OF ARTS AND SCIENCES. 2oo 



also of the bromine in the bromide of antimony, which is the basis of 

 this atomic weight investigation. By comparing b G and b 7 with b 4 

 and b 5 respectively, we obtain the following data : — 



1. 2.9749 gram, of silver gave 5.1782 gram, bromide of silver. 



2. 2.4745 „ „ „ 4.3076 



Hence it follows that, as shown by these experiments, the propor- 

 tions of the silver to the bromine were respectively : — 



1. 108.00 Silver to 79.99 Bromine. 



2. 108.00 „ „ 80.01 „ 



Mean value, 108.00 „ „ 80.00 „ 



This is the ratio of the atomic w-eight of silver to that of bromine, 

 and corresponds to the second decimal place with the determinations 

 of Stas as well as with those of Dumas. 



In conclusion it gives us pleasure to express our obligations to Mr. 

 G. De N. Hough and Mr. G. M. Hyams, two students of this labora- 

 tory, who have greatly aided us in the experimental work of this 

 investigation. 



