196 SULPHURETS. 



together, or when a salt of cadmium is precipi- 

 tated by sulphuretted hydrogen the sulphuret 

 has a fine yellow colour. In a white heat it 

 melts, and crystallizes in cooling ; and the crys- 

 tals are a fine lemon yellow. It dissolves in mu- 

 riatic acid, without depositing any sulphur, but 

 with the evolution of sulphuretted hydrogen gas. 

 Hence, its constituents are 



1 atom cadmium . 7 



1 atom sulphur . 2 



Tin, 16. Sulphuret of tin. Three sulphurets of tin 



are known. 



(1.) Protosulphuret of tin is obtained when 

 sulphur and tin are heated together in a close 

 vessel. To saturate the tin with sulphur, the 

 process should be repeated a second time, mix- 

 ing the sulphuret intimately with a new portion 

 of sulphur, and exposing the mixture to a full 

 red heat, to drive off all excess. The sulphuret 

 thus formed has the metallic lustre, a bluish grey 

 colour, and fibrous and crystalline appearance. 

 It dissolves in concentrated muriatic acid, with- 

 out depositing any sulphur ; and the gas extri- 

 cated is totally absorbed by caustic potash. 

 Hence the constituents of this sulphuret are 



