KTCKEL AND COBALT, HCX 



The fcarcUf of this beautiful mineral has precluded me Dcfcr'ption ani 

 from operating on fuch a Cufficient quantity, as a regular and ^in^ral from 

 rigid analyfis required. ComwalJ. 



The, fubfiance, wliich is held in folulion by ammonia, has 

 feme peculiar properties that feem to diftingoifh it from 

 uranium. And if this mineral be the uran-glimmer, I have 

 certainly dete6ied the oxide of lead, lime, and filica in it, 

 which have not hitherto been confidered as ingredients of 

 that foflil. The green cryttals riiti'er in no refpefl from 

 tlie yellow, except in containing a little of the oxide of 

 copper. 



XVIL 



Examination of dijftrevt Methods nf feparativg Nickel from Co' 

 bait. %M. C. F. BucHOLz.* 



A HE want of nickel and cobalt in a (late of purity indiyced 

 M. Bucholz, to make experiments himfelf on the means of 

 procuring them, and to repeat thofe of others. 



A. The able chemift Hermftadt propofed to feparate oxide M. Bucbolx re- 

 ef cobalt and oxide of nickel, by dlfTolving the nitrate or ful- ^"cit's mcihod, 

 phate of cobalt, impregnated with nickel. In ammonia; and 

 expofing the folution to a fingle evaporation. This M. Bu- 

 cholz tried in the following manner, for the reverfed pur- 

 pofe. 



1, An ounce of cobalt ore (cobalt Jpeife) was diflblved with One oz. eotalt 

 heat in four ounces of nitric acid of the Ipecific gravity 1,220. rJtric' acid!^** "* 

 and mixed with an equal quantity of water; which produced Depofus 3 drains 

 a refidue of three drams of oxide of arfenic, In the form of "^^ arfemc. 

 fmall cryftals. When the folution mixed with half the quan- The folution^ 

 tity of water, coloured of a dull green, had been filtered and j^jt^j depofits'I 

 diluted with a great quantity of water, it depofited a little of little bifmuth 

 the oxide of bifmuth, Cauftic ammonia was then mized with^''^^^';^ ammo- 

 it to excefs, until no farther apparent folution took place of nia added. 

 the precipitate obtained. That which was not diflblved, of ^J^^^"f^^°|.^_'* 

 a dull reddifti white, was a compofiiion of arleniate of cobalt niate of cobalt, 



with a little of the oxide of bifmuth, and the oxide of iron. ^^'5^ oxides of 



' bifmuth and 



Iron. 

 • Bucholz, &c. Journal cffChera. III. p. 2. 



The 



