398
ELEMENTS OE MATEIIIA MEDICA.
anrl are connected by curv ed earthen tubes with the receiving pots whichLire on the outside of the furnace. At La Vendee neither vessels nortubes are used: the ore is placed on the bed of a reverberatory furnace, inwhich is an aperture to allow of the passage of the fused sesquisulpliurctwhich flows into a receiving vessel placed externally to the furnace.(Dumas, Traite de Chimie, iv. 1(10.)
Properties. —The fused sesquisulphuret (called common or crude anti-mony) occurs in commerce in roundish masses, called loaves or cakes:these when broken present a striated crystalline appearance, a dark steelor lead grey colour, and a metallic brilliancy. The commercial sesqui-sulphuret is opaque, tasteless, odourless, brittle, easily pulverizable, andhas a sp. gr. of about 4’6. Its powder is black, but that of pure sesqui-sulphuret is reddish black. It is a little less fusible than metallic anti-mony. It is volatile but cannot be distilled, and it appears to be par-tially decomposed by heat, for when heated in an earthen crucible for anhour it loses from 10 to 20 per cent, of its weight (Berthier, Traite desEssais, ii. 490). By roasting it is converted into antimony-ash or cinisantimonii (a mixture of antimonious acid and sesquioxide of antimony,with more or less unbumed sesquisulphuret: Liebig , Handwbrterb. deChemie, i. 419) and sulphurous acid, the latter of which escapes. Whenreduced to a very fine powder by levigation and elutriation it constitutesthe antimonii sulphuretum pneparatum of the Edinburgh , Dublin, andUnited States Pharmacopoeias .
Characteristics.— It fuses and is dissipated before the blow-pipewith the smell of sulphurous acid and the formation of a white smoke.Digested in hydrochloric acid it evolves liydrosulphuric acid, and formsa solution of sesquichloride of antimony, which produces a whitish pre-cipitate ( powder of Algaroth, or oxychloruret of antimony) with water,and an orange red one with liydrosulphuric acid. If a current of hydrogengas be passed over heated sesquisulphuret of antimony, metallic anti-mony and liydrosulphuric acid gas are obtained : the metal decomposesnitric acid and yields a white powder : it readily dissolves in nitro-liydrochloric acid.
Composition.— Sesquisulphuret of antimony has the following com-position :—
Antimony. 1 ... 65 ... 73 . . 72'8 . . . 73’77
Sulphur.If . . . 24 . . . 27 . . 27'2 . . . 26'23
Sesquisulphuret of Antimony 1 . . . 89 . . . 100 . . lOO'O . . . lOO'OO
Impurities. —The crude antimony of commerce is rarely, if ever, quitepure. It frequently contains the sulphurets of iron, lead, arsenicum, andcopper, and on this account is not adapted for medicinal use. Whenpure it is completely soluble in hydrochloric acid: but when mixed withsulphuret of arsenicum this remains undissolved, and may be detected byreducing it with a mixture of charcoal and carbonate of soda {vide p. 378.)If the hydrochloric solution be diluted with water (so as to precipitatethe greater part of the antimony), and filtered, the presence of lead, iron,or copper, may be determined by the appropriate tests for these metals,hereafter to be mentioned.
Physiological Effects, (a.) On animals. —Rayer {Diet, de Med. etChir. Pratiq. iii. 54) introduced half an ounce of it into the cellular