The Botanic Garden Volume I Part 3

[_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 l.u.s.tres 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 sensible electrometer improved by Mr. Bennett, it consists of two slips of gold- leaf suspended from a tin cap in a gla.s.s cylinder, which has a partial coating without, communicating with the wooden pedestal. If a stick of sealing wax be rubbed for a moment on a dry cloth, and then held in the air _at the distance of two or three feet_ from the cap of this instrument, the gold leaves seperate, such is its astonishing sensibility to electric influence! (See Bennet on electricity, Johnson, Lond.) The nerves of sense of animal bodies do not seem to be affected by less quant.i.ties of light or heat!]

[_The holy Halo_. l. 358. I believe it is not known with certainty at what time the painters first introduced the luminous circle round the head to import a Saint or holy person. It is now become a part of the symbolic language of painting, and it is much to be wished that this kind of hieroglyphic character was more frequent in that art; as it is much wanted to render historic pictures both more intelligible, and more sublime; and why should not painting as well as poetry express itself in metaphor, or in indistinct allegory? A truly great modern painter lately endeavoured to enlarge the sphere of pictorial language, by putting a demon behind the pillow of a wicked man on his death bed. Which unfortunately for the scientific part of painting, the cold criticism of the present day has depreciated; and thus barred perhaps the only road to the further improvement in this science.]

"YOU crowd in coated jars the denser fire, 360 Pierce the thin gla.s.s, 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 of nerves in animal bodies for the purpose of perceiving heat; since the degree of this fluid is so necessary to health that we become presently injured either by its access or defect; and because almost every part of our bodies is supplied with branches from different pairs of nerves, which would not seem necessary for their motion alone: It is therefore probable, that our sensation of electricity is only of its violence in pa.s.sing through our system by its suddenly distending the muscles, like any other mechanical violence; and that it is general pain alone that we feel, and not any sensation a.n.a.logous to the specific quality of the object. Nature may seem to have been n.i.g.g.ardly to mankind in bestowing upon them so few senses; since a sense to have perceived electricity, and another to have perceived magnetism might have been of great service to them, many ages before these fluids were discovered by accidental experiment, but it is possible an increased number of senses might have incommoded us by adding to the size of our bodies.]

[_Palsy's cold hands_. l. 367. Paralytic limbs are in general only incapable 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 stretch themselves, (which is not a voluntary motion,) that the affected limb moves at the same time. The temporary motion of a paralytic limb is likewise caused by pa.s.sing the electric shock through it; which would seem to indicate some a.n.a.logy between the electric fluid, and the nervous fluid, which is seperated from the blood by the brain, and thence diffused along the nerves for the purposes of motion and sensation. It probably destroys life by its sudden expansion of the nerves or fibres of the brain; in the same manner as it fuses metals and splinters wood or stone, and removes the atmosphere, when it pa.s.ses from one 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 natural philosophy at Petersburgh about the year 1763, elevated an insulated metallic rod to collect the aerial electricity, as Dr. Franklin had previously done at Philadelphia; and as he was observing the repulsion of the b.a.l.l.s of his electrometer approached too near the conductor, and receiving the lightening in his head with a loud explosion, was struck dead 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 LOVE 390 s.n.a.t.c.h'd the raised lightning from the arm of JOVE; Quick o'er his knee the triple bolt He bent, The cl.u.s.ter'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 G.o.ds 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 that discovered that lightening consisted of electric matter, he elevated a tall rod with a wire wrapped round it, and fixing the bottom of a rod into a gla.s.s 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. This great discovery taught us to defend houses and ships and temples from lightning, and also to understand, _that people are always perfectly safe in a room during a thunder storm if they keep themselves at three or four feet distance from the walls_; for the matter of lightning in pa.s.sing 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 other elevated object; except there be some moister body, as an animal in contact with them, or nearly so; and in that case the lightning leaves the wall or tree, and pa.s.ses through the animal; but as it can pa.s.s through metals with still greater facility, it will leave animal bodies to pa.s.s through metallic ones.

If a person in the open air be surprized by a thunderstorm, he will know his danger by observing on a second watch the time which pa.s.ses between the flash and the crack, and reckoning a mile for every four seconds and a half, and a little more. For sound travels at the rate of 1142 feet in a second of time, and the velocity of light through such small distances is not to be estimated. In these circ.u.mstances a person will be safer by lying down on the ground, than erect, and still safer if within a few feet of his horse; which being then a more elevated animal will receive the shock, in preference as the cloud pa.s.ses 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 of his purpose. It is expressed on an agate in the Great Duke's collection at 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 sp.a.w.n; Nurse with soft lap, and warm with fragrant breath 410 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 on animal heat has endeavoured to prove, that during the combination of the pure part of the atmosphere with the phlogistic part of the blood, that much of the matter of the heat is given out from the air; and that this is the great and perpetual source of the heat of animals; to which we may add that the phosphoric acid is probably produced by this combination; by which acid the colour of the blood is changed in the lungs from a deep crimson to a bright scarlet. There seems to be however another source of animal heat, though of a similar nature; and that is from the chemical combinations produced in all the glands; since by whatever cause any glandular secretion is increased, as by friction or topical imflammation, the heat of that part becomes increased at the same 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 any increased pulmonary action. BESIDES THIS there would seem to be another material received from the air by respiration; which is so necessary to life, that the embryon must learn to breathe almost within a minute after its birth, or it dies. The perpetual necessity of breathing shews, that the material thus acquired is perpetually consuming or escaping, and on that account requires perpetual renovation. Perhaps the spirit of animation itself is thus acquired from the atmosphere, which if it be supposed to be finer or more subtle than the electric matter, could not long be retained in our bodies, and must therefore require perpetual renovation.]

"Thus when the Egg of Night, on Chaos hurl'd, Burst, and disclosed the cradle of the world; 415 First from the gaping sh.e.l.l 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 belonging to the antient mythology, one much elder than the other. The elder cupid, or Eros, or divine Love, was the first that came out of the great egg of night, which floated in Chaos, and was broken by the horns of the celestial bull, that is, was hatched by the warmth of the spring. He was winged and armed, and by his arrows and torch pierced and vivified all things, producing life and joy. Bacon, Vol. V. p. 197. Quarto edit.

Lond. 1778. "At this time, (says Aristophanes,) sable-winged night produced an egg, from whence sprung up like a blossom Eros, the lovely, the desirable, with his glossy golden wings." Avibus. Bryant's Mythology, Vol. II. p. 350. second edition. This interesting moment of this sublime allegory Mrs. Cosway has chosen for her very beautiful painting. She has represented Eros or divine Love with large wings having the strength of the eagle's wings, and the splendor of the peac.o.c.ks, with his hair floating in the form of flame, and with a halo of light vapour round his head; which illuminates the painting; while he is in the act of springing forwards, and with his hands separating the elements.]

IX. The G.o.dDESS 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, ILl.u.s.tRIOUS NYMPHS! your radiant powers, Call from their long repose the VERNAL HOURS.

Wake with soft touch, with rosy hands unbind 430 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 h.o.a.ry 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 a.s.sail, 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 princ.i.p.al frosts of this country are accompanied 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 air brought from the north, which appear to acquire an easterly direction as they advance; and the S.W. winds consist of regions of air brought from the south, which appear to acquire a westerly direction as they advance.

The surface of the earth nearer the pole moves slower than it does in our lat.i.tude; whence the regions of air brought from thence, move slower, when they arrive hither, than the earth's surface with which they now become in contact; that is they acquire an apparent easterly direction, as the earth moves from west to east faster than this new part of its atmosphere. The S.W. winds on the contrary consist of regions of air brought from the south, where the surface of the earth moves faster than in our lat.i.tude; and have therefore a westerly direction when they arrive hither by their moving faster than the surface of the earth, with which they are in contact; and in general the nearer to the west and the greater the velocity of these winds the warmer they should be in respect to the season of the year, since they have been brought more expeditiously from the south, than those winds which have less westerly direction, and have thence been less cooled in their pa.s.sage.

Sometimes I have observed the thaw to commence immediately on the change of the wind, even within an hour, if I am not mistaken, or sooner. At other times the S.W. wind has continued a day, or even two, before the thaw has commenced; during which time some of the frosty air, which had gone southwards, is driven back over us; and in consequence has taken a westerly direction, as well as a southern one. At other times I have observed 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, x.x.xIII.]

[_The Fiend of Frost_. l. 439. The princ.i.p.al injury done to vegetation by frost is from the expansion of the water contained in the vessels of plants. Water converted into ice occupies a greater s.p.a.ce than it did before, as appears by the bursting of bottles filled with water at the time of their freezing. Hence frost destroys those plants of our island first, which are most succulent; and the most succulent parts first of other plants; as their leaves and last year's shoots; the vessels of which are distended and burst by the expansion of their freezing fluids, while the drier or more resinous plants, as pines, yews, laurels, and other ever-greens, are less liable to injury from cold. The trees in vallies are on this account more injured by the vernal frosts than those on eminencies, because their early succulent shoots come out sooner.

Hence fruit trees covered by a six-inch coping of a wall are less injured by the vernal frosts because their being shielded from showers and the descending night-dews has prevented them from being moist at the time of their being frozen: which circ.u.mstance has given occasion to a vulgar error amongst gardeners, who suppose frost to descend.

As the common heat of the earth in this climate is 48 degrees, those tender trees which will bear bending down, are easily secured from the frost by spreading them upon the ground, and covering them with straw or fern. This particularly suits fig-trees, as they easily bear bending to the ground, and are furnished with an acrid juice, which secures them from the depredations of insects; but are nevertheless liable to be eaten 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 const.i.tute what is termed by Linneus the Hybernaculum, or winter cradle of the embryon vegetable. The buds arise from the bark on the branches of trees, and the bulbs from the caudex of bulbous-rooted plants, or the part from which the fibres of the root are produced, they are defended from too much moisture, and from frosts, and from the depredations of insects by various contrivances, as by scales, hairs, resinous varnishes, and by acrid rinds.

The buds of trees are of two kinds, either flower-buds or leaf buds; the former of these produce their seeds and die; the latter produce other leaf buds or flower buds and die. So that all the buds of trees may be considered as annual plants, having their embryon produced during the preceeding summer. The same seems to happen with respect to bulbs; thus a tulip produces annually one flower-bearing bulb, sometimes two, and several leaf-bearing bulbs; and then the old root perishes. Next year the flower-bearing bulb produces seeds and other bulbs and perishes; while the leaf-bearing bulb, producing other bulbs only, perishes likewise; these circ.u.mstances establish a strict a.n.a.logy between bulbs and buds. See additional notes, No. XIV.]

[_Viewless floods of heat_. l. 462. The fluid matter of heat, or Calorique, in which all bodies are immersed, is as necessary to vegetable as to animal existence. It is not yet determinable whether heat and light be different materials, or modifications of the same materials, as they have some properties in common. They appear to be both of them equally necessary to vegetable health, since without light green vegetables become first yellow, that is, they lose the blue colour, which contributed to produce the green; and afterwards they also lose the yellow and become white; as is seen in cellery blanched or etiolated for the table by excluding the light from it.

The upper surface of leaves, which I suppose to be their organ of respiration, seems to require light as well as air; since plants which grow in windows on the inside of houses are equally sollicitous to turn the upper side of their leaves to the light. Vegetables at the same time exsude or perspire a great quant.i.ty from their leaves, as animals do from their lungs; this perspirable matter as it rises from their fine vessels, (perhaps much finer than the pores of animal skins,) is divided into inconcievable tenuity; and when acted upon by the Sun's light appears to be decomposed; the hydrogene becomes a part of the vegetable, composing oils or resins; and the Oxygene combined with light or calorique ascends, producing the pure part of the atmosphere or vital air. Hence during the light of the day vegetables give up more pure air than their respiration injures; but not so in the night, even though equally exposed to warmth. This single fact would seem to shew, that light is essentially different from heat; and it is perhaps by its combination with bodies, that their combined or latent heat is set at liberty, and becomes sensible. See additional note, x.x.xIV.]

[_Electric torrents pour_. l. 463. The influence of electricity in forwarding the germination of plants and their growth seems to be pretty well established; though Mr. Ingenhouz did not succeed in his experiments, and thence doubts the success of those of others. And though M. Rouland from his new experiments believes, that neither positive nor negative electricity increases vegetation; both which philosophers had previously been supporters of the contrary doctrine; for many other naturalists have since repeated their experiments relative to this object, and their new results have confirmed their former ones. Mr. D'Ormoy and the two Roziers have found the same success in numerous experiments which they have made in the last two years; and Mr. Carmoy has shewn in a convincing manner that electricity accelerates germination.

Mr. D'Ormoy not only found various seeds to vegetate sooner, and to grow taller which were put upon his insulated table and supplied with electricity, but also that silk-worms began to spin much sooner which were kept electrified than those of the same hatch which were kept in the same place and manner, except that they were not electrified. These experiments of M. D'Ormoy are detailed at length in the Journal de Physique of Rozier, Tom. x.x.xV. p. 270.

M. Bartholon, who had before written a tract on this subject, and proposed ingenious methods for applying electricity to agriculture and gardening, has also repeated a numerous set of experiments; and shews both that natural electricity, as well as the artificial, increases the growth of plants, and the germination of seeds; and opposes Mr.

Ingenhouz by very numerous and conclusive facts. Ib. Tom. x.x.xV. p. 401.

Since by the late discoveries or opinions of the Chemists there is reason 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 of its oils, rosins, gums, sugar, &c. and lastly as electricity decomposes water into these two airs termed Oxygene and Hydrogene, there is a powerful a.n.a.logy to induce us to believe that it accelerates or contributes to the growth of vegetation, and like heat may possibly enter into combination with many bodies, or form the basis of some yet una.n.a.lised acid.]