C. Keferstein on White Copper. ]2l 



monia, by which the precipitate first occasioned was almost 

 entirely redissolved ; the fluid however still appeared a little 

 turbid, and was filtered on that account, by which a residuum 

 of 1 grain was found, proving to be oxide of nickel, which 

 had probably escaped the action of the ammonia, and which 

 must be reckoned as 0*787 of metallic nickel. 



C. 



The ammoniacal liquid B was again supersaturated with 

 nitric acid. Although there are different methods of separat- 

 ing oxide of nickel from oxide of copper, yet that by which 

 the copper is first separated by iron, or that by which the 

 oxide ot nickel is precipitated by caustic potassa, has not en- 

 abled us to effect the separation of those oxides, so perfectly 

 as the method in which sulphuretted hydrogen is employed : 

 for this reason the acidulated fluid was precipitated by sul- 

 phuretted hydrogen, and a precipitate of bi-sulphuret of cop- 

 per of 132-8 grains was obtained, indicating 88 grains of me- 

 tallic copper. 



D. 



The fluid C was now heated, and caustic potash added to it, 

 by which means 10-25 grains of anhydrous oxide of nickel 

 were obtained =7-966 grains of metallic nickel. The fluid 

 separated from the oxide of nickel now contained no other 

 substance, except a trifling portion of copper, which does not 

 appear to be always completely separated when a solution of 

 that metal is supersaturated. 



E. Results. 

 The ore examined, therefore, according to the above analysis, 

 contains 



Copper . . . (C) ... 88-000 

 Nickel (B 0-787 + D 7-966 . = 8-753 

 Sulphur, with a little antimony (A) 0*750 

 Silex, clay, and iron (A) . . . 1-750 



99-253 

 This ore, in its pure state, appears to be nothing but an 

 alloy of copper and nickel. The other substances are pro- 

 bably to be considered as appertaining to the slag. 



It yet remains to be observed that this cupreous mineral, 

 of a bright copper colour, exists in small globules, and also in 

 large roundish pieces, in plates and similar forms, in a black 

 slag-like mass ; — the analysis was made with such pieces as 

 had been purified in the most careful manner from the slags, 

 but the black slag itself likewise contains copper and nickel. 



Vol 69. No. 310. Feb. 1824. Q Report 



