6 Professor Thomas Thomson m the Oxides of Bismuth. 



Now 21*4 grains of yellow oxido arc composed of 

 Bismuth, 19*26 

 Oxygen, 2-14 



21-40 

 Hence the suboxide must have been composed of 

 Bismuth, 19-26 or 13-5 

 Oxygen, 0*74 or 051 



20-00 

 There seems no reason to doubt from this analysis, that the sub- 

 oxide of bismuth is a compound of 



1 atom bismuth, 13*5 

 i atom oxygen, 0-5 



14 

 and that its atomic weight is 14. Like other suboxides it does not 

 seem capable of combining with acids. No doubt it is a compound of 



2 atoms bismuth, 27 

 1 atom oxygen, 1 



28 



3. There is another oxide of bismuth which was discovered by 

 Bucholz and Brandes in the year 1818, while engaged in the analysis 

 of a copper ore from Hungary * 



During the analysis they obtained a mixture of silver and oxide of 

 bismuth, which they fused with caustic potash and digested in water. 

 A yellow powder remained, which disengaged chlorine when treated 

 with muriatic acid, and which by exposure to heat was converted (with 

 a loss of weight) into yellow oxide. From these and other experi- 

 ments, which it is needless to state, it is evident that the oxide of 

 bismuth obtained by them, contained more oxygen than the yellow 

 oxide of that metal ; but the conclusion which they drew, that it con- 

 tained 50 per cent, of oxygen, was so inconsistent with every thing 

 known of the constitution of the yellow oxide, that nobody for 

 several years thought of examining into the existence of this new 

 oxide of bismuth. 



Stromeyer repeated their experiment in 1832, and found that when 

 the yellow oxide of bismuth is exposed to a moderate heat when mixed 

 with potash, it becomes brown, and after being washed, a brown pow- 

 der remains, which disengages chlorine when mixed with muriatic 

 acid.t The greatest part of the yellow oxide, however, when thus 

 treated remains unaltered. 



* Schweigger's Journal, Bd. 22, p. 27. 

 t PoggendorfiTs Annalen, Bd. 26, p. 548, and Ann. de Chim. et de Phys., t. 51, p. 267. 



