Mr. Cavendish has since demonstrated that two parts of vital air or oxygene, and one part of phlogistic air or azote, being long exposed to electric shocks, unite, and produce nitrous acid. Philos. Trans. Vols. LXXV. and LXXVIII.
Azote is one of the most abundant elements in nature, and combined with calorique or heat, it forms azotic gas or phlogistic air, and composes two thirds of the atmosphere; and is one of the principal component parts of animal bodies, and when united to vital air or oxygene produces the nitrous acid. Mr. Lavoisier found that 211/2 parts by weight of azote, and 431/2 parts of oxygene produced 64 parts of nitrous gas, and by the further addition of 36 parts of oxygene nitrous acid was produced. Traité de Chimie. When two airs become united so as to produce an unelastic liquid much calorique or heat is of necessity expelled from the new combination, though perhaps nitrous acid and oxygenated marine acid 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 wove
160 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 askance
180 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 the decomposition of vegetable bodies is perpetually presented to our view; the waters oozing from all morasses are chalybeate, and deposit their ochre on being exposed to the air, the iron acquiring a calciform state from its union with oxygene or vital air. Where thin morasses lie on beds of gravel the latter are generally stained by the filtration of some of the chalybeate water through them. This formation of iron from vegetable recrements is further evinced by the fern leaves and other parts of vegetables, so frequently found in the centre of the knobs or nodules of some iron-ores.
In some of these nodules there is a nucleus of whiter iron-earth surrounded by many concentric strata of darker and lighter iron-earth alternately. In one, which now lies before me, the nucleus is a prism of a triangular form with blunted angles, and about half an inch high, and an inch and half broad; on every side of this are concentric strata of similar iron-earth alternately browner and less brown; each stratum is about a tenth of an inch in thickness and there are ten of them in number. To what known cause can this exactly regular distribution of so many earthy strata of different colours surrounding the nucleus be ascribed? I don't know that any mineralogists have attempted an explanation of this wonderful phenomenon. I suspect it is owing to the polarity of the central nucleus. If iron-filings be regularly laid on paper by means of a small sieve, and a magnet be placed underneath, the filings will dispose themselves in concentric curves with vacant intervals between them. Now if these iron-filings are conceived to be suspended 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 easy to foresee that the iron filings would dispose themselves into concentric spheres, with intervals of the circumnatant fluid between them, exactly as is seen in these nodules of iron-earth. As all the lavas consist of one fourth of iron, (Kirvan's Mineral) and almost all other known bodies, whether of animal or vegetable origin, possess more or less of this property, may not the distribution of a great portion of the globe of the earth into strata of greater or less regularity be owing to the polarity of the whole?]
[And turn to adamant. l. 192. The circumstances which render iron more valuable to mankind than any other metal are, 1. its property of being rendered hard to so great a degree and thus constituting such excellent tools. 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 hot and applied together by hammering, they unite compleatly, unless any scale of iron intervenes; and to prevent this it is usual for smiths to dip the very hot bar in sand, a little of which fuses into fluid glass with the scale and is squeezed out from between the uniting parts by the force of hammering. 3. Its power of acquiring magnetism.
It is however to be wished that gold or silver were discovered in as great quantity as iron, since these metals being indestructible by exposure to air, water, fire or any common acids would supply wholesome vessels for cookery, so much to be desired, and so difficult to obtain, and would form the most light and durable coverings for houses, as well as indestructible fire-grates, ovens, and boiling vessels. See additional 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 to have been in very early times; it is mentioned by Plato, Lucretius, Pliny, and Galen, and is said to have taken its name of magnes from Magnesia, a sea-port of antient Lybia.