ATOMIC WEIGHTS 89 



Ratio. 



74.089 

 74.098 

 74.074 

 74.088 

 74.085 

 74.069 

 74.059 



Eichards and Cushman also give one direct determination of the ratio, 

 in which 2.10289 grammes of silver yielded 3.66066 of bromide. Eatio, 

 74.078. Including this in the foregoing series, the mean becomes 74.080, 

 ±.0030. 



Similar data appear in the memoirs of Eichards and Baxter ' on the 

 atomic weight of cobalt. Their analyses of cobalt bromide gave the 

 following equivalent figures : 



Ratio. 

 74.102 

 74.046 



74.055 

 74.073 

 74.059 

 74.086 

 74.093 

 74.072 



There are also in these two memoirs by Eichards and Baxter, three 

 direct determinations of the ratio, as follows: 



Ratio. 

 74.081 

 74.073 

 74.074 



Taking these with the previous eight determinations as one series, 

 the mean value for the ratio is 74.074, ±.0033. 



Prom the analyses of uranium bromide, by Richards and Merigold," 

 the following figures are obtained : 



Ag. AgBr. Ratio 



1.39365 2.42588 74.066 



.82559 1.43713 74.073 



1.43617 2.50009 74.080 ' 



Mean, 74.073, ± .0027 



iProc. Amer. Acad., 33, 115, 1S97; and 34, 351, 1899. 

 ='Proc. Amer. Acad., 37, 393. 1902. 



