Volume I Part 15 (1/2)
A bird of our own country called a willow-wren (Motacilla) runs up the stem of the crown-imperial (Frittillaria coronalis) and sips the pendulous drops within its petals. This species of Motacilla is called by Ray Regulus non cristatus. White's Hist. of Selborne.]
[Ill.u.s.tration: _Cypripedium. London, Published Dec'r 1st 1791 by J.
Johnson, St. Paul's Church Yard._]
2. ”s.h.i.+eld the young Harvest from devouring blight, The s.m.u.t'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 gla.s.s unneal'd 520 Runs in white lines along the lucid field; Crack follows crack, to laws elastic just, And the frail fabric s.h.i.+vers into dust.
[_s.h.i.+eld the young harvest_. l. 511. Linneus enumerates but four diseases of plants; Erysyche, the white mucor or mould, with sessile tawny heads, with which the leaves are sprinkled, as is frequent on the hop, humulus, maple, acer, &c. Rubigo, the ferrugineous powder sprinkled under the leaves frequent in lady's mantle, alchemilla, &c.
Clavus, when the seeds grow out into larger horns black without, as in rye. This is called Ergot by the french writers.
Ustulago, when the fruit instead of seed produces a black powder, as in barley, oats, &c. To which perhaps the honey-dew ought to have been added, and the canker, in the former of which the nouris.h.i.+ng fluid of the plant seems to be exsuded by a retrograde motion of the cutaneous lymphatics, as in the sweating sickness of the last century. The latter is a phagedenic ulcer of the bark, very destructive to young apple- trees, and which in cherry-trees is attended with a deposition of gum arabic, which often terminates in the death of the tree.]
[_Ergot's horn_. l. 513. There is a disease frequently affects the rye in France, and sometimes in England in moist seasons, which is called Ergot, or horn seed; the grain becomes considerably elongated and is either straight or crooked, containing black meal along with the white, and appears to be pierced by insects, which were probably the cause of the disease. Mr. Duhamel ascribes it to this cause, and compares it to galls on oak-leaves. By the use of this bad grain amongst the poor diseases have been produced attended with great debility and mortification of the extremities both in France and England. Dict.
Raison. art. Siegle. Philosop. Transact.]
[_On gla.s.s unneal'd_. l. 519. The gla.s.s makers occasionally make what they call _proofs_, which are cooled hastily, whereas the other gla.s.s vessels are removed from warmer ovens to cooler ones, and suffered to cool by slow degrees, which is called annealing, or nealing them. If an unnealed gla.s.s be scratched by even a grain of sand falling into it, it will seem to consider of it for some time, or even a day, and will then crack into a thousand pieces.
The same happens to a smooth surfaced lead-ore in Derbys.h.i.+re, the workmen having cleared a large face of it scratch it with picks, and in a few hours many tons of it crack to pieces and fall, with a kind of explosion. Whitehurst's Theory of Earth.
Gla.s.s dropped into cold water, called Prince Rupert's drops, explode when a small part of their tails are broken off, more suddenly indeed, but probably from the same cause. Are the internal particles of these elastic bodies kept so far from each other by the external crust that they are nearly in a state of repulsion into which state they are thrown by their vibrations from any violence applied? Or, like elastic b.a.l.l.s in certain proportions suspended in contact with each other, can motion once 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 blus.h.i.+ng 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 s.h.i.+eld, 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.
[Ill.u.s.tration: _Erythrina Corallodendron. London Published Dec'r 1st by J. Johnson St. Paul's Church Yard._]
[_With ambrosial slumbers_. l. 538. Many vegetables during the night do not seem to respire, but to sleep like the dormant animals and insects in winter. This appears from the mimosa and many other plants closing the upper sides of their leaves together in their sleep, and thus precluding that side of them from both light and air. And from many flowers closing up the polished or interior side of their petals, which we have also endeavoured to shew to be a respiratory organ.
The irritability of plants is abundantly evinced by the absorption and pulmonary circulation of their juices; their sensibility is shewn by the approaches of the males to the females, and of the females to the males in numerous instances; and, as the essential circ.u.mstance of sleep consists in the temporary abolition of voluntary power alone, the sleep of plants evinces that they possess voluntary power; which also indisputably appears in many of them by closing their petals or their leaves 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 matra.s.s 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 ma.s.s Metallic roots across the netted gla.s.s; 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 earliest antiquity have used the same characters to represent the metals and the planets, which were most probably outlines or abstracts of the original hieroglyphic figures of Egypt. These afterwards acquired niches in their temples, and represented G.o.ds as well as metals and planets; whence silver 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 and moderately strong; mix this solution with about twenty ounces of distilled water; add to this two ounces of mercury, and let it remain at rest. In about four days there will form upon the mercury a tree of silver with branches imitating vegetation.
1. As the mercury has a greater affinity than silver with the nitrous acid, the silver becomes precipitated; and, being deprived of the nitrous oxygene by the mercury, sinks down in its metallic form and l.u.s.tre. 2. The attraction between silver and mercury, which causes them readily to amalgamate together, occasions the precipitated silver to adhere to the surface of the mercury in preference to any other part of the vessel. 3. The attraction of the particles of the precipitated silver to each other causes the beginning branches to thicken and elongate into trees and shrubs rooted on the mercury. For other circ.u.mstances concerning this beautiful experiment see Mr. Keir's Chemical Dictionary, art. Arbor Dianae; a work perhaps of greater utility to mankind than the lost Alexandrian Library; the continuation of which is so eagerly expected by all, who are occupied in the arts, or attached 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 gla.s.s-built fanes the stranger flowers 570 With milder gales, and steep with warmer showers.