Cuprum Pharm. Lond. Cuprum five Venus Pharm. Edinb. Copper: a reddish metal, nearly nine times specifically heavier than water; requiring for its fusion a strong white heat, and calcining by a continuance of a weaker red heat into a dark reddish powder; contracting, from long exposure to the air, a greenish rust; solu-ble in all acids and in volatile alkaline spirits, and exhibiting, when dissolved, a blue or green colour, or a colour composed of the two. Volatile spirits, in particular, receive from a small proportion of it a beautiful deep blue; and if added to solutions of it made in acids, when so far diluted as to appear almost or altogether colour-less, change them immediately to the same fine colour. If a piece of bright iron be immersed in the acid solutions, the acid quits the copper to attack the iron; and the copper, in its separation from the menstruum, adheres to the iron, which soon appears covered with a cupreous coat. On these principles, very minute quantities of copper, dissolved in liquors, may be readily discovered.

(a) Hiftoire dt l'acad. roy. des scienc, dc Paris, pour l'ann. 1719.

There are considerable mines of copper in England, Sweden, Germany, and many other parts of the world. The ores are often, wholly or in part, of beautiful blue or green colours like those of the solutions: all the mineral stones, tinctured with these colours, are supposed to receive them from this metal. Most of the ores abound with sulphur: which this metal very strongly retains, and which is difficultly sepa-rated by repeated calcinations and fusions.

Pure copper, in its metallic state, or calcined by fire, appears to be indissoluble, and of no considerable effect, in the bodies of animals. There are instances of pieces of copper having been swallowed, and lying long in the bowels, without seeming to act any otherwise than by their bulk or figure.

Dissolved in the nitrous or marine acids, and cryslallized or exsiccated by heat, it proves a strong caustic. These preparations, particularly that with the nitrous acid, were formerly some-times made use of in this intention; but have long been laid aside, on account of their great disposition to liquefy.

Combined with the vitriolic acid, or with the acids of the vegetable kingdom, or corroded by the air, it acts, when externally applied, as an efficacious detergent and a gentle escharotic; when taken internally, as a virulent emetic and cathartic. Some have ventured on small doses of these preparations, as quick emetics, for procuring immediate evacuation where poisonous substances have been swallowed: but that end may surely be obtained by less dangerous means, A more particular account of these preparations is given under their respective names, aerugo and Vitriolum.

A saturated solution of the metal in volatile spirits is recommended by Boerhaave in disorders proceeding from an acrid, weak, cold, phlegmatic cause. He says, that if three drops be taken in the morning with a glass of mead, and the dose doubled every day to twenty-four drops, it proves attenuating, warming, and diuretic: that by this medicine he once cured a confirmed afcites, though in other cases of the same kind it failed: that it is the only preparation of copper which does not prove emetic; and that, as it does no harm, it may be tried with safety (a). It is probable, that this preparation differs from the preceding only in containing less copper, the quantity which volatile spirits dissolve being extremely small; and that in considerable doses, it would exert the same virulent operation with the other solutions or soluble preparations of this metal. *A solid preparation of this kind made by rubbing together in a glass mortar two parts of blue vitriol and three of the volatile falt procured from sal ammoniac, till all effer-vescence has ceased, and then gently drying the concrete, is ordered in the last Edinburgh pharmacopoeia. It has frequently been given with success in epileptic and convulsive disorders.

A tincture, differing little in its cupreous impregnation from that made with volatile spirits, is used in the shops as an external detergent, and for consuming specks or films of the eyes. This is prepared with a solution offal ammoniac in lime-water, in the proportion of a dram† or four scruples‡ of the falt to a pint of the liquor; which solution is tinged of a sapphire blue colour by (landing for some days with some flips of copper or in a copper vessel †, or by the addition of eight grains of verdigris.

(a) Element a chemiae, process. 192. & Prax. med. torn. v. A 174.

Cuprum am-moniacum Ph. Ed.

Copper vessels, in certain circumstances, give a taint to almost all kinds of liquors, even to pure water; more especially if they have not been thoroughly cleansed from the rust which they contract by lying exposed to a moist air: in certain circumstances, however, they appear to resist even liquors of considerable acidity. Mod of the vegetable acids, so long as they are kept boiling in copper vessels, have little or no action on the metal; though in a gentle heat, or in the cold, they become in a short time impregnated with its ill taste and with its pernicious qualities, corroding it chiefly at the surface of the liquor: if the metal is only moistened and exposed to the air, it is corroded more speedily; and sooner still if exposed to the vapours of the acid. The most acid syrups are prepared by the confectioners, by boiling in copper ves-sels kept perfectly clean, without receiving any hurtful impregnation; whereas the far less acid liquor, that rises towards the end of long protracted distillations of simple waters, corrodes, in its passage through the copper head, in the form of vapour, so much of the metal as to prove emetic.

Brass is a combination of copper with the metallic part of calamine, that is, with zinc, a metallic body still easier of dissolution than the copper itself. The two metals, nevertheless, form by their coalition a new compound, which does not rust in the air, or dissolve in vegetable acids, or calcine in the fire, near so soon a* either of them separately.

Aq. cupri ammoniat. † Pb. Lond.

Aq. sapphirin.

‡ Pb. Ed.