A REVISION OF THE ATOMIC WEIGHT OF BROMINE. 



6l 



series equally, so that this striking agreement is strong proof that both series 

 are free from such errors. 



The Atomic Weight of Bromine. Series II. AgBr:AgCl. 

 Ag = 107.880 CI = 35-457< 



It has already been pointed out that the average of Stas's syntheses, 79.917, 

 probably represents with considerable accuracy the atomic weight of bromine, 

 and that certainly his determinations are more accurate than those of later 

 experimenters. His syntheses are few in number, however, and difler among 

 themselves by several thousandths of a unit, so that they do not define within 

 this amount the constant in question. Their average, however, confirms the 

 value obtained in this paper. From all the experiments here described the 

 number 79.916 seems to be the most probable value for the atomic weight of 

 bromine, if silver has the atomic weight 107.880. If silver is taken at 107. S70, 

 bromine becomes 79.909. 



In conclusion, attention may be called to the fact that a diminution in the 

 atomic weight of bromine referred to silver raises slightly all atomic weights 

 resulting from the analysis of metallic bromides by precipitation with silver. 



I am deeply indebted to the Cyrus M. Warren Fund for Research in Harvard 

 University for assistance in pursuing this investigation. 



