NICKEL AND COBALT. 165 



hydrogen, and obtained values ranging from 58.2 to 58.6, 

 when = 16. Their results were not very concordant, and 

 the lowest was probably the best. 



In 1856, incidentally to other work, Deville* found that 

 100 parts of pure metallic nickel yielded 262 of sulphate ; 

 whence Ni = 59.15. 



To none of the foregoing estimations can any importance 

 now be attached. The modern discussion of the atomie 

 weights under consideration began with the researches of 

 Schneider t in 1857. This chemist examined the oxalates 

 of both metals, determining carbon by the combustion of 

 the salts with copper oxide in a stream of dr}' air. The 

 carbon dioxide thus formed was collected as usual in a 

 potash bulb, which, in weighing, was counterpoised by a 

 similar bulb, so as to eliminate errors due to the hygroscopic 

 character of the glass. The metal in each oxalate was esti- 

 mated, first by ignition in a stream of dry air, followed by 

 intense heating in hydrogen. Pure nickel or cobalt Avas 

 left behind in good condition for weighing. Four analyses 

 of each oxalate were made, with the results given below. 

 The nickel salt contained three molecules of water, and the 

 cobalt salt two molecules : 



Mean, 44.09S, =t: .027 



The following percentages of nickel were found in this 



salt: 



29.107 

 29.082 

 29.066 

 29.082 



Mean, 29.084, dz .006 



*Ann. Chim. Phys., (3,) 46, 182. 1856. 

 f Poggend. Annal., loi, 387. 1857. 



