SALTS OF NICKEL. 333 



11. SALTS OF NICKEL. 



Only the protoxide of nickel, as far as is 

 known, combines with bases. These salts have 

 hitherto been very imperfectly investigated. 



1. Sulphate of nickel. This salt has a beauti- Sulphate, 

 fill grass green colour, and crystallizes in two 

 forms: 1. Rhombic prisms, exactly similar to 

 those of sulphate of zinc. 2. In square prisms. 

 This last is the form which they assume when 

 there is an excess of acid in the solution; I 

 have analyzed both without finding any dif- 

 ference between them. Mr. R. Phillips found 



a very slight excess of acid in the square prisms, 

 which was probably only mechanically lodged 

 between the plates of the crystals. The consti- 

 tuents of this salt are 



1 atom sulphuric acid 



1 atom protoxide of nickel 



7 atoms water 



17-125 



2. Nitrate of nickel. This salt crystallizes in Nitrate, 

 four-sided oblique prisms ; it has a green colour, 



not quite so fine as that of sulphate of nickel. 

 I do not find it to undergo any alteration though 

 left exposed to the air. Its composition, ac- 

 cording to the analysis of it made in my labora- 

 tory, is as follows : 



1G 



