[ 193 J 



XXXIX. Examination of different V roc esses for olfain'ma 

 the Separation of ISi itkel from Cobalt. By Christian 



FllEDEKIC BuCHOLZ*. 



J- HE want of pure nickel and oxide of cobalt determined 

 nie, for the sake of obtaining it, not onlv to make experi- 

 ments of my own invention, but also to repeat difrerent pro- 

 cesses proposed for the, same object. As it happens but 

 loo frequently that some accidental circumstances in expe- 

 riments are omitted by their authors, or that we are unable, 

 from ignorance of certain indicative characters, to employ 

 the most scrupulous exactness in examining the products 

 obtained,— a circumstance which makes the process we fol- 

 low give evidence of its own insufficiency, — it will be agree- 

 able to chemists to find here an abridged explanation of my 

 experiments on this matter: the results they have yielded 

 me, added to those which the labours of other chemists 

 have afforded them, will point out the most convenient 

 way to the end proposed, while they save unfruitful trouble 

 and expense. 



A. The able chemist Hermstadt had proposed for making 

 the separation of oxide of cobalt from the oxide of nickel^ 

 a method which consists in dissolving in ammonia the ni- 

 trate or the sulphate of cobalt impregnated with nickel, and 

 to expose the solution to a single evaporation. I proposed 

 to try this process with the contrary desion. 



1. An ounce of ore of earthy cobalt was therefore dis- 

 solved by heat in four ounces of nitric acid of the specific 

 gravity of 1-220, in which had been put an equal quantity 

 of water, which gave in residue three gros of oxide of ar- 

 senic under the form of little crystals. The solution, di- 

 luted with a portion of water, was'of a dingey green colour. 

 It was filtered, and diluted with a greater quantity of water, 

 and a little oxide of bismuth was separated. Caustic am- 

 monia was added in excels until it made no more sensible 

 solution in the obtained precipitate. That whi.h was not 

 dissolved, being of a reddish white, was a composite of the 

 arseniate of cobalt with a little oxide of bismuth and oxide 

 of iron. The filtered solution, which was of a beautiful 

 blue, was evaporated in a gentle heat, by which means 

 about two gros of a beautiful clear green matter was depo- 

 sited, which on examination was found to be an oxide of 



♦ From the New Umccrsul Journal of Chanuliu of Mes»r«. Bucholz, Crell, 

 Ac, vol. iii. 



Vol. '2?,. No. 91 . DU. 1805. N uickel 



