428 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



These percentages are practically identical, and lead to essentially the 

 same mean value for each atomic weight, namely, 



Ni =58.742 

 Co =58.738 



In a later paper Eussell ' confirmed the foregoing results by a different 

 process. He dissolved metallic nickel and cobalt in hydrochloric acid 

 and measured the hydrogen evolved. Thus the ratio between the metal 

 and his ultimate standard was fixed without the intervention of any 

 other element. About two-tenths of a gramme of metal, or less, was 

 taken in each experiment. The data obtained were as follows; the last 

 column giving the weight of hydrogen, computed from its volume, yielded 

 by 100 parts of cobalt or nickel : 



Nickel. 



iJourn. Chem. Soc. (2), 7, 294. 1S69. 



