362 IRON, NICKEL, COBALT, &c. 



deprived of the whole of its water of crystalliza- 

 tion without losing any of its acid. 

 Sulphate of i. 9-25 grains of anhydrous sulphate of cobalt 



cobalt ana- L 



were dissolved in water, and the liquid mixed 

 with a solution gf I3*%5 grains of chloride of ba- 

 rium. A double decomposition took place ; sul- 

 phate of barytes precipitated, and the clear re- 

 sidual liquid being examined, was not affected 

 by sulphate of soda or muriate of barytes show- 

 ing that it contained neither barytes nor sulphu- 

 ric acid. From this experiment it is obvious, 

 that 9*25 grains of anhydrous sulphate of cobalt 

 contain exactly 5 grains of sulphuric acid : the 

 remaining 4-5 grains must be protoxide of co- 

 balt. Consequently, this salt is composed of 



Sulphuric acid . . 5 

 Protoxide of cobalt . 4-25 



The salt being neutral, and 5 being the atomic 

 Atom of weight of sulphuric acid, 4'&5 must be the atomic 



protoxide . , ,, 



of cobalt weight ot protoxide of cobalt. 



2. When 17'125 grains of crystallized sulphate 

 of cobalt are exposed to an incipient red heat in 

 a platinum crucible, they lose 7*875 grains of 

 their weight. Now, this is equivalent to 7 atoms 

 of water. It is obvious from this experiment, 

 that sulphate of cobalt is composed precisely as 

 sulphate of nickel, or of 



