes not seem improbable on several accounts. 1. Because from thisdiscovery of Dr. Wilson it appears that the internal parts of the sunare not in a state of inflammation or of ejecting light, like theexternal part or luminous ocean which covers it; and hence that agreater degree of heat or inflammation and consequent expansion orexplosion may occasionally be produced in its internal or dark nucleus. 2. Because the solar spots or cavities are frequently increased ordiminished in size. 3. New ones are often produced. 4. And old onesvanish. 5. Because there are brighter or more luminous parts of thesun's disk, called faculae by Scheiner and Hevelius, which would seem tobe volcanos in the sun, or, as Dr. Wilson calls them, "eructations ofmatter more luminous than that which covers the sun's surface. " 6. Towhich may be added that all the planets added together with theirsatellites do not amount to more than one six hundred and fiftieth partof the mass of the sun according to Sir Isaac Newton. Now if it could be supposed that the planets were originally thrown outof the sun by larger sun-quakes than those frequent ones which occasionthese spots or excavations above-mentioned, what would happen? 1. According to the observations and opinion of Mr. Herschel the sun itselfand all its planets are moving forwards round some other centre with anunknown velocity, which may be of opake matter corresponding with thevery antient and general idea of a chaos. Whence if a ponderous planet, as Saturn, could be supposed to be projected from the sun by anexplosion, the motion of the sun itself might be at the same timedisturbed in such a manner as to prevent the planet from falling againinto it. 2. As the sun revolves round its own axis its form must be thatof an oblate spheroid like the earth, and therefore a body projectedfrom its surface perpendicularly upwards from that surface would notrise perpendicularly from the sun's centre, unless it happened to beprojected exactly from either of its poles or from its equator. Whenceit may not be necessary that a planet if thus projected from the sun byexplosion should again fall into the sun. 3. They would part from thesun's surface with the velocity with which that surface was moving, andwith the velocity acquired by the explosion, and would therefore moveround the sun in the same direction in which the sun rotates on itsaxis, and perform eliptic orbits. 4. All the planets would move the sameway round the sun, from this first motion acquired at leaving itssurface, but their orbits would be inclined to each other according tothe distance of the part, where they were thrown out, from the sun'sequator. Hence those which were ejected near the sun's equator wouldhave orbits but little inclined to each other, as the primary planets;the plain of all whose orbits are inclined but seven degrees and a halffrom each other. Others which were ejected near the sun's poles wouldhave much more eccentric orbits, as they would partake so much less ofthe sun's rotatory motion at the time they parted from his surface, andwould therefore be carried further from the sun by the velocity they hadgained by the explosion which ejected them, and become comets. 5. Theywould all obey the same laws of motion in their revolutions round thesun; this has been determined by astronomers, who have demonstrated thatthey move through equal areas in equal times. 6. As their annual periodswould depend on the height they rose by the explosion, these woulddiffer in them all. 7. As their diurnal revolutions would depend on oneside of the exploded matter adhering more than the other at the time itwas torn off by the explosion, these would also differ in the differentplanets, and not bear any proportion to their annual periods. Now as allthese circumstances coincide with the known laws of the planetarysystem, they serve to strengthen this conjecture. This coincidence of such a variety of circumstances induced M. De Buffonto suppose that the planets were all struck off from the sun's surfaceby the impact of a large comet, such as approached so near the sun'sdisk, and with such amazing velocity, in the year 1680, and is expectedto return in 2255. But Mr. Buffon did not recollect that these cometsthemselves are only planets with more eccentric orbits, and thattherefore it must be asked, what had previously struck off these cometsfrom the sun's body? 2. That if all these planets were struck off fromthe sun at the same time, they must have been so near as to haveattracted each other and have formed one mass: 3. That we shall want newcauses for separating the secondary planets from the primary ones, andmust therefore look out for some other agent, as it does not appear howthe impulse of a comet could have made one planet roll round another atthe time they both of them were driven off from the surface of the sun. If it should be asked, why new planets are not frequently ejected fromthe sun? it may be answered, that after many large earthquakes manyvents are left for the elastic vapours to escape, and hence, by thepresent appearance of the surface of our earth, earthquakes prodigiouslylarger than any recorded in history have existed; the same circumstancesmay have affected the sun, on whose surface there are appearances ofvolcanos, as described above. Add to this, that some of the comets, andeven the georgium sidus, may, for ought we know to the contrary, havebeen emitted from the sun in more modern days, and have been divertedfrom their course, and thus prevented from returning into the sun, bytheir approach to some of the older planets, which is somewhatcountenanced by the opinion several philosophers have maintained, thatthe quantity of matter of the sun has decreased. Dr. Halley observed, that by comparing the proportion which the periodical time of the moonbore to that of the sun in former times, with the proportion betweenthem at present, that the moon is found to be somewhat accelerated inrespect to the sun. Pemberton's View of Sir Isaac Newton, p. 247. And solarge is the body of this mighty luminary, that all the planets thusthrown out of it would make scarcely any perceptible diminution of it, as mentioned above. The cavity mentioned above, as measured by Dr. Wilson of 4000 miles in depth, not penetrating an hundredth part of thesun's semi-diameter; and yet, as its width was many times greater thanits depth, was large enough to contain a greater body than ourterrestrial world. I do not mean to conceal, that from the laws of gravity unfolded by SirIsaac Newton, supposing the sun to be a sphere and to have noprogressive motion, and not liable itself to be disturbed by thesupposed projection of the planets from it, that such planets mustreturn into the sun. The late Rev. William Ludlam, of Leicester, whosegenius never met with reward equal to its merits, in a letter to me, dated January, 1787, after having shewn, as mentioned above, thatplanets so projected from the sun would return to it, adds, "That a bodyas large as the moon so projected, would disturb the motion of the earthin its orbit, is certain; but the calculation of such disturbing forcesis difficult. The body in some circumstances might become a satellite, and both move round their common centre of gravity, and that centre becarried in an annual orbit round the sun. " There are other circumstances which might have concurred at the time ofsuch supposed explosions, which would render this idea not impossible. 1. The planets might be thrown out of the sun at the time the sun itselfwas rising from chaos, and be attracted by other suns in their vicinityrising at the same time out of chaos, which would prevent them fromreturning into the sun. 2. The new planet in its course or ascent fromthe sun, might explode and eject a satellite, or perhaps more than one, and thus by its course being affected might not return into the sun. 3. If more planets were ejected at the same time from the sun, they mightattract and disturb each others course at the time they left the body ofthe sun, or very soon afterwards, when they would be so much nearer eachother. NOTE XVI. --CALCAREOUS EARTH. _While Ocean wrap'd it in his azure robe_. CANTO II. L. 34. From having observed that many of the highest mountains of the worldconsist of lime-stone replete with shells, and that these mountains bearthe marks of having been lifted up by subterraneous fires from theinterior parts of the globe; and as lime-stone replete with shells isfound at the bottom of many of our deepest mines some philosophers haveconcluded that the nucleus of the earth was for many ages covered withwater which was peopled with its adapted animals; that the shells andbones of these animals in a long series of time produced solid strata inthe ocean surrounding the original nucleus. These strata consist of the accumulated exuviae of shell-fish, theanimals perished age after age but their shells remained, and inprogression of time produced the amazing quantities of lime-stone whichalmost cover the earth. Other marine animals called coralloids raisedwalls and even mountains by the congeries of their calcareoushabitations, these perpendicular corralline rocks make some parts of theSouthern Ocean highly dangerous, as appears in the journals of Capt. Cook. From contemplating the immense strata of lime-stone, both inrespect to their extent and thickness, formed from these shells ofanimals, philosophers have been led to conclude that much of the waterof the sea has been converted into calcareous earth by passing throughtheir organs of digestion. The formation of calcareous earth seems moreparticularly to be an animal process as the formation of clay belongs tothe vegetable economy; thus the shells of crabs and other testaceousfish are annually reproduced from the mucous membrane beneath them; theshells of eggs are first a mucous membrane, and the calculi of thekidneys and those found in all other parts of our system which sometimescontain calcareous earth, seem to originate from inflamed membranes; thebones themselves consist of calcareous earth united with the phosphoricor animal acid, which may be separated by dissolving the ashes ofcalcined bones in the nitrous acid; the various secretions of animals, as their saliva and urine, abound likewise with calcareous earth, asappears by the incrustations about the teeth and the sediments of urine. It is probable that animal mucus is a previous process towards theformation of calcareous earth; and that all the calcareous earth in theworld which is seen in lime-stones, marbles, spars, alabasters, marls, (which make up the greatest part of the earth's crust, as far as it hasyet been penetrated, ) have been formed originally by animal andvegetable bodies from the mass of water, and that by these means thesolid part of the terraqueous globe has perpetually been in anincreasing state and the water perpetually in a decreasing one. After the mountains of shells and other recrements of aquatic animalswere elevated above the water the upper heaps of them were graduallydissolved by rains and dews and oozing through were either perfectlycrystallized in smaller cavities and formed calcareous spar, or wereimperfectly crystallized on the roofs of larger cavities and producedstalactes; or mixing with other undissolved shells beneath them formedmarbles, which were more or less crystallized and more or less pure; orlastly, after being dissolved, the water was exhaled from them in such amanner that the external parts became solid, and forming an archprevented the internal parts from approaching each other so near as tobecome solid, and thus chalk was produced. I have specimens of chalkformed at the root of several stalactites, and in their central parts;and of other stalactites which are hollow like quills from a similarcause, viz. From the external part of the stalactite hardening first byits evaporation, and thus either attracting the internal dissolvedparticles to the crust, or preventing them from approaching each otherso as to form a solid body. Of these I saw many hanging from the archedroof of a cellar under the high street in Edinburgh. If this dissolved limestone met with vitriolic acid it was convertedinto alabaster, parting at the same time with its fixable air. If it metwith the fluor acid it became fluor; if with the siliceous acid, flint;and when mixed with clay and sand, or either of them, acquires the nameof marl. And under one or other of these forms composes a great part ofthe solid globe of the earth. Another mode in which limestone appears is in the form of roundgranulated particles, but slightly cohering together; of this kind a bedextends over Lincoln heath, perhaps twenty miles long by ten wide. Theform of this calcareous sand, its angles having been rubbed off, and theflatness of its bed, evinces that that part of the country was so formedunder water, the particles of sand having thus been rounded, like allother rounded pebbles. This round form of calcareous sand and of otherlarger pebbles is produced under water, partly by their being more orless soluble in water, and hence the angular parts become dissolved, first, by their exposing a larger surface to the action of themenstruum, and secondly, from their attrition against each other by thestreams or tides, for a great length of time, successively as they werecollected, and perhaps when some of them had not acquired their hardeststate. This calcareous sand has generally been called ketton-stone and believedto resemble the spawn of fish, it has acquired a form so much rounderthan siliceous sand from its being of so much softer a texture and alsomuch more soluble in water. There are other soft calcareous stonescalled tupha which are deposited from water on mosses, as at Matlock, from which moss it is probable the water may receive something whichinduces it the readier to part with its earth. In some lime-stones the living animals seem to have been buried as wellas their shells during some great convulsion of nature, these shellscontain a black coaly substance within them, in others some phlogistonor volatile alcali from the bodies of the dead animals remains mixedwith the stone, which is then called liver-stone as it emits asulphurous smell on being struck, and there is a stratum about sixinches thick extends a considerable way over the iron ore at Wingerworthnear Chesterfield in Derbyshire which seems evidently to have beenformed from the shells of fresh-water muscles. There is however another source of calcareous earth besides the aquaticone above described and that is from the recrements of land animals andvegetables as found in marls, which consist of various mixtures ofcalcareous earth, sand, and clay, all of them perhaps principally fromvegetable origin. Dr. Hutton is of opinion that the rocks of marble have been softened byfire into a fluid mass, which he thinks under immense pressure might bedone without the escape of their carbonic acid or fixed air. Edinb. Transact. Vol. I. If this ingenious idea be allowed it might account forthe purity of some white marbles, as during their fluid state theremight be time for their partial impurities, whether from the bodies ofthe animals which produced the shells or from other extraneous matter, either to sublime to the uppermost part of the stratum or to subside tothe lowermost part of it. As a confirmation of this theory of Dr. Hutton's it may be added that some calcareous stones are found mixedwith lime, and have thence lost a part of their fixed air or carbonicgas, as the bath-stone, and on that account hardens on being exposed tothe air, and mixed with sulphur produces calcareous liver of sulphur. Falconer on Bath-water. Vol. I. P. 156. And p. 257. Mr. Monnet foundlime in powder in the mountains of Auvergne, and suspected it ofvolcanic origin. Kirwan's Min. P. 22. NOTE XVII. --MORASSES. _Gnomes! you then taught transuding dews to pass Through time-fallen woods, and root-inwove morass_. CANTO II. L. 115. Where woods have repeatedly grown and perished morasses are in processof time produced, and by their long roots fill up the interstices tillthe whole becomes for many yards deep a mass of vegetation. This fact iscuriously verified by an account given many years ago by the Earl ofCromartie, of which the following is a short abstract. In the year 1651 the EARL OF CROMARTIE being then nineteen years of agesaw a plain in the parish of Lockburn covered over with a firm standingwood, which was so old that not only the trees had no green leaves uponthem but the bark was totally thrown off, which he was there informed bythe old countrymen was the universal manner in which fir-woodsterminated, and that in twenty or thirty years the trees would castthemselves up by the roots. About fifteen years after he had occasion totravel the same way and observed that there was not a tree nor theappearance of a root of any of them; but in their place the whole plainwhere the wood stood was covered with a flat green moss or morass, andon asking the country people what was become of the wood he was informedthat no one had been at the trouble to carry it away, but that it hadall been overturned by the wind, that the trees lay thick over eachother, and that the moss or bog had overgrown the whole timber, whichthey added was occasioned by the moisture which came down from the highhills above it and stagnated upon the plain, and that nobody could yetpass over it, which however his Lordship was so incautious as to attemptand slipt up to the arm-pits. Before the year 1699 that whole piece ofground was become a solid moss wherein the peasants then dug turf orpeat, which however was not yet of the best sort. Philos. Trans. No. 330. Abridg. Vol. V. P. 272. Morasses in great length of time undergo variety of changes, first byelutriation, and afterwards by fermentation, and the consequent heat. 1. By water perpetually oozing through them the most soluble parts arefirst washed away, as the essential salts, these together with the saltsfrom animal recrements are carried down the rivers into the sea, whereall of them seem to decompose each other except the marine salt. Hencethe ashes of peat contain little or no vegetable alcali and are not usedin the countries, where peat constitutes the fuel of the lower people, for the purpose of washing linen. The second thing which is always seenoozing from morasses is iron in solution, which produces chalybeatesprings, from whence depositions of ochre and variety of iron ores. Thethird elutriation seems to consist of vegetable acid, which by meansunknown appears to be converted into all other acids. 1. Into marine andnitrous acids as mentioned above. 2. Into vitriolic acid which is foundin some morasses so plentifully as to preserve the bodies of animalsfrom putrefaction which have been buried in them, and this acid carriedaway by rain and dews and meeting with calcareous earth produces gypsumor alabaster, with clay it produces alum, and deprived of its vital airproduces sulphur. 3. Fluor acid which being washed away and meeting withcalcareous earth produces fluor or cubic spar. 4. The siliceous acidwhich seems to have been disseminated in great quantity either bysolution in water or by solution in air, and appears to have producedthe sand in the sea uniting with calcareous earth previously dissolvedin that element, from which were afterwards formed some of the grit-stone rocks by means of a siliceous or calcareous cement. By its unionwith the calcareous earth of the morass other strata of siliceous sandhave been produced; and by the mixture of this with clay and lime arosethe beds of marl. In other circumstances, probably where less moisture has prevailed, morasses seem to have undergone a fermentation, as other vegetablematter, new hay for instance is liable to do from the great quantity ofsugar it contains. From the great heat thus produced in the lower partsof immense beds of morass the phlogistic part, or oil, or asphaltum, becomes distilled, and rising into higher strata becomes again condensedforming coal-beds of greater or less purity according to their greateror less quantity of inflammable matter; at the same time the clay bedsbecome purer or less so, as the phlogistic part is more or lesscompletely exhaled from them. Though coal and clay are frequentlyproduced in this manner, yet I have no doubt, but that they are likewiseoften produced by elutriation; in situations on declivities the clay iswashed away down into the valleys, and the phlogistic part or coal leftbehind; this circumstance is seen in many valleys near the beds ofrivers, which are covered recently by a whitish impure clay, calledwater-clay. See note XIX. XX. And XXIII. LORD CROMARTIE has furnished another curious observation on morasses inthe paper above referred to. In a moss near the town of Eglin in Murray, though there is no river or water which communicates with the moss, yetfor three or four feet of depth in the moss there are little shell-fishresembling oysters with living fish in them in great quantities, thoughno such fish are found in the adjacent rivers, nor even in the waterpits in the moss, but only in the solid substance of the moss. Thiscurious fact not only accounts for the shells sometimes found on thesurface of coals, and in the clay above them; but also for a thinstratum of shells which sometimes exists over iron-ore. NOTE XVIII. --IRON. _Cold waves, immerged, the glowing mass congeal, And turn to adamant the hissing Steel. _ CANTO II. L. 191. As iron is formed near the surface of the earth, it becomes exposed tostreams of water and of air more than most other metallic bodies, andthence becomes combined with oxygene, or vital air, and appears veryfrequently in its calciform state, as in variety of ochres. Manganese, and zinc, and sometimes lead, are also found near the surface of theearth, and on that account become combined with vital air and areexhibited in their calciform state. The avidity with which iron unites with oxygene, or vital air, in whichprocess much heat is given out from the combining materials, is shewn bya curious experiment of M. Ingenhouz. A fine iron wire twisted spirallyis fixed to a cork, on the point of the spire is fixed a match made ofagaric dipped in solution of nitre; the match is then ignited, and thewire with the cork put immediately into a bottle full of vital air, thematch first burns vividly, and the iron soon takes fire and consumeswith brilliant sparks till it is reduced to small brittle globules, gaining an addition of about one third of its weight by its union, withvital air. Annales de Chymie. Traité de Chimie, per Lavoisier, c. Iii. STEEL. It is probably owing to a total deprivation of vital air which it holdswith so great avidity, that iron on being kept many hours or days inignited charcoal becomes converted into steel, and thence acquires thefaculty of being welded when red hot long before it melts, and also thepower of becoming hard when immersed in cold water; both which I supposedepend on the same cause, that is, on its being a worse conductor ofheat than other metals; and hence the surface both acquires heat muchsooner, and loses it much sooner, than the internal parts of it, in thiscircumstance resembling glass. When steel is made very hot, and suddenly immerged in very cold water, and moved about in it, the surface of the steel becomes cooled first, and thus producing a kind of case or arch over the internal part, prevents that internal part from contracting quite so much as itotherwise would do, whence it becomes brittler and harder, like theglass-drops called Prince Rupert's drops, which are made by droppingmelted glass into cold water. This idea is countenanced by thecircumstance that hardened steel is specifically lighter than steelwhich is more gradually cooled. (Nicholson's Chemistry, p. 313. ) Why thebrittleness and hardness of steel or glass should keep pace or becompanions to each other may be difficult to conceive. When a steel spring is forcibly bent till it break, it requires lesspower to bend it through the first inch than the second, and lessthrough the second than the third; the same I suppose to happen if awire be distended till it break by hanging weights to it; this shewsthat the particles may be forced from each other to a small distance byless power, than is necessary to make them recede to a greater distance;in this circumstance perhaps the attraction of cohesion differs fromthat of gravitation, which exerts its power inversely as the squares ofthe distance. Hence it appears that if the innermost particles of asteel bar, by cooling the external surface first, are kept fromapproaching each other so nearly as they otherwise would do, that theybecome in the situation of the particles on the convex side of a bentspring, and can not be forced further from each other except by agreater power than would have been necessary to have made them recedethus far. And secondly, that if they be forced a little further fromeach other they separate; this may be exemplified by laying two magneticneedles parallel to each other, the contrary poles together, thendrawing them longitudinally from each other, they will slide with smallforce till they begin to separate, and will then require a strongerforce to really separate them. Hence it appears, that hardness andbrittleness depend on the same circumstance, that the particles areremoved to a greater distance from each other and thus resist any powermore forcibly which is applied to displace them further, thisconstitutes hardness. And secondly, if they are displaced by suchapplied force they immediately separate, and this constitutesbrittleness. Steel may be thus rendered too brittle for many purposes, on whichaccount artists have means of softening it again, by exposing it tocertain degrees of heat, for the construction of different kinds oftools, which is called tempering it. Some artists plunge large tools invery cold water as soon as they are compleatly ignited, and moving itabout, take it out as soon as it ceases to be luminous beneath thewater; it is then rubbed quickly with a file or on sand to clean thesurface, the heat which the metal still retains soon begins to produce asuccession of colours; if a hard temper be required, the piece is dippedagain and stirred about in cold water as soon as the yellow tingeappears, if it be cooled when the purple tinge appears it becomes fitfor gravers' tools used in working upon metals; if cooled while blue itis proper for springs. Nicholson's Chemistry, p. 313. Keir's ChemicalDictionary. MODERN PRODUCTION OF IRON. The recent production of iron is evinced from the chalybeate waterswhich flow from morasses which lie upon gravel-beds, and which musttherefore have produced iron after those gravel-beds were raised out ofthe sea. On the south side of the road between Cheadle and Okeymoor inStaffordshire, yellow stains of iron are seen to penetrate the gravelfrom a thin morass on its surface. There is a fissure eight or ten feetwide, in a gravel-bed on the eastern side of the hollow road ascendingthe hill about a mile from Trentham in Staffordshire, leading towardDrayton in Shropshire, which fissure is filled up with nodules of iron-ore. A bank of sods is now raised against this fissure to prevent theloose iron nodules from falling into the turnpike road, and thus thisnatural curiosity is at present concealed from travellers. A similarfissure in a bed of marl, and filled up with iron nodules and with somelarge pieces of flint, is seen on the eastern side of the hollow roadascending the hill from the turnpike house about a mile from Derby inthe road towards Burton. And another such fissure filled with ironnodes, appears about half a mile from Newton-Solney in Derbyshire, inthe road to Burton, near the summit of the hill. These collections ofiron and of flint must have been produced posterior to the elevation ofall those hills, and were thence evidently of vegetable or animalorigin. To which should be added, that iron is found in general in bedseither near the surface of the earth, or stratified with clay coals orargillaceous grit, which are themselves productions of the modern world, that is, from the recrements of vegetables and air-breathing animals. Not only iron but manganese, calamy, and even copper and lead appear insome instances to have been of recent production. Iron and manganese aredetected in all vegetable productions, and it is probable other metallicbodies might be found to exist in vegetable or animal matters, if we hadtests to detect them in very minute quantities. Manganese and calamy arefound in beds like iron near the surface of the earth, and in acalciform state, which countenances their modern production. The recentproduction of calamy, one of the ores of zinc, appears from itsfrequently incrusting calcareous spar in its descent from the surface ofthe earth into the uppermost fissures of the limestone mountains ofDerbyshire. That the calamy has been carried by its solution ordiffusion in water into these cavities, and not by its ascent from belowin form of steam, is evinced from its not only forming a crust over thedogtooth spar, but by its afterwards dissolving or destroying the sparrycrystal. I have specimens of calamy in the form of dogtooth spar, twoinches high, which are hollow, and stand half an inch above thediminished sparry crystal on which they were formed, like a sheath agreat deal too big for it; this seems to shew, that this process wascarried on in water, otherwise after the calamy had incrusted its spar, and dissolved its surface, so as to form a hollow cavern over it, itcould not act further upon it except by the interposition of somemedium. As these spars and calamy are formed in the fissures ofmountains they must both have been formed after the elevation of thosemountains. In respect to the recent production of copper, it was before observed innote on Canto II. L. 394, that the summit of the grit-stone mountain atHawkstone in Shropshire, is tinged with copper, which from theappearance of the blue stains seems to have descended to the parts ofthe rock beneath. I have a calciform ore of copper consisting of thehollow crusts of cubic cells, which has evidently been formed oncrystals of fluor, which it has eroded in the same manner as the calamyerodes the calcareous crystals, from whence may be deduced in the samemanner, the aqueous solution or diffusion, as well as the recentproduction of this calciform ore of copper. Lead in small quantities is sometimes found in the fissures of coal-beds, which fissures are previously covered with spar; and sometimes innodules of iron-ore. Of the former I have a specimen from near Caulk inDerbyshire, and of the latter from Colebrook Dale in Shropshire. Thoughall these facts shew that some metallic bodies are formed from vegetableor animal recrements, as iron, and perhaps manganese and calamy, allwhich are found near the surface of the earth; yet as the other metalsare found only in fissures of rocks, which penetrate to unknown depths, they may be wholly or in part produced by ascending steams fromsubterraneous fires, as mentioned in note on Canto II. L. 398. SEPTARIA OF IRON-STONE. Over some lime works at Walsall in Staffordshire, I observed some yearsago a stratum of iron earth about six inches thick, full of very largecavities; these cavities were evidently produced when the materialpassed from a semifluid state into a solid one; as the frit of thepotters, or a mixture of clay and water is liable to crack in drying;which is owing to the further contraction of the internal part, afterthe crust is become hard. These hollows are liable to receive extraneousmatter, as I believe gypsum, and sometimes spar, and even lead; acurious specimen of the last was presented to me by Mr. Darby ofColebrook Dale, which contains in its cavity some ounces of lead-ore. But there are other septaria of iron-stone which seem to have had a verydifferent origin, their cavities having been formed in cooling orcongealing from an ignited state, as is ingeniously deduced by Dr. Hutton from their internal structure. Edinb. Transact. Vol. I. P. 246. The volcanic origin of these curious septaria appears to me to befurther evinced from their form and the places where they are found. They consist of oblate spheroids and are found in many parts of theearth totally detached from the beds in which they lie, as at EastLothian in Scotland. Two of these, which now lie before me, were foundwith many others immersed in argillaceous shale or shiver, surrounded bybroken limestone mountains at Bradbourn near Ashbourn in Derbyshire, andwere presented to me by Mr. Buxton, a gentleman of that town. One ofthese is about fifteen inches in its equatorial diameter, and about sixinches in its polar one, and contains beautiful star-like septariaincrusted and in part filled with calcareous spar. The other is abouteight inches in its equatorial diameter, and about four inches in itspolar diameter, and is quite solid, but shews on its internal surfacemarks of different colours, as if a beginning separation had takenplace. Now as these septaria contain fifty per cent, of iron, accordingto Dr. Hutton, they would soften or melt into a semifluid globule bysubterraneous fire by less heat than the limestone in their vicinity;and if they were ejected through a hole or fissure would gain a circularmotion along with their progressive one by their greater friction oradhesion to one side of the hole. This whirling motion would produce theoblate spheroidical form which they possess, and which as far as I knowcan not in any other way be accounted for. They would then harden in theair as they rose into the colder parts of the atmosphere; and as theydescended into so soft a material as shale or shiver, their forms wouldnot be injured in their fall; and their presence in materials sodifferent from themselves becomes accounted for. About the tropics of the large septarium above mentioned, are circulareminent lines, such as might have been left if it had been coarselyturned in a lathe. These lines seem to consist of a fluid matter, whichseems to have exsuded in circular zones, as their edges appear bluntedor retracted; and the septarium seems to have split easier in suchsections parallel to its equator. Now as the crust would first begin tocool and harden after its ejection in a semifluid state, and theequatorial diameter would become gradually enlarged as it rose in theair; the internal parts being softer would slide beneath the polarcrust, which might crack and permit part of the semifluid to exsude, andit is probable the adhesion would thus become less in sections parallelto the equator. Which further confirms this idea of the production ofthese curious septaria. A new-cast cannon ball red-hot with its crustonly solid, if it were shot into the air would probably burst in itspassage; as it would consist of a more fluid material than theseseptaria; and thus by discharging a shower of liquid iron would producemore dreadful combustion, if used in war, than could be effected by aball, which had been cooled and was heated again: since in the lattercase the ball could not have its internal parts made hotter than thecrust of it, without first loosing its form. NOTE XIX. --FLINT. _Transmute to glittering flints her chalky lands, Or sink on Ocean's bed in countless sands. _ CANTO II. L. 217. 1. SILICEOUS ROCKS. The great masses of siliceous sand which lie in rocks upon the beds oflimestone, or which are stratified with clay, coal, and iron-ore, areevidently produced in the decomposition of vegetable or animal matters, as explained in the note on morasses. Hence the impressions of vegetableroots and even whole trees are often found in sand-stone, as well as incoals and iron-ore. In these sand-rocks both the siliceous acid and thecalcareous base seem to be produced from the materials of the morass;for though the presence of a siliceous acid and of a calcareous basehave not yet been separately exhibited from flints, yet from the analogyof flint to fluor, and gypsum, and marble, and from the conversion ofthe latter into flint, there can be little doubt of their existence. These siliceous sand-rocks are either held together by a siliceouscement, or have a greater or less portion of clay in them, which in someacts as a cement to the siliceous crystals, but in others is in suchgreat abundance that in burning them they become an imperfect porcelainand are then used to repair the roads, as at Chesterfield in Derbyshire;these are called argillaceous grit by Mr. Kirwan. In other places acalcareous matter cements the crystals together; and in other places thesiliceous crystals lie in loose strata under the marl in the form ofwhite sand; as at Normington about a mile from Derby. The lowest beds of siliceous sand-stone produced from morasses seem toobtain their acid from the morass, and their calcareous base from thelimestone on which it rests; These beds possess a siliceous cement, andfrom their greater purity and hardness are used for course grinding-stones and scyth stones, and are situated on the edges of limestonecountries, having lost the other strata of coals, or clay, or iron, which were originally produced above them. Such are the sand-rocksincumbent on limestone near Matlock in Derbyshire. As these siliceoussand-rocks contain no marine productions scattered amongst them, theyappear to have been elevated, torn to pieces, and many fragments of themscattered over the adjacent country by explosions, from fires within themorass from which they have been formed; and which dissipated everything inflammable above and beneath them, except some stains of iron, with which they are in some places spotted. If these sand-rocks had beenaccumulated beneath the sea, and elevated along with the beds oflimestone on which they rest, some vestiges of marine shells either intheir siliceous or calcareous state must have been discerned amongstthem. 2. SILICEOUS TREES. In many of these sand-rocks are found the impressions of vegetableroots, which seem to have been the most unchangeable parts of the plant, as shells and shark's teeth are found in chalk-beds from their being themost unchangeable parts of the animal. In other instances the wooditself is penetrated, and whole trees converted into flint; specimens ofwhich I have by me, from near Coventry, and from a gravel-pit inShropshire near Child's Archal in the road to Drayton. Other polishedspecimens of vegetable flints abound in the cabinets of the curious, which evidently shew the concentric circles of woody fibres, and theirinterstices filled with whiter siliceous matter, with the branching offof the knots when cut horizontally, and the parallel lines of wood whencut longitudinally, with uncommon beauty and variety. Of these I possesssome beautiful specimens, which were presented to me by the Earl ofUxbridge. The colours of these siliceous vegetables are generally brown, from theiron, I suppose, or manganese, which induced them to crystallize or tofuse more easily. Some of the cracks of the wood in drying are filledwith white flint or calcedony, and others of them remain hollow, linedwith innumerable small crystals tinged with iron, which I suppose had ashare in converting their calcareous matter into siliceous crystals, because the crystals called Peak-diamonds are always found bedded in anochreous earth; and those called Bristol-stones are situated onlimestone coloured with iron. Mr. F. French presented me with acongeries of siliceous crystals, which he gathered on the crater (as hesupposes) of an extinguished volcano at Cromach Water in Cumberland. Thecrystals are about an inch high in the shape of dogtooth or calcareousspar, covered with a dark ferruginous matter. The bed on which they restis about an inch in thickness, and is stained with iron on itsundersurface. This curious fossil shews the transmutation of calcareousearth into siliceous, as much as the siliceous shells which abound inthe cabinets of the curious. There may sometime be discovered in thisage of science, a method of thus impregnating wood with liquid flint, which would produce pillars for the support, and tiles for the coveringof houses, which would be uninflammable and endure as long as the earthbeneath them. That some siliceous productions have been in a fluid state without muchheat at the time of their formation appears from the vegetable flintsabove described not having quite lost their organized appearance; fromshells, and coralloids, and entrochi being converted into flint withoutloosing their form; from the bason of calcedony round Giesar in Iceland;and from the experiment of Mr. Bergman, who obtained thirteen regularformed crystals by suffering the powder of quartz to remain in a vesselwith fluor acid for two years; these crystals were about the size ofsmall peas, and were not so hard as quartz. Opusc. De Terrâ Siliceâ, p. 33. Mr. Achard procured both calcareous and siliceous crystals, one fromcalcareous earth, and the other from the earth of alum, both dissolvedin water impregnated with fixed air; the water filtrating very slowlythrough a porous bottom of baked clay. See Journal de Physique, forJanuary, 1778. 3. AGATES, ONYXES, SCOTS-PEBBLES. In small cavities of these sand-rocks, I am informed, the beautifulsiliceous nodules are found which are called Scot's-pebbles; and whichon being cut in different directions take the names of agates, onyxes, sardonyxes, &c. According to the colours of the lines or strata whichthey exhibit. Some of the nodules are hollow and filled with crystals, others have a nucleus of less compact siliceous matter which isgenerally white, surrounded with many concentric strata coloured withiron, and other alternate strata of white agate or calcedony, sometimesto the number of thirty. I think these nodules bear evident marks of their having been in perfectfusion by either heat alone, or by water and heat, under great pressure, according to the ingenious theory of Dr. Hutton; but I do not imagine, that they were injected into cavities from materials from without, butthat some vegetables or parts of vegetables containing more iron ormanganese than others, facilitated the compleat fusion, thus destroyingthe vestiges of vegetable organization, which were conspicuous in thesiliceous trees above mentioned. Some of these nodules being hollow andlined with crystals, and others containing a nucleus of white siliceousmatter of a looser texture, shew they were composed of the materialsthen existing in the cavity; which consisting before of loose sand, musttake up less space when fused into a solid mass. These siliceous nodules resemble the nodules of iron-stone mentioned innote on Canto II. L. 183, in respect to their possessing a great numberof concentric spheres coloured generally with iron, but they differ inthis circumstance, that the concentric spheres generally obey the formof the external crust, and in their not possessing a chalybeate nucleus. The stalactites formed on the roofs of caverns are often coloured inconcentric strata, by their coats being spread over each other atdifferent times; and some of them, as the cupreous ones, possess greatbeauty from this formation; but as these are necessarily more or less ofa cylindrical or conic form, the nodules or globular flints abovedescribed cannot have been constructed in this manner. To what law ofnature then is to be referred the production of such numerous concentricspheres? I suspect to the law of congelation. When salt and water are exposed to severe frosty air, the salt is saidto be precipitated as the water freezes; that is, as the heat, in whichit was dissolved, is withdrawn; where the experiment is tried in a bowlor bason, this may be true, as the surface freezes first, and the saltis found at the bottom. But in a fluid exposed in a thin phial, I foundby experiment, that the extraneous matter previously dissolved by theheat in the mixture was not simply set at liberty to subside, but wasdetruded or pushed backward as the ice was produced. The experiment wasthis: about two ounces of a solution of blue vitriol were accidentallyfrozen in a thin phial, the glass was cracked and fallen to pieces, theice was dissolved, and I found a pillar of blue vitriol standing erecton the bottom of the broken bottle. Nor is this power of congelationmore extraordinary, than that by its powerful and sudden expansion itshould burst iron shells and coehorns, or throw out the plugs with whichthe water was secured in them above one hundred and thirty yards, according to the experiments at Quebec by Major Williams. Edinb. Transact. Vol. II. P. 23. In some siliceous nodules which now lie before me, the external crustfor about the tenth of an inch consists of white agate, in others it ismuch thinner, and in some much thicker; corresponding with this crustthere are from twenty to thirty superincumbent strata, of alternatelydarker and lighter colour; whence it appears, that the external crust asit cooled or froze, propelled from it the iron or manganese which wasdissolved in it; this receded till it had formed an arch or vault strongenough to resist its further protrusion; then the next inner sphere orstratum as it cooled or froze, propelled forwards its colouring matterin the same manner, till another arch or sphere produced sufficientresistance to this frigoriscent expulsion. Some of them have detrudedtheir colouring matter quite to the centre, the rings continuing tobecome darker as they are nearer it; in others the chalybeate arch seemsto have stopped half an inch from the centre, and become thicker byhaving attracted to itself the irony matter from the white nucleus, owing probably to its cooling less precipitately in the central partsthan at the surface of the pebble. A similar detrusion of a marly matter in circular arches or vaultsobtains in the salt mines in Cheshire; from whence Dr. Hutton veryingeniously concludes, that the salt must have been liquified by heat;which would seem to be much confirmed by the above theory. Edinb. Transact. Vol. I. P. 244. I cannot conclude this account of Scots-pebbles without observing thatsome of them on being sawed longitudinally asunder, seem still topossess some vestiges of the cylindrical organization of vegetables;others possess a nucleus of white agate much resembling some bulbousroots with their concentric coats, or the knots in elm-roots or crab-trees; some of these I suppose were formed in the manner aboveexplained, during the congelation of masses of melted flint and iron;others may have been formed from a vegetable nucleus, and retain somevestiges of the organization of the plant. 4. SAND OF THE SEA. The great abundance of siliceous sand at the bottom of the ocean may inpart be washed down from the siliceous rocks above described, but ingeneral I suppose it derives its acid only from the vegetable and animalmatter of morasses, which is carried down by floods or by theatmosphere, and becomes united in the sea with its calcareous base fromshells and coralloids, and thus assumes its crystalline form at thebottom of the ocean, and is there intermixed with gravel or othermatters washed from the mountains in its vicinity. 5. CHERT, OR PETROSILEX. The rocks of marble are often alternately intermixed with strata ofchert, or coarse flint, and this in beds from one to three feet thick, as at Ham and Matlock, or of less than the tenth of an inch inthickness, as a mile or two from Bakewell in the road to Buxton. It isdifficult to conceive in what manner ten or twenty strata of eitherlimestone or flint, of different shades of white and black, could belaid quite regularly over each other from sediments or precipitationsfrom the sea; it appears to me much easier to comprehend, by supposingwith Dr. Hutton, that both the solid rocks of marble and the flint hadbeen fused by great heat, (or by heat and water, ) under immensepressure; by its cooling or congealing the colouring matter might bedetruded, and form parallel or curvilinean strata, as above explained. The colouring matter both of limestone and flint was probably owing tothe flesh of peculiar animals, as well as the siliceous acid, whichconverted some of the limestone into flint; or to some strata of shell-fish having been overwhelmed when alive with new materials, while othersdying in their natural situations would lose their fleshy parts, eitherby its putrid solution in the water or by its being eaten by other sea-insects. I have some calcareous fossil shells which contain a blackcoaly matter in them, which was evidently the body of the animal, andothers of the same kind filled with spar instead of it. The Labradorestone has I suppose its colours from the nacre or mother-pearl shells, from which it was probably produced. And there is a stratum ofcalcareous matter about six or eight inches thick at Wingerworth inDerbyshire over the iron-beds, which is replete with shells of fresh-water muscles, and evidently obtains its dark colour from them, asmentioned in note XVI. Many nodules of flint resemble in colour as wellas in form the shell of the echinus or sea-urchin; others resemble somecoralloids both in form and colour; and M. Arduini found in the Monte dePancrasio, red flints branching like corals, from whence they seem tohave obtained both their form and their colour. Ferber's Travels inItaly, p. 42. 6. NODULES OF FLINT IN CHALK-BEDS. As the nodules of flint found in chalk-beds possess no marks of havingbeen rounded by attrition or solution, I conclude that they have gainedtheir form as well as their dark colour from the flesh of the shell-fishfrom which they had their origin; but which have been so compleatlyfused by heat, or heat and water, as to obliterate all vestiges of theshell, in the same manner as the nodules of agate and onyx were producedfrom parts of vegetables, but which had been so completely fused as toobliterate all marks of their organization, or as many iron-nodules haveobtained their form and origin from peculiar vegetables. Some nodules in chalk-beds consist of shells of echini filled up withchalk, the animal having been dissolved away by putrescence in water, oreaten by other sea-insects; other shells of echini, in which I supposethe animal's body remained, are converted into flint but still retainthe form of the shell. Others, I suppose as above, being more completelyfused, have become flint coloured by the animal flesh, but without theexact form either of the flesh or shell of the animal. Many of these arehollow within and lined with crystals, like the Scot's-pebbles abovedescribed; but as the colouring matter of animal bodies differs butlittle from each other compared with those of vegetables, these flintsvary less in their colours than those above mentioned. At the same timeas they cooled in concentric spheres like the Scot's-pebbles, they oftenpossess faint rings of colours, and always break in conchoide formslike them. This idea of the production of nodules of flint in chalk-beds iscountenanced from the iron which generally appears as these flintsbecome decomposed by the air; which by uniting with the iron in theircomposition reduces it from a vitrescent state to that of calx, and thusrenders it visible. And secondly, by there being no appearance in chalk-beds of a string or pipe of siliceous matter connecting one nodule withanother, which must have happened if the siliceous matter, or its acid, had been injected from without according to the idea of Dr. Hutton. Andthirdly, because many of them have very large cavities at their centres, which should not have happened had they been formed by the injection ofa material from without. When shells or chalk are thus converted from calcareous to siliceousmatter by the flesh of the animal, the new flint being heavier than theshell or chalk occupies less space than the materials it was producedfrom; this is the cause of frequent cavities within them, where thewhole mass has not been completely fused and pressed together. InDerbyshire there are masses of coralloid and other shells which havebecome siliceous, and are thus left with large vacuities sometimeswithin and sometimes on the outside of the remaining form of the shell, like the French millstones, and I suppose might serve the same purpose;the gravel of the Derwent is full of specimens of this kind. Since writing the above I have received a very ingenious account ofchalk-beds from Dr. MENISH of Chelmsford. He distinguishes chalk-bedsinto three kinds; such as have been raised from the sea with littledisturbance of their strata, as the cliffs of Dover and Margate, whichhe terms _intire_ chalk. Another state of chalk is where it has sufferedmuch derangement, as the banks of the Thames at Gravesend and Dartford. And a third state where fragments of chalk have been rounded by water, which he terms _alluvial_ chalk. In the first of these situations ofchalk he observes, that the flint lies in strata horizontally, generallyin distinct nodules, but that he has observed two instances of solidplates or strata of flint, from an inch to two inches in thickness, interposed between the chalk-beds; one of these is in a chalk-bank bythe road side at Berkhamstead, the other in a bank on the road fromChatham leading to Canterbury. Dr. Menish has further observed, thatmany of the echini are crushed in their form, and yet filled with flint, which has taken the form of the crushed shell, and that though manyflint nodules are hollow, yet that in some echini the siliceum seems tohave enlarged, as it passed from a fluid to a solid state, as it swellsout in a protuberance at the mouth and anus of the shell, and thatthough these shells are so filled with flint yet that in many places theshell itself remains calcareous. These strata of nodules and plates offlint seem to countenance their origin from the flesh of a stratum ofanimals which perished by some natural violence, and were buried intheir shells. 7. ANGLES OF SILICEOUS SAND. In many rocks of siliceous sand the particles retain their angular form, and in some beds of loose sand, of which there is one of considerablepurity a few yards beneath the marl at Normington about a mile south ofDerby. Other siliceous sands have had their angles rounded off, like thepebbles in gravel-beds. These seem to owe their globular form to twocauses; one to their attrition against each other, when they may forcenturies have lain at the bottom of the sea, or of rivers; where theymay have been progressively accumulated, and thus progressively at thesame time rubbed upon each other by the dashing of the water, and wherethey would be more easily rolled over each other by their gravity beingso much less than in air. This is evidently now going on in the riverDerwent, for though there are no limestone rocks for ten or fifteenmiles above Derby, yet a great part of the river-gravel at Derbyconsists of limestone nodules, whose angles are quite worn off in theirdescent down the stream. There is however another cause which must have contributed to round theangles both of calcareous and siliceous fragments; and that is, theirsolubility in water; calcareous earth is perpetually found suspended inthe waters which pass over it; and the earth of flints was observed byBergman to be contained in water in the proportion of one grain to agallon. Kirwan's Mineralogy, p. 107. In boiling water, however, it issoluble in much greater proportion, as appears from the siliceous earthsublimed in the distillation of fluor acid in glass vessels; and fromthe basons of calcedony which surrounded the jets of hot water nearmount Heccla in Iceland. Troil on Iceland. It is probable most siliceoussands or pebbles have at some ages of the world been long exposed toaqueous steams raised by subterranean fires. And if fragments of stonewere long immersed in a fluid menstrum, their angular parts would befirst dissolved, on account of their greater surface. Many beds of siliceous gravel are cemented together by a siliceouscement, and are called breccia; as the plumb-pudding stones ofHartfordshire, and the walls of a subterraneous temple excavated by Mr. Curzon, at Hagley near Rugely in Staffordfshire; these may have beenexposed to great heat as they were immersed in water; which water undergreat pressure of superincumbent materials may have been rendered red-hot, as in Papin's digester; and have thus possessed powers of solutionwith which we are unacquainted. 8. BASALTES AND GRANITES. Another source of siliceous stones is from the granite, or basaltes, orporphyries, which are of different hardnesses according to the materialsof their composition, or to the fire they have undergone; such are thestones of Arthur's-hill near Edinburgh, of the Giant's Causway inIreland, and of Charnwood Forest in Leicestershire; the uppermoststratum of which last seems to have been cracked either by itselevation, or by its hastily cooling after ignition by the contact ofdews or snows, and thus breaks into angular fragments, such as thestreets of London are paved with; or have had their angles rounded byattrition or by partial solution; and have thus formed the common pavingstones or bowlers; as well as the gravel, which is often rolled intostrata amid the siliceous sand-beds, which are either formed orcollected in the sea. In what manner such a mass of crystallized matter as the Giant's Causwayand similar columns of basaltes, could have been raised without othervolcanic appearances, may be a matter not easy to comprehend; but thereis another power in nature besides that of expansile vapour which mayhave raised some materials which have previously been in igneous oraqueous solution; and that is the act of congelation. When the water inthe experiments above related of Major Williams had by congelationthrown out the plugs from the bomb-shells, a column of ice rose from thehole of the bomb six or eight inches high. Other bodies I suspectincrease in bulk which crystallize in cooling, as iron and type-metal. Iremember pouring eight or ten pounds of melted brimstone into a pot tocool and was surprized to see after a little time a part of the fluidbeneath break a hole in the congealed crust above it, and gradually riseinto a promontory several inches high; the basaltes has many marks offusion and of crystallization and may thence, as well as many otherkinds of rocks, as of spar, marble, petrosilex, jasper, &c. Have beenraised by the power of congelation, a power whose quantity has not yetbeen ascertained, and perhaps greater and more universal than that ofvapours expanded by heat. These basaltic columns rise sometimes out ofmountains of granite itself, as mentioned by Dr. Beddoes, (Phil. Transact. Vol. LXXX. ) and as they seem to consist of similar materialsmore completely fused, there is still greater reason to believe them tohave been elevated in the cooling or crystallization of the mass. Seenote XXIV. NOTE XX. --CLAY. _Whence ductile Clays in wide expansion spread, Soft as the Cygnet's down, their snow-white bed. _ CANTO II. L. 277. The philosophers, who have attended to the formation of the earth, haveacknowledged two great agents in producing the various changes which theterraqueous globe has undergone, and these are water and fire. Some ofthem have perhaps ascribed too much to one of these great agents ofnature, and some to the other. They have generally agreed that thestratification of materials could only be produced from sediments orprecipitations, which were previously mixed or dissolved in the sea; andthat whatever effects were produced by fire were performed afterwards. There is however great difficulty in accounting for the universalstratification of the solid globe of the earth in this manner, sincemany of the materials, which appear in strata, could not have beensuspended in water; as the nodules of flint in chalk-beds, the extensivebeds of shells, and lastly the strata of coal, clay, sand, and iron-ore, which in most coal-countries lie from five to seven times alternatelystratified over each other, and none of them are soluble in water. Addto this if a solution of them or a mixture of them in water could besupposed, the cause of that solution must cease before a precipitationcould commence. 1. The great masses of lava, under the various names of granite, porphyry, toadstone, moor-stone, rag, and slate, which constitute theold world, may have acquired the stratification, which some of themappear to possess, by their having been formed by successive eruptionsof a fluid mass, which at different periods of antient time arose fromvolcanic shafts and covered each other, the surface of the interior massof lava would cool and become solid before the superincumbent stratumwas poured over it; to the same cause may be ascribed their differentcompositions and textures, which are scarcely the same in any two partsof the world. 2. The stratifications of the great masses of limestone, which wereproduced from sea-shells, seem to have been formed by the differenttimes at which the innumerable shells were produced and deposited. Acolony of echini, or madrepores, or cornua ammonis, lived and perishedin one period of time; in another a new colony of either similar ordifferent shells lived and died over the former ones, producing astratum of more recent shell over a stratum of others which had began topetrify or to become marble; and thus from unknown depths to what arenow the summits of mountains the limestone is disposed in strata ofvarying solidity and colour. These have afterwards undergone variety ofchanges by their solution and deposition from the water in which theywere immersed, or from having been exposed to great heat under greatpressure, according to the ingenious theory of Dr. Hutton. Edinb. Transact. Vol. I. See Note XVI. 3. In most of the coal-countries of this island there are from five toseven beds of coal stratified with an equal number of beds, though ofmuch greater thickness, of clay and sandstone, and occasionally of iron-ores. In what manner to account for the stratification of thesematerials seems to be a problem of greater difficulty. Philosophers havegenerally supposed that they have been arranged by the currents of thesea; but considering their insolubility in water, and their almostsimilar specific gravity, an accumulation of them in such distinct bedsfrom this cause is altogether inconceiveable, though some coal-countriesbear marks of having been at some time immersed beneath the waves andraised again by subterranean fires. The higher and lower parts of morasses were necessarily produced atdifferent periods of time, see Note XVII. And would thus originally beformed in strata of different ages. For when an old wood perished, andproduced a morass, many centuries would elapse before another wood couldgrow and perish again upon the same ground, which would thus produce anew stratum of morass over the other, differing indeed principally inits age, and perhaps, as the timber might be different, in theproportions of its component parts. Now if we suppose the lowermost stratum of a morass become ignited, likefermenting hay, (after whatever could be carried away by solution inwater was gone, ) what would happen? Certainly the inflammable part, theoil, sulphur, or bitumen, would burn away, and be evaporated in air; andthe fixed parts would be left, as clay, lime, and iron; while some ofthe calcareous earth would join with the siliceous acid, and producesand, or with the argillaceous earth, and produce marl. Thence aftermany centuries another bed would take fire, but with less degree ofignition, and with a greater body of morass over it, what then wouldhappen? The bitumen and sulphur would rise and might become condensedunder an impervious stratum, which might not be ignited, and there formcoal of different purities according to its degree of fluidity, whichwould permit some of the clay to subside through it into the place fromwhich it was sublimed. Some centuries afterwards another similar process might take place, andeither thicken the coal-bed, or produce a new clay-bed, or marl, orsand, or deposit iron upon it, according to the concomitantcircumstances above mentioned. I do not mean to contend that a few masses of some materials may nothave been rolled together by currents, when the mountains were much moreelevated than at present, and in consequence the rivers broader and morerapid, and the storms of rain and wind greater both in quantity andforce. Some gravel-beds may have been thus washed from the mountains;and some white clay washed from morasses into valleys beneath them; andsome ochres of iron dissolved and again deposited by water; and somecalcareous depositions from water, (as the bank for instance on whichstand the houses at Matlock-bath;) but these are of small extent orconsequence compared to the primitive rocks of granite or porpyhry whichform the nucleus of the earth, or to the immense strata of limestonewhich crust over the greatest part of this granite or porphyry; orlastly to the very extensive beds of clay, marl, sandstone, coal, andiron, which were probably for many millions of years the only parts ofour continents and islands, which were then elevated above the level ofthe sea, and which on that account became covered with vegetation, andthence acquired their later or superincumbent strata, which constitute, what some have termed, the new world. There is another source of clay, and that of the finest kind, fromdecomposed granite, this is of a snowy white and mixed with miningparticles of mica, of this kind is an earth from the country ofCherokees. Other kinds are from less pure lavas; Mr. Ferber asserts thatthe sulphurous steams from Mount Vesuvius convert the lava into clay. "The lavas of the antient Solfatara volcano have been undoubtedly of avitreous nature, and these appear at present argillaceous. Somefragments of this lava are but half or at one side changed into clay, which either is viscid or ductile, or hard and stoney. Clays by fire aredeprived of their coherent quality, which cannot be restored to them bypulverization, nor by humectation. But the sulphureous Solfatara steamsrestore it, as may be easily observed on the broken pots wherein theygather the sal ammoniac; though very well baked and burnt at Naples theyare mollified again by the acid steams into a viscid clay which keepsthe former fire-burnt colour. " Travels in Italy, p. 156. NOTE XXI. --ENAMELS. _Smear'd her huge dragons with metallic hues, With golden purples, and cobaltic blues;_ CANTO II. L. 287. The fine bright purples or rose colours which we see on china cups arenot producible with any other material except gold, manganese indeedgives a purple but of a very different kind. In Europe the application of gold to these purposes appears to be ofmodern invention. Cassius's discovery of the precipitate of gold by tin, and the use of that precipitate for colouring glass and enamels, are nowgenerally known, but though the precipitate with tin be more successfulin producing the ruby glass, or the colourless glass which becomes redby subsequent ignition, the tin probably contributing to prevent thegold from separating, (which it is very liable to do during the fusion;yet, for enamels, the precipitates made by alcaline salts answer equallywell, and give a finer red, the colour produced by the tin precipitatebeing a bluish purple, but with the others a rose red. I am informedthat some of our best artists prefer aurum fulminans, mixing it, beforeit has become dry, with the white composition or enamel flux; when onceit is divided by the other matter, it is ground with great safety, andwithout the least danger of explosion, whether moist or dry. The colouris remarkably improved and brought forth by long grinding, whichaccordingly makes an essential circumstance in the process. The precipitates of gold, and the colcothar or other red preparations ofiron, are called _tender_ colours. The heat must be no greater than isjust sufficient to make the enamel run upon the piece, for if greater, the colours will be destroyed or changed to a different kind. When thevitreous matter has just become fluid it seems as if the colouredmetallic calx remained barely _intermixed_ with it, like a colouredpowder of exquisite tenuity suspended in water: but by stronger fire thecalx is _dissolved_, and metallic colours are altered by _solution_ inglass as well as in acids or alcalies. The Saxon mines have till very lately almost exclusively supplied therest of Europe with cobalt, or rather with its preparations, zaffre andsmalt, for the exportation of the ore itself is there a capital crime. Hungary, Spain, Sweden, and some other parts of the continent, are nowsaid to afford cobalts equal to the Saxon, and specimens have beendiscovered in our own island, both in Cornwall and in Scotland; buthitherto in no great quantity. Calces of cobalt and of copper differ very materially from those abovementioned in their application for colouring enamels. In those the calxhas previously acquired the intended colour, a colour which bears a redheat without injury, and all that remains is to fix it on the piece by avitreous flux. But the blue colour of cobalt, and the green or bluishgreen of copper, are _produced_ by vitrification, that is, by _solution_in the glass, and a strong fire is necessary for their perfection. Thesecalces therefore, when mixed with the enamel flux, are melted incrucibles, once or oftener, and the deep coloured opake glass, thenceresulting, is ground into unpalpable powder, and used for enamel. Onepart of either of these calces is put to ten, sixteen, or twenty partsof the flux, according to the depth of colour required. The heat of theenamel kiln is only a full red, such as is marked on Mr. Wedgwood'sthermometer 6 degrees. It is therefore necessary that the flux be soadjusted as to melt in that low heat. The usual materials are flint, orflint-glass, with a due proportion of red-led, or borax, or both, andsometimes a little tin calx to give opacity. _Ka-o-lin_ is the name given by the Chinese to their porcelain clay, and_pe-tun-tse_ to the other ingredient in their China ware. Specimens ofboth these have been brought into England, and found to agree in qualitywith some of our own materials. Kaolin is the very same with the claycalled in Cornwall [Transcriber's note: word missing] and the petuntseis a granite similar to the Cornish moorstone. There are differences, both in the Chinese petuntses, and the English moorstones; all of themcontain micaceous and quartzy particles, in greater or less quantity, along with feltspat, which last is the essential ingredient for theporcelain manufactory. The only injurious material commonly found inthem is iron, which discolours the ware in proportion to its quantity, and which our moorstones are perhaps more frequently tainted with thanthe Chinese. Very fine porcelain has been made from English materialsbut the nature of the manufacture renders the process precarious and theprofit hazardous; for the semivitrification, which constitutesporcelain, is necessarily accompanied with a degree of softness, orsemifusion, so that the vessels are liable to have their forms alteredin the kiln, or to run together with any accidental augmentations of thefire. NOTE XXII. --PORTLAND VASE. _Or bid Mortality rejoice or mourn O'er the fine forms of Portland's mystic urn. _ CANTO II. L. 319. The celebrated funereal vase, long in possession of the Barberinifamily, and lately purchased by the Duke of Portland for a thousandguineas, is about ten inches high and six in diameter in the broadestpart. The figures are of most exquisite workmanship in bas relief ofwhite opake glass, raised on a ground of deep blue glass, which appearsblack except when held against the light. Mr. Wedgwood is of opinionfrom many circumstances that the figures have been made by cutting awaythe external crust of white opake glass, in the manner the finestcameo's have been produced, and that it must thence have been the labourof a great many years. Some antiquarians have placed the time of itsproduction many centuries before the christian aera; as sculpture wassaid to have been declining in respect to its excellence in the time ofAlexander the Great. See an account of the Barberini or Portland vase byM. D'Hancarville, and by Mr. Wedgwood. Many opinions and conjectures have been published concerning the figureson this celebrated vase. Having carefully examined one of Mr. Wedgwood'sbeautiful copies of this wonderful production of art, I shall add onemore conjecture to the number. Mr. Wedgwood has well observed that it does not seem probable that thePortland vase was purposely made for the ashes of any particular persondeceased, because many years must have been necessary for itsproduction. Hence it may be concluded, that the subject of itsembellishments is not private history but of a general nature. Thissubject appears to me to be well chosen, and the story to be finelytold; and that it represents what in antient times engaged the attentionof philosophers, poets, and heroes, I mean a part of the Eleusinianmysteries. These mysteries were invented in Aegypt, and afterwards transferred toGreece, and flourished more particularly at Athens, which was at thesame time the seat of the fine arts. They consisted of scenicalexhibitions representing and inculcating the expectation of a futurelife after death, and on this account were encouraged by the government, insomuch that the Athenian laws punished a discovery of their secretswith death. Dr. Warburton has with great learning and ingenuity shewnthat the descent of Aeneas into hell, described in the Sixth Book ofVirgil, is a poetical account of the representations of the future statein the Eleusinian mysteries. Divine Legation, Vol. I. P. 210. And though some writers have differed in opinion from Dr. Warburton onthis subject, because Virgil has introduced some of his own heroes intothe Elysian fields, as Deiphobus, Palinurus, and Dido, in the samemanner as Homer had done before him, yet it is agreed that the receivednotions about a future state were exhibited in these mysteries, and asthese poets described those received notions, they may be said, as faras these religious doctrines were concerned, to have described themysteries. Now as these were emblematic exhibitions they must have been as welladapted to the purposes of sculpture as of poetry, which indeed does notseem to have been uncommon, since one compartment of figures in thesheild of Aeneas represented the regions of Tartarus. Aen. Lib. X. Theprocession of torches, which according to M. De St. Croix was exhibitedin these mysteries, is still to be seen in basso relievo, discovered bySpon and Wheler. Memoires sur le Mysteres par De St. Croix. 1784. And itis very probable that the beautiful gem representing the marriage ofCupid and Psyche, as described by Apuleus, was originally descriptive ofanother part of the exhibitions in these mysteries, though afterwards itbecame a common subject of antient art. See Divine Legat. Vol. I. P. 323. What subject could have been imagined so sublime for the ornamentsof a funereal urn as the mortality of all things and theirresuscitation? Where could the designer be supplied with emblems forthis purpose, before the Christian era, but from the Eleusinianmysteries? 1. The exhibitions of the mysteries were of two kinds, those which thepeople were permitted to see, and those which were only shewn to theinitiated. Concerning the latter, Aristides calls them "the mostshocking and most ravishing representations. " And Stoboeus asserts thatthe initiation into the grand mysteries exactly resembles death. DivineLegat. Vol. I. P. 280, and p. 272. And Virgil in his entrance to theshades below, amongst other things of terrible form, mentions death. Aen. VI. This part of the exhibition seems to be represented in one ofthe compartments of the Portland vase. Three figures of exquisite workmanship are placed by the side of aruined column whose capital is fallen off, and lies at their feet withother disjointed stones, they sit on loose piles of stone beneath atree, which has not the leaves of any evergreen of this climate, but maybe supposed to be an elm, which Virgil places near the entrance of theinfernal regions, and adds, that a dream was believed to dwell underevery leaf of it. Aen. VI. L. 281. In the midst of this group reclines afemale figure in a dying attitude, in which extreme languor isbeautifully represented, in her hand is an inverted torch, an antientemblem of extinguished life, the elbow of the same arm resting on astone supports her as she sinks, while the other hand is raised andthrown over her drooping head, in some measure sustaining it and giveswith great art the idea of fainting lassitude. On the right of her sitsa man, and on the left a woman, both supporting themselves on theirarms, as people are liable to do when they are thinking intensely. Theyhave their backs towards the dying figure, yet with their faces turnedtowards her, as if seriously contemplating her situation, but withoutstretching out their hands to assist her. This central figure then appears to me to be an hieroglyphic orEleusinian emblem of MORTAL LIFE, that is, the lethum, or death, mentioned by Virgil amongst the terrible things exhibited at thebeginning of the mysteries. The inverted torch shews the figure to beemblematic, if it had been designed to represent a real person in theact of dying there had been no necessity for the expiring torch, as thedying figure alone would have been sufficiently intelligible;--it wouldhave been as absurd as to have put an inverted torch into the hand of areal person at the time of his expiring. Besides if this figure hadrepresented a real dying person would not the other figures, or one ofthem at least, have stretched out a hand to support her, to have easedher fall among loose stones, or to have smoothed her pillow? Thesecircumstances evince that the figure is an emblem, and therefore couldnot be a representation of the private history of any particular familyor event. The man and woman on each side of the dying figure must be considered asemblems, both from their similarity of situation and dress to the middlefigure, and their being grouped along with it. These I think arehieroglyphic or Eleusinian emblems of HUMANKIND, with their backs towardthe dying figure of MORTAL LIFE, unwilling to associate with her, yetturning back their serious and attentive countenances, curious indeed tobehold, yet sorry to contemplate their latter end. These figures bringstrongly to one's mind the Adam and Eve of sacred writ, whom some havesupposed to have been allegorical or hieroglyphic persons of Aegyptianorigin, but of more antient date, amongst whom I think is Dr. Warburton. According to this opinion Adam and Eve were the names of twohieroglyphic figures representing the early state of mankind; Abel wasthe name of an hieroglyphic figure representing the age of pasturage, and Cain the name of another hieroglyphic symbol representing the age ofagriculture, at which time the uses of iron were discovered. And as thepeople who cultivated the earth and built houses would increase innumbers much faster by their greater production of food, they wouldreadily conquer or destroy the people who were sustained by pasturage, which was typified by Cain slaying Abel. 2. On the other compartment of this celebrated vase is exhibited anemblem of immortality, the representation of which was well known toconstitute a very principal part of the shews at the Eleusinianmysteries, as Dr. Warburton has proved by variety of authority. Thehabitation of spirits or ghosts after death was supposed by the antientsto be placed beneath the earth, where Pluto reigned, and dispensedrewards or punishments. Hence the first figure in this group is of theMANES or GHOST, who having passed through an open portal is descendinginto a dusky region, pointing his toe with timid and unsteady step, feeling as it were his way in the gloom. This portal Aeneas enters, which is described by Virgil, --patet atri janua ditis, Aen. VI. L. 126;as well as the easy descent, --facilis descensus Averni. Ib. The darknessat the entrance to the shades is humorously described by Lucian. Div. Legat. Vol. I. P. 241. And the horror of the gates of hell was in thetime of Homer become a proverb; Achilles says to Ulysses, "I hate a liarworse than the gates of hell;" the same expression is used in Isaiah, ch. Xxxviii. V. 10. The MANES or GHOST appears lingering and fearful, and wishes to drag after him a part of his mortal garment, which howeveradheres to the side of the portal through which he has passed. Thebeauty of this allegory would have been expressed by Mr. Pope, by "Wefeel the ruling passion strong in death. " A little lower down in the group the manes or ghost is received by abeautiful female, a symbol of IMMORTAL LIFE. This is evinced by herfondling between her knees a large and playful serpent, which from itsannually renewing its external skin has from great antiquity, even asearly as the fable of Prometheus, been esteemed an emblem of renovatedyouth. The story of the serpent acquiring immortal life from the ass ofPrometheus, who carried it on his back, is told in Bacon's Works, Vol. V. P. 462. Quarto edit. Lond. 1778. For a similar purpose a serpent waswrapped round the large hieroglyphic egg in the temple of Dioscuri, asan emblem of the renewal of life from a state of death. Bryant'sMythology, Vol II. P. 359. Sec. Edit. On this account also the serpentwas an attendant on Aesculapius, which seems to have been the name ofthe hieroglyphic figure of medicine. This serpent shews this figure tobe an emblem, as the torch shewed the central figure of the othercompartment to be an emblem, hence they agreeably correspond, andexplain each other, one representing MORTAL LIFE, and the other IMMORTALLIFE. This emblematic figure of immortal life sits down with her feet towardsthe figure of Pluto, but, turning back her face towards the timid ghost, she stretches forth her hand, and taking hold of his elbow, supports histottering steps, as well as encourages him to advance, both whichcircumstances are thus with wonderful ingenuity brought to the eye. Atthe same time the spirit loosely lays his hand upon her arm, as onewalking in the dark would naturally do for the greater certainty offollowing his conductress, while the general part of the symbol ofIMMORTAL LIFE, being turned toward the figure of Pluto, shews that sheis leading the phantom to his realms. In the Pamphili gardens at Rome, Perseus in assisting Andromeda todescend from the rock takes hold of her elbow to steady or support herstep, and she lays her hand loosely on his arm as in this figure. Admir. Roman. Antiq. The figure of PLUTO can not be mistaken, as is agreed by most of thewriters who have mentioned this vase; his grisley beard, and his havingone foot buried in the earth, denotes the infernal monarch. He is placedat the lowest part of the group, and resting his chin on his hand, andhis arm upon his knee, receives the stranger-spirit with inquisitiveattention; it was before observed that when people think attentivelythey naturally rest their bodies in some easy attitude, that more animalpower may be employed on the thinking faculty. In this group of figuresthere is great art shewn in giving an idea of a descending plain, viz. From earth to Elysium, and yet all the figures are in reality on anhorizontal one. This wonderful deception is produced first by thedescending step of the manes or ghost; secondly, by the arm of thesitting figure of immortal life being raised up to receive him as hedescends; and lastly, by Pluto having one foot sunk into the earth. There is yet another figure which is concerned in conducing the manes orghost to the realms of Pluto, and this is LOVE. He precedes thedescending spirit on expanded wings, lights him with his torch, andturning back his beautiful countenance beckons him to advance. Theantient God of love was of much higher dignity than the modern Cupid. Hewas the first that came out of the great egg of night, (Hesiod. Theog. V. CXX. Bryant's Mythol. Vol. II. P. 348. ) and is said to possess thekeys of the sky, sea, and earth. As he therefore led the way into thislife, he seems to constitute proper emblem for leading the way to afuture life. See Bacon's works. Vol. I. P. 568. And Vol. III. P. 582. Quarto edit. The introduction of love into this part of the mysteries requires alittle further explanation. The Psyche of the Aegyptians was one oftheir most favourite emblems, and represented the soul, or a futurelife; it was originally no other than the aurelia, or butterfly, but inafter times was represented by a lovely female child with the beautifulwings of that insect. The aurelia, after its first stage as an eruca orcaterpillar, lies for a season in a manner dead, and is inclosed in asort of coffin, in this state of darkness it remains all the winter, butat the return of spring it bursts its bonds and comes out with new life, and in the most beautiful attire. The Aegyptians thought this a veryproper picture of the soul of man, and of the immortality to which itaspired. But as this was all owing to divine Love, of which EROS was anemblem, we find this person frequently introduced as a concomitant ofthe soul in general or Psyche. (Bryant's Mythol. Vol. II. P. 386. ) EROS, or divine Love, is for the same reason a proper attendant on the manesor soul after death, and much contributes to tell the story, that is, toshew that a soul or manes is designed by the descending figure. Fromthis figure of Love M. D'Hancarville imagines that Orpheus and Eurydiceare typified under the figure of the manes and immortal life as abovedescribed. It may be sufficient to answer, first, that Orpheus is alwaysrepresented with a lyre, of which there are prints of four differentgems in Spence's Polymetis, and Virgil so describes him, Aen. VI. Cytharâ fretus. And secondly, that it is absurd to suppose that Eurydicewas fondling and playing with a serpent that had slain her. Add to thisthat Love seems to have been an inhabitant of the infernal regions, asexhibited in the mysteries, for Claudian, who treats more openly of theEleusinian mysteries, when they were held in less veneration, invokesthe deities to disclose to him their secrets, and amongst other thingsby what torch Love softens Pluto. Dii, quibus in numerum, &c. Vos mihi sacrarum penetralia pandite rerum, Et vestri secreta poli, quâ lampade Ditem Flexit amor. In this compartment there are two trees, whose branches spread over thefigures, one of them has smoother leaves like some evergreens, and mightthence be supposed to have some allusion to immortality, but they mayperhaps have been designed only as ornaments, or to relieve the figures, or because it was in groves, where these mysteries were originallycelebrated. Thus Homer speaks of the woods of Proserpine, and mentionsmany trees in Tartarus, as presenting their fruits to Tantalus; Virgilspeaks of the pleasant groves of Elysium; and in Spence's Polymetisthere are prints of two antient gems, one of Orpheus charming Cerberuswith his lyre, and the other of Hercules binding him in a cord, each ofthem standing by a tree. Polymet. P. 284. As however these trees haveall different foliage so clearly marked by the artist, they may have hadspecific meanings in the exhibitions of the mysteries, which have notreached posterity, of this kind seem to have been the tree of knowledgeof good and evil, and the tree of life, in sacred writ, both which musthave been emblematic or allegorical. The masks, hanging to the handlesof the vase, seem to indicate that there is a concealed meaning in thefigures besides their general appearance. And the priestess at thebottom, which I come now to describe, seems to shew this concealedmeaning to be of the sacred or Eleusinian kind. 3. The figure on the bottom of the vase is on a larger scale than theothers, and less finely finished, and less elevated, and as this bottompart was afterwards cemented to the upper part, it might be executed byanother artist for the sake of expedition, but there seems no reason tosuppose that it was not originally designed for the upper part of it assome have conjectured. As the mysteries of Ceres were celebrated byfemale priests, for Porphyrius says the antients called the priestessesof Ceres, Melissai, or bees, which were emblems of chastity. Div. Leg. Vol. I. P. 235. And as, in his Satire against the sex, Juvenal says, that few women are worthy to be priestesses of Ceres. Sat. VI. Thefigure at the bottom of the vase would seem to represent a PRIESTESS orHIEROPHANT, whose office it was to introduce the initiated, and pointout to them, and explain the exhibitions in the mysteries, and toexclude the uninitiated, calling out to them, "Far, far retire, yeprofane!" and to guard the secrets of the temple. Thus the introductoryhymn sung by the hierophant, according to Eusebius, begins, "I willdeclare a secret to the initiated, but let the doors be shut against theprofane. " Div. Leg. Vol. I. P. 177. The priestess or hierophant appearsin this figure with a close hood, and dressed in linen, which fits closeabout her; except a light cloak, which flutters in the wind. Wool, astaken from slaughtered animals, was esteemed profane by the priests ofAegypt, who were always dressed in linen. Apuleus, p. 64. Div. Leg. Vol. I. P. 318. Thus Eli made for Samuel a linen ephod. Samuel i. 3. Secrecy was the foundation on which all mysteries rested, when publiclyknown they ceased to be mysteries; hence a discovery of them was notonly punished with death by the Athenian law; but in other countries adisgrace attended the breach of a solemn oath. The priestess in thefigure before us has her finger pointing to her lips as an emblem ofsilence. There is a figure of Harpocrates, who was of Aegyptian origin, the same as Orus, with the lotus on his head, and with his fingerpointing to his lips not pressed upon them, in Bryant's Mythol. Vol. II. P. 398, and another female figure standing on a lotus, as if just risenfrom the Nile, with her finger in the same attitude, these seem to havebeen representations or emblems of male and female priests of the secretmysteries. As these sort of emblems were frequently changed by artistsfor their more elegant exhibition, it is possible the foliage over thehead of this figure may bear some analogy to the lotus above mentioned. This figure of secrecy seems to be here placed, with great ingenuity, asa caution to the initiated, who might understand the meaning of theemblems round the vase, not to divulge it. And this circumstance seemsto account for there being no written explanation extant, and notradition concerning these beautiful figures handed down to us alongwith them. Another explanation of this figure at the bottom of the vase would seemto confirm the idea that the basso relievos round its sides arerepresentations of a part of the mysteries, I mean that it is the headof ATIS. Lucian says that Atis was a young man of Phrygia, of uncommonbeauty, that he dedicated a temple in Syria to Rhea, or Cybele, andfirst taught her mysteries to the Lydians, Phrygians, and Samothracians, which mysteries he brought from India. He was afterwards made an eunuchby Rhea, and lived like a woman, and assumed a feminine habit, and inthat garb went over the world teaching her ceremonies and mysteries. Dict. Par M. Danet, art. Atis. As this figure is covered with clothes, while those on the sides of the vase are naked, and has a Phrygian capon the head, and as the form and features are so soft, that it isdifficult to say whether it be a male or female figure, there is reasonto conclude, 1. That it has reference to some particular person of someparticular country; 2. That this person is Atis, the first greathierophant, or teacher of mysteries, to whom M. De la Chausse says thefigure itself bears a resemblance. Museo. Capitol. Tom. IV. P. 402. In the Museum Etruscum, Vol. I. Plate 96, there is the head of Atis withfeminine features, clothed with a Phrygian cap, and rising from verybroad foliage, placed on a kind of term supported by the paw of a lion. Goreus in his explanation of the figure says that it is placed on alion's foot because that animal was sacred to Cybele, and that it risesfrom very broad leaves because after he became an eunuch he determinedto dwell in the groves. Thus the foliage, as well as the cap andfeminine features, confirm the idea of this figure at the bottom of thevase representing the head of Atis the first great hierophant, and thatthe figures on the sides of the vase are emblems from the antientmysteries. I beg leave to add that it does not appear to have been uncommon amongstthe antients to put allegorical figures on funeral vases. In thePamphili palace at Rome there is an elaborate representation of Life andof Death, on an antient sarcophagus. In the first Prometheus isrepresented making man, and Minerva is placing a butterfly, or the soul, upon his head. In the other compartment Love extinguishes his torch inthe bosom of the dying figure, and is receiving the butterfly, orPsyche, from him, with a great number of complicated emblematic figuresgrouped in very bad taste. Admir. Roman. Antiq. NOTE XXIII. --COAL _Whence sable Coal his massy couch extends, And stars of gold the sparkling Pyrite blends. _ CANTO II. L. 349. To elucidate the formation of coal-beds I shall here describe a fountainof fossil tar, or petroleum, discovered lately near Colebrook Dale inShropshire, the particulars of which were sent me by Dr. Robert Darwinof Shrewsbury. About a mile and a half below the celebrated iron-bridge, constructed bythe late Mr. DARBY near Colebrook Dale, on the east side of the riverSevern, as the workmen in October 1786 were making a subterranean canalinto the mountain, for the more easy acquisition and conveyance of thecoals which lie under it, they found an oozing of liquid bitumen, orpetroleum; and as they proceeded further cut through small cavities ofdifferent sizes from which the bitumen issued. From ten to fifteenbarrels of this fossil tar, each barrel containing thirty-two gallons, were at first collected in a day, which has since however graduallydiminished in quantity, so that at present the product is about sevenbarrels in fourteen days. The mountain, into which this canal enters, consists of siliceous sand, in which however a few marine productions, apparently in their recentstate, have been found, and are now in the possession of Mr. WILLIAMREYNOLDS of Ketly Bank. About three hundred yards from the entrance intothe mountain, and about twenty-eight yards below the surface of it, thetar is found oozing from the sand-rock above into the top and sides ofthe canal. Beneath the level of this canal a shaft has been sunk through a greyargillaceous substance, called in this country clunch, which is said tobe a pretty certain indication of coal; beneath this lies a stratum ofcoal, about two or three inches thick, of an inferior kind, yieldinglittle flame in burning, and leaving much ashes; below this is a rock ofa harder texture; and beneath this are found coals of an excellentquality; for the purpose of procuring which with greater facility thecanal, or horizontal aperture, is now making into the mountain. July, 1788. Beneath these coals in some places is found salt water, in other partsof the adjacent country there are beds of iron-stone, which also containsome bitumen in a less fluid state, and which are about on a level withthe new canal, into which the fossil tar oozes, as above described. There are many interesting circumstances attending the situation andaccompaniments of this fountain of fossil tar, tending to develop themanner of its production. 1. As the canal passing into the mountain runsover the beds of coals, and under the reservoir of petroleum, it appearsthat a _natural distillation_ of this fossil in the bowels of the earthmust have taken place at some early period of the world, similar to theartificial distillation of coal, which has many years been carried on inthis place on a smaller scale above ground. When this reservoir ofpetroleum was cut into, the slowness of its exsudation into the canalwas not only owing to its viscidity, but to the pressure of theatmosphere, or to the necessity there was that air should at the sametime insinuate itself into the small cavities from which the petroleumdescended. The existence of such a distillation at some antient time isconfirmed by the thin stratum of coal beneath the canal, (which coversthe hard rock, ) having been deprived of its fossil oil, so as to burnwithout flame, and thus to have become a natural coak, or fossilcharcoal, while the petroleum distilled from it is found in the cavitiesof the rock above it. There are appearances in other places, which favour this idea of thenatural distillation of petroleum, thus at Matlock in Derbyshire a hardbitumen is found adhering to the spar in the clefts of the lime-rocks inthe form of round drops about the size of peas; which could perhaps onlybe deposited there in that form by sublimation. 2. The second deduction, which offers itself, is, that these beds ofcoal have been _exposed to a considerable degree of heat_, since thepetroleum above could not be separated, as far as we know, by any othermeans, and that the good quality of the coals beneath the hard rock wasowing to the impermeability of this rock to the bituminous vapour, andto its pressure being too great to permit its being removed by theelasticity of that vapour. Thus from the degree of heat, the degree ofpressure, and the permeability of the superincumbent strata, many of thephenomena attending coal-beds receive an easy explanation, which muchaccords with the ingenious theory of the earth by Dr. Hutton, Trans. OfEdinb. Vol. I. In some coal works the fusion of the strata of coal has been so slight, that there remains the appearance of ligneus fibres, and the impressionof leaves, as at Bovey near Exeter, and even seeds of vegetables, ofwhich I have had specimens from the collieries near Polesworth inWarwickshire. In some, where the heat was not very intense and theincumbent stratum not permeable to vapour, the fossil oil has only risento the upper part of the coal-bed, and has rendered that much moreinflammable than the lower parts of it, as in the collieries nearBeaudesert, the seat of the EARL OF UXBRIDGE in Staffordshire, where theupper stratum is a perfect cannel, or candle-coal, and the lower one ofan inferior quality. Over the coal-beds near Sir H. HARPUR'S house inDerbyshire a thin lamina of asphaltum is found in some places near thesurface of the earth, which would seem to be from a distillation ofpetroleum from the coals below, the more fluid part of which had inprocess of time exhaled, or been consolidated by its absorption of air. In other coal-works the upper part of the stratum is of a worse kindthan the lower one, as at Alfreton and Denbigh in Derbyshire, owing tothe supercumbent stratum having permitted the exhalation of a great partof the petroleum; whilst at Widdrington in Northumberland there is firsta seam of coal about six inches thick of no value, which lies underabout four fathom of clay, beneath this is a white freestone, then ahard stone, which the workmen there call a whin, then two fathoms ofclay, then another white stone, and under that a vein of coals threefeet nine inches thick, of a similar nature to the Newcastle coal. Phil. Trans. Abridg. Vol. VI. Plate II. P. 192. The similitude between thecircumstances of this colliery, and of the coal beneath the fountain oftar above described, renders it highly probable that this upper thinseam of coal has suffered a similar distillation, and that theinflammable part of it had either been received into the clay above inthe form of sulphur, which when burnt in the open air would producealum; or had been dissipated for want of a receiver, where it could becondensed. The former opinion is perhaps in this case more probable asin some other coal-beds, of which I have procured accounts, the surfaceof the coal beneath clunch or clay is of an inferior quality, as at WestHallum in Nottinghamshire. The clunch probably from hence acquires itsinflammable part, which on calcination becomes vitriolic acid. Igathered pieces of clunch converted partially into alum at a collierynear Bilston, where the ground was still on fire a few years ago. The heat, which has thus pervaded the beds of morass, seems to have beenthe effect of the fermentation of their vegetable materials; as new haysometimes takes fire even in such very small masses from the sugar itcontains, and seems hence not to have been attended with any expulsionof lava, like the deeper craters of volcanos situated in beds ofgranite. 3. The marine shells found in the loose sand-rock above this reservoirof petroleum, and the coal-beds beneath it, together with the existenceof sea-salt beneath these coals, prove that these coal beds have been_at the bottom of the sea_, during some remote period of time, and wereafterwards raised into their present situation by subterraneousexpansions of vapour. This doctrine is further supported by the marks ofviolence, which some coal-beds received at the time they were raised outof the sea, as in the collieries at Mendip in Somersetshire. In thesethere are seven strata of coals, equitant upon each other, with beds ofclay and stone intervening; amongst which clay are found shells and fernbranches. In one part of this hill the strata are disjoined, and aquantity of heterogeneous substances fill up the chasm which disjoinsthem, on one side of this chasm the seven strata of coal are seencorresponding in respect to their reciprocal thickness and goodness withthe seven strata on the other side of the cavity, except that they havebeen elevated several yards higher. Phil. Trans. No. 360. Abridg. Vol. V. P. 237. The cracks in the coal-bed near Ticknall in Derbyshire, and in the sand-stone rock over it, in both of which specimens of lead-ore and spar arefound, confirm this opinion of their having been forcibly raised up bysubterraneous fires. Over the colliery at Brown-hills near Lichfield, there is a stratum of gravel on the surface of the ground; which may beadduced as another proof to shew that those coals had some time beenbeneath the sea, or the bed of a river. Nevertheless, these argumentsonly apply to the collieries above mentioned, which are few comparedwith those which bear no marks of having been immersed in the sea. On the other hand the production of coals from morasses, as described innote XX. Is evinced from the vegetable matters frequently found in them, and in the strata over them; as fern-leaves in nodules of iron-ore, andfrom the bog-shells or fresh water muscles sometimes found over them, ofboth which I have what I believe to be specimens; and is further provedfrom some parts of these beds being only in part transformed to coal;and the other part still retaining not only the form, but some of theproperties of wood; specimens of which are not unfrequent in thecabinets of the curious, procured from Loch Neigh in Ireland, from Boveynear Exeter, and other places; and from a famous cavern called theTemple of the Devil, near the town of Altorf in Franconia, at the footof a mountain covered with pine and savine, in which are found largecoals resembling trees of ebony; which are so far mineralized as to beheavy and compact; and so to effloresce with pyrites in some parts as tocrumble to pieces; yet from other parts white ashes are produced oncalcination, from which _fixed alcali_ is procured; which evinces theirvegetable origin. (Dict. Raisonné, art. Charbon. ) To these may be addedanother argument from the oil which is distilled from coals, and whichis analogous to vegetable oil, and does not exist in any bodies trulymineral. Keir's Chemical Dictionary, art. Bitumen. Whence it would appear, that though most collieries with their attendantstrata of clay, sand-stone, and iron, were formed on the places wherethe vegetables grew, from which they had their origin; yet that othercollections of vegetable matter were washed down from eminences bycurrents of waters into the beds of rivers, or the neighbouring seas, and were there accumulated at different periods of time, and underwent agreat degree of heat from their fermentation, in the same manner asthose beds of morass which had continued on the plains where they wereproduced. And that by this fermentation many of them had been raisedfrom the ocean with sand and sea-shells over them; and others from thebeds of rivers with accumulations of gravel upon them. 4. For the purpose of bringing this history of the products of morassesmore distinctly to the eye of the reader, I shall here subjoin two orthree accounts of sinking or boring for coals, out of above twenty whichI have procured from various places, though the terms are not veryintelligible, being the language of the overseers of coal-works. 1. _Whitfield mine_ near the Pottery in Staffordshire. Soil 1 foot. Brick-clay 3 feet. Shale 4. Metal which is hard brown and falls in theweather 42. Coal 3. Warrant clay 6. Brown gritstone 36. Coal 31/2. Warrantclay 31/2. Bass and metal 531/2. Hardstone 4. Shaly bass 11/2. Coal 4. Warrant clay, depth unknown. In all about 55 yards. 2. _Coal-mine at Alfreton_ in Derbyshire. Soil and clay 7 feet. Fragments of stone 9. Bind 13. Stone 6. Bind 34. Stone 5. Bind 2. Stone2. Bind 10. Coal 11/2. Bind 11/2. Stone 37. Bind 7. Soft coal 3. Bind 3. Stone 20. Bind 16. Coal 71/2. In all about 61 yards. 3. _A basset coal-mine at Woolarton_ in Nottinghamshire. Sand and gravel6 feet. Bind 21. Stone 10. Smut or effete coal 1. Clunch 4. Bind 21. Stone 18. Bind 18. Stone-bind 15. Soft coal 2. Clunch and bind 21. Coal7. In all about 48 yards. 4. _Coal-mine at West-Hallam_ in Nottinghamshire. Soil and clay 7 feet. Bind 48. Smut 11/2. Clunch 4. Bind 3. Stone 2. Bind 1. Stone 1. Bind 3. Stone 1. Bind 16. Shale 2. Bind 12. Shale 3. Clunch, stone, and a bed ofcank 54. Soft coal 4. Clay and dun 1. Soft coal 41/2. Clunch and bind 21. Coal 1. Broad bind 26. Hard coal 6. In all about 74 yards. As these strata generally lie inclined, I suppose parallel with thelimestone on which they rest, the upper edges of them all come out today, which is termed bassetting; when the whole mass was ignited by itsfermentation, it is probable that the inflammable part of some stratamight thus more easily escape than of others in the form of vapour; asdews are known to slide between such strata in the production ofsprings; which accounts for some coal-beds being so much worse thanothers. See note XX. From this account of the production of coals from morasses it wouldappear, that coal-beds are not to be expected beneath masses of lime-stone. Nevertheless I have been lately informed by my friend Mr. Michellof Thornhill, who I hope will soon favour the public with his geologicalinvestigations, that the beds of chalk are the uppermost of all thelimestones; and that they rest on the granulated limestone, calledketton-stone; which I suppose is similar to that which covers the wholecountry from Leadenham to Sleaford, and from Sleaford to Lincoln; andthat, thirdly, coal-delphs are frequently found beneath these twouppermost beds of limestone. Now as the beds of chalk and of granulated limestone may have beenformed by alluviation, on or beneath the shores of the sea, or invallies of the land; it would seem, that some coal countries, which inthe great commotions of the earth had been sunk beneath the water, werethus covered with alluvial limestone, as well as others with alluvialbasaltes, or common gravel-beds. Very extensive plains which now consistof alluvial materials, were in the early times covered with water; whichhas since diminished as the solid parts of the earth have increased. Forthe solid parts of the earth consisting chiefly of animal and vegetablerecrements must have originally been formed or produced from the waterby animal and vegetable processes; and as the solid parts of the earthmay be supposed to be thrice as heavy as water, it follows that thricethe quantity of water must have vanished compared with the quantity ofearth thus produced. This may account for many immense beds of alluvialmaterials, as gravel, rounded sand granulated limestone, and chalk, covering such extensive plains as Lincoln-heath, having become drywithout the supposition of their having been again elevated from theocean. At the same time we acquire the knowledge of one of the uses orfinal causes of the organized world, not indeed very flattering to ourvanity, that it converts water into earth, forming islands andcontinents by its recrements or exuviae. NOTE XXIV. --GRANITE. _Climb the rude steeps, the Granite-cliffs surround. _ CANTO II. L. 523. The lowest stratum of the earth which human labour has arrived to, isgranite; and of this likewise consists the highest mountains of theworld. It is known under variety of names according to some differencein its appearance or composition, but is now generally considered byphilosophers as a species of lava; if it contains quartz, feltspat, andmica in distinct crystals, it is called granite; which is found inCornwall in rocks; and in loose stones in the gravel near Drayton inShropshire, in the road towards Newcastle. If these parts of thecomposition be less distinct, or if only two of them be visible to theeye, it is termed porphyry, trap, whinstone, moorstone, slate. And if itappears in a regular angular form, it is called basaltes. The affinityof these bodies has lately been further well established by Dr. Beddoesin the Phil. Trans. Vol. LXXX. These are all esteemed to have been volcanic productions that haveundergone different degrees of heat; it is well known that in Papin'sdigester water may be made red hot by confinement, and will thendissolve many bodies which otherwise are little or not at all acted uponby it. From hence it may be conceived, that under immense pressure ofsuperincumbent materials, and by great heat, these masses of lava mayhave undergone a kind of aqueous solution, without any tendency tovitrification, and might thence have a power of crystallization, whenceall the varieties above mentioned from the different proportion of thematerials, or the different degrees of heat they may have undergone inthis aqueous solution. And that the uniformity of the mixture of theoriginal earths, as of lime, argil, silex, magnesia, and barytes, whichthey contain, was owing to their boiling together a longer or shortertime before their elevation into mountains. See note XIX. Art. 8. The seat of volcanos seems to be principally, if not entirely, in thesestrata of granite; as many of them are situated on granite mountains, and throw up from time to time sheets of lava which run down over theproceeding strata from the same origin; and in this they seem to differfrom the heat which has separated the clay, coal, and sand in morasses, which would appear to have risen from a kind of fermentation, and thusto have pervaded the whole mass without any expuition of lava. [Illustration: _Section of the Earth. A sketch of a supposed Section ofthe Earth in respect to the disposition of the Strata over each otherwithout regard to their proportions or number. London Published Dec'r1st 1791 by J. Johnson St Paul's Church Yard. _] All the lavas from Vesuvius contain one fourth part of iron, (Kirwan'sMin. ) and all the five primitive earths, viz. Calcareous, argillaceous, siliceous, barytic, and magnesian earths, which are also evidentlyproduced now daily from the recrements of animal and vegetable bodies. What is to be thence concluded? Has the granite stratum in very antienttimes been produced like the present calcareous and siliceous masses, according to the ingenious theory of Dr. Hutton, who says new continentsare now forming at the bottom of the sea to rise in their turn, and thatthus the terraqueous globe has been, and will be, eternal? Or shall wesuppose that this internal heated mass of granite, which forms thenucleus of the earth, was a part of the body of the sun before it wasseparated by an explosion? Or was the sun originally a planet, inhabitedlike ours, and a satellite to some other greater sun, which has longbeen extinguished by diffusion of its light, and around which thepresent sun continues to revolve, according to a conjecture of thecelebrated Mr. Herschell, and which conveys to the mind a most sublimeidea of the progressive and increasing excellence of the works of theCreator of all things? For the more easy comprehension of the facts and conjectures concerningthe situation and production of the various strata of the earth, I shallhere subjoin a supposed section of the globe, but without any attempt togive the proportions of the parts, or the number of them, but only theirrespective situation over each other, and a geological recapitulation. GEOLOGICAL RECAPITULATION. 1. The earth was projected along with the other primary planets from thesun, which is supposed to be on fire only on its surface, emitting lightwithout much internal heat like a ball of burning camphor. 2. The rotation of the earth round its axis was occasioned by itsgreater friction or adhesion to one side of the cavity from which it wasejected; and from this rotation it acquired its spheroidical form. As itcooled in its ascent from the sun its nucleus became harder; and itsattendant vapours were condensed, forming the ocean. 3. The masses or mountains of granite, porphery, basalt, and stones ofsimilar structure, were a part of the original nucleus of the earth; orconsist of volcanic productions since formed. 4. On this nucleus of granite and basaltes, thus covered by the ocean, were formed the calcareous beds of limestone, marble, chalk, spar, fromthe exuviae of marine animals; with the flints, or chertz, whichaccompany them. And were stratified by their having been formed atdifferent and very distant periods of time. 5. The whole terraqueous globe was burst by central fires; islands andcontinents were raised, consisting of granite or lava in some parts, andof limestone in others; and great vallies were sunk, into which theocean retired. 6. During these central earthquakes the moon was ejected from the earth, causing new tides; and the earth's axis suffered some change in itsinclination, and its rotatory motion was retarded. 7. On some parts of these islands and continents of granite or limestonewere gradually produced extensive morasses from the recrements ofvegetables and of land animals; and from these morasses, heated byfermentation, were produced clay, marle, sandstone, coal, iron, (withthe bases of variety of acids;) all which were stratified by theirhaving been formed at different, and very distant periods of time. 8. In the elevation of the mountains very numerous and deep fissuresnecessarily were produced. In these fissures many of the metals areformed partly from descending materials, and partly from ascending onesraised in vapour by subterraneous fires. In the fissures of granite orporphery quartz is formed; in the fissures of limestone calcareous sparis produced. 9. During these first great volcanic fires it is probable the atmospherewas either produced, or much increased; a process which is perhaps nowgoing on in the moon; Mr. Herschell having discovered a volcanic craterthree miles broad burning on her disk. 10. The summits of the new mountains were cracked into innumerablelozenges by the cold dews or snows falling upon them when red hot. Fromthese summits, which were then twice as high as at present, cubes andlozenges of granite, and basalt, and quartz in some countries, and ofmarble and flints in others, descended gradually into the valleys, andwere rolled together in the beds of rivers, (which were then so large asto occupy the whole valleys, which they now only intersect;) andproduced the great beds of gravel, of which many valleys consist. 11. In several parts of the earth's surface subsequent earthquakes, fromthe fermentation of morasses, have at different periods of time derangedthe position of the matters above described. Hence the gravel, which wasbefore in the beds of rivers, has in some places been raised intomountains, along with clay and coal strata which were formed frommorasses and washed down from eminences into the beds of rivers or theneighbouring seas, and in part raised again with gravel or marine shellsover them; but this has only obtained in few places compared with thegeneral distribution of such materials. Hence there seem to have existedtwo sources of earthquakes, which have occurred at great distance oftime from each other; one from the granite beds in the central parts ofthe earth, and the other from the morasses on its surface. All thesubsequent earthquakes and volcanos of modern days compared with theseare of small extent and insignificant effect. 12. Besides the argillaceous sand-stone produced from morasses, which isstratified with clay, and coal, and iron, other great beds of siliceoussand have been formed in the sea by the combination of an unknown acidfrom morasses, and the calcareous matters of the ocean. 13. The warm waters which are found in many countries, are owing tosteam arising from great depths through the fissures of limestone orlava, elevated by subterranean fires, and condensed between the strataof the hills over them; and not from any decomposition of pyrites ormanganese near the surface of the earth. 14. The columns of basaltes have been raised by the congelation orexpansion of granite beds in the act of cooling from their semi-vitreousfusion. NOTE XXV. --EVAPORATION. _Aquatic nymphs! you lead with viewless march The winged vapour up the aerial arch. _ CANTO III. L. 13. I. The atmosphere will dissolve a certain quantity of moisture as achemical menstruum, even when it is much below the freezing point, asappears from the diminution of ice suspended in frosty air, but a muchgreater quantity of water is evaporated and suspended in the air bymeans of heat, which is perhaps the universal cause of fluidity, forwater is known to boil with less heat in vacuo, which is a proof that itwill evaporate faster in vacuo, and that the air therefore ratherhinders than promotes its evaporation in higher degrees of heat. Thequick evaporation occasioned in vacuo by a small degree of heat isagreeably seen in what is termed a pulse-glass, which consists of anexhausted tube of glass with a bulb at each end of it and with about twothirds of the cavity filled with alcohol, in which the spirit isinstantly seen to boil by the heat of the finger-end applied on a bubbleof steam in the lower bulb, and is condensed again in the upper bulb bythe least conceivable comparative coldness. 2. Another circumstance evincing that heat is the principal cause ofevaporation is that at the time of water being converted into steam, agreat quantity of heat is taken away from the neighbouring bodies. If athermometer be repeatedly dipped in ether, or in rectified spirit ofwine, and exposed to a blast of air, to expedite the evaporation byperpetually removing the saturated air from it, the thermometer willpresently sink below freezing. This warmth, taken from the ambientbodies at the time of evaporation by the steam, is again given out whenthe steam is condensed into water. Hence the water in a worm-tub duringdistillation so soon becomes hot; and hence the warmth accompanying thedescent of rain in cold weather. 3. The third circumstance, shewing that heat is the principal cause ofevaporation, is, that some of the steam becomes again condensed when anypart of the heat is withdrawn. Thus when warmer south-west winds repletewith moisture succeed the colder north-east winds all bodies that aredense and substantial, as stone walls, brick floors, &c. Absorb some ofthe heat from the passing air, and its moisture becomes precipitated onthem, while the north-east winds become warmer on their arrival in thislatitude, and are thence disposed to take up more moisture, and aretermed drying winds. 4. Heat seems to be the principal cause of the solution of many otherbodies, as common salt, or blue vitriol dissolved in water, which whenexposed to severe cold are precipitated, or carried, to the part of thewater last frozen; this I observed in a phial filled with a solution ofblue vitriol which was frozen; the phial was burst, the ice thawed, anda blue column of cupreous vitriol was left standing upright on thebottom of the broken glass, as described in note XIX. II. Hence water may either be dissolved in air, and may then be calledan aerial solution of water; or it may be dissolved in the fluid matterof heat, according to the theory of M. Lavoisier, and may then be calledsteam. In the former case it is probable there are many other vapourswhich may precipitate it, as marine acid gas, or fluor acid gas. Soalcaline gas and acid gas dissolved in air precipitate each other, nitrous gas precipitates vital air from its azote, and inflammable gasmixed with vital air ignited by an electric spark either produces orprecipitates the water in both of them. Are there any subtle exhalationsoccasionally diffused in the atmosphere which may thus cause rain? 1. But as water is perhaps many hundred times more soluble in the fluidmatter of heat than in air, I suppose the eduction of this heat, bywhatever means it is occasioned, is the principal cause of devaporation. Thus if a region of air is brought from a warmer climate, as the S. W. Winds, it becomes cooled by its contact with the earth in this latitude, and parts with so much of its moisture as was dissolved in the quantityof calorique, or heat, which it now looses, but retains that part whichwas suspended by its attraction to the particles of air, or by aerialsolution, even in the most severe frosts. 2. A second immediate cause of rain is a stream of N. E. Wind descendingfrom a superior current of air, and mixing with the warmer S. W. Windbelow; or the reverse of this, viz. A superior current of S. W. Windmixing with an inferior one of N. E. Wind; in both these cases the wholeheaven becomes instantly clouded, and the moisture contained in the S. W. Current is precipitated. This cause of devaporation has been ingeniouslyexplained by Dr. Hutton in the Transact. Of Edinburgh, Vol. I, and seemsto arise from this circumstance; the particles of air of the N. E. Windeduce part of the heat from the S. W. Wind, and therefore the water whichwas dissolved by that quantity of _heat_ is precipitated; all the otherpart of the water, which was suspended by its attraction to theparticles of air, or dissolved in the remainder of the heat, continuesunprecipitated. 3. A third method by which a region of air becomes cooled, and inconsequence deposits much of its moisture, is from the mechanicalexpansion of air, when part of the pressure is taken off. In this casethe expanded air becomes capable of receiving or attracting more of thematter of heat into its interstices, and the vapour, which waspreviously dissolved in this heat, is deposited, as is seen in thereceiver of an air-pump, which becomes dewy, as the air within becomesexpanded by the eduction of part of it. See note VII. Hence when themercury in the barometer sinks without a change of the wind the airgenerally becomes colder. See note VII. On Elementary Heat. And it isprobably from the varying pressure of the incumbent air that in summerdays small black clouds are often thus suddenly produced, and again soonvanish. See a paper in Philos. Trans. Vol. LXXVIII. Intitled FrigorificExperiments on the Mechanical Expansion of Air. 4. Another portion of atmospheric water may possibly be held in solutionby the electric fluid, since in thunder storms a precipitation of thewater seems to be either the cause or the consequence of the eduction ofthe electricity. But it appears more probable that the water iscondensed into clouds by the eduction of its heat, and that then thesurplus of electricity prevents their coalescence into larger drops, which immediately succeeds the departure of the lightning. 5. The immediate cause why the barometer sinks before rain is, first, because a region of warm air, brought to us in the place of the cold airwhich it had displaced, must weigh lighter, both specifically andabsolutely, if the height of the warm atmosphere be supposed to be equalto that of the preceeding cold one. And secondly, after the drops ofrain begin to fall in any column of air, that column becomes lighter, the falling drops only adding to the pressure of the air in proportionto the resistance which they meet with in passing through that fluid. If we could suppose water to be dissolved in air without heat, or invery low degrees of heat, I suppose the air would become heavier, ashappens in many chemical solutions, but if water dissolved in the matterof heat, or calorique, be mixed with an aerial solution of water, therecan be no doubt but an atmosphere consisting of such a mixture mustbecome lighter in proportion to the quantity of calorique. On the samecircumstance depends the visible vapour produced from the breath ofanimals in cold weather, or from a boiling kettle; the particles of coldair, with which it is mixed, steal a part of its heat, and becomethemselves raised in temperature, whence part of the water isprecipitated in visible vapour, which, if in great quantity sinks to theground; if in small quantity, and the surrounding air is not previouslysaturated, it spreads itself till it becomes again dissolved. NOTE XXVI. --SPRINGS _Your lucid bands condense with fingers chill The blue mist hovering round the gelid hill_. CANTO III. L. 19. The surface of the earth consists of strata many of which were formedoriginally beneath the sea, the mountains were afterwards forced up bysubterraneous fires, as appears from the fissures in the rocks of whichthey consist, the quantity of volcanic productions all over the world, and the numerous remains of craters of volcanos in mountainouscountries. Hence the strata which compose the sides of mountains lieslanting downwards, and one or two or more of the external strata notreaching to the summit when the mountain was raised up, the second orthird stratum or a more inferior one is there exposed to day; this maybe well represented by forceably thrusting a blunt instrument throughseveral sheets of paper, a bur will stand up with the lowermost sheetstanding highest in the center of it. On this uppermost stratum, whichis colder as it is more elevated, the dews are condensed in largequantities; and sliding down pass under the first or second or thirdstratum which compose the sides of the hill; and either form a morassbelow, or a weeping rock, by oozing out in numerous places, or many ofthese less currents meeting together burst out in a more copious rill. The summits of mountains are much colder than the plains in theirvicinity, owing to several causes; 1. Their being in a manner insulatedor cut off from the common heat of the earth, which is always of 48degrees, and perpetually counteracts the effects of external coldbeneath that degree. 2. From their surfaces being larger in proportionto their solid contents, and hence their heat more expeditiously carriedaway by the ever-moving atmosphere. 3. The increasing rarity of the airas the mountain rises. All those bodies which conduct electricity wellor ill, conduct the matter of heat likewise well or ill. See note VII. Atmospheric air is a bad conductor of electricity and thence confines iton the body where it is accumulated, but when it is made very rare, asin the exhausted receiver, the electric aura passes away immediately toany distance. The same circumstance probably happens in respect to heat, which is thus kept by the denser air on the plains from escaping, but isdissipated on the hills where the air is thinner. 4. As the currents ofair rise up the sides of mountains they become mechanically rarefied, the pressure of the incumbent column lessening as they ascend. Hence theexpanding air absorbs heat from the mountain as it ascends, as explainedin note VII. 5. There is another, and perhaps more powerful cause, Isuspect, which may occasion the great cold on mountains, and in thehigher parts of the atmosphere, and which has not yet been attended to;I mean that the fluid matter of heat may probably gravitate round theearth, and form an atmosphere on its surface, mixed with the aerialatmosphere, which may diminish or become rarer, as it recedes from theearth's surface, in a greater proportion than the air diminishes. 6. The great condensation of moisture on the summits of hills hasanother cause, which is the dashing of moving clouds against them, inmisty days this is often seen to have great effect on plains, where aneminent tree by obstructing the mist as it moves along shall have a muchgreater quantity of moisture drop from its leaves than falls at the sametime on the ground in its vicinity. Mr. White, in his History ofSelborne gives an account of a large tree so situated, from which astream flowed during a moving mist so as to fill the cart-ruts in a laneotherwise not very moist, and ingeniously adds, that trees planted aboutponds of stagnant water contribute much by these means to supply thereservoir. The spherules which constitute a mist or cloud are kept fromuniting by so small a power that a little agitation against the leavesof a tree, or the greater attraction of a flat moist surface, condensesor precipitates them. If a leaf has its surface moistened and particles of water separate fromeach other as in a mist be brought near the moistened surface of a leaf, each particle will be attracted more by that plain surface of water onthe leaf than it can be by the surrounding particles of the mist, because globules only attract each other in one point, whereas a plainattracts a globule by a greater extent of its surface. The common cold springs are thus formed on elevated grounds by thecondensed vapours, and hence are stronger when the nights are cold afterhot days in spring, than even in the wet days of winter. For the warmatmosphere during the day has dissolved much more water than it cansupport in solution during the cold of the night, which is thusdeposited in large quantities on the hills, and yet so gradually as tosoak in between the strata of them, rather than to slide off over theirsurfaces like showers of rain. The common heat of the internal parts ofthe earth is ascertained by springs which arise from strata of earth toodeep to be affected by the heat of summer or the frosts of winter. Thosein this country are of 48 degrees of heat, those about Philidelphia weresaid by Dr. Franklin to be 52; whether this variation is to be accountedfor by the difference of the sun's heat on that country, according tothe ingenious theory of Mr. Kirwan, or to the vicinity of subterraneanfires is not yet, I think, decided. There are however subterraneousstreams of water not exactly produced in this manner, as streams issuingfrom fissures in the earth, communicating with the craters of oldvolcanoes; in the Peak of Derbyshire are many hollows, called swallows, where the land floods sink into the earth, and come out at some milesdistant, as at Ilam near Ashborne. See note on Fica, Vol. II. Other streams of cold water arise from beneath the snow on the Alps andAndes, and other high mountains, which is perpetualy thawing at itsunder surface by the common heat of the earth, and gives rise to largerivers. For the origin of warm springs see note on Fucus, Vol. II. NOTE XXVII. --SHELL FISH. _You round Echinus ray his arrowy mail, Give the keel'd Nautilus his oar and sail. Firm to his rock with silver cords suspend The anchored Pinna, and his Cancer-friend_. CANTO III. L. 67. The armour of the Echinus, or Sea-hedge Hog, consists generally ofmoveable spines; (_Linnei System. Nat. _ Vol. I. P. 1102. ) and in thatrespect resembles the armour of the land animal of the same name. Theirregular protuberances on other sea-shells, as on some species of thePurpura, and Murex, serve them as a fortification against the attacks oftheir enemies. It is said that this animal foresees tempestuous weather, and sinking tothe bottom of the sea adheres firmly to sea-plants, or other bodies bymeans of a substance which resembles the horns of snails. Above twelvehundred of these fillets have been counted by which this animal fixesitself; and when afloat, it contracts these fillets between the bases ofits points, the number of which often amounts to two thousand. Dictraisonne. Art. Oursin. De mer. There is a kind of Nautilus, called by Linneus, Argonauta, whose shellhas but one cell; of this animal Pliny affirms, that having exoneratedits shell by throwing out the water, it swims upon the surface, extending a web of wonderful tenuity, and bending back two of its armsand rowing with the rest, makes a sail, and at length receiving thewater dives again. Plin. IX. 29. Linneus adds to his description of thisanimal, that like the Crab Diogenes or Bernhard, it occupies a housenot its own, as it is not connected to its shell, and is thereforeforeign to it; who could have given credit to this if it had not beenattested by so many who have with their own eyes seen this argonaut inthe act of sailing? Syst. Nat p. 1161. The Nautilus, properly so named by Linneus, has a shell consisting ofmany chambers, of which cups are made in the East with beautifulpainting and carving on the mother-pearl. The animal is said to inhabitonly the uppermost or open chamber, which is larger than the rest; andthat the rest remain empty except that the pipe, or siphunculus, whichcommunicates from one to the other of them is filled with an appendageof the animal like a gut or string. Mr. Hook in his Philos. Exper. P. 306, imagines this to be a dilatable or compressible tube, like the air-bladders of fish, and that by contracting or permitting it to expand, itrenders its shell boyant or the contrary. See Note on Ulva, Vol. II. The Pinna, or Sea-wing, is contained in a two-valve shell, weighingsometimes fifteen pounds, and emits a beard of fine long glossy silk-like fibres, by which it is suspended to the rocks twenty or thirty feetbeneath the surface of the sea. In this situation it is so successfullyattacked by the eight-footed Polypus, that the species perhaps could notexist but for the exertions of the Cancer Pinnotheris, who lives in thesame shell as a guard and companion. Amoen. Academ. Vol. II. P. 48. Lin. Syst. Nat. Vol. I. P. 1159, and p. 1040. The Pinnotheris, or Pinnophylax, is a small crab naked like Bernard theHermit, but is furnished with good eyes, and lives in the same shellwith the Pinna; when they want food the Pinna opens its shell, and sendsits faithful ally to forage; but if the Cancer sees the Polypus, hereturns suddenly to the arms of his blind hostess, who by closing theshell avoids the fury of her enemy; otherwise, when it has procured abooty, it brings it to the opening of the shell, where it is admitted, and they divide the prey. This was observed by Haslequist in his voyageto Palestine. The Byssus of the antients, according to Aristotle, was the beard of thePinna above mentioned, but seems to have been used by other writersindiscriminately for any spun material, which was esteemed finer or morevaluable than wool. Reaumur says the threads of this Byssus are not lessfine or less beautiful than the silk, as it is spun by the silk-worm;the Pinna on the coasts of Italy and Provence (where it is fished up byiron-hooks fixed on long poles) is called the silk-worm of the sea. Thestockings and gloves manufactured from it, are of exquisite fineness, but too warm for common wear, and are thence esteemed useful inrhumatism and gout. Dict. Raisonné art. Pinne-marine. The warmth of theByssus, like that of silk, is probably owing to their being badconductors of heat, as well as of electricity. When these fibres arebroken by violence, this animal as well as the muscle has the power toreproduce them like the common spiders, as was observed by M. Adanson. As raw silk, and raw cobwebs, when swallowed, are liable to producegreat sickness (as I am informed) it is probable the part of muscles, which sometimes disagrees with the people who eat them, may be thissilky web, by which they attach themselves to stones. The large kind ofPinna contains some mother-pearl of a reddish tinge, according to M. D'Argenville. The substance sold under the name of Indian weed, and usedat the bottom of fish-lines, is probably a production of this kind;which however is scarcely to be distinguished by the eye from thetendons of a rat's tail, after they have been separated by putrefactionin water, and well cleaned and rubbed; a production, which I was onceshewn as a great curiosity; it had the uppermost bone of the tailadhering to it, and was said to have been used as an ornament in alady's hair. NOTE XXVIII. --STURGEON. _With worm-like hard his toothless lips array, And teach the unweildy Sturgeon to betray. _ CANTO III. L. 71. The Sturgeon, _Acipenser, Strurio. _ Lin. Syst. Nat. Vol. I. P. 403. Is afish of great curiosity as well as of great importance; his mouth isplaced under the head, without teeth, like the opening of a purse, whichhe has the power to push suddenly out or retract. Before this mouthunder the beak or nose hang four tendrils some inches long, and which soresemble earth-worms that at first sight they may be mistaken for them. This clumsy toothless fish is supposed by this contrivance to keephimself in good condition, the solidity of his flesh evidently shewinghim to be a fish of prey. He is said to hide his large body amongst theweeds near the sea-coast, or at the mouths of large rivers, onlyexposing his cirrhi or tendrils, which small fish or sea-insectsmistaking for real worms approach for plunder, and are sucked into thejaws of their enemy. He has been supposed by some to root into the soilat the bottom of the sea or rivers; but the cirrhi, or tendrillsabovementioned, which hang from his snout over his mouth, mustthemselves be very inconvenient for this purpose, and as it has no jawsit evidently lives by suction, and during its residence in the sea aquantity of sea-insects are found in its stomach. The flesh was so valued in the time of the Emperor Severus, that it wasbrought to table by servants with coronets on their heads, and precededby music, which might give rise to its being in our country presented bythe Lord Mayor to the King. At present it is caught in the Danube, andthe Walga, the Don, and other large rivers for various purposes. Theskin makes the best covering for carriages; isinglass is prepared fromparts of the skin; cavear from the spawn; and the flesh is pickled orsalted, and sent all over Europe. NOTE XXIX. --OIL ON WATER. _Who with fine films, suspended o'er the deep, Of Oil effusive lull the waves to sleep. _ CANTO III. L. 87. There is reason to believe that when oil is poured upon water, the twosurfaces do not touch each other, but that the oil is suspended over thewater by their mutual repulsion. This seems to be rendered probable bythe following experiment: if one drop of oil be droped on a bason ofwater, it will immediately diffuse itself over the whole, for therebeing no friction between the two surfaces, there is nothing to preventits spreading itself by the gravity of the upper part of it, except itsown tenacity, into a pellicle of the greatest tenuity. But if a seconddrop of oil be put upon the former, it does not spread itself, butremains in the form of a drop, as the other already occupied the wholesurface of the bason, and there is friction in oil passing over oil, though none in oil passing over water. Hence when oil is diffused on the surface of water gentle breezes haveno influence in raising waves upon it; for a small quantity of oil willcover a very great surface of water, (I suppose a spoonful will diffuseitself over some acres) and the wind blowing upon this carries itgradually forwards; and there being no friction between the two surfacesthe water is not affected. On which account oil has no effect instilling the agitation of the water after the wind ceases, as was foundby the experiments of Dr. Franklin. This circumstance lately brought into notice by Dr. Franklin had beenmentioned by Pliny, and is said to be in use by the divers for pearls, who in windy weather take down with them a little oil in their mouths, which they occasionally give out when the inequality of the supernatantwaves prevents them from seeing sufficiently distinctly for theirpurpose. The wonderful tenuity with which oil can be spread upon water is evincedby a few drops projected from a bridge, where the eye is properly placedover it, passing through all the prismatic colours as it diffusesitself. And also from another curious experiment of Dr. Franklin's: hecut a piece of cork to about the size of a letter-wafer, leaving a pointstanding off like a tangent at one edge of the circle. This piece ofcork was then dipped in oil and thrown into a large pond of water, andas the oil flowed off at the point, the cork-wafer continued to revolvein a contrary direction for several minutes. The oil flowing off allthat time at the pointed tangent in coloured streams. In a small pond ofwater this experiment does not so well succeed, as the circulation ofthe cork stops as soon as the water becomes covered with the pellicle ofoil. See Additional Note, No. XIII. And Note on Fucus, Vol. II. The ease with which oil and water slide over each other is agreeablyseen if a phial be about half filled with equal parts of oil and water, and made to oscillate suspended by a string, the upper surface of theoil and the lower one of the water will always keep smooth; but theagitation of the surfaces where the oil and water meet, is curious; fortheir specific gravities being not very different, and their friction oneach other nothing, the highest side of the water, as the phial descendsin its oscillation, having acquired a greater momentum than the lowestside (from its having descended further) would rise the highest on theascending side of the oscillation, and thence pushes the then uppermostpart of the water amongst the oil. NOTE XXX. --SHIP-WORM. _Meet fell Teredo, as he mines the keel With beaked head, and break his lips of steel. _ CANTO III. L. 91. The Teredo, or ship-worm, has two calcareous jaws, hemispherical, flatbefore, and angular behind. The shell is taper, winding, penetratingships and submarine wood, and was brought from India into Europe, LinneiSystem. Nat. P. 1267. The Tarieres, or sea-worms, attack and erode shipswith such fury, and in such numbers, as often greatly to endanger them. It is said that our vessels have not known this new enemy above fiftyyears, that they were brought from the sea about the Antilles to ourparts of the ocean, where they have increased prodigiously. They boretheir passage in the direction of the fibres of the wood, which is theirnourishment, and cannot return or pass obliquely, and thence when theycome to a knot in the wood, or when two of them meet together with theirstony mouths, they perish for want of food. In the years 1731 and 1732 the United Provinces were under a dreadfulalarm concerning these insects, which had made great depredation on thepiles which support the banks of Zeland, but it was happily discovered afew years afterwards that these insects had totally abandoned thatisland, (Dict Raisonné, art, Vers Rongeurs, ) which might have beenoccasioned by their not being able to live in that latitude when thewinter was rather severer than usual. NOTE XXXI. --MAELSTROM. _Turn the broad helm, the fluttering canvas urge From Maelstrom's fierce innavigable surge. _ CANTO III. L. 93. On the coast of Norway there is an extensive vortex, or eddy, which liesbetween the islands of Moskoe and Moskenas, and is called Moskoestrom, or Maelstrom; it occupies some leagues in circumference, and is said tobe very dangerous and often destructive to vessels navigating theseseas. It is not easy to understand the existence of a constantdescending stream without supposing it must pass through a subterraneancavity to some other part of the earth or ocean which may lie beneathits level; as the Mediterranean seems to lie beneath the level of theAtlantic ocean, which therefore constantly flows into it through theStraits; and the waters of the Gulph of Mexico lie much above the levelof the sea about the Floridas and further northward, which gives rise tothe Gulph-stream, as described in note on Cassia in Vol. II. The Maelstrom is said to be still twice in about twenty-four hours whenthe tide is up, and most violent at the opposite times of the day. Thisis not difficult to account for, since when so much water is broughtover the subterraneous passage, if such exists, as compleatly to fill itand stand many feet above it, less disturbance must appear on thesurface. The Maelstrom is described in the Memoires of the SwedishAcademy of Sciences, and Pontoppiden's Hist. Of Norway, and in UniversalMuseum for 1763, p. 131. The reason why eddies of water become hollow in the middle is becausethe water immediately over the centre of the well, or cavity, fallsfaster, having less friction to oppose its descent, than the water overthe circumference or edges of the well. The circular motion or gyrationof eddies depends on the obliquity of the course of the stream, or tothe friction or opposition to it being greater on one side of the wellthan the other; I have observed in water passing through a hole in thebottom of a trough, which was always kept full, the gyration of thestream might be turned either way by increasing the opposition of oneside of the eddy with ones finger, or by turning the spout, throughwhich the water was introduced, a little more obliquely to the hole onone side or on the other. Lighter bodies are liable to be retained longin eddies of water, while those rather heavier than water are soonthrown out beyond the circumference by their acquired momentum becominggreater than that of the water. Thus if equal portions of oil and waterbe put into a phial, and by means of a string be whirled in a circleround the hand, the water will always keep at the greater distance fromthe centre, whence in the eddies formed in rivers during a flood aperson who endeavours to keep above water or to swim is liable to bedetained in them, but on suffering himself to sink or dive he is saidreadily to escape. This circulation of water in descending through ahole in a vessel Dr. Franklin has ingeniously applied to the explanationof hurricanes or eddies of air. NOTE XXXII. --GLACIERS. _While round dark crags imprison'd waters bend Through rifted ice, in ivory veins descend. _ CANTO III. L. 113. The common heat of the interior parts of the earth being always 48degrees, both in winter and summer, the snow which lies in contact withit is always in a thawing state; Hence in ice-houses the external partsof the collection of ice is perpetually thawing and thus preserves theinternal part of it; so that it is necessary to lay up many tons for thepreservation of one ton. Hence in Italy considerable rivers have theirsource from beneath the eternal glaciers, or mountains of snow and ice. In our country when the air in the course of a frost continues a day ortwo at very near 32 degrees, the common heat of the earth thaws the iceon its surface, while the thermometer remains at the freezing point. This circumstance is often observable in the rimy mornings of spring;the thermometer shall continue at the freezing point, yet all the rimewill vanish, except that which happens to lie on a bridge, a board, oron a cake of cow-dung, which being thus as it were insulated or cut offfrom so free a communication with the common heat of the earth by meansof the air under the bridge, or wood, or dung, which are bad conductorsof heat, continues some time longer unthawed. Hence when the ground iscovered thick with snow, though the frost continues, and the sun doesnot shine, yet the snow is observed to decrease very sensibly. For thecommon heat of the earth melts the under surface of it, and the upperone evaporates by its solution in the air. The great evaporation of icewas observed by Mr. Boyle, which experiment I repeated some time ago. Having suspended a piece of ice by a wire and weighed it with carewithout touching it with my hand, I hung it out the whole of a clearfrosty night, and found in the morning it had lost nearly a fifth of itsweight. Mr. N. Wallerius has since observed that ice at the time of itscongelation evaporates faster than water in its fluid form; which may beaccounted for from the heat given out at the instant of freezing;(Saussure's Essais sur Hygromet. P. 249. ) but this effect is onlymomentary. Thus the vegetables that are covered with snow are seldom injured;since, as they lie between the thawing snow, which has 32 degrees ofheat, and the covered earth which has 48, they are preserved in a degreeof heat between these; viz. In 40 degrees of heat. Whence the moss onwhich the rein-deer feed in the northern latitudes vegetates beneath thesnow; (See note on Muschus, Vol. II. ) and hence many Lapland and Alpineplants perished through cold in the botanic garden at Upsal, for intheir native situations, though the cold is much more intense, yet atits very commencement they are covered deep with snow, which remainstill late in the spring. For this fact see Amaenit. Academ. Vol. I. No. 48. In our climate such plants do well covered with dried fern, underwhich they will grow, and even flower, till the severe vernal frostscease. For the increase of glaciers see Note on Canto I. L. 529. NOTE XXXIII. --WINDS. _While southern gales o'er western oceans roll, And Eurus steals his ice-winds from the pole. _ CANTO IV. L. 15. The theory of the winds is yet very imperfect, in part perhaps owing tothe want of observations sufficiently numerous of the exact times andplaces where they begin and cease to blow, but chiefly to our yetimperfect knowledge of the means by which great regions of air areeither suddenly produced or suddenly destroyed. The air is perpetually subject to increase or diminution from itscombination with other bodies, or its evolution from them. The vitalpart of the air, called oxygene, is continually produced in this climatefrom the perspiration of vegetables in the sunshine, and probably fromthe action of light on clouds or on water in the tropical climates, where the sun has greater power, and may exert some yet unknown laws ofluminous combination. Another part of the atmosphere, which is calledazote, is perpetually set at liberty from animal and vegetable bodies byputrefaction or combustion, from many springs of water, from volatilealcali, and probably from fixed alcali, of which there is an exhaustlesssource in the water of the ocean. Both these component parts of the airare perpetually again diminished by their contact with the soil, whichcovers the surface of the earth, producing nitre. The oxygene isdiminished in the production of all acids, of which the carbonic andmuriatic exist in great abundance. The azote is diminished in the growthof animal bodies, of which it constitutes an important part, and in itscombinations with many other natural productions. They are both probably diminished in immense quantities by uniting withthe inflammable air, which arises from the mud of rivers and lakes atsome seasons, when the atmosphere is light: the oxygene of the airproducing water, and the azote producing volatile alcali by theircombinations with this inflammable air. At other seasons of the yearthese principles may again change their combinations, and theatmospheric air be reproduced. Mr. Lavoisier found that one pound of charcoal in burning consumed twopounds nine ounces of vital air, or oxygene. The consumption of vitalair in the process of making red lead may readily be reduced tocalculation; a small barrel contains about twelve hundred weight of thiscommodity, 1200 pounds of lead by calcination absorb about 144 pounds ofvital air; now as a cubic foot of water weighs 1000 averdupois ounces, and as vital air is above 800 times lighter than water, it follows thatevery barrel of red lead contains nearly 2000 cubic feet of vital air. If this can be performed in miniature in a small oven, what may not bedone in the immense elaboratories of nature! These great elaboratories of nature include almost all her fossil aswell as her animal and vegetable productions. Dr. Priestley obtained airof greater or less purity, both vital and azotic, from almost all thefossil substances he subjected to experiment. Four ounce-weight of lavafrom Iceland heated in an earthen retort yielded twenty ounce-measuresof air. 4 ounce-weight of lava gave 20 ounce measures of air. 7 ............... Basaltes .... 104 ...................... 2 ............... Toadstone .... 40 ...................... 11/2 ............... Granite .... 20 ...................... 1 ............... Elvain .... 30 ...................... 7 ............... Gypsum .... 230 ...................... 4 ............... Blue slate .... 230 ...................... 4 ............... Clay .... 20 ...................... 4 ............... Limestone-spar .... 830 ...................... 5 ............... Limestone .... 1160 ...................... 3 ............... Chalk .... 630 ...................... 31/2 ............... White iron-ore .... 560 ...................... 4 ............... Dark iron-ore .... 410 ...................... 1/2 ............... Molybdena .... 25 ...................... 1/2 ............... Stream tin .... 20 ...................... 2 ............... Steatites .... 40 ...................... 2 ............... Barytes .... 26 ...................... 2 ............... Black wad .... 80 ...................... 4 ............... Sand stone .... 75 ...................... 3 ............... Coal .... 700 ...................... In this account the fixed air was previously extracted from thelimestones by acids, and the heat applied was much less than wasnecessary to extract all the air from the bodies employed. Add to thisthe known quantities of air which are combined with the calciform ores, as the ochres of iron, manganese, calamy, grey ore of lead, and someidea may be formed of the great production of air in volcanic eruptions, as mentioned in note on Chunda, Vol. II. And of the perpetualabsorptions and evolutions of whole oceans of air from every part of theearth. But there would seem to be an officina aeris, a shop where air is bothmanufactured and destroyed in the greatest abundance within the polarcircles, as will hereafter be spoken of. Can this be effected by someyet unknown law of the congelation of aqueous or saline fluids, whichmay set at liberty their combined heat, and convert a part both of theacid and alcali of sea-water into their component airs? Or on thecontrary can the electricity of the northern lights convert inflammableair and oxygene into water, whilst the great degree of cold at the polesunites the azote with some other base? Another officina aeris, ormanufacture of air, would seem to exist within the tropics or at theline, though in a much less quantity than at the poles, owing perhaps tothe action of the sun's light on the moisture suspended in the air, aswill also be spoken of hereafter; but in all other parts of the earththese absorptions and evolutions of air in a greater or less degree areperpetually going on in inconceivable abundance; increased probably, anddiminished at different seasons of the year by the approach orretrocession of the sun's light; future discoveries must elucidate thispart of the subject. To this should be added that as heat andelectricity, and perhaps magnetism, are known to displace air, that itis not impossible but that the increased or diminished quantities ofthese fluids diffused in the atmosphere may increase its weight a wellas its bulk; since their specific attractions or affinities to matterare very strong, they probably also possess general gravitation to theearth; a subject which wants further investigation. See Note XXVI. SOUTH-WEST WINDS. The velocity of the surface of the earth in moving round its axisdiminishes from the equator to the poles. Whence if a region of air inthis country should be suddenly removed a few degrees towards the northit must constitute a western wind, because from the velocity it hadpreviously acquired in this climate by its friction with the earth itwould for a time move quicker than the surface of the country it wasremoved to; the contrary must ensue when a region of air is transportedfrom this country a few degrees southward, because the velocity it hadacquired in this climate would be less than that of the earth's surfacewhere it was removed to, whence it would appear to constitute a windfrom the east, while in reality the eminent parts of the earth would becarried against the too slow air. But if this transportation of air fromsouth to north be performed gradually, the motion of the wind will blowin the diagonal between south and west. And on the contrary if a regionof air be gradually removed from north to south it would also blowdiagonally between the north and east, from whence we may safelyconclude that all our winds in this country which blow from the north oreast, or any point between them, consist of regions of air brought fromthe north; and that all our winds blowing from the south or west, orfrom any point between them, are regions of air brought from the south. It frequently happens during the vernal months that after a north-eastwind has passed over us for several weeks, during which time thebarometer has flood at above 301/2 inches, it becomes suddenly succeededby a south-west wind, which also continues several weeks, and thebarometer sinks to nearly 281/2 inches. Now as two inches of the mercuryin the barometer balance one-fifteenth part of the whole atmosphere, animportant question here presents itself, _what is become of all thisair_. 1. This great quantity of air can not be carried in a superior currenttowards the line, while the inferior current slows towards the poles, because then it would equally affect the barometer, which should nottherefore subside from 301/2 inches to 281/2 for six weeks together. 2. It cannot be owing to the air having lost all the moisture which waspreviously dissolved in it, because these warm south-west winds arereplete with moisture, and the cold north-east winds, which weigh up themercury in the barometer to 31 inches, consist of dry air. 3. It can not be carried over the polar regions and be accumulated onthe meridian, opposite to us in its passage towards the line, as such anaccumulation would equal one-fifteenth of the whole atmosphere, and cannot be supposed to remain in that situation for six weeks together. 4. It can not depend on the existence of tides in the atmosphere, sinceit must then correspond to lunar periods. Nor to accumulations of airfrom the specific levity of the upper regions of the atmosphere, sinceits degree of fluidity must correspond with its tenuity, andconsequently such great mountains of air can not be supposed to existfor so many weeks together as the south west winds sometimes continue. 5. It remains therefore that there must be at this time a great andsudden absorption of air in the polar circle by some unknown operationof nature, and that the south wind runs in to supply the deficiency. Nowas this south wind consists of air brought from a part of the earth'ssurface which moves faster than it does in this climate it must have atthe same time a direction from the west by retaining part of thevelocity it had previously acquired. These south-west winds coming froma warmer country, and becoming colder by their contact with the earth ofthis climate, and by their expansion, (so great a part of thesuperincumbent atmosphere having vanished, ) precipitate their moisture;and as they continue for several weeks to be absorbed in the polarcircle would seem to receive a perpetual supply from the tropicalregions, especially over the line, as will hereafter be spoken of. It may sometimes happen that a north-east wind having passed over us maybe bent down and driven back before it has acquired any heat from theclimate, and may thus for a few hours or a day have a south-westdirection, and from its descending from a higher region of theatmosphere may possess a greater degree of cold than an inferior northeast current of air. The extreme cold of Jan. 13, 1709, at Paris came on with a gentle southwind, and was diminished when the wind changed to the north, which isaccounted for by Mr. Homberg from a reflux of air which had been flowingfor some time from the north. Chemical Essays by R. Watson, Vol. V. P. 182. It may happen that a north-east current may for a day or two pass overus and produce incessant rain by mixing with the inferior south-westcurrent; but this as well as the former is of short duration, as itsfriction will soon carry the inferior current along with it, and dry orfrosty weather will then succeed. NORTH-EAST WINDS. The north-east winds of this country consist of regions of air from thenorth, travelling sometimes at the rate of about a mile in two minutesduring the vernal months for several weeks together from the polarregions toward the south, the mercury in the barometer standing above30. These winds consist of air greatly cooled by the evaporation of theice and snow over which it passes, and as they become warmer by theircontact with the earth of this climate are capable of dissolving moremoisture as they pass along, and are thence attended with frosts inwinter and with dry hot weather in summer. 1. This great quantity of air can not be supplied by superior currentspassing in a contrary direction from south to north, because suchcurrents must as they arise into the atmosphere a mile or two highbecome exposed to so great cold as to occasion them to deposit theirmoisture, which would fall through the inferior current upon the earthin some part of their passage. 2. The whole atmosphere must have increased in quantity, because itappears by the barometer that there exists one-fifteenth part more airover us for many weeks together, which could not be thus accumulated bydifference of temperature in respect to heat, or by any aerostatic lawsat present known, or by any lunar influence. From whence it would appear that immense masses of air were set atliberty from their combinations with solid bodies, along with asufficient quantity of combined heat, within the polar circle, or insome region to the north of us; and that they thus perpetually increasethe quantity of the atmosphere; and that this is again at certain timesre-absorbed, or enters into new combinations at the line or tropicalregions. By which wonderful contrivance the atmosphere is perpetuallyrenewed and rendered fit for the support of animal and vegetable life. SOUTH-EAST WINDS. The south-east winds of this country consist of air from the north whichhad passed by us, or over us, and before it had obtained the velocity ofthe earth's surface in this climate had been driven back, owing to adeficiency of air now commencing at the polar regions. Hence these aregenerally dry or freezing winds, and if they succeed north-east windsshould prognosticate a change of wind from north-east to south-west; thebarometer is generally about 30. They are sometimes attended with cloudyweather, or rain, owing to their having acquired an increased degree ofwarmth and moisture before they became retrograde; or to their beingmixed with air from the south. 2. Sometimes these south-east winds consist of a vertical eddy of north-east air, without any mixture of south-west air; in that case thebarometer continues above 30, and the weather is dry or frosty for fouror five days together. It should here be observed, that air being an elastic fluid must be moreliable to eddies than water, and that these eddies must extend intocylinders or vortexes of greater diameter, and that if a vertical eddyof north-east air be of small diameter or has passed but a little way tothe south of us before its return, it will not have gained the velocityof the earth's surface to the south of us, and will in consequencebecome a south-east wind. --But if the vertical eddy be of largediameter, or has passed much to the south of us, it will have acquiredvelocity from its friction with the earth's surface to the south of us, and will in consequence on its return become a south-west wind, producing great cold. NORTH-WEST WINDS. There seem to be three sources of the north-west winds of thishemisphere of the earth. 1. When a portion of southern air, which waspassing over us, is driven back by accumulation of new air in the polarregions. In this case I suppose they are generally moist or rainy winds, with the barometer under 30, and if the wind had previously been in thesouth-west, it would seem to prognosticate a change to the north-east. 2. If a current of north wind is passing over us but a few miles high, without any easterly direction; and is bent down upon us, it mustimmediately possess a westerly direction, because it will now movefaster than the surface of the earth where it arrives; and thus becomeschanged from a north-east to a north-west wind. This descent of a north-east current of air producing a north-west wind may continue some dayswith clear or freezing weather, as it may be simply owing to a verticaleddy of north-east air, as will be spoken of below. It may otherwise beforced down by a current of south-west wind passing over it, and in thiscase it will be attended with rain for a few days by the mixture of thetwo airs of different degrees of heat; and will prognosticate a changeof wind from north-east to south-west if the wind was previously in thenorth-east quarter. 3. On the eastern coast of North America the north-west winds bringfrost, as the north-east winds do in this country, as appears fromvariety of testimony. This seems to happen from a vertical spiral eddymade in the atmosphere between the shore and the ridge of mountainswhich form the spine or back-bone of that continent. If a current ofwater runs along the hypothenuse of a triangle an eddy will be made inthe included angle, which will turn round like a water-wheel as thestream passes in contact with one edge of it. The same must happen whena sheet of air flowing along from the north-east rises from the shore ina straight line to the summit of the Apalachian mountains, a part of thestream of north-east air will flow over the mountains, another part willrevert and circulate spirally between the summit of the country and theeastern shore, continuing to move toward the south; and thus be changedfrom a north-east to a north-west wind. This vertical spiral eddy having been in contact with the cold summitsof these mountains, and descending from higher parts of the atmospherewill lose part of its heat, and thus constitute one cause of the greatercoldness of the eastern sides of North America than of the Europeanshores opposite to them, which is said to be equal to twelve degrees ofnorth latitude, which is a wonderful fact, not otherwise easy to beexplained, since the heat of the springs at Philadelphia is said to be50, which is greater than the medium heat of the earth in this country. The existence of vertical eddies, or great cylinders of air rolling onthe surface of the earth, is agreeable to the observations of theconstructors of windmills; who on this idea place the area of the sailsleaning backwards, inclined to the horizon; and believe that then theyhave greater power than when they are placed quite perpendicularly. Thesame kind of rolling cylinders of water obtain in rivers owing to thefriction of the water against the earth at their bottoms; as is known bybodies having been observed to float upon their surfaces quicker thanwhen immersed to a certain depth. These vertical eddies of air probablyexist all over the earth's surface, but particularly at the bottom orsides of mountains; and more so probably in the course of the south-westthan of the north-east winds; because the former fall from an eminence, as it were, on a part of the earth where there is a deficiency of thequantity of air; as is shewn by the sinking of the barometer: whereasthe latter are pushed or squeezed forward by an addition to theatmosphere behind them, as appears by the rising of the barometer. TRADE-WINDS. A column of heated air becomes lighter than before, and will thereforeascend, by the pressure of the cold air which surrounds it, like a corkin water, or like heated smoke in a chimney. Now as the sun passes twice over the equator for once over eithertropic, the equator has not time to become cool; and on this account itis in general hotter at the line than at the tropics; and therefore theair over the line, except in some few instances hereafter to bementioned, continues to ascend at all seasons of the year, pressedupwards by regions of air brought from the tropics. This air thus brought from the tropics to the equator, would constitutea north wind on one side of the equator, and a south wind on the other;but as the surface of the earth at the equator moves quicker than thesurface of the earth at the tropics, it is evident that a region of airbrought from either tropic to the equator, and which had previously onlyacquired the velocity of the earth's surface at the tropics, will nowmove too slow for the earth's surface at the equator, and will thenceappear to move in a direction contrary to the motion of the earth. Hencethe trade-winds, though they consist of regions of air brought from thenorth on one side of the line, and from the south on the other, willappear to have the diagonal direction of north-east and south-westwinds. Now it is commonly believed that there are superior currents of airpassing over these north-east and south-west currents in a contrarydirection, and which descending near the tropics produce verticalwhirlpools of air. An important question here again presents itself, _What becomes of the moisture which this heated air ought to deposit, asit cools in the upper regions of the atmosphere in its journey to thetropics?_ It has been shewn by Dr. Priestley and Mr. Ingenhouz that thegreen matter at the bottom of cisterns, and the fresh leaves of plantsimmersed in water, give out considerable quantities of vital air in thesun-shine; that is, the perspirable matter of plants (which is watermuch divided in its egress from their minute pores) becomes decomposedby the sun's light, and converted into two kinds of air, the vital andinflammable airs. The moisture contained or dissolved in the ascendingheated air at the line must exist in great tenuity; and by being exposedto the great light of the sun in that climate, the water may bedecomposed, and the new airs spread on the atmosphere from the line tothe poles. 1. From there being no constant deposition of rains in the usual courseof the trade-winds, it would appear that the water rising at the line isdecomposed in its ascent. 2. From the observations of M. Bougner on the mountain Pinchinca, one ofthe Cordelieres immediately under the line, there appears to be nocondensible vapour above three or four miles high. Now though theatmosphere at that height may be cold to a very considerable degree; yetits total deprivation of condensible vapour would seem to shew, that itswater was decomposed; as there are no experiments to evince that anydegree of cold hitherto known has been able to deprive air of itsmoisture; and great abundance of snow is deposited from the air thatflows to the polar regions, though it is exposed to no greater degreesof cold in its journey thither than probably exists at four miles heightin the atmosphere at the line. 3. The hygrometer of Mr. Sauffure also pointed to dryness as he ascendedinto rarer air; the single hair of which it was constructed, contractingfrom deficiency of moisture. Essais sur l'Hygromet. P. 143. From these observations it appears either that rare and cold airrequires more moisture to saturate it than dense air; or that themoisture becomes decomposed and converted into air, as it ascends intothese cold and rare regions of the atmosphere. 4. There seems some analogy between the circumstance of air beingproduced or generated in the cold parts of the atmosphere both at theline and at the poles. MONSOONS AND TORNADOES. 1. In the Arabian and Indian seas are winds, which blow six months oneway, and six months the other, and are called Monsoons; by theaccidental dispositions of land and sea it happens, that in some placesthe air near the tropic is supposed to become warmer when the sun isvertical over it, than at the line. The air in these placesconsequently ascends pressed upon one side by the north-east regions ofair, and on the other side by the south-west regions of air. For as theair brought from the south has previously obtained the velocity of theearth's surface at the line, it moves faster than the earth's surfacenear the tropic where it now arrives, and becomes a south-west wind, while the air from the north becomes a north-east wind as beforeexplained. These two winds do not so quietly join and ascend as thenorth-east and south-east winds, which meet at the line with equalwarmth and velocity and form the trade-winds; but as they meet incontrary directions before they ascend, and cannot be supposedaccurately to balance each other, a rotatory motion will be produced asthey ascend like water falling through a hole, and an horizontal orspiral eddy is the consequence; these eddies are more or less rapid, andare called Tornadoes in their most violent state, raising water from theocean in the west or sand from the deserts of the east, in less violentdegrees they only mix together the two currents of north-east and south-west air, and produce by this means incessant rains, as the air of thenorth-east acquires some of the heat from the south-west wind, asexplained in Note XXV. This circumstance of the eddies produced by themonsoon-winds was seen by Mr. Bruce in Abyssinia; he relates that formany successive mornings at the commencement of the rainy monsoon, heobserved a cloud of apparently small dimensions whirling round withgreat rapidity, and in few minutes the heavens became covered with darkclouds with consequent great rains. See Note on Canto III. L. 129. 2. But it is not only at the place where the air ascends at the northernextremity of the rainy monsoon, and where it forms tornadoes, asobserved above by Mr. Bruce, but over a great tract of country severaldegrees in length in certain parts as in the Arabian sea, a perpetualrain for several months descends, similar to what happens for weekstogether in our own climate in a less degree during the south-westwinds. Another important question presents itself here, _if the climateto which this south-west wind arrives, it not colder than that it comesfrom, why should it deposit its moisture during its whole journey? if itbe a colder climate, why does it come thither?_ The tornadoes of airabove described can extend but a little way, and it is not easy toconceive that a superior cold current of air can mix with an inferiorone, and thus produce showers over ten degrees of country, since atabout three miles high there is perpetual frost; and what can inducethese narrow and shallow currents to flow over each other so manyhundred miles? Though the earth at the northren extremity of this monsoon may be moreheated by certain circumstances of situation than at the line, yet itseems probable that the intermediate country between that and the line, may continue colder than the line (as in other parts of the earth) andhence that the air coming from the line to supply this ascent ordestruction of air at the northern extremity of the monsoon will becooled all the way in its approach, and in consequence deposit itswater. It seems probable that at the northern extremity of this monsoon, where the tornadoes or hurricanes exist, that the air not only ascendsbut is in part converted into water, or otherwise diminished inquantity, as no account is given of the existence of any superiorcurrents of it. As the south-west winds are always attended with a light atmosphere, anincipient vacancy, or a great diminution of air must have taken place tothe northward of them in all parts of the earth wherever they exist, anda deposition of their moisture succeeds their being cooled by theclimate they arrive at, and not by a contrary current of cold air overthem, since in that case the barometer would not sink. They may thus inour own country be termed monsoons without very regular periods. 3. Another cause of TORNADOES independent of the monsoons is ingeniouslyexplained by Dr. Franklin, when in the tropical countries a stratum ofinferior air becomes so heated by its contact with the warm earth, thatits expansion is increased more than is equivalent to the pressure ofthe stratum of air over it; or when the superior stratum becomes morecondensed by cold than the inferior one by pressure, the upper regionwill descend and the lower one ascend. In this situation if one part ofthe atmosphere be hotter from some fortuitous circumstances, or, hasless pressure over it, the lower stratum will begin to ascend at thispart, and resemble water falling through a hole as mentioned above. Ifthe lower region of air was going forwards with considerable velocity, it will gain an eddy by riling up this hole in the incumbent heavy air, so that the whirlpool or tornado has not only its progressive velocity, but its circular one also, which thus lifts up or overturns every thingwithin its spiral whirl. By the weaker whirlwinds in this country thetrees are sometimes thrown down in a line of only twenty or forty yardsin breadth, making a kind of avenue through a country. In the WestIndies the sea rises like a cone in the whirl, and is met by blackclouds produced by the cold upper air and the warm lower air beingrapidly mixed; whence are produced the great and sudden rains calledwater-spouts; while the upper and lower airs exchange their plus orminus electricity in perpetual lightenings. LAND AND SEA-BREEZES. The sea being a transparent mass is less heated at its surface by thesun's rays than the land, and its continual change of surfacecontributes to preserve a greater uniformity in the heat of the airwhich hangs over it. Hence the surface of the tropical islands is moreheated during the day than the sea that surrounds them, and cools morein the night by its greater elevation: whence in the afternoon when thelands of the tropical islands have been much heated by the sun, the airover them ascends pressed upwards by the cooler air of the incirclingocean, in the morning again the land becoming cooled more than the sea, the air over it descends by its increased gravity, and blows over theocean near its shores. CONCLUSION. 1. There are various irregular winds besides those above described, which consist of horizontal or vertical eddies of air owing to theinequality of the earth's surface, or the juxtaposition of the sea. Other irregular winds have their origin from increased evaporation ofwater, or its sudden devaporation and descent in showers; others fromthe partial expansion and condensation of air by heat and cold; by theaccumulation or defect of electric fluid, or to the air's new productionor absorption occasioned by local causes not yet discovered. See NotesVII. And XXV. 2. There seem to exist only two original winds: one consisting of airbrought from the north, and the other of air brought from the south. Theformer of these winds has also generally an apparent direction from theeast, and the latter from the west, arising from the differentvelocities of the earth's surface. All the other winds above describedare deflections or retrogressions of some parts of these currents of airfrom the north or south. 3. One fifteenth part of the atmosphere is occasionally destroyed, andoccasionally reproduced by unknown causes. These causes are brought intoimmediate activity over a great part of the surface of the earth atnearly the same time, but always act more powerful to the northward thanto the southward of any given place; and would hence seem to have theirprincipal effect in the polar circles, existing nevertheless though withless power toward the tropics or at the line. For when the north-east wind blows the barometer rises, sometimes from281/2 inches to 301/2, which shews a great new generation of air in thenorth; and when the south-west wind blows the barometer sinks as much, which shews a great destruction of air in the north. But as the north-east winds sometimes continue for five or six weeks, the newly-generatedair must be destroyed at those times in the warmer climates to the southof us, or circulate in superior currents, which has been shewn to beimprobable from its not depositing its water. And as the south-westwinds sometimes continue for some weeks, there must be a generation ofair to the south at those times, or superior currents, which last hasbeen shewn to be improbable. 4. The north-east winds being generated about the poles are pushedforwards towards the tropics or line, by the pressure from behind, andhence they become warmer, as explained in Note VII. As well as by theircoming into contact with a warmer part of the earth which contributes tomake these winds greedily absorb moisture in their passage. On thecontrary, the south-west winds, as the atmosphere is suddenly diminishedin the polar regions, are drawn as it were into an incipient vacancy, and become therefore expanded in their passage, and thus generate cold, as explained in Note VII. And are thus induced to part with theirmoisture, as well as by their contact with a colder part of the earth'ssurface. Add to this, that the difference in the sound of the north-eastand south-west winds may depend on the former being pushed forwards by apressure behind, and the latter falling as it were into a partial orincipient vacancy before; whence the former becomes more condensed, andthe latter more rarefied as it passes. There is a whistle, termed alark-call, which consists of a hollow cylinder of tin-plate, closed ateach end, about half an inch in diameter and a quarter of an inch high, with opposite holes about the size of a goose-quill through the centreof each end; if this lark-whistle be held between the lips the sound ofit is manifestly different when the breath is forceably blown through itfrom within outwards, and when it is sucked from without inwards. Perhaps this might be worthy the attention of organ-builders. 5. A stop is put to this new generation of air, when about a fifteenthof the whole is produced, by its increasing pressure; and a similarboundary is fixed to its absorption or destruction by the decrease ofatmospheric pressure. As water requires more heat to convert it intovapour under a heavy atmosphere than under a light one, so in lettingoff the water from muddy fish-ponds great quantities of air-bubbles areseen to ascend from the bottom, which were previously confined there bythe pressure of the water. Similar bubbles of inflammable air are seento arise from lakes in many seasons of the year, when the atmospheresuddenly becomes light. 6. The increased absorptions and evolutions of air must, like its simpleexpansions, depend much on the presence or absence of heat and light, and will hence, in respect to the times and places of its production anddestruction, be governed by the approach or retrocession of the sun, andon the temperature, in regard to heat, of various latitudes, and partsof the same latitude, so well explained by Mr. Kirwan. 7. Though the immediate cause of the destruction or reproduction ofgreat masses of air at certain times, when the wind changes from northto south, or from south to north can not yet be ascertained; yet asthere appears greater difficulty in accounting for this change of windfor any other known causes, we may still suspect that there exists inthe arctic and antarctic circles a BEAR or DRAGON yet unknown tophilosophers, which at times suddenly drinks up, and as suddenly atother times vomits out one-fifteenth part of the atmosphere: and hopethat this or some future age will learn how to govern and domesticate amonster which might be rendered of such important service to mankind. INSTRUMENTS. If along with the usual registers of the weather observations were madeon the winds in many parts of the earth with the three followinginstruments, which might be constructed at no great expence, some usefulinformation might be acquired. 1. To mark the hour when the wind changes from north-east to south-west, and the contrary. This might be managed by making a communication fromthe vane of a weathercock to a clock; in such a manner, that if the vanemould revolve quite round, a tooth on its revolving axis should stop theclock, or put back a small bolt on the edge of a wheel revolving once intwenty-four hours. 2. To discover whether in a year more air passed from north to south, orthe contrary. This might be effected by placing a windmill-sail ofcopper about nine inches diameter in a hollow cylinder about six incheslong, open at both ends, and fixed on an eminent situation exactly northand south. Thence only a part of the north-east and south-west currentswould affect the sail so as to turn it; and if its revolutions werecounted by an adapted machinery, as the sail would turn one way with thenorth currents of air, and the contrary one with the south currents, theadvance of the counting finger either way would shew which wind hadprevailed most at the end of the year. 3. To discover the rolling cylinders of air, the vane of a weathercockmight be so suspended as to dip or rise vertically, as well as to haveits horizontal rotation. RECAPITULATION. NORTH-EAST WINDS consist of air flowing from the north, where it seemsto be occasionally produced; has an apparent direction from the eastowing to its not having acquired in its journey the increasing velocityof the earth's surface; these winds are analogous to the trade-windsbetween the tropics, and frequently continue in the vernal months forfour and six weeks together, with a high barometer, and fair or frostyweather. 2. They sometimes consist of south-west air, which had passedby us or over us, driven back by a new accumulation of air in the north, These continue but a day or two, and are attended with rain. See NoteXXV. SOUTH-WEST WIND consists of air flowing from the south, and seemsoccasionally absorbed at its arrival to the more northern latitudes. Ithas a real direction from the west owing to its not having lost in itsjourney the greater velocity it had acquired from the earth's surfacefrom whence it came. These winds are analogous to the monsoons betweenthe tropics, and frequently continue for four or six weeks together, with a low barometer and rainy weather. 2. They sometimes consist ofnorth-east air, which had passed by us or over us, which becomesretrograde by a commencing deficiency of air in the north. These windscontinue but a day or two, attended with severer frost with a sinkingbarometer; their cold being increased by their expansion, as theyreturn, into an incipient vacancy. NORTH-WEST WINDS consist, first, of south-west winds, which have passedover us, bent down and driven back towards the south by newly generatednorthern air. They continue but a day or two, and are attended with rainor clouds. 2. They consist of north-east winds bent down from the higherparts of the atmosphere, and having there acquired a greater velocitythan, the earth's surface; are frosty or fair. 3. They consist of north-east winds formed into a vertical spiral eddy, as on the eastern coastsof North America, and bring severe frost. SOUTH-EAST WINDS consist, first, of north-east winds become retrograde, continue for a day or two, frosty or fair, sinking barometer. 2. Theyconsist of north-east winds formed into a vertical eddy not a spiralone, frost or fair. NORTH WINDS consist, first, of air flowing slowly from the north, sothat they acquire the velocity of the earth's surface as they approach, are fair or frosty, seldom occur. 2. They consist of retrograde southwinds; these continue but a day or two, are preceded by south-westwinds; and are generally succeeded by north-east winds, cloudy or rainy, barometer rising. SOUTH WINDS consist, first, of air flowing slowly from the south, loosing their previous western velocity by the friction of the earth'ssurface as they approach, moist, seldom occur, 2. They consist ofretrograde north winds; these continue but a day or two, are preceded bynorth-east winds, and generally succeeded by south-west winds, colder, barometer sinking. EAST WINDS consist of air brought hastily from the north, and notimpelled farther southward, owing to a sudden beginning absorption ofair in the northern regions, very cold, barometer high, generallysucceeded by south-west wind. WEST WINDS consist of air brought hastily from the south, and checkedfrom proceeding further to the north by a beginning production of air inthe northern regions, warm and moist, generally succeeded by north-eastwind. 2. They consist of air bent down from the higher regions of theatmosphere, if this air be from the south, and brought hastily itbecomes a wind of great velocity, moving perhaps 60 miles an hour, iswarm and rainy; if it consists of northern air bent down it is of lessvelocity and colder. _Application of the preceding Theory to Some Extracts from a Journal of the Weather. _ _Dec. 1, 1790. _ The barometer sunk suddenly, and the wind, which hadbeen some days north-east with frost, changed to south-east with anincessant though moderate fall of snow. A part of the northern air, which had passed by us I suppose, now became retrograde before it hadacquired the velocity of the earth's surface to the south of us, andbeing attended by some of the southern air in its journey, the moistureof the latter became condensed and frozen by its mixture mith theformer. _Dec. 2, 3. _ The wind changed to north-west and thawed the snow. A partof the southern air, which had passed by us or over us, with theretrograde northern air above described, was now in its turn drivenback, before it had lost the velocity of the surface of the earth to thesouth of us, and consequently became a north-west wind; and not havinglost the warmth it brought from the south produced a thaw. _Dec. 4, 5. _ Wind changed to north-east with frost and a risingbarometer. The air from the north continuing to blow, after it haddriven back the southern air as above described, became a north-eastwind, having less velocity than the surface of the earth in thisclimate, and produced frost from its coldness. _Dec. 6, 7. _ Wind now changed to the south-west with incessant rain anda sinking barometer. From unknown causes I suppose the quantity of airto be diminished in the polar regions, and the southern air cooled bythe earth's surface, which was previously frozen, deposits its moisturefor a day or two; afterwards the wind continued south-west without rain, as the surface of the earth became warmer. _March 18, 1785. _ There has been a long frost; a few days ago thebarometer sunk to 291/2, and the frost became more severe. Because the airbeing expanded by a part of the pressure being taken off became colder. This day the mercury rose to 30, and the frost ceased, the windcontinuing as before between north and east. _March 19. _ Mercury above30, weather still milder, no frost, wind north-east. _March 20. _ Thesame, for the mercury rising shews that the air becomes more compressedby the weight above, and in consequence gives out warmth. _April 4, 5. _ Frost, wind north-east, the wind changed in the middle ofthe day to the north-west without rain, and has done so for three orfour days, becoming again north-east at night. For the sun now givinggreater degrees of heat, the air ascends as the sun passes the zenith, and is supplied below by the air on the western side as well as on theeastern side of the zenith during the hot part of the day; whence for afew hours, on the approach of the hot part of the day, the air acquiresa westerly direction in this longitude. If the north-west wind had beencaused by a retrograde motion of some southern air, which had passedover us, it would have been attended with rain or clouds. _April 10. _ It rained all day yesterday, the wind north-west, thismorning there was a sharp frost. The evaporation of the moisture, (whichfell yesterday) occasioned by the continuance of the wind, produced somuch cold as to freeze the dew. _May 12. _ Frequent showers with a current of colder wind preceding everyshower. The sinking of the rain or cloud pressed away the air frombeneath it in its descent, which having been for a time shaded from thesun by the floating cloud, became cooled in some degree. _June 20. _ The barometer sunk, the wind became south-west, and the wholeheaven was instantly covered with clouds. A part of the incumbentatmosphere having vanished, as appeared by the sinking of the barometer, the remainder became expanded by its elasticity, and thence attractedsome of the matter of heat from the vapour intermixed with it, and thusin a few minutes a total devaporation took place, as in exhausting thereceiver of an air-pump. See note XXV. At the place where the air isdestroyed, currents both from the north and south flow in to supply thedeficiency, (for it has been shewn that there are no other proper windsbut these two) and the mixture of these winds produces so suddencondensation of the moisture, both by the coldness of the northern airand the expansion of both of them, that lightning is given out, and anincipient tornado takes place; whence thunder is said frequently toapproach against the wind. _August 28, 1732. _ Barometer was at 31, and _Dec. 30_, in the same year, it was at 28 2-tenths. Medical Essays, Edinburgh, Vol. II. P. 7. Itappears from these journals that the mercury at Edinburgh variessometimes nearly three inches, or one tenth of the whole atmosphere. From the journals kept by the Royal Society at London it appears seldomto vary more than two inches, or one-fifteenth of the whole atmosphere. The quantity of the variation is said still to decrease nearer the line, and to increase in the more northern latitudes; which much confirms theidea that there exists at certain times a great destruction orproduction of air within the polar circle. _July 2, 1732. _ The westerly winds in the journal in the Medical Essays, Vol. II. Above referred to, are frequently marked with the number threeto shew their greater velocity, whereas the easterly winds seldomapproach to the number two. The greater velocity of the westerly windsthan the easterly ones is well known I believe in every climate of theworld; which may be thus explained from the theory above delivered. 1. When the air is still, the higher parts of the atmosphere move quickerthan those parts which touch the earth, because they are at a greaterdistance from the axis of motion. 2. The part of the atmosphere wherethe north or south wind comes from is higher than the part of it whereit comes to, hence the more elevated parts of the atmosphere continue todescend towards the earth as either of those winds approach. 3. Whensouthern air is brought to us it possesses a westerly direction also, owing to the velocity it had previously acquired from the earth'ssurface; and if it consists of air from the higher parts of theatmosphere descending nearer the earth, this westerly velocity becomesincreased. But when northern air is brought to us, it possesses anapparent easterly direction also, owing to the velocity which it hadpreviously acquired from the earth's surface being less than that of theearth's surface in this latitude; now if the north-east wind consists ofair descending from higher parts of the atmosphere, this deficiency ofvelocity will be less, in consequence of the same cause, viz. The higherparts of the atmosphere descending, as the wind approaches, increasesthe real velocity of the western winds, and decreases the apparentvelocity of the eastern ones. _October 22. _ Wind changed from south-east to south-west. There is apopular prognostication that if the wind changes from the north towardsthe south passing through the east, it is more likely to continue in thesouth, than if it passes through the west, which may be thus accountedfor. If the north-east wind changes to a north-west wind, it shewseither that a part of the northern air descends upon us in a spiraleddy, or that a superior current of southern air is driven back; but ifa north-east wind be changed into a south-east wind it shews that thenorthern air is become retrograde, and that in a day or two, as soon asthat part of it has passed, which has not gained the velocity of theearth's surface in this latitude, it will become a south wind for a fewhours, and then a south-west wind. The writer of this imperfect sketch of anemology wishes it may incitesome person of greater leizure and ability to attend to this subject, and by comparing the various meteorological journals and observationsalready published, to construct a more accurate and methodical treatiseon this interesting branch of philosophy. NOTE XXXIV. --VEGETABLE PERSPIRATION. _And wed the enamoured Oxygene to Light. _ CANTO IV. L. 34. When points or hairs are put into spring-water, as in the experiments ofSir B. Thompson, (Philos. Trans. Vol. LXXVII. ) and exposed to the lightof the sun, much air, which loosely adhered to the water, rises inbubbles, as explained in note on Fucus, Vol. II. A still greaterquantity of air, and of a purer kind, is emitted by Dr. Priestley'sgreen matter, and by vegetable leaves growing in water in the sun-shine, according to Mr. Ingenhouze's experiments; both which I suspect to beowing to a decomposition of the water perspired by the plant, for theedge of a capillary tube of great tenuity may be considered as a circleof points, and as the oxygene, or principle of vital air, may beexpanded into a gas by the sun's light; the hydrogene or inflammable airmay be detained in the pores of the vegetable. Hence plants growing in the shade are white, and become green by beingexposed to the sun's light; for their natural colour being blue, theaddition of hydrogene adds yellow to this blue, and _tans_ them green. Isuppose a similar circumstance takes place in animal bodies; theirperspirable matter as it escapes in the sun-shine becomes decomposed bythe edges of their pores as in vegetables, though in less quantity, astheir perspiration is less, and by the hydrogene being retained the skinbecomes _tanned_ yellow. In proof of this it must be observed that bothvegetable and animal substances become bleached white by the sun-beamswhen they are dead, as cabbage-stalks, bones, ivory, tallow, bees-wax, linen and cotton cloth; and hence I suppose the copper-coloured nativesof sunny countries might become etiolated or blanched by being kept fromtheir infancy in the dark, or removed for a few generations to morenortherly climates. It is probable that on a sunny morning much pure air becomes separatedfrom the dew by means of the points of vegetables on which it adheres, and much inflammable air imbibed by the vegetable, or combined with it;and by the sun's light thus decomposing water the effects of it inbleaching linen seems to depend (as described in Note X. ): the water isdecomposed by the light at the ends or points of the cotton or thread, and the vital air unites with the phlogistic or colouring matters of thecloth, and produces a new acid, which is either itself colourless orwashes out, at the same time the inflammable part of the water escapes. Hence there seems a reason why cotton bleaches so much sooner thanlinen, viz. Because its fibres are three or four times shorter, andtherefore protrude so many more points, which seem to facilitate theliberation of the vital air from the inflammable part of the water. Bee's wax becomes bleached by exposure to the sun and dews in a similarmanner as metals become calcined or rusty, viz. By the water on theirsurface being decomposed; and hence the inflammable material whichcaused the colour becomes united with vital air forming a new acid, andis washed away. Oil close stopped in a phial not full, and exposed long to the sun'slight, becomes bleached, as I suppose, by the decomposition of the waterit contains; the inflammable air rising above the surface, and the vitalair uniting with the colouring matter of the oil. For it is remarkable, that by shutting up a phial of bleached oil in a dark drawer, it in alittle time becomes coloured again. The following experiment shews the power of light in separating vitalair from another basis, viz. From azote. Mr. Scheel inverted a glassvessel filled with colourless nitrous acid into another glass containingthe same acid, and on exposing them to the sun's light, the invertedglass became partly filled with pure air, and the acid at the same timebecame coloured. Scheel in Crell's Annal. 1786. But if the vessel ofcolourless nitrous acid be quite full and stopped, so that no space isleft for the air produced to expand itself into, no change of colourtakes place. Priestley's Exp. VI. P. 344. See Keir's very excellentChemical Dictionary, p. 99. New edition. A sun-flower three feet and half high according to the experiment of Dr. Hales, perspired two pints in one day (Vegetable Statics. ) which is manytimes as much in proportion to its surface, as is perspired from thesurface and lungs of animal bodies; it follows that the vital airliberated from the surfaces of plants by the sunshine must much exceedthe quantity of it absorbed by their respiration, and that hence theyimprove the air in which they live during the light part of the day, andthus blanched vegetables will sooner become _tanned into green_ by thesun's light, than etiolated animal bodies will become _tanned yellow_ bythe same means. It is hence evident, that the curious discovery of Dr. Priestley, thathis green vegetable matter and other aquatic plants gave out vital airwhen the sun shone upon them, and the leaves of other plants did thesame when immersed in water, as observed by Mr. Ingenhouze, refer to theperspiration of vegetables not to their respiration. Because Dr. Priestley observed the pure air to come from both sides of the leavesand even from the stalks of a water-flag, whereas one side of the leafonly serves the office of lungs, and certainly not the stalks. Exper. OnAir, Vol. III. And thus in respect to the circumstance in which plantsand animals seemed the furtherest removed from each other, I mean intheir supposed mode of respiration, by which one was believed to purifythe air which the other had injured, they seem to differ only in degree, and the analogy between them remains unbroken. Plants are said by many writers to grow much faster in the night than inthe day; as is particularly observable in seedlings at their rising outof the ground. This probably is a consequence of their sleep rather thanof the absence of light; and in this I suppose they also resemble animalbodies. NOTE XXXV. --VEGETABLE PLACENTATION. _While in bright veins the silvery sap ascends. CANTO IV. L. 419. As buds are the viviparous offspring of vegetables, it becomes necessarythat they should be furnished with placental vessels for theirnourishment, till they acquire lungs or leaves for the purpose ofelaborating the common juices of the earth into nutriment. These vesselsexist in bulbs and in seeds, and supply the young plant with a sweetjuice till it acquires leaves, as is seen in converting barley intomalt, and appears from the sweet taste of onions and potatoes, when theybegin to grow. The placental vessels belonging to the buds of trees are placed aboutthe roots of most, as the vine; so many roots are furnished with sweetor mealy matter as fern-root, bryony, carrot, turnip, potatoe, or in thealburnum or sap-wood as in those trees which produce manna, which isdeposited about the month of August, or in the joints of sugar cane, andgrasses; early in the spring the absorbent mouths of these vessels drinkup moisture from the earth, with a saccharine matter lodged for thatpurpose during the preceding autumn, and push this nutritive fluid upthe vessels of the alburnum to every individual bud, as is evinced bythe experiments of Dr. Hales, and of Mr. Walker in the EdinburghPhilosophical Transact. The former observed that the sap from the stumpof a vine, which he had cut off in the beginning of April, arose twenty-one feet high in tubes affixed to it for that purpose, but in a fewweeks it ceased to bleed at all, and Dr. Walker marked the progress ofthe ascending sap, and found likewise that as soon as the leaves becameexpanded the sap ceased to rise; the ascending juice of some trees is socopious and so sweet during the sap-season that it is used to make wine, as the birch, betula, and sycamore, acer pseudo-platinus, andparticularly the palm. During this ascent of the sap-juice each individual leaf-bud expands itsnew leaves, and shoots down new roots, covering by their intertexturethe old bark with a new one; and as soon as these new roots (or bark)are capable of absorbing sufficient juices from the earth for thesupport of each bud, and the new leaves are capable of performing theiroffice of exposing these juices to the influence of the air; theplacental vessels cease to act, coalesce, and are transformed from sap-wood, or alburnum, into inert wood; serving only for the support of thenew tree, which grows over them. Thus from the pith of the new bud of the horse-chesnut five vessels passout through the circle of the placental vessels above described, andcarry with them a minuter circle of those vessels; these five bundles ofvessels unite after their exit, and form the footstalk or petiole of thenew five-fingered leaf, to be spoken of hereafter. This structure iswell seen by cutting off a leaf of the horse-chesnut (AesculusHippocastanum) in September before it falls, as the buds of this treeare so large that the flower may be seen in them with the naked eye. After a time, perhaps about midsummer, another bundle of vessels passesfrom the pith through the alburnum or sap-vessels in the bosom of eachleaf, and unites by the new bark with the leaf, which becomes either aflower-bud or a leaf-bud to be expanded in the ensuing spring, for whichpurpose an apparatus of placental vessels are produced with propernutriment during the progress of the summer and autumn, and thus thevegetable becomes annually increased, ten thousand buds often existingon one tree, according to the estimate of Linneus. Phil. Bot. The vascular connection of vegetable buds with the leaves in whosebosoms they are formed is confirmed by the following experiment, (Oct. 20, 1781. ) On the extremity of a young bud of the Mimosa (sensitiveplant) a small drop of acid of vitriol was put by means of a pen, and, after a few seconds, the leaf in whose axilla it dwelt closed and openedno more, though the drop of vitriolic acid was so small as apparentlyonly to injure the summit of the bud. Does not this seem to shew thatthe leaf and its bud have connecting vessels though they arise atdifferent times and from different parts of the medulla or pith? And, asit exists previously to it, that the leaf is the parent of the bud? This placentation of vegetable buds is clearly evinced from thesweetness of the rising sap, and from its ceasing to rise as soon as theleaves are expanded, and thus compleats the analogy between buds andbulbs. Nor need we wonder at the length of the umbilical cords of budssince that must correspond with their situation on the tree, in the samemanner as their lymphatics and arteries are proportionally elongated. It does not appear probable that any umbilical artery attends theseplacental absorbents, since, as there seems to be no system of veins invegetables to bring back the blood from the extremities of theirarteries, (except their pulmonary veins, ) there could not be anyvegetable fluids to be returned to their placenta, which in vegetablesseems to be simply an organ for nutrition, whereas the placenta of theanimal foetus seems likewise to serve as a respiratory organ like thegills of fishes. NOTE XXXVI--VEGETABLE CIRCULATION. _And refluent blood in milky eddies bends. _ CANTO IV. L. 420. The individuality of vegetable buds was spoken of before, and isconfirmed by the method of raising all kinds of trees by Mr. Barnes. (Method of propagating Fruit Trees. 1759. Lond. Baldwin. ) He cut abranch into as many pieces as there were buds or leaves upon it, andwiping the two wounded ends dry he quickly applied to each a cement, previously warmed a little, which consisted principally of pitch, andplanted them in the earth. The use of this cement I suppose to consistin its preventing the bud from bleeding to death, though the authorascribes it to its antisceptic quality. These buds of plants, which are thus each an individual vegetable, inmany circumstances resemble individual animals, but as animal bodies aredetached from the earth, and move from place to place in search of food, and take that food at considerable intervals of time, and prepare it fortheir nourishiment within their own bodies after it is taken, it isevident they must require many organs and powers which are not necessaryto a stationary bud. As vegetables are immoveably fixed to the soil fromwhence they draw their nourishment ready prepared, and this uniformlynot at returning intervals, it follows that in examining their anatomewe are not to look for muscles of locomotion, as arms and legs; nor fororgans to receive and prepare their nourishment, as a stomach andbowels; nor for a reservoir for it after it is prepared, as a generalsystem of veins, which in locomotive animals contains and returns thesuperfluous blood which is left after the various organs of secretionhave been supplied, by which contrivance they are enabled to live a longtime without new supplies of food. The parts which we may expert to find in the anatome of vegetablescorrespondent to those in the animal economy are, 1. A system ofabsorbent vessels to imbibe the moisture of the earth similar to thelacteal vessels, as in the roots of plants; and another system ofabsorbents similar to the lymphatics of animal bodies, opening itsmouths on the internal cells and external surfaces of vegetables; and athird system of absorbent vessels correspondent with those of theplacentation of the animal foetus. 2. A pulmonary system correspondentto the lungs or gills of quadrupeds and fish, by which the fluidabsorbed by the lacteals and lymphatics may be exposed to the influenceof the air, this is done by the green leaves of plants, those in the airresembling lungs, and those in the water resembling gills; and by thepetals of flowers. 3. Arterial systems to convey the fluid thuselaborated to the various glands of the vegetable for the purposes ofits growth, nutrition, and various secretions. 4. The various glandswhich separate from the vegetable blood the honey, wax, gum, resin, starch, sugar, essential oil, &c. 5. The organs adapted for theirpropagation or reproduction. 6. Muscles to perform several motions oftheir parts. I. The existence of that branch of the absorbent vessels of vegetableswhich resembles the lacteals of animal bodies, and imbibes theirnutriment from the moist earth, is evinced by their growth so long asmoisture is applied to their roots, and their quickly withering when itis withdrawn. Besides these absorbents in the roots of plants there are others whichopen their mouths on the external surfaces of the bark and leaves, andon the internal surfaces of all the cells, and between the bark and thealburnum or sap-wood; the existence of these is shewn, because a leafplucked off and laid with its under side on water will not wither sosoon as if left in the dry air, --the same if the bark alone of a branchwhich is separated from a tree be kept moist with water, --and lastly, bymoistening the alburnum or sap-wood alone of a branch detached from atree it will not so soon wither as if left in the dry air. By thefollowing experiment these vessels were agreeably visible by a commonmagnifying glass, I placed in the summer of 1781 the footstalks of somelarge fig-leaves about an inch deep in a decoction of madder, (rubiatinctorum, ) and others in a decoction of logwood, (haematoxylumcampechense, ) along with some sprigs cut off from a plant of picris, these plants were chosen because their blood is white, after some hours, and on the next day, on taking out either of these and cutting off fromits bottom about a quarter of an inch of the stalk an internal circle ofred points appeared, which were the ends of absorbent vessels colouredred with the decoction, while an external ring of arteries was seen tobleed out hastily a milky juice, and at once evinced both the absorbentand arterial system. These absorbent vessels have been called by Grew, and Malphigi, and some other philosophers, bronchi, and erroneouslysupposed to be air-vessels. It is probable that these vessels, when cutthrough, may effuse their fluids, and receive air, their sides being toostiff to collapse; since dry wood emits air-bubles in the exhaustedreceiver in the same manner as moist wood. The structure of these vegetable absorbents consists of a spiral line, and not of a vessel interrupted with valves like the animal lymphatics, since on breaking almost any tender leaf and drawing out some of thefibres which adhere longest this spiral structure becomes visible evento the naked eye, and distinctly so by the use of a common lens. SeeGrew, Plate 51. In such a structure it is easy to conceive how a vermicular orperistaltic motion of the vessel beginning at the lowest part of it, each spiral ring successively contracting itself till it fills up thetube, must forcibly push forwards its contents, as from the roots ofvines in the bleeding season; and if this vermicular motion should beginat the upper end of the vessel it is as easy to see how it must carryits contained fluid in a contrary direction. The retrograde motion ofthe vegetable absorbent vessels is shewn by cutting a forked branch froma tree, and immersing a part of one of the forks in water, which willfor many days prevent the other from withering; or it is shewn byplanting a willow branch with the wrong end upwards. This structure insome degree obtains in the esophagus or throat of cows, who by similarmeans convey their food first downwards and afterward upwards by aretrograde motion of the annular muscles or cartilages for the purposeof a second mastication of it. II. The fluids thus drank up by the vegetable absorbent vessels from theearth, or from the atmosphere, or from their own cells and interfaces, are carried to the foot-stalk of every leaf, where the absorbentsbelonging to each leaf unite into branches, forming so many pulmonaryarteries, and are thence dispersed to the extremities of the leaf, asmay be seen in cutting away slice after slice the footstalk of a horse-chesnut in September before the leaf falls. There is then a compleatcirculation in the leaf; a pulmonary vein receiving the blood from theextremities of each artery on the upper side of the leaf, and joiningagain in the footstalk of the leaf these veins produce so many arteries, or aortas, which disperse the new blood over the new bark, elongatingits vessels, or producing its secretions; but as a reservoir of bloodcould not be wanted by a vegetable bud which takes in its nutriment atall times, I imagine there is no venous system, no veins properly socalled, which receive the blood which was to spare, and return it intothe pulmonary or arterial system. The want of a system of veins was countenanced by the followingexperiment; I cut off several stems of tall spurge, (Euphorbiahelioscopia) in autumn, about the centre of the plant, and observedtenfold the quantity of milky juice ooze from the upper than from thelower extremity, which could hardly have happened if there had been avenous system of vessels to return the blood from the roots to theleaves. Thus the vegetable circulation, complete in the lungs, but probably inthe other part of the system deficient in respect to a system ofreturning veins, is carried forwards without a heart, like thecirculation through the livers of animals where the blood brought fromthe intestines and mesentery by one vein is dispersed through the liverby the vena portarum, which assumes the office of an artery. See NoteXXXVII. At the same time so minute are the vessels in the intertexture of thebarks of plants, which belong to each individual bud, that a generalcirculation may possibly exist, though we have not yet been able todiscover the venous part of it. There is however another part of the circulation of vegetable juicesvisible to the naked eye, and that is in the corol or petals of flowers, in which a part of the blood of the plant is exposed to the influence ofthe air and light in the same manner as in the foliage, as will bementioned more at large in Notes XXXVII and XXXIX. These circulations of their respective fluids seem to be carried on inthe vessels of plants precisely as in animal bodies by theirirritability to the stimulus of their adapted fluids, and not by anymechanical or chemical attraction, for their absorbent vessels propelthe juice upwards, which they drink up from the earth, with greatviolence; I suppose with much greater than is exerted by the lacteals ofanimals, probably owing to the greater minuteness of these vessels invegetables and the greater rigidity of their coats. Dr. Hales in thespring season cut off a vine near the ground, and by fixing tubes on theremaining stump of it, found the sap to rise twenty-one feet in the tubeby the propulsive power of these absorbents of the roots of it. Veget. Stat. P. 102. Such a power can not be produced by capillary attraction, as that could only raise a fluid nearly to the upper edge of theattracting cylinder, but not enable it to flow over that edge, and muchless to rise 21 feet above it. What then can this power be owing to?Doubtless to the living activity of the absorbent vessels, and to theirincreased vivacity from the influence of the warmth of the springsucceeding the winter's cold, and their thence greater susceptibility toirritation from the juices which they absorb, resembling in allcircumstances the action of the living vessels of animals. NOTE XXXVII--VEGETABLE RESPIRATION. _While spread in air the leaves respiring play. _ CANTO IV. L. 421. I. There have been various opinions concerning the use of the leaves ofplants in the vegetable oeconomy. Some have contended that they areperspiratory organs; this does not seem probable from an experiment ofDr. Hales, Veg. Stat. P. 30. He found by cutting off branches of treeswith apples on them, and taking off the leaves, that an apple exhaledabout as much as two leaves, the surfaces of which were nearly equal tothe apple; whence it would appear that apples have as good a claim to betermed perspiratory organs as leaves. Others have believed themexcretory organs of excrementious juices; but as the vapour exhaled fromvegetables has no taste, this idea is no more probable than the other;add to this that in moist weather, they do not appear to perspire orexhale at all. The internal surface of the lungs or air-vessels in men, are said to beequal to the external surface of the whole body, or about fifteen squarefeet; on this surface the blood is exposed to the influence of therespired air through the medium however of a thin pellicle; by thisexposure to the air it has its colour changed from deep red to brightscarlet, and acquires something so necessary to the existence of life, that we can live scarcely a minute without this wonderful process. The analogy between the leaves of plants and the lungs or gills ofanimals seems to embrace so many circumstances, that we can scarcelywithhold our assent to their performing similar offices. I. The great surface of the leaves compared to that of the trunk andbranches of trees is such, that it would seem to be an organ welladapted for the purpose of exposing the vegetable juices to theinfluence of the air; this however we shall see afterwards is probablyperformed only by their upper surfaces, yet even in this case thesurface of the leaves in general bear a greater proportion to thesurface of the tree, than the lungs of animals to their externalsurfaces. 2. In the lungs of animal, the blood after having been exposed to theair in the extremities of pulmonary artery, is changed in colour fromdeep red to bright scarlet, and certainly in some of its essentialproperties; it is then collected by the pulmonary vein and returned tothe heart. To shew a similarity of circumstance in the leaves of plantsthe following experiment was made, June 24, 1781: A stalk with leavesand seed-vessels of large spurge (Euphorbia helioscopia) had beenseveral days placed in a decoction of madder (Rubia tinctorum) so thatthe lower part of the stem, and two of the undermost leaves wereimmersed in it. After having washed the immersed leaves in clear water, I could readily discern the colour of the madder passing along themiddle rib of each leaf. This red artery was beautifully visible both onthe under and upper surface of the leaf; but on the upper side many redbranches were seen going from it to the extremities of the leaf, whichon the other side were not visible except by looking through it againstthe light. On this under side a system of branching vessels carrying apale milky fluid were seen coming from the extremities of the leaf, andcovering the whole underside of it, and joining into two large veins, one on each side of the red artery in the middle rib of the leaf, andalong with it descending to the footstalk or petiole. On slitting one ofthese leaves with scissars, and having a common magnifying lens ready, the milky blood was seen oozing out of the returning veins on each sideof the red artery in the middle rib, but none of the red fluid from theartery. All these appearances were more easily seen in a leaf of Picris treatedin the same manner; for in this milky plant the stems and middle rib ofthe leaves are sometimes naturally coloured reddish, and hence thecolour of the madder seemed to pass further into the ramifications oftheir leaf-arteries, and was there beautifully visible with thereturning branches of milky veins on each side. 3. From these experiments the upper surface of the leaf appeared to bethe immediate organ of respiration, because the coloured fluid wascarried to the extremities of the leaf by vessels most conspicuous onthe upper surface, and there changed into a milky fluid, which is theblood of the plant, and then returned by concomitant veins on the undersurface, which were seen to ooze when divided with scissars, and whichin Picris, particularly render the under surface of the leaves greatlywhiter than the upper one. 4. As the upper surface of leaves constitutes the organ of respiration, on which the sap is exposed in the terminations of arteries beneath athin pellicle to the action of the atmosphere, these surfaces in manyplants strongly repel moisture, as cabbage-leaves, whence the particlesof rain lying over their surfaces without touching them, as observed byMr. Melville (Essays Literary and Philosop. Edinburgh) have theappearance of globules of quicksilver. And hence leaves laid with theupper surfaces on water, wither as soon as in the dry air, but continuegreen many days, if placed with the under surfaces on water, as appearsin the experiments of Mons. Bonnet (Usage des Fevilles. ) Hence someaquatic plants, as the Water-lily (Nymphoea) have the lower sides oftheir leaves floating on the water, while the upper surfaces remain dryin the air. 5. As those insects, which have many spiracula, or breathing apertures, as wasps and flies, are immediately suffocated by pouring oil uponthem, I carefully covered with oil the surfaces of several leaves ofPhlomis, of Portugal Laurel, and Balsams, and though it would notregularly adhere, I found them all die in a day or two. Of aquatic leaves, see Note on Trapa and on Fucus, in Vol. II. To whichmust be added that many leaves are furnished with muscles about theirfootstalks, to turn their upper surfaces to the air or light, as Mimosaand Hedysarum gyrans. From all these analogies I think there can be nodoubt but that leaves of trees are their lungs, giving out a phlogisticmaterial to the atmosphere, and absorbing oxygene or vital air. 6. The great use of light to vegetation would appear from this theory tobe by disengaging vital air from the water which they perspire, andthence to facilitate its union with their blood exposed beneath the thinsurface of their leaves; since when pure air is thus applied, it isprobable, that it can be more readily absorbed. Hence in the curiousexperiments of Dr. Priestley and Mr. Ingenhouze, some plants purifiedair less than others, that is, they perspired less in the sunshine; andMr. Scheele found that by putting peas into water, which about half-covered them, that they converted the vital air into fixed air, orcarbonic acid gas, in the same manner as in animal respiration. See NoteXXXIV. 7. The circulation in the lungs or leaves of plants is very similar tothat of fish. In fish the blood after having passed through their gillsdoes not return to the heart as from the lungs of air-breathing animals, but the pulmonary vein taking the structure of an artery after havingreceived the blood from the gills, which there gains a more florridcolour, distributes it to the other parts of their bodies. The samestructure occurs in the livers of fish, whence we see in those animalstwo circulations independent of the power of the heart, viz. Thatbeginning at the termination of the veins of the gills, and branchingthrough the muscles; and that which passes through the liver; both whichare carried on by the action of those respective arteries and veins. Monro's Physiology of Fish, p. 19. The course of the fluids in the roots, leaves, and buds of vegetablesseems to be performed in a manner similar to both these. First theabsorbent vessels of the roots and surfaces unite at the footstalk ofthe leaf; and then, like the Vena Portarum, an artery commences withoutthe intervention of a heart, and spreads the sap in its numerousramifications on the upper surface of the leaf; here it changes itscolour and properties, and becomes vegetable blood; and is againcollected by a pulmonary vein on the under surface of the leaf. Thisvein, like that which receives the blood from the gills of fish, assumesthe office and name of an artery, and branching again disperses theblood upward to the bud from the footstalk of the leaf, and downward tothe roots; where it is all expended in the various secretions, thenourishment and growth of the plant, as fast as it is prepared. II. The organ of respiration already spoken of belongs particularly tothe shoots or buds, but there is another pulmonary system, perhapstotally independent of the green foliage, which belongs to thefructification only, I mean the corol or petals. In this there is anartery belonging to each petal, which conveys the vegetable blood to itsextremities, exposing it to the light and air under a delicate membranecovering the internal surface of the petal, where it often changes itscolour, as is beautifully seen in some party-coloured poppies; though itis probable some of the iridescent colours of flowers may be owing tothe different degrees of tenuity of the exterior membrane of the leafrefracting the light like soap-bubbles, the vegetable blood is thenreturned by correspondent vegetable veins, exactly as in the greenfoliage; for the purposes of the important secretions of honey, wax, thefiner essential oil, and the prolific dust of the anthers. 1. The vascular structure of the corol as above described, and which isvisible to the naked eye, and its exposing the vegetable juices to theair and light during the day, evinces that it is a pulmonary organ. 2. As the glands which produce the prolific dust of the anthers, thehoney, wax, and frequently some odoriferous essential oil, are generallyattached to the corol, and always fall off and perish with it, it isevident that the blood is elaborated or oxygenated in this pulmonarysystem for the purpose of these important secretions. 3. Many flowers, as the Colchicum, and Hamamelis arise naked in autumn, no green leaves appearing till the ensuing spring; and many others putforth their flowers and complete their impregnation early in the springbefore the green foliage appears, as Mezereon, cherries, pears, whichshews that these corols are the lungs belonging to the fructification. 4. This organ does not seem to have been necessary for the defence ofthe stamens and pistils, since the calyx of many flowers, as Tragopogon, performs this office; and in many flowers these petals themselves are sotender as to require being shut up in the calyx during the night, forwhat other use then can such an apparatus of vessels be designed? 5. In the Helleborus-niger, Christmas-rose, after the seeds are grown toa certain size, the nectaries and stamens drop off, and the beautifullarge white petals change their colour to a deep green, and graduallythus become a calyx inclosing and defending the ripening seeds, hence itwould seem that the white vessels of the corol served the office ofexposing the blood to the action of the air, for the purposes ofseparating or producing the honey, wax, and prolific dust, and whenthese were no longer wanted, that these vessels coalesced like theplacental vessels of animals after their birth, and thus ceased toperform that office and lost at the same time their white colour. Whyshould they loose their white colour, unless they at the same time lostsome other property besides that of defending the seed-vessel, whichthey still continue to defend? 6. From these observations I am led to doubt whether green leaves beabsolutely necessary to the progress of the fruit-bud after the lastyear's leaves are fallen off. The green leaves serve as lungs to theshoots and foster the new buds in their bosoms, whether these buds beleaf-buds or fruit-buds; but in the early spring the fruit-buds expandtheir corols, which are their lungs, and seem no longer to require greenleaves; hence the vine bears fruit at one joint without leaves, and putsout a leaf-bud at another joint without fruit. And I suppose the greenleaves which rise out of the earth in the spring from the Colchicum arefor the purpose of producing the new bulb, and its placenta, and not forthe giving maturity to the seed. When currant or goosberry trees losetheir leaves by the depredation of insects the fruit continues to beformed, though less sweet and less in size. 7. From these facts it appears that the flower-bud after the corol fallsoff, (which is its lungs, ) and the stamens and nectary along with it, becomes simply an uterus for the purpose of supplying the growingembryon with nourishment, together with a system of absorbent vesselswhich bring the juices of the earth to the footstalk of the fruit, andwhich there changes into an artery for the purpose of distributing thesap for the secretion of the saccharine or farinaceous or acescentmaterials for the use of the embryon. At the same time as all thevessels of the different buds of trees inosculate or communicate witheach other, the fruit becomes sweeter and larger when the green leavescontinue on the tree, but the mature flowers themselves, (the succeedingfruit not considered) perhaps suffer little injury from the green leavesbeing taken off, as some florists have observed. 8. That the vessels of different vegetable buds inosculate in variousparts of their circulation is rendered probable by the increased growthof one bud, when others in its vicinity are cut away; as it thus seemsto receive the nourishment which was before divided amongst many. NOTE XXXVIII. --VEGETABLE IMPREGNATION. _Love out their hour and leave their lives in air. _ CANTO IV. L. 456. From the accurate experiments and observations of Spallanzani it appearsthat in the Spartium Junceum, rush-broom, the very minute seeds werediscerned in the pod at least twenty days before the flower is in fullbloom, that is twenty days before fecundation. At this time also thepowder of the anthers was visible, but glued fast to their summits. Theseeds however at this time, and for ten days after the blossom hadfallen off, appeared to consist of a gelatinous substance. On theeleventh day after the falling of the blossom the seeds became heart-shape, with the basis attached by an appendage to the pod, and a whitepoint at the apex; this white point was on pressure found to be a cavityincluding a drop of liquor. On the 25th day the cavity which at first appeared at the apex was muchenlarged and still full of liquor, it also contained a very small semi-transparent body, of a yellowish colour, gelatinous, and fixed by itstwo opposite ends to the sides of the cavity. In a month the seed was much enlarged and its shape changed from a heartto a kidney, the little body contained in the cavity was increased inbulk and was less transparent, and gelatinous, but there yet appeared noorganization. On the 40th day the cavity now grown larger was quite filled with thebody, which was covered with a thin membrane; after this membrane wasremoved the body appeared of a bright green, and was easily divided bythe point of a needle into two portions, which manifestly formed the twolobes, and within these attached to the lower part the exceedingly smallplantule was easily perceived. The foregoing observations evince, 1. That the seeds exist in theovarium many days before fecundation. 2. That they remain for some timesolid, and then a cavity containing a liquid is formed in them. 3. Thatafter fecundation a body begins to appear within the cavity fixed by twopoints to the sides, which in process of time proves to be two lobescontaining a plantule. 4. That the ripe seed consists of two lobesadhering to a plantule, and surrounded by a thin membrane which isitself covered with a husk or cuticle. Spalanzani's Dissertations, Vol. II. P. 253. The analogy between seeds and eggs has long been observed, and isconfirmed by the mode of their production. The egg is known to be formedwithin the hen long before its impregnation; C. F. Wolf asserts that theyolk of the egg is nourished by the vessels of the mother, and that ithas from those its arterial and venous branches, but that afterimpregnation these vessels gradually become impervious and obliterated, and that new ones are produced from the fetus and dispersed into theyolk. Haller's Physiolog. Tom. VIII. P. 94. The young seed afterfecundation, I suppose, is nourished in a similar manner from thegelatinous liquor, which is previously deposited for that purpose; theuterus of the plant producing or secreting it into a reservoir or amniosin which the embryon is lodged, and that the young embryon is furnishedwith vessels to absorb a part of it, as in the very early embryon in theanimal uterus. The spawn of frogs and of fish is delivered from the female before itsimpregnation. M. Bonnet says that the male salamander darts his semeninto the water, where it forms a little whitish cloud which isafterwards received by the swoln anus of the female, and she isfecundated. --He adds that marine plants approach near to these animals, as the male does not project a fine powder but a liquor which in likemanner forms a little cloud in the water. --And further adds, who knowsbut the powder of the stamina of certain plants may not make someimpression on certain germs belonging to the animal kingdom! LetterXLIII. To Spalanzani, Oevres Philos. Spalanzani found that the seminal fluid of frogs and dogs even whendiluted with much water retained its prolific quality. Whether thisquality be simply a stimulus exciting the egg into animal action, whichmay be called a vivifying principle, or whether part of it be actuallyconjoined with the egg is not yet determined, though the latter seemsmore probable from the frequent resemblance of the fetus to the maleparent. A conjunction however of both the male and female influenceseems necessary for the purpose of reproduction throughout all organizednature, as well in hermaphrodite insects, microscopic animals, andpolypi, and exists as well in the formation of the buds of vegetables asin the production of their seeds, which is ingeniously conceived andexplained by Linneus. After having compared the flower to the larva of abutterfly, confining of petals instead of wings, calyxes instead ofwing-sheaths, with the organs of reproduction, and having shewn the useof the farina in fecundating the egg or seed, he proceeds to explain theproduction of the bud. The calyx of a flower, he says, is an expansionof the outer bark, the petals proceed from the inner bark or rind, thestamens from the alburnum or woody circle, and the style from the pith. In the production and impregnation of the seed a commixture of thesecretions of the stamens and style are necessary; and for theproduction of a bud he thinks the medulla or pith bursts its integumentsand mixes with the woody part or alburnum, and these forcing theirpassage through the rind and bark constitute the bud or viviparousprogeny of the vegetable. System of Vegetables translated from Linneus, p. 8. It has been supposed that the embryon vegetable after fecundation, byits living activity or stimulus exerted on the vessels of the parentplant, may produce the fruit or seed-lobes, as the animal fetus producesits placenta, and as vegetable buds may be supposed to produce theirumbilical vessels or roots down the bark of the tree. This in respect tothe production of the fruit surrounding the seeds of trees has beenassimilated to the gall-nuts on oak-leaves, and to the bedeguar onbriars, but there is a powerful objection to this doctrine, viz. Thatthe fruit of figs, all which are female in this country, grow nearly aslarge without fecundation, and therefore the embryon has in them noself-living principle. NOTE XXXIX. --VEGETABLE GLANDULATION. _Seeks, where fine pores their dulcet balm distil. _ CANTO IV. L. 503. The glands of vegetables which separate from their blood the mucilage, starch, or sugar for the placentation or support of their seeds, bulbs, and buds; or those which deposit their bitter, acrid, or narcotic juicesfor their defence from depredations of insects or larger animals; orthose which secrete resins or wax for their protection from moisture orfrosts, consist of vessels too fine for the injection or absorption ofcoloured fluids, and have not therefore yet been exhibited to theinspection even of our glasses, and can therefore only be known by theireffects, but one of the most curious and important of all vegetablesecretions, that of honey, is apparent to our naked eyes, though beforethe discoveries of Linneus the nectary or honey-gland had not evenacquired a name. The odoriferous essential oils of several flowers seem to have beendesigned for their defence against the depredations of insects, whiletheir beautiful colours were a necessary consequence of the size of theparticles of their blood, or of the tenuity of the exterior membrane ofthe petal. The use of the prolific dust is now well ascertained, the waxwhich covers the anthers prevents this dust from receiving moisture, which would make it burst prematurely and thence prevent its applicationto the stigma, as sometimes happens in moist years and is the cause ofdeficient fecundation both of our fields and orchards. The universality of the production of honey in the vegetable world, andthe very complicated apparatus which nature has constructed in manyflowers, as well as the acrid or deleterious juices she has furnishedthose flowers with (as in the Aconite) to protect this honey from rainand from the depredations of insects, seem to imply that this fluid isof very great importance in the vegetable economy; and also that it wasnecessary to expose it to the open air previous to its reabsorption intothe vegetable vessels. In the animal system the lachrymal gland separates its fluid into theopen air for the purpose of moistening the eye, of this fluid the partwhich does not exhale it absorbed by the puncta lachrymalia and carriedinto the nostrils; but as this is not a nutritive fluid the analogy goesno further than its secretion into the open air and its reabsorptioninto the system; every other secreted fluid in the animal body is inpart absorbed again into the system, even those which are esteemedexcrementitious, as the urine and perspirable matter, of which thelatter is secreted, like the honey, into the external air. That thehoney is a nutritious fluid, perhaps the most so of any vegetableproduction, appears from its great similarity to sugar, and from itsaffording sustenance to such numbers of insects, which live upon itsolely during summer, and lay it up for their winter provision. Theseproofs of its nutritive nature evince the necessity of its reabsorptioninto the vegetable system for some useful purpose. This purpose however has as yet escaped the researches of philosophicalbotanists. M. Pontedera believes it designed to lubricate the vegetableuterus, and compares the horn-like nectaries of some flowers to theappendicle of the caecum intestinum of animals. (Antholog. P. 49. )Others have supposed that the honey, when reabsorbed, might serve thepurpose of the liquor amnii, or white of the egg, as a nutriment for theyoung embryon or fecundated seed in its early state of existence. But asthe nectary is found equally general in male flowers as in female ones;and as the young embryon or seed grows before the petals and nectary areexpanded, and after they fall off; and, thirdly, as the nectary so soonfalls off after the fecundation of the pistillum; these seem to beinsurmountable objections to both the above-mentioned opinions. In this state of uncertainty conjectures may be of use so far as theylead to further experiment and investigation. In many tribes of insects, as the silk-worm, and perhaps in all the moths and butterflies, the maleand female parents die as soon as the eggs are impregnated and excluded;the eggs remaining to be perfected and hatched at some future time. Thesame thing happens in regard to the male and female parts of flowers;the anthers and filaments, which constitute the male parts of theflower, and the stigma and style, which constitute the female part ofthe flower, fall off and die as soon as the seeds are impregnated, andalong with these the petals and nectary. Now the moths and butterfliesabove-mentioned, as soon as they acquire the passion and the apparatusfor the reproduction of their species, loose the power of feeding uponleaves as they did before, and become nourished by what?--by honey alone. Hence we acquire a strong analogy for the use of the nectary orsecretion of honey in the vegetable economy, which is, that the maleparts of flowers, and the female parts, as soon as they leave theirfetus-state, expanding their petals, (which constitute their lungs, )become sensible to the passion, and gain the apparatus for thereproduction of their species, and are fed and nourished with honey likethe insects above described; and that hence the nectary begins itsoffice of producing honey, and dies or ceases to produce honey at thesame time with the birth and death of the stamens and the pistils;which, whether existing in the same or in different flowers, areseparate and distinct animated beings. Previous to this time the anthers with their filaments, and the stigmaswith their styles, are in their fetus-state sustained by their placentalvessels, like the unexpanded leaf-bud; with the seeds existing in thevegetable womb yet unimpregnated, and the dust yet unripe in the cellsof the anthers. After this period they expand their petals, which havebeen shewn above to constitute the lungs of the flower; the placentalvessels, which before nourished the anthers and the stigmas, coalesce orcease to nourish them; and they now acquire blood more oxygenated by theair, obtain the passion and power of reproduction, are sensible to heat, and cold, and moisture, and to mechanic stimulus, and become in realityinsects fed with honey, similar in every respect except their beingattached to the tree on which they were produced. Some experiments I have made this summer by cutting out the nectaries ofseveral flowers of the aconites before the petals were open, or hadbecome much coloured, some of these flowers near the summit of theplants produced no seeds, others lower down produced seeds; but theywere not sufficiently guarded from the farina of the flowers in theirvicinity; nor have I had opportunity to try if these seeds wouldvegetate. I am acquainted with a philosopher, who contemplating this subjectthinks it not impossible, that the first insects were the anthers orstigmas of flowers; which had by some means loosed themselves from theirparent plant, like the male flowers of Vallisneria; and that many otherinsects have gradually in long process of time been formed from these;some acquiring wings, others fins, and others claws, from theirceaseless efforts to procure their food, or to secure themselves frominjury. He contends, that none of these changes are moreincomprehensible than the transformation of tadpoles into frogs, andcaterpillars into butterflies. There are parts of animal bodies, which do not require oxygenated bloodfor the purpose of their secretions, as the liver; which for theproduction of bile takes its blood from the mesenteric veins, after itmust have lost the whole or a great part of its oxygenation, which ithad acquired in its passage through the lungs. In like manner thepericarpium, or womb of the flower, continues to secrete its properjuices for the present nourishment of the newly animated embryon-seed;and the saccharine, acescent, or starchy matter of the fruit or seed-lobes for its future growth; in the same manner as these things went onbefore fecundation; that is, without any circulation of juices in thepetals, or production of honey in the nectary; these having perished andfallen off with the male and female apparatus for impregnation. It is probable that the depredations of insects on this nutritious fluidmust be injurious to the products of vegetation, and would be much moreso, but that the plants have either acquired means to defend their honeyin part, or have learned to make more than is absolutely necessary fortheir own economy. In the same manner the honey-dew on trees is veryinjurious to them; in which disease the nutritive fluid, the vegetable-sap-juice, seems to be exsuded by a retrograde motion of the cutaneouslymphatics, as in the sweating sickness of the last century. To preventthe depredation of insects on honey a wealthy man in Italy is said tohave poisoned his neighbour's bees perhaps by mixing arsnic with honey, against which there is a most flowery declamation in Quintilian. No. XIII. As the use of the wax is to preserve the dust of the anthers frommoisture, which would prematurely burst them, the bees which collectthis for the construction of the combs or cells, must on this accountalso injure the vegetation of a country where they too much abound. It is not easy to conjecture why it was necessary that this secretion ofhoney should be exposed to the open air in the nectary or honey-cup, forwhich purpose so great an apparatus for its defence from insects andfrom showers became necessary. This difficulty increases when werecollect that the sugar in the joints of grass, in the sugar-cane, andin the roots of beets, and in ripe fruits is produced without theexposure to the air. On supposition of its serving for nutriment to theanthers and stigmas it may thus acquire greater oxygenation for thepurpose of producing greater powers of sensibility, according to adoctrine lately advanced by a French philosopher, who has endeavoured toshew that the oxygene, or base of vital air, is the constituentprinciple of our power of sensibility. From this provision of honey for the male and female parts of flowers, and from the provision of sugar, starch, oil, and mucilage, in thefruits, seed-cotyledons, roots, and buds of plants laid up for thenutriment of the expanding fetus, not only a very numerous class ofinsects, but a great part of the larger animals procure their food; andthus enjoy life and pleasure without producing pain to others, for theseseeds or eggs with the nutriment laid up in them are not yet endued withsensitive life. The secretions from various vegetable glands hardened in the air producegums, resins, and various kinds of saccharine, saponaceous, and wax-likesubstances, as the gum of cherry or plumb-trees, gum tragacanth from theastragalus tragacantha, camphor from the laurus camphora, elemi fromamyris elemifera, aneme from hymenoea courbaril, turpentine frompistacia terebinthus, balsam of Mecca from the buds of amyrisopobalsamum, branches of which are placed in the temples of the East onaccount of their fragrance, the wood is called xylobalsamum, and thefruit carpobalsamum; aloe from a plant of the same name; myrrh from aplant not yet described; the remarkably elastic resin is brought intoEurope principally in the form of flasks, which look like black leather, and are wonderfully elastic, and not penetrable by water, rectifiedether dissolves it; its flexibility is encreased by warmth and destroyedby cold; the tree which yields this juice is the jatropha elastica, itgrows in Guaiana and the neighbouring tracts of America; its juice issaid to resemble wax in becoming soft by heat, but that it acquires noelasticity till that property is communicated to it by a secret art, after which it is poured into moulds and well dried and can no longer berendered fluid by heat. Mr. De la Borde physician at Cayenne has giventhis account. Manna is obtained at Naples from the fraxinus ornus, ormanna-ash, it partly issues spontaneously, which is preferred, andpartly exsudes from wounds made purposely in the month of August, manyother plants yield manna more sparingly; sugar is properly made from thesaccharum officinale, or sugar-cane, but is found in the roots of beetand many other plants; American wax is obtained from the myricacerifera, candle-berry myrtle, the berries are boiled in water and agreen wax separates, with luke-warm water the wax is yellow: the seed ofcroton sebiferum are lodged in tallow; there are many other vegetableexsudations used in the various arts of dyeing, varnishing, tanning, lacquering, and which supply the shop of the druggist with medicines andwith poisons. There is another analogy, which would seem to associate plants withanimals, and which perhaps belongs to this Note on Glandulation, I meanthe similarity of their digestive powers. In the roots of growingvegetables, as in the process of making malt, the farinaceous part ofthe seed is converted into sugar by the vegetable power of digestion inthe same manner as the farinaceous matter of seeds are converted intosweet chyle by the animal digestion. The sap-juice which rises in thevernal months from the roots of trees through the alburnum or sap-wood, owes its sweetness I suppose to a similar digestive power of theabsorbent system of the young buds. This exists in many vegetables ingreat abundance as in vines, sycamore, birch, and most abundantly in thepalm-tree, (Isert's Voyage to Guinea, ) and seems to be a similar fluidin all plants, as chyle is similar in all animals. Hence as the digested food of vegetables consists principally of sugar, and from that is produced again their mucilage, starch, and oil, andsince animals are sustained by these vegetable productions, it wouldseem that the sugar-making process carried on in vegetable vessels wasthe great source of life to all organized beings. And that if ourimproved chemistry should ever discover the art of making sugar fromfossile or aerial matter without the assistance of vegetation, food foranimals would then become as plentiful as water, and mankind might liveupon the earth as thick as blades of grass, with no restraint to theirnumbers but the want of local room. It would seem that roots fixed in the earth, and leaves innumerablewaving in the air were necessary for the decomposition of water, and theconversion of it into saccharine matter, which would have been not onlycumberous but totally incompatible with the locomotion of animal bodies. For how could a man or quadruped have carried on his head or back aforest of leaves, or have had long branching lacteal or absorbentvessels terminating in the earth? Animals therefore subsist onvegetables; that is, they take the matter so far prepared, and haveorgans to prepare it further for the purposes of higher animation, andgreater sensibility. In the same manner the apparatus of green leavesand long roots were found inconvenient for the more animated andsensitive parts of vegetable-flowers, I mean the anthers and stigmas, which are therefore separate beings, endued with the passion and powerof reproduction, with lungs of their own, and fed with honey, a foodready prepared by the long roots and green leaves of the plant, andpresented to their absorbent mouths. From this outline a philosopher may catch a glimpse of the generaleconomy of nature; and like the mariner cast upon an unknown shore, whorejoiced when he saw the print of a human foot upon the sand, he may cryout with rapture, "A GOD DWELLS HERE. " CONTENTS OF THE ADDITIONAL NOTES. NOTE I ... METEORS. There are four strata of the atmosphere, and four kinds of meteors. 1. Lightning is electric, exists in visible clouds, its short course, andred light. 2. Shooting stars exist in invisible vapour, without sound, white light, have no luminous trains. 3. Twilight; fire-balls movethirty miles in a second, and are about sixty miles high, have luminoustrains, occasioned by an electric spark passing between the aerial andinflammable strata of the atmosphere, and mixing them and setting themon fire in its passage; attracted by volcanic eruptions; one thousandmiles through such a medium resists less than the tenth of an inch ofglass. 4. Northern lights not attracted to a point but diffused; theircolours; passage of electric fire in vacuo dubious; Dr. Franklin'stheory of northern lights countenanced in part by the supposition ofa superior atmosphere of inflammable air; antiquity of their appearance;described in Maccabees. NOTE II ... PRIMARY COLOURS. The rainbow was in part understood before Sir Isaac Newton; the sevencolours were discovered by him; Mr. Gallon's experiments on colours;manganese and lead produce colourless glass. NOTE III ... COLOURED CLOUDS. The rays refracted by the convexity of the atmosphere; the particles ofair and of water are blue; shadow by means of a candle in the day; haloround the moon in a fog; bright spot in the cornea of the eye; lightfrom cat's eyes in the dark, from a horse's eyes in a cavern, colouredby the choroid coat within the eye. NOTE IV ... COMETS. Tails of comets from rarified vapour, like northern lights, fromelectricity; twenty millions of miles long; expected comet. NOTE V ... SUN'S RAYS. Dispute about phlogiston; the sun the fountain from whence allphlogiston is derived; its rays not luminous till they arrive at ouratmosphere; light owing to their combustion with air, whence an unknownacid; the sun is on fire only on its surface; the dark spots on it areexcavations through its luminous crust. NOTE VI ... CENTRAL FIRES. Sun's heat much less than that from the fire at the earth's centre;sun's heat penetrates but a few feet in summer; some mines are warm;warm springs owing to subterraneous fire; situations of volcanos on highmountains; original nucleus of the earth; deep vallies of the ocean;distant perception of earthquakes; great attraction of mountains;variation of the compass; countenance the existence of a cavity or fluidlava within the earth. NOTE VII ... ELEMENTARY HEAT. Combined and sensible heat; chemical combinations attract heat, solutions reject heat; ice cools boiling water six times as much as coldwater cools it; cold produced by evaporation; heat by devaporation;capacities of bodies in respect to heat, 1. Existence of the matter ofheat shewn from the mechanical condensation and rarefaction of air, fromthe steam produced in exhausting a receiver, snow from rarefied air, cold from discharging an air-gun, heat from vibration or friction; 2. Matter of heat analogous to the electric fluid in many circumstances, explains many chemical phenomena. NOTE VIII ... MEMNON'S LYRE. Mechanical impulse of light dubious; a glass tube laid horizontallybefore a fire revolves; pulse-glass suspended on a centre; black leathercontracts in the sunshine; Memnon's statue broken by Cambyses. NOTE IX ... LUMINOUS INSECTS. Eighteen species of glow-worm, their light owing to their respiration intransparent lungs; Acudia of Surinam gives light enough to read and drawby, use of its light to the insect; luminous sea-insects adhere to theskin of those who bathe in the ports of Languedoc, the light may arisefrom putrescent slime. NOTE X ... PHOSPHORUS. Discovered by Kunkel, Brandt, and Boyle; produced in respiration, and byluminous insects, decayed wood, and calcined shells; bleaching a slowcombustion in which the water is decomposed; rancidity of animal fatowing to the decomposition of water on its surface; aerated marine aciddoes not whiten or bleach the hand. NOTE XI ... STEAM-ENGINE. Hero of Alexandria first applied steam to machinery, next a Frenchwriter in 1630, the Marquis of Worcester in 1655, Capt. Savery in 1689, Newcomen and Cawley added the piston; the improvements of Watt andBoulton; power of one of their large engines equal to two hundredhorses. NOTE XII ... FROST. Expansion of water in freezing; injury done by vernal frosts; fish, eggs, seeds, resist congelation; animals do not resist the increase ofheat; frosts do not meliorate the ground, nor are in general salubrious;damp air produces cold on the skin by evaporation; snow less perniciousto agriculture than heavy rains for two reasons. NOTE XIII ... ELECTRICITY. 1. _Points_ preferable to knobs for defence of buildings; why pointsemit the electric fluid; diffusion of oil on water; mountains are pointson the earth's globe; do they produce ascending currents of air? 2. _Fairy-rings_ explained; advantage of paring and burning ground. NOTE XIV ... BUDS AND BULBS. A tree is a swarm of individual plants; vegetables are either oviparousor viviparous; are all annual productions like many kinds of insects?Hybernacula, a new bark annually produced over the old one in trees andin some herbaceous plants, whence their roots seem end-bitten; allbulbous roots perish annually; experiment on a tulip-root; both theleaf-bulbs and the flower-bulbs are annually renewed. NOTE XV ... SOLAR VOLCANOS. The spots in the sun are cavities, some of them four thousand miles deepand many times as broad; internal parts of the sun are not in a state ofcombustion; volcanos visible in the sun; all the planets together areless than one six hundred and fiftieth part of the sun; planets wereejected from the sun by volcanos; many reasons shewing the probabilityof this hypothesis; Mr. Buffon's hypothesis that planets were struck offfrom the sun by comets; why no new planets are ejected from the sun;some comets and the georgium sidus may be of later date; Sun's matterdecreased; Mr. Ludlam's opinion, that it is possible the moon might beprojected from the earth. NOTE XVI ... CALCAREOUS EARTH. High mountains and deep mines replete with shells; the earth's nucleuscovered with limestone; animals convert water into limestone; all thecalcareous earth in the world formed in animal and vegetable bodies;solid parts of the earth increase; the water decreases; tops ofcalcareous mountains dissolved; whence spar, marbles, chalk, stalactites; whence alabaster, fluor, flint, granulated limestone, fromsolution of their angles, and by attrition; tupha deposited on moss;limestones from shells with animals in them; liver-stone from fresh-water muscles; calcareous earth from land-animals and vegetables, asmarl; beds of marble softened by fire; whence Bath-stone contains limeas well as limestone. NOTE XVII ... MORASSES. The production of morasses from fallen woods; account by the EarlCromartie of a new morass; morasses lose their salts by solution inwater; then their iron; their vegetable acid is converted into marine, nitrous, and vitriolic acids; whence gypsum, alum, sulphur; into fluor-acid, whence fluor; into siliceous acid, whence flint, the sand of thesea, and other strata of siliceous sand and marl; some morasses fermentlike new hay, and, subliming their phlogistic part, form coal-beds aboveand clay below, which are also produced by elutriation; shell-fish insome morasses, hence shells sometimes found on coals and over iron-stone. NOTE XVIII ... IRON Calciform ores; combustion of iron in vital air; steel from deprivationof vital air; welding; hardness; brittleness like Rupert's drops;specific levity; hardness and brittleness compared; steel tempered byits colours; modern production of iron, manganese, calamy; septaria ofiron-stone ejected from volcanos; red-hot cannon balls. NOTE XIX ... FLINT. 1. _Siliceous rocks_ from morasses; their cements. 2. _Siliceous trees_;coloured by iron or manganese; Peak-diamonds; Bristol-stones; flint inform of calcareous spar; has been fluid without much heat; obtained frompowdered quartz and fluor-acid by Bergman and by Achard. 3. _Agates andonyxes_ found in sand-rocks; of vegetable origin; have been in completefusion; their concentric coloured circles not from superinduction butfrom congelation; experiment of freezing a solution of blue vitriol;iron and manganese repelled in spheres as the nodule of flint cooled;circular stains of marl in salt-mines; some flint nodules resemble knotsof wood or roots. 4. _Sand of the sea_; its acid from morasses; its basefrom shells. 5. _Chert or petrosilex_ stratified in cooling; theircolour and their acid from sea-animals; labradore-stone from mother-pearl. 6. _Flints in chalk-beds_; their form, colour, and acid, from theflesh of sea-animals; some are hollow and lined with crystals; containiron; not produced by injection from without; coralloids converted toflint; French-millstones; flints sometimes found in solid strata. 7. _Angles of sand_ destroyed by attrition and solution in steam; siliceousbreccia cemented by solution in red-hot water. 8. _Basaltes andgranites_ are antient lavas; basaltes raised by its congelation not bysubterraneous fire. NOTE XX ... CLAY. Fire and water two great agents; stratification from precipitation; manystratified materials not soluble in water. 1. Stratification of lavafrom successive accumulation. 2. Stratifications of limestone from thedifferent periods of time in which the shells were deposited. 3. Stratifications of coal, and clay, and sandstone, and iron-ores, notfrom currents of water, but from the production of morass-beds atdifferent periods of time; morass-beds become ignited; their bitumen andsulphur is sublimed; the clay, lime, and iron remain; whence sand, marle, coal, white clay in valleys, and gravel-beds, and some ochres, and some calcareous depositions owing to alluviation; clay fromdecomposed granite; from the lava of Vesuvius; from vitreous lavas. NOTE XXI ... ENAMELS. Rose-colour and purple from gold; precipitates of gold by alcaline saltpreferable to those by tin; aurum fulminans long ground; tender coloursfrom gold or iron not dissolved but suspended in the glass; cobalts;calces of cobalt and copper require a strong fire; Ka-o-lin andPe-tun-tse the same as our own materials. NOTE XXII ... PORTLAND VASE. Its figures do not allude to private history; they represent a part ofthe Elusinian mysteries; marriage of Cupid and Psyche; procession oftorches; the figures in one compartment represent MORTAL LIFE in the actof expiring, and HUMANKIND attending to her with concern; Adam and Evehyeroglyphic figures; Abel and Cain other hyeroglyphic figures; on theother compartment is represented IMMORTAL LIFE, the Manes or Ghostdescending into Elisium is led on by DIVINE LOVE, and received byIMMORTAL LIFE, and conducted to Pluto; Tree of Life and Knowledge areemblematical; the figure at the bottom is of Atis, the first greatHierophant, or teacher of mysteries. NOTE XXIII ... COAL. 1. A fountain of fossile tar in Shropshire; has been distilled from thecoal-beds beneath, and condensed in the cavities of a sand-rock; thecoal beneath is deprived of its bitumen in part; bitumen sublimed atMatlock into cavities lined with spar. 2. Coal has been exposed to heat;woody fibres and vegetable seeds in coal at Bovey and Polesworth; upperpart of coal-beds more bituminous at Beaudesert; thin stratum ofasphaltum near Caulk; upper part of coal-bed worse at Alfreton; upperstratum of no value at Widdrington; alum at West-Hallum; at Bilston. 3. Coal at Coalbrooke-Dale has been immersed in the sea, shewn by sea-shells; marks of violence in the colliery at Mendip and at Ticknal;Lead-ore and spar in coal-beds; gravel over coal near Lichfield; Coalproduced from morasses shewn by fern-leaves, and bog-shells, and muscle-shells; by some parts of coal being still woody; from Lock Neagh andBovey, and the Temple of the devil; fixed alcali; oil. NOTE XXIV ... GRANITE. Granite the lowest stratum of the earth yet known; porphory, trap, Moor-stone, Whin-stone, slate, basaltes, all volcanic productions dissolvedin red-hot water; volcanos in granite strata; differ from the heat ofmorasses from fermentation; the nucleus of the earth ejected from thesun? was the sun originally a planet? supposed section of the globe. NOTE XXV ... EVAPORATION. I. Solution of water in air; in the matter of heat; pulse-glass. 2. Heatis the principal cause of evaporation; thermometer cooled by evaporationof ether; heat given from steam to the worm-tub; warmth accompanyingrain. 3. Steam condensed on the eduction of heat; moisture on coldwalls; south-west and north-east winds. 4. Solution of salt and of bluevitriol in the matter of heat. II. Other vapours may precipitate steamand form rain. 1. Cold the principal cause of devaporation; hence thesteam dissolved in heat is precipitated, but that dissolved in airremains even in frosts; south-west wind. 2. North-east winds mixing withsouth-west winds produce rain; because the cold particles of air of thenorth-east acquire some of the matter of heat from the south-west winds. 3. Devaporation from mechanical expansion of air, as in the receiver ofan air-pump; summer-clouds appear and vanish; when the barometers sinkwithout change of wind the weather becomes colder. 4. Solution of waterin electric fluid dubious. 5. Barometer sinks from the lessened gravityof the air, and from the rain having less pressure as it falls; amixture of a solution of water in calorique with an aerial solution ofwater is lighter than dry air; breath of animals in cold weather whycondensed into visible vapour and dissolved again. NOTE XXVI ... SPRINGS. Lowest strata of the earth appear on the highest hills; springs fromdews sliding between them; mountains are colder than plains; 1. Fromtheir being insulated in the air; 2. From their enlarged surface; 3. From the rarety of the air it becomes a better conductor of heat; 4. Bythe air on mountains being mechanically rarefied as it ascends; 5. Gravitation of the matter of heat; 6. The dashing of clouds againsthills; of fogs against trees; springs stronger in hot days with coldnights; streams from subterranean caverns; from beneath the snow on theAlps. NOTE XXVII ... SHELL-FISH. The armour of the Echinus moveable; holds itself in storms to stones by1200 or 2000 strings: Nautilus rows and sails; renders its shellbuoyant: Pinna and Cancer; Byssus of the antients was the beard of thePinna; as fine as the silk is spun by the silk-worm; gloves made of it;the beard of muscles produces sickness; Indian weed; tendons of ratstails. NOTE XXVIII ... STURGEON. Sturgeon's mouth like a purse; without teeth; tendrils like worms hangbefore his lips, which entice small fish and sea-insects mistaking themfor worms; his skin used for covering carriages; isinglass made from it;cavear from the spawn. NOTE XXIX ... OIL ON WATER. Oil and water do not touch; a second drop of oil will not diffuse itselfon the preceeding one; hence it stills the waves; divers for pearl carryoil in their mouths; oil on water produces prismatic colours; oiled corkcirculates on water; a phial of oil and water made to oscillate. NOTE XXX ... SHIP-WORM. The Teredo has calcareous jaws; a new enemy; they perish when they meettogether in their ligneous canals; United Provinces alarmed for thepiles of the banks of Zeland; were destroyed by a severe winter. NOTE XXXI ... MAELSTROM. A whirlpool on the coast of Norway; passes through a subterraneouscavity; less violent when the tide is up; eddies become hollow in themiddle; heavy bodies are thrown out by eddies; light ones retained; oiland water whirled in a phial; hurricanes explained. NOTE XXXII ... GLACIERS. Snow in contact with the earth is in a state of thaw; ice-houses; riversfrom beneath the snow; rime in spring vanishes by its contact with theearth; and snow by its evaporation and contact with the earth; mossvegetates beneath the snow; and Alpine plants perish at Upsal for wantof show. NOTE XXXIII ... WINDS. Air is perpetually subject to increase and to diminution; Oxygene isperpetually produced from vegetables in the sunshine, and from clouds inthe light, and from water; Azote is perpetually produced from animal andvegetable putrefaction, or combustion; from springs of water; volatilealcali; fixed alcali; sea-water; they are both perpetually diminished bytheir contact with the soil, producing nitre; Oxygene is diminished inthe production of all acids; Azote by the growth of animal bodies;charcoal in burning consumes double its weight of pure air; every barrelof red-lead absorbes 2000 cubic feet of vital air; air obtained fromvariety of substances by Dr. Priestley; Officina aeris in the polarcircle, and at the Line. _South-west winds_; their westerly directionfrom the less velocity of the earth's surface; the contrary in respectto north-east winds; South-west winds consist of regions of air from thesouth; and north-east winds of regions of air from the north; when thesouth-west prevails for weeks and the barometer sinks to 28, whatbecomes of above one fifteenth part of the atmosphere; 1. It is notcarried back by superior currents; 2. Not from its loss of moisture; 3. Not carried over the pole; 4. Not owing to atmospheric tides ormountains; 5. It is absorbed at the polar circle; hence south-west windsand rain; south-west sometimes cold. _North-east winds_ consist of airfrom the north; cold by the evaporation of ice; are dry winds; 1. Notsupplied by superior current; 2. The whole atmosphere increased inquantity by air set at liberty from its combinations in the polarcircles. _South-east winds_ consist of north winds driven back. _North-west winds_ consist of south-west winds driven back; north-west winds ofAmerica bring frost; owing to a vertical spiral eddy of air between theeastern coast and the Apalachian mountains; hence the greater cold ofNorth America. _Trade-winds_; air over the Line always hotter than atthe tropics; trade-winds gain their easterly direction from the greatervelocity of the earth's surface at the line; not supplied by superiorcurrents; supplied by decomposed water in the sun's great light; 1. Because there are no constant rains in the tract of the trade-winds; 2. Because there is no condensible vapour above three or four miles high atthe line. _Monsoons and tornadoes_; some places at the tropic becomewarmer when the sun is vertical than at the line; hence the air ascends, supplied on one side by the north-east winds, and on the other by thesouth-west; whence an ascending eddy or tornado, raising water from thesea, or sand from the desert, and incessant rains; air diminished to thenorthward produces south-west winds; tornadoes from heavier air abovesinking through lighter air below, which rises through a perforation;hence trees are thrown down in a narrow line of twenty or forty yardsbroad, the sea rises like a cone, with great rain and lightning. _Landand sea breezes_; sea less heated than land; tropical islands moreheated in the day than the sea, and are cooled more in the night. _Conclusion_; irregular winds from other causes; only two original windsnorth and south; different sounds of north-east and south-west winds; aBear or Dragon in the arctic circle that swallows at times anddisembogues again above one fifteenth part of the atmosphere; wind-instruments; recapitulation. NOTE XXXIV ... VEGETABLE PERSPIRATION. Pure air from Dr. Priestley's vegetable matter, and from vegetableleaves, owing to decomposition of water; the hydrogene retained by thevegetables; plants in the shade are _tanned_ green by the sun's light;animal skins are _tanned_ yellow by the retention of hydrogene; muchpure air from dew on a sunny morning; bleaching why sooner performed oncotton than linen; bees wax bleached; metals calcined by decompositionof water; oil bleached in the light becomes yellow again in the dark;nitrous acid coloured by being exposed to the sun; vegetables perspiremore than animals, hence in the sun-shine they purify air more by theirperspiration than they injure it by their respiration; they grow fastestin their sleep. NOTE XXXV ... VEGETABLE PLACENTATION. Buds the viviparous offspring of vegetables; placentation in bulbs andseeds; placentation of buds in the roots, hence the rising of sap in thespring, as in vines, birch, which ceases as soon as the leaves expand;production of the leaf of Horse-chesnut, and of its new bud; oil ofvitriol on the bud of Mimosa killed the leaf also; placentation shewnfrom the sweetness of the sap; no umbilical artery in vegetables. NOTE XXXVI ... VEGETABLE CIRCULATION. Buds set in the ground will grow if prevented from bleeding to death bya cement; vegetables require no muscles of locomotion, no stomach orbowels, no general system of veins; they have, 1. Three systems ofabsorbent vessels; 2. Two pulmonary systems; 3. Arterial systems; 4. Glands; 5. Organs of reproduction; 6. Muscles. I. Absorbent systemevinced by experiments by coloured absorptions in fig-tree and picris;called air-vessels erroneously; spiral structure of absorbent vessels;retrograde motion of them like the throats of cows. II. Pulmonaryarteries in the leaves, and pulmonary veins; no general system of veinsshewn by experiment; no heart; the arteries act like the vena portarumof the liver; pulmonary system in the petals of flowers; circulationowing to living irritability; vegetable absorption more powerful thananimal, as in vines; not by capillary attraction. NOTE XXXVII ... VEGETABLE RESPIRATION. I. Leaves not perspiratory organs, nor excretory ones; lungs of animals. 1. Great surfaces of leaves. 2. Vegetable blood changes colour in theleaves; experiment with spurge; with picris. 3. Upper surface of theleaf only acts as a respiratory organ. 4. Upper surface repels moisture;leaves laid on water. 5. Leaves killed by oil like insects; muscles atthe foot-stalks of leaves. 6. Use of light to vegetable leaves;experiments of Priestley, Ingenhouze, and Scheel. 7. Vegetablecirculation similar to that of fish. II. Another pulmonary systembelongs to flowers; colours of flowers. 1. Vascular structure of thecorol. 2. Glands producing honey, wax, &c. Perish with the corol. 3. Many flowers have no green leaves attending them, as Colchicum. 4. Corols not for the defence of the stamens. 5. Corol of Helleborus Nigerchanges to a calyx. 6. Green leaves not necessary to the fruit-bud;green leaves of Colchicum belong to the new bulb not to the flower. 7. Flower-bud after the corol falls is simply an uterus; mature flowers notinjured by taking of the green leaves. 8. Inosculation of vegetablevessels. NOTE XXXVIII ... VEGETABLE IMPREGNATION. Seeds in broom discovered twenty days before the flower opens; progressof the seed after impregnation; seeds exist before fecundation; analogybetween seeds and eggs; progress of the egg within the hen; spawn offrogs and of fish; male Salamander; marine plants project a liquor not apowder; seminal fluid diluted with water, if a stimulus only? Male andfemale influence necessary in animals, insects, and vegetables, both inproduction of seeds and buds; does the embryon seed produce thesurrounding fruit, like insects in gall-nuts? NOTE XXXIX ... VEGETABLE GLANDULATION. Vegetable glands cannot be injected with coloured fluids; essential oil;wax; honey; nectary, its complicate apparatus; exposes the honey to theair like the lacrymal gland; honey is nutritious; the male and femaleparts of flowers copulate and die like moths and butterflies, and arefed like them with honey; anthers supposed to become insects;depredation of the honey and wax injurious to plants; honey-dew; honeyoxygenated by exposure to air; necessary for the production ofsensibility; the provision for the embryon plant of honey, sugar, starch, &c. Supplies food to numerous classes of animals; variousvegetable secretions as gum tragacanth, camphor, elemi, anime, turpentine, balsam of Mecca, aloe, myrrh, elastic resin, manna, sugar, wax, tallow, and many other concrete juices; vegetable digestion;chemical production of sugar would multiply mankind; economy of nature. THE END