440 Mr. R, Phillips's Analysis of Sulphate of Nickel, [Dec. 



thoroughly separated by washing. If we then consider the 

 deficiency of the weight, as water of crystallization, the salt is 

 composed of 



Sulphuric acid 28*16 



Oxide of nickel 26-30 



Water 45-54 



100-00 



If we suppose an atom of oxide of nickel to be = 37, the 

 composition of the salt will be : 



Sulphuric acid 28-57 



Oxide of nickel 26-43 



Water 45-00 



100-00 



These proportions, it will be observed, do not differ much 

 from those stated by M. Berzelius and Mr. Brande. 



One hundred grains of the square prisms of sulphate of nickel 

 were treated as above described : the mean of the experiments 

 gave 88*65 of sulphate of barytes, equivalent to 30 of sulphuric 

 acid; the oxide of nickel amounted to 26-2 grains. This salt, 

 therefore, consists of 



Sulphuric acid 30-0 



Oxide of nickel 26-2 



Water 43-8 



100-0 

 The excess of sulphuric acid contained in the square prisms, 

 amounting to less than 2 per cent, cannot, I think, be consi- 

 dered as existing in a state of combination, but merely of 

 mixture ; and as such, we should not expect that it would 

 influence the crystalline form of the salt. 



It will be proper to state, that the result of Mr. Cooper's analy- 

 sis agreed very nearly with my own, and that I confirmed the ac- 

 curacy of his observations with respect to the different effects 

 produced on these salts by exposure to the air ; the rhombic 

 prisms lost one atom of water, while 100 grains of the square 

 prisms suffered a diminution of only one-tenth of a grain in 

 weight. 



Mr. Cooper informs me that he has analyzed the sulphate of 

 nickel and potash, and finds that it is composed of 



Sulphuric acid 37*90 



Oxide of nickel 17-54 



Potash 20*48 



Water 24*08 



100-OC 



