ON ARSENIC 133 



SECTION XXXI. UPON BISMUTH. 



(a) Bismuth, during digestion with acid of arsenic, is 

 covered with a white powder ; water precipitates the solution. 

 The powder consists of calcined bismuth and acid of arsenic. 

 (b) One part of bismuth was distilled with three parts of dry 

 acid of arsenic. The mass entered into fusion, the bismuth 

 was calcined, but remained at the bottom undissolved ; a 

 little arsenic rose into the neck ; after the retort became cool, 

 water was poured upon the residuum, which dissolved the 

 acid, but the calx of bismuth remained unchanged, (c) 

 Bismuth dissolved in nitrous acid was precipitated by the 

 acid of arsenic. This precipitate, as well as the calx (6), are 

 very difficult of fusion ; but on adding a little charcoal 

 powder they melt immediately ; the arsenic goes off in 

 vapours, and the bismuth is reduced. 



SECTION XXXII. UPON REGULUS OF ANTIMONY. 



(a) During its digestion with the acid of arsenic, a 

 quantity of white powder is separated from the regulus of 

 antimony. If a little of the clear solution be dropped into 

 water, a white powder is likewise precipitated, which consists 

 of calcined regulus of antimony and of acid of arsenic. It 

 is soluble only in muriatic acid, and may be again precipitated 

 by water. (&) One part of regulus of antimony was distilled 

 with three parts of arsenical acid; as soon as the mass 

 entered into fusion, an inflammation ensued, and regulus of 

 arsenic and a little red sublimate were sublimed. A little 



I volatile sulphureous acid came over into the receiver. The 

 residuum was boiled in water, upon which the acid was 

 dissolved ; a white shining powder remained behind, which 



