1891.] 



On certain Ternary Alloys. 



169 



another eight hours. In this way a farther separation was brought 

 about in the case of the alloys prepared with smaller proportions of 

 silver, but no material alteration in the case of those made with 

 larger proportions, just as with the lead-silver-zinc alloys. On 

 plotting the results, a curve was obtained (No. 2, fig. 5) from which 

 the first maximum, at approximately the point representing the com- 

 pound AgZn-, had completely disappeared, as had also the subsequent 

 fall, the curve exhibiting a progressive rise from beginning to end. 



Series III was similarly made with the heavier alloys thus sepa- 

 rated from the lighter ones ; the results, when plotted (curve No, 2, 

 fig. 6), showed that the abnormally large percentages of zinc observed 

 in the earlier part of the series had disappeared, whilst the diminution 

 in amount of zinc dissolved relatively to the bismuth present down to 

 a minimum and subsequent rise again was still well marked, the 

 position of the minimum corresponding, as before, with a ratio of 

 zinc to silver not far from that indicated by the formula Ag 4 Zn-. 



Series III. Limiting Composition of Heavier Alloys. 



Position of minimum : 



Silver. Zinc. Ratio of zinc to silver. 



1H-14 9-01 1 to 1-45 



Calculated for Ag 4 Zn 5 1 to 1'33 



AgZn 1 to 1-66 



The following tables represent the mean solubility curves deduced 

 all the preceding results, omitting the earlier alloys in Series I, 

 rhere, owing to the presence of undecomposed AgZn 6 , excess of lead 

 ras present in the lighter alloys, and excess of zinc in the heavier 

 ics. 



N 2 



