part m. Metallic Preparations. — Antimony.

643

red in adopting the same preparation of antimony for the form-ation of this important salt.

Qualities. Tartrate of antimony and potass is procuredin small regular tetrahedral crystals, of a white colour, ino-dorous, nearly insipid, and efflorescent. It should be boughtin crystals; and to ascertain its purity, a few of these shouldbe put into a dilute solution of ammonia: sulphuretum, whentheir goodness may be judged of by the quantity of orange-coloured precipitate that forms. If the crystals deliquesce, itspurity may be suspected. It is soluble in about 15 parts ofwater at 60°, and in 2 parts at 212°, forming, when the salt isgood, a perfectly clear, transparent solution. It is spontane-ously decomposed when kept in aqueous solution; and is alsodecomposed by heat, the strong acids, the alkalies and alkalinecarbonates, the earths, hydrosulphurets, some of the metals,and by the decoctions or infusions of many bitter and astrin-gent vegetables, as those of Cinchona bark, rhubarb, galls,and catechu; with which, therefore, it ought never to beconjoined in extemporaneous prescription. According to theanalysis of Thenard', its constituents are 35 - 4 of tartaric acid,3 9 "6 of oxide, 16'7 of potass, and8 - 3 of water; but these pro-portions must necessarily vary with the different modes of pre-paration.

Medical properties and uses. — This triple salt is emetic,diaphoretic, expectorant, alterative, and rubefacient ; and itoperates also sometimes as a cathartic. It is certainly themost important of the antimonial preparations, and whenthe dose is properly apportioned may supersede the use of allthe others. It is given as an emetic in the commencement offevers, in doses of from one to two grains dissolved in distilledwater. To obtain its diaphoretic effect, the dose is from one-sixteenth to one-fourth of a grain ,■ and the same or a smallerdose combined with squill, ammoniacum, and camphor, re-peated every three hours, operates as an expectorant. Invery minute doses combined with calomel, it is a powerful al-terative in many cutaneous diseases; and when jiij. of it aretriturated with ^j. of lard into an ointment, r.id applied to theskin, it occasions a local pustular eruption, and hence hasproved very serviceable in mania, white swellings, and deep-seated inflammations as a counter irritant.

When taken in large doses, tartar-emetic acts as a corrosivepoison, producing violent vomiting, hiccough, a sensation ofburning in the stomach, colic, hypercatharsis, syncope, dif-ficult respiration, convulsions, and death. The treatment,when assistance is demanded in time, consists in carrying thepoison out of the stomach by bland, oily liquids freely taken;

1 Annates de Chimie, xxxviii. 39.1- T 2