ATOMIC WEIGHTS 



195 



This mean is subject to a small correction due to loss of chlorine on 

 drying the chloride, which reduces it to 112.073. Omitting Turner's 

 single determination as unimportant, and assigning to the work of Ber- 

 zelius and of Struve equal weight with that of Marignac, the measure- 

 ments of this ratio combine thus: 



Berzelius 112.175, ± .0071 



Struve 112.094, ± .0071 



Marignac 112.011, ± .0071 



Richards 112.073, ± .0017 



General mean 112.075, ±: .0016 



In an earlier paper than the one previously cited, Eichards ^ studied 

 with great care the ratios connecting barium bromide with silver and 

 silver bromide. The barium bromide was prepared by several distinct 

 processes, its behavior upon dehydration and even upon fusion was 

 studied, and its specific gravity Avas determined. The ratio with silver 

 was measured by titration, a solution of hydrobromic acid being used 

 for titrating back. The data are subjoined, with the BaBro equivalent 

 to 100 parts of silver stated : 



.0015 



Hence Ba= 137.360. 



The silver bromide in most of these determinations, and in some others, 

 was collected and weighed in a Gooch crucible with all necessary pre- 



1 Proc. Amer. Acad., 28, 1. 1893. 



