The more obvious properties of silver are well known. Its specific gravity is 10.4743, nor can it be calcined, or raised in vapour by any heat hitherto tried. It yields only to the nitrous acid and hepatic preparations, whether fluid or in the form of gas. When dissolved, its salts are peculiarly acrid; and coloured, or in some degree reduced by light. Silver itself is so little affected by any chemical agents, that it was preferred as the material of vessels, in which the nicest and minutest chemical experiments were usually made; but as we have now learnt to render platina malleable, the latter is preferred, since copper, the almost necessary alloy of silver, is affected by many bodies which do not act on the metal itself. Van Swieten tells us, that wine kept in a silver vessel in this way, became deleterious.
Nitrous acid or aqua fortis is almost its only solvent; and we thus prepare what is styled the lunar caustic for external use. Pure silver is dissolved in four times its weight of diluted nitrous acid, and the water evaporated. The salt is melted at first with a moderate fire, till the ebullition ceases, then with a stronger, till the matter runs like oil, in which state it is cast in moulds. The caustic thus formed deliquesces in the air, and is inflammable; the silver, during the combustion, separating in a pure state. For its mode of application see Cauteria under Escharotica.
The nitrated solution of silver, previous to the evaporation, should be transparent. It has been used, under the appellation of aqua graeca, to blacken the hair; but must be greatly diluted, and employed with caution.
The lapis infernalis, under the name of nitrated silver, has been given internally by Boyle and Boer-haave. The latter thought highly of its virtues in dropsy when mixed with an equal quantity of nitre, and has told us that it occasioned the discharge of water in large quantities. Modern practice has recommended it in epilepsies, and angina pectoris. We have already had occasion to remark that all metals are apparently tonics or antispasmodics, and silver is probably of this number From its acrimony it may also prove cathartic, as has been said, but our own experience has been too inconsiderable with this medicine to enable us to recommend it from observation. The dose should not exceed A of a grain: it is perhaps best to begin with 1/6 or 1/8.
Angelus Sala recommended for similar diseases the catharticum lunae, magisterium hydragogum, or dejectorium. This was a filtrated solution of nitrated silver crystallized. Of this salt he gave from six to eight grains, but found it so rough and uncertain that he soon disused it. Of his luna potabilis, recommended in delirium, he has given no formula: but his bezoardicum lunare consisted of equal parts of glass of antimony and calx of silver. Lemery's tinctura lunjf. was made with the impure metal, and owed its chief virtue to the copper with which the silver was alloyed.
Argentum vivum; called also hydrargyria:; a term now used by the college of London, mercurius, liquor metallicus, metallum fluidum, argentum fusum, et mobile, mercurius, chemicorum, vomica liquoris aeterni; aludit; anatris; alambic; alborca unterit; daedalus; al-carith, alecarith, alkaut, ebesmech; fons chemiae; gery-on; guma; ignis; almarkasita; alohar; alohoc; mus-salis; massariam; mater metallorum; ziback; alosat; altaris; quicksilver. Hauy, vol. iii. p. 423.
Its chemical character is which denotes that the inside is pure gold, but the outer part is of the colour of silver, with a corrosive underneath.
Its being a metal has been disputed; but it is now found that at about 40° below 0 of Fahrenheit it becomes solid and malleable. In the Venetian territories are the greatest quantity of mines producing quicksilver; the East Indies, Spain, and Hungary, afford great quantities of it; in China, Japan, and about Montpelier in France, there are mines in which it is found.
It is found in the earth in a fluid form, sometimes so pure as not to require refining, when it is called virgin quicksilver; but most frequently it is mixed with other substances. The most general state in which it is met with in the mines is in sulphureous ores of a red colour, called cinnabar, whose colour is deeper in proportion to its richness.
From the ore it is separated by washing in water, grinding with vinegar and a little salt, which dissolves the metalline impurities; and by distillation, either alone or with the addition of lime, potash, or iron filings.
The people who work in the quicksilver mines soon die: when first affected they are seized with tremors, after which a salivation comes on, their teeth drop out, and pains of the whole body, particularly of the bones, seize them.
Hippocrates does not seem to have been acquainted with this mineral; Aristotle and Dioscorides rank it amongst poisons; Galen says that it is corrosive; Mes-sue, the Arabian, was the first who used it medicinally, and he only applied it in the form of an ointment in cutaneous distempers. Avicenna observes that it maybe swallowed crude, and that it passes through the body. About the end of the thirteenth century it was introduced into Europe as a medicine, but not esteemed a safe one until the venereal disease was found to yield to its efficacy. The first internal mercurial medicine which gained real credit was the pilul. Barbarossae, which was composed of quicksilver, rhubarb, and musk. The term quack, originally quacksalber, was a name of this metal, and applied to the irregular indiscriminate use of it.
It is the heaviest of all bodies except gold. Mercury-is to gold nearly as 3 to 4; and to water as 13.5681 to 1.0000.