266 Disulphuret of Bismuth. 



(d) The filtered solution and washings from which carbonate of 

 bismuth had been precipitated, vide (c), was treated with muriate 

 of baryta to precipitate the sulphuric acid, which had been formed 

 by the oxidation of a part of the sulphur by the nitric acid, during 

 the solution of the disulphuret of bismuth. The precipitated sul- 

 phate of baryta was washed, dried, and ignited. It weighed 40 

 grains =5.423 grains of sulphur. 



16.156 



154.945 

 4.899 



176.000 

 The disulphuret of bismuth operated on, weighed 176 grains, and 

 so great a loss as 4.899, equal to about 3 per cent., indicates a solu- 

 bihty of the carbonate of bismuth, either in the water used in wash- 

 ing it, vide (d), or in the carbonate of ammonia used as a pi^ecipi- 

 tant.* Some sulphur was also probably carried off in the fumes of 

 nitrous acid, as sulphurous acid, causing a small loss. 



If we calculate the atomic proportions from the numbers of sulphur 

 and bismuth obtained, there would be 2|^ atoms of bismuth, combined 

 with 1 sulphur, for 9x bis. : 154.945 bis. : : 2 sul. : 16.156 sulphur, 

 whence x—2^. This comes so near to 2 atoms of bismuth to 1 sul- 

 phur, that there can be little doubt that the compound formed by 

 melting 3 bismuth and 1 sulphur, and keeping the mass at a red 

 heat, is a true combination of 



Bismuth, 2 atoms, ----- 18 

 Sulphur, 1 do. - - - - - 2 



20 



* Since the above was written, I find that Stromeyer has noticed the solubility 

 of this carbonate of bismuth in alkaline carbonates. Vide Annales de Chimie et 

 de Physique, Tom. li, p. 272. 



