15' 



32 



17 



10 



25 



1 823 .] Mr, R. Phillips's Anali/sis of Sulphate of NickeL 439 



and I afterwards received some good crys- 

 tals of it from Mr. Cooper, as a double salt. 

 The primary form is an oblique rhombic 

 prism. 



PonM,orM' 102° 



P on e, or e' r 154 



Pone' 116 



M on M 109 



Monk 125 



Sulphate of Nickel and Zinc. 



Observing the similarity of the forms of one of the sulphates 

 of nickel and of the sulphate of zinc, Mr. Phillips dissolved 

 equivalent proportions of the two salts in water, and obtained 

 from the solution a new salt, having the same form and measure- 

 ments as the crystals which had been dissolved. I have 

 attempted to cleave several crystals of this double salt, but 

 without discovering any decided cleavage planes in any di- 

 rection. 



Article X. 



Analysis of the Sulphates of Nickel, described in the preceding 

 . Paper. By R. PhiUips, FRS. L. and E. &c. 



Sulphate of nickel has been several times analysed; my 

 intention, therefore, in subjecting this salt to examination was 

 to attempt a discovery of the causes to which the different crystal- 

 line forms it presents are referable. The composition of sulphate 

 of nickel is stated as follows by 



Dr. Thomson. M. Berzelius. Mr. Brande. 



Sulphuric acid .... 29-2 28-51 28-25 



Oxide of nickel. .* 24-8 26-72 26-50 



Water 46-0 44-77 45-00 



100-0 



100-00 



99-75 



One hundred grains of the crystals of this salt, in the form of 

 rhombic prisms, were dissolved in water, and decomposed by 

 nitrate of barytes ; the sulphate of barytes obtained, taking the 

 mean of two experiments, weighed 83*08 grains, equivalent to 

 28-16 of sulphuric acid. 



Of the same salt 100 grains were decomposed by soda, and 

 the precipitated oxide of nickel, after the requisite washing, was 

 dried and ignited. It weighed 26-3 grains. I repeated this 

 experiment, and obtained rather more oxide, but I had afterwards 

 reason to suppose that the sulphate of soda formed had not been 



