NICKEL. 87 



H. Sainte-Claire Deville : 



100 parts fused nickel, containing three-tenths per cent, 

 silicon and one-tenth per cent, copper, gave 262 parts anhy- 

 drous, yellow nickel sulphate, " corresponding to the atomic 

 weight as given by Berzelius." [Annal. de Chim. et de Phi/s., 

 (3,) 46, 1856, 182.) 



R. Schneider : 58.05 (O = 16) ; 362.8 (0 =100). 



Determined from four analyses of the oxalate. The car- 

 bon determinations were made by the ordinary method of 

 organic analysis, because some hydrocarbon forms when 

 the salt is decomposed by heat alone. The metal was de- 

 termined by heating a known weight of the salt first in air 

 and then in a current of oxygen, and subsequent reduction 

 by hydrogen. In the preparation of the salt the usual pre- 

 cipitate with ammonium sulphide was washed with dilute 

 chlorhydric acid, and the cobalt separated w^ith barium car- 

 bonate and chlorine. From the nickel salt obtained the 

 oxalate was precipitated with oxalic acid. The number is 

 the mean of four analyses; extreme difference, 0.082 for 

 = 8. [Poggend. Ann. 101, 1857, 396.) 



C. Marignac : 59 (0 = 16). 



Marignac made two analyses of the sulphate by decom- 

 posing the salt by heat. The decomposition is perfect. To 

 avoid errors arising from possible reduction of a portion of 

 the oxide, it was moistened with nitric acid, and recalcined 

 at a moderate temperature. The results obtained were Ni 

 =: 29.2 and 29.5. The sulphate was purified by recrystalli- 

 zation. He also made experiments on the chloride by titra- 

 tion with argentic nitrate, according to Pelouze's modifica- 

 tion of Gay-Lussac's method. Three such analyses gave 

 from 29.4 to 29.5. In one experiment he also evaporated 

 the nickel nitrate, after filtering ofl' the argentic chloride, 

 and converted it into oxide by heat. This experiment gave 

 Ni = 29.64. The chloride, whether it be distilled or cal- 

 cined with ammonium chloride, is apt to leave an insoluble 

 residue the weight of which must be deducted. S = 16 ; 

 Ag = 108 ; CI = 35.5. {Bibl. Univ. Arch, des Sciences, (2,) 

 1, 1858, 375.) 



J. Dumas : 59.028 (0 = 16). 



The number is the mean result of five experiments on 

 the titration of the chloride with argentic nitrate ; ex- 



