204 



PROCEEDINGS OF THE AMERICAN ACADEMY 



Since atomic weights are in any case relative, the ratio * Ag : Br 

 := 108.00 : 80.007 will be assumed as the present standard of refer- 

 ence, for the sake of convenience and comparison with previous work. 

 Later, all values will be translated into the various generally accepted 

 etandards. 



The second series of analyses was made from the more dilute solu- 

 tion of a new sample of the salt, prepared in the same manner as the 

 first, but perhaps somewhat less pure. The object was to seek fur- 

 ther evidence of the constancy of the composition of dissolved cupric 

 bromide, and it will be seen that the result agrees moderately well 

 with the former one. 



Pkeliminart Results : Second Series. 

 Determination of Copper. 



Determination of Bromine. 



Atomic Weight of Copper 63.618 



* Although this ratio is not materially different from 108 : 80, we select it 

 as the mean value of all the most accurate determinations. 



