ATOMIC WEIGHTS -J 45 



The third memoir of Richards and Baxter gives analyses of cobalt 

 chloride and oxide. First, the chloride was reduced to metal by heating 

 in hydrogen. Hempel and Thiele worked in the opposite direction, 

 heating cobalt in chlorine and thereby effecting the synthesis of the 

 compound. For uniformity of statement I give Eichards and Baxter's 

 series in the same form, as the ratio CU: Co:: 100 :rr.- 



Mean, 83.206, ± .0087 



Hence Co = 59.050. 



Hempel and Thiele's figures give for this ratio the figure 82.873, ± 

 .0241. The general mean of both series is 83.220, ±.0082. 



Five reductions of cobalt oxide in hydrogen are given, three in one 

 series and two separate experiments with varied methods of manipula- 

 tion. The results obtained are regarded by Richards and Baxter as 

 unimportant, and they point out the difficulties of the process. Their 

 data, arranged as one series, follow : 



Mean, 78.659, ± .0051 



Hence Co = 58.973. 



This mean combines with former means as follows: 



Russell 78.592, ± .0023 



Zimmermann 78.635, ± .0002 



Remmler 78.613, ± .0099 



Hempel and Thiele 78.666, ± .0074 



Richards and Baxter 78.659, ±.0051 



General mean 78.6324, ± .0002 



Here Zimmermann's determinations practically appear alone. 



The analyses of cobalt chloride by Baxter and Coffin' were made by 



^ Journ. Amer. Chein. Soc, 28, 1580. 1906. Zeitsch. anorg:. Chem., 51, 171. 

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