OP ARTS AND SCIENCES. 



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tested with uniformly negative result for the presence of traces of 

 metal in solution. It is almost needless to state, that, in every oper- 

 ation involving the quantitative transference of liquid, the original 

 contiiining vessel was washed out with the most scrupulous care, and 

 finally tested to prove the absence of any trace of its former contents. 

 Below is the series of four results obtained from the first cupric 

 bromide solution. About two weeks elapsed between the first and 

 last determinations of this series. 



Preliminart Results : First Series. 

 Determination of Copper, 



Determination of Bromine. 



Atomic Weight of Copper. 



From above results, if Ag : Br = 108.00 : 80.007, Cu = 63.644. 



From results of previous paper, if Ag : Br = 108.00 : 80.007, Cu = 63.640. 



According to Hampe, on same basis, Cu = 63.37±. 



