168 



Dr. Alder Wright and Mr. C. Thompson. [Feb. 12, 



This reduction of zinc to a minimum is far more strongly marked 

 than in the case of the lead-zinc-silver alloys ; the point where it 

 occurs is not far from that where the silver and zinc present are in 

 the ratio indicated by the formula Ag 4 Zn 5 . 



Silver. Zinc. Ratio of zinc to silver. 

 14-39 10-37 1 to 1-39 



Calculated for Ag 4 Zii- 1 to 1 '33 



Whence it may be concluded that, whereas AgZn 5 is much more 

 soluble in fused bismuth than pure zinc (relatively to the zinc present 

 in each case), the same is not the case with the compound Ag 4 Zn 6 , 

 which dissolves in bismuth to a much less extent than would zinc 

 alone in the absence of silver. 



Series II was prepared in precisely the same way as the correspond- 

 ing series with the lead-silver-zinc alloys ; i.e., mixtures of the three 

 metals were made and fused for eight hours as in Series I ; the com- 

 pound ingots thus obtained were cut in two so as to separate from 

 one another the lighter and heavier alloys thus formed, and the former 

 parts separately fused at the same temperature (700 800) for 



Series II. Limiting Composition of Lighter Alloys. 



