ATOMIC WEIGHTS 



351 



Mean, 77.268, ± .0041 



Hence Cr = 52.13. 



Baxter, Mueller and Hines ^ determined the atomic weight of chromium 

 through the analysis of silver ehromate. The weighed salt was dissolved 

 in nitric acid and reduced either by sulphurous acid or hydrazine sul- 

 phate. The silver was then precipitated as chloride or bromide, by weak 

 hydrochloric or hydrobromic acid, and the halide compound was weighed. 

 All modern precautions were taken in this work, such as determining 

 traces of moisture in the ehromate, and also the traces of silver chloride 

 or bromide remaining in solution. The chloride series, with vacuum 

 weights, was as follows : 



Mean, 115.728, 

 Hence Cr= 52.005. 



This combines with previous series as follows : 



Berlin 115.956, ±: .023 



Meineke 115.737, ± .0072 



Baxter et al 115.728, ± .0024 



General mean 115.731, ± .0023 



.0024 



For the bromide series, all corrections applied, the data arc these 



Ratio. 

 88.336 

 88.337 

 88.340 

 88.336 

 88.335 

 88.336 



1 Jouni. Amer. Clieni. Soc, 31, 529. 1909. 



