NICKEL AND COBALT. 301 



Cohalt. 



CoO. 



6.3947 

 6.6763 

 5. 6668 

 2.9977 

 8.7446 

 3.2625 

 6.3948 

 8.2156 

 9.4842 

 9.9998 



Shortly after the discovery of nickel carbonyl, NiC^O^, Mond, Langer, 

 and Quincke* made use of it with reference to the atomic weight of 

 nickel. The latter was purified by distillation as nickel carbonjd, then 

 converted into oxide, and that was reduced by hydrogen in the usual 

 way. 



NiO. Ni. Per cent. Ni. 



.2414 .1896 7^-542 



.3186 .2503 78.562 



.3391 .2663 78.531 



Mean, 78.545, ± .0061 



Schutzenberger's experiments,! published in 1892, were also few in 

 number. First, nickel sulphate, dehydrated at 440°, was calcined to 

 oxide. 



3.505 grm. NiSO^ gave 1. 690 NiO. 48.217 per cent. 



2 6008 " 1. 2561 " 48. 297 " 



Mean, 48.257, ± .027 



Second, nickel oxide was reduced in hydrogen, as follows : 



1.6865 grm. NiO gave 1.3245 Ni. 78.535 per cent. 



1.2527 " .9838 " 78.533 " 



Mean, 78.534 



In one experiment with cobalt oxide, .3.491 grm. gave 2.757 Co, or 

 78.975 per cent. In view of the many determinations of this ratio by 

 other observers, this single estimation may be neglected. The experi- 

 ments on nickel sulphate, however, should be combined with those of 

 Marignac and Baubigny, giving the latter equal weight with Schutzen- 

 berger's, thus: 



*Journ. Chem. Soc, 57, 753. 1890. 

 tCompt. Rend., 114, 1149. 1S92. 



