188 SULPHURETS. 



drogen gas over red hot lime : water was formed, 

 and the reduced calcium united with the sulphur 

 of the gas. The sulphuret, thus obtained, was 

 composed of 



Calcium ... 2-5 



Sulphur . . . 1-988 



Hence, it is obviously aprotosulphuret composed 

 of 



] atom calcium . . 2-5 



1 atom sulphur . . 2 



4-5 



Berthier formed it by heating anhydrous sulphate 

 of lime in a charcoal crucible : the sulphuret 

 of calcium obtained was white, dissolved com- 

 pletely in water, and was not altered by roasting. 

 Its constituents were 



Calcium . . . 2-5 



Sulphur . . . 1-91 



It was, therefore, a protosulphuret of calcium, 

 like that obtained by Berzelius. 



Barium, 5. Sulphuret of barium was formed by Ber- 

 thier from sulphate of barytes, precisely in the 

 same way as he had obtained sulphuret of calci- 

 um. This sulphuret is white, with grey spots 

 slightly cohering, capable of being kneaded be- 

 tween the fingers, and in crystalline grains. It 

 dissolved completely in water, and the solution 



