Stannum Pharm. Land. & Edinb. Trn: a silver-coloured metal, not liable to rust, but losing its brightness in the air; easily flexible, and making a crackling noise in being bent; little more than seven times specifically heavier than water; fusible in a heat far below ignition, and somewhat less than that in which lead melts. Heated till almost ready to melt, it proves extremely brittle, so as to fall in pieces from a blow. Melted, and nimbly agitated at the time of its beginning to congeal (as by shaking in a wooden box rubbed on the inside with chalk it is reduced partly, and by repetitions of the pro-cess totally, into powder. Continued in fusion for some time, and kept stirring with an iron rod, it changes into a dusky calx; which, urged longer in the fire, gains a perfect whiteness, a mark of the purity of the tin. It is corroded by vegetable acids, and renders them turbid and whitish: the nitrous acid pretty readily dissolves it, but soon deposites a part in form of a thick mucilage, especially if the acid has any admixture of the vitriolic: the. vitriolic and marine acids are very difficultly made to act upon it: its most perfect menstruum is a mixture of the marine and nitrous.

(a) See White's cases in Surgery.

(b) See Wilmer's cases in Surgery, and Proffer on the Bronchocele.

Spongia ufta Ph. Lond. & Ed,

Stannum pulveratum

Ph. Lond.

Starnri pulvis Ph Ed,

The principal use of this metal in the present practice is as an anthelmintic: even the flat worms, which too often elude the force of other medicines, are said to be effectually destroyed by powdered tin. The common dose, of the powder is from a scruple to a dram, but Dr. Alston affirms, in the Edinburgh medical essays, that its success depends chiefly on its being given in much larger quantities, as half an ounce or an ounce. It is poslible, that the anthelmintic virtues of tin may proceed, not so much from the pure metal, as from a certain substance of a different nature, which there are grounds to suspect that the purest sorts of tin usually met with, participate of; filings of tin, held in the flame of a candle, emit a thick fume smelling like garlick: Mr. Marggras reports (a), that by gentle dislblution in aqua regis and flow evaporation, he obtained crystals, which on being exposed to the fire, with the addition of some fixt alkaline salt to absorb their acid, su-blimed into a white concrete; and that this exhaled in the fire in fumes of a strong garlick smell, formed with sulphur yellow and red compounds, and whitened copper (see Arsenium), It must be observed, however, that notwithstanding these strong presumptions, not to say proofs, of an arsenical impregnation in tin, the metal taken in substance has not been observed to be noxious, though the fumes which it emits in a red heat are undoubtedly so.

(a) Memoires de l'acad. roy. des sciences de Berlin, torn. iii.

A sparkling gold-coloured preparation of tin, called mosaic gold, is prepared by adding six ounces of quicksilver to twelve of melted tin, pulverizing the mass when grown cold, mixing with it seven ounces of flowers of sulphur and six of sal ammoniac, and subliming in a matras: the mosaic gold is found under the sublimed matter, with some dross at the bottom. This preparation is chiefly valued for its beautiful appearance: as a medicine it is at present little regarded, though formerly held in considerable esteem against hysterical and hypochondriacal complaints, malignant fevers, and venereal dis-orders. It appeared, upon experiment, to be little more than a calx of tin: tin, calcined by itself, gains nearly as much in weight, as it does by being made into mosaic gold; and the mosaic gold, melted with inflammable fluxes, is revived into tin again without suffering much more loss than the simple calx. The volatile ingredients, sal ammoniac, sulphur, and quicksilver, sublime in the process, partly escaping, and partly forming the scorise: great part of the sulphur and mercury are found united together into the form of cinnabar.

A salt of tin is directed to be prepared, from twelve ounces of calx of tin and four of aqua regia diluted with twenty-four of water: after digestion for two days, the vessel is to be shaken, the more ponderous part of the undis-solved calx suffered to settle, the turbid liquor poured off and evaporated nearly to dryness, and the mass further exsiccated on brown paper: to the remaining calx, half the quantity of fresh menstruum is to be added, and the process repeated. Of the virtues of this salt I can say nothing from experience, except that it is in taste very sharp and almost corrosive. Nor do I apprehend the use of calcining the metal, as tin uncalcined dissolves much more easily and more plentifully: the solution is in both cases the same, the fire in the calcination dissipating only the inflammable principle of the tin, which the acid equally does in the solution and evaporation. Hoffman says, that solution of tin is a strong purgative.

Sal Jovis.