196 On the Separation of Nickel from Cobalt. 



tion, was dissolved, discng;!ging much of the oxygenated 

 muriatic acid, on being spread upon paper, and warmed, it 

 showed the colour of a svnipallietic ink well saturated with 

 cobalt; from whence it follows that it was more rich in 

 cobalt liian that collected by precipitation. 



The oxides, collected in a different manner, were dissolved 

 in the nitric and sulphuric acids after becoming grav. I 

 believed that this happened because the oxide of the nickel 

 had been perhaps the hrst dissolved, and because the oxide 

 of cobalt was, at least for the most part, the last remain- 

 ing; which, however, was not confirmed by the experi- 

 ments made on this subject. When exposed to a low red 

 heat, these oxides changed their colour into a blackish gray, 

 and then (as was also the case by the addition of sulphuric 

 acid) they threw down some lesiduum by evaporation of the 

 nitrous acid, which was also separated from it by the addi- 

 tion of an alkaline lixivium. In other respects it acted with 

 ammonia, &c. in the maimer that has already been men- 

 tioned. 



The following is the result of what has been so far 

 stated : 



a. The sulphates and the nitrates of ammoniacal nickel 

 drawn from the ore of cobalt contain always some cobalt 

 in their composition : it is impossible by the process of 

 Hermstadt, modified in the preceding manner, to have the 

 oxide of nickel without a mixture of cobalt. 



I. By partially decomposing the nitrate of ammoniacal 

 cobalt by evaporation, there is obtained an oxide of nickel 

 very rich in cobalt which contains nitric acid, and the oxide 

 of nickel which is found in tliis salt not yet decomposed 

 contains a very small quantity of cobalt. 



B. Dr. Schnaubert has shov/n {Journal de Pharmacle, 

 par Tromsdorlf, vol. :i. no. 2. p. QQ.) a process for ob- 

 taining an oxide of pure nickel; that is, to dissolve the 

 metal of nickel mixed with cobalt, or its oxide already dis- 

 engaged from other substances, in nitric acid, to precipitate 

 it by carbonate of potash, and to expose it to a white heat 

 after washing and drying. In this manner he always ob- 

 tained a yellow oxide, on which he afterwards boiled sul- 

 phuric acid sufficiently strong, which gave him a solution of 

 oxide of nickel of a grass green, while the oxide of cobalt 

 showed itself, in the residuum under a yellow colour. He 

 proved the purity of the sulphate of nickel prepared in this- 

 way, by the property which ammonia had to precipitate it 

 of a clear green colour, and, when added in excess, to rc- 

 dissolvc it of a beautiful dark blue colour. This argument 

 - ■• • - will: 



