1890.] On certain Ternary Alloys. 41 



results obtained in Series I and II with mixtures of metals con- 

 taining less than 28 41 per cent, of silver, and yielding heavier 

 alloys after the first fusion, containing less than 5 or 6 per cent, of 

 silver. 



Series IV. Limiting Compositions of Heavier Alloys. 



Silver. Lead. Zinc. 



0-38 98-33 1-29 



075 97-98 1-27 



1-52 97-30 1-18 



4-03 94-72 1-25 



8-44 90-00 1-56 



11-09 87-20 1-71 



14-82 83-25 1-93 



The dotted carve No. 3, fig. 6, represents these values, which 

 obviously imply that the method of treatment adopted had, as with 

 the lighter alloys, sufficed to decompose completely the compound 

 AgZn 5 originally present, and hence to prevent any larger propor- 

 tion of zinc being present than that due to the normal solubility in 

 lead of Ag 4 Zn 5 mixed with free zinc, in the case of the alloys earliest 

 in the series, or to the solubility in lead containing surplus silver of 

 the compound Ag 4 Zn 5 , in those occurring later in the series. 



The following tables are derived from all the foregoing results, 

 excepting the earlier alloys of Series I and II, where excess of lead 

 was present in the lighter alloy, or of zinc in the heavier one, owing 

 to the presence of undecomposed AgZn 5 ; they represent the mean 

 composition of the zinc-lead-silver alloys, producible under such con- 

 ditions that no AgZn 5 is present to increase the amount of zinc 

 contained in the heavier, and of lead in the lighter, alloys respec- 

 tively : 



