232 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



Mean, 104.392, Mean, 59.967, 

 ± .0054 ± .0027 



At the end of the same pai:)er, Eichards alone gives two more series of 

 determinations made upon zinc bromide prepared by the action of pure 

 bromine upon pure electrolytic zinc. The bromide so obtained was 

 further refined by sublimation or distillation, and dried by heating in a 

 stream of carbon dioxide and gaseous hydrobromic acid. Thus was 

 ensured the absence of basic salts and water. The weights and results 

 found in the two series were as follows : 



Series C. 



.0007 



.0004 



In some details of manipulation these series ditl'er from those given 

 by Richards and Rogers jointly, but their minutitB are not essential to 

 the present discussion. 



Combining these several series, we have- — 



For 2Ag : ZnBr./. : 100 : x. 



Series B 104.392, ± .0054 



Series C 104.379, ± .0007 



General mean 104.380, ± .0007 



