I4# Crocus of Antimony-^ -&c. [Book VL 



a faline part above of a paler colour. The former is 

 the object of the operation, and is called crocus of 

 antimony. The College direct a fmall quantity of 

 fea fait to be ufed in this preparation, which promotes 

 fufion, and probably increafes the activity of the com- 

 pofition. 



Fixed alkalies have a great degree of activity with 

 crude antimony, on account of their attraction for the 

 fulpkur. The eafieft mode of combining them is 

 fufion. The firft effect of the alkali is to combine 

 with the fulphur, and form a liver of fulphur, which 

 by a continuance of heat feems to diffolve the recnilus 



> D 



of antimony. This compound is readily difTolved by 

 boiling water, and if we add to the folution an acid, 

 the metallic matter and fulphur are depofited of a 

 yellow colour. This fubftancc, however, which is 

 called fulphur antimonii prsecipitatum, may be ob- 

 tained in an eafier manner, by boiling crude antimony 

 in a folution of alkali, and then precipitating the ful- 

 phurated antimony with the vitriolic acid. 



The antimonium tartarifaturrij or tartar emetic, may 

 be obtained either by the ufe of the crccus or the glafs 

 of antimony. The former is, however, preferred by 

 the London College, who adopt the following pro- 

 cefs : Take of crocus of antimony powdered one pound 

 and a half, cryftals of tartar two pounds, diftilled water 

 two gallons ; boil them in a glafs veflel about a 

 quarter of an hour ; filter the liquor through paper a 

 and fefit by to cryftallize. Tartar emetic confifts of 

 the acid of tartar united to vegetable alkali and anti- 

 mony paitially calcined. 



'The pulvis fcntimonialis of the pharmacopoeia, 

 which is thought to be nearly the fame as James's 

 powders, is prepared by expoflng equal parts of anti- 

 imonyand hartfliorn (havings to a moderate heat, with 

 H fee acccfs of air. With refptct to the peculiar 



merits, 



