1892.] 



On certain Ternary Alloys. 



393 



with tin as solvent. As shown below, the same relationship also 

 holds with bismuth-zinc-silver and bismuth-zinc-tin curves. 



Alloys of Bismuth, Silver, and Zinc.' 



The experiments described in Part III show that with bismuth- 

 zinc-silver alloys, as with those of lead-zinc-silver, the position of 

 the limiting point lies to the left (bismuth side) of the central line. 

 Accordingly, a number of additional experiments were made with 

 silver percentages upwards of twenty, and with zinc and bismuth in 

 the proportions 1 : 1*33 to 1 : 1'5, so as to deduce more accurately and 

 completely the upper portion of the critical curve, only those points 

 being re-valued where the influence of the formation of the compound 

 AgZn 8 had become inappreciable. 



The following table exhibits the average results thus obtained, 

 together with those described in Series I (Part II), the temperature 

 throughout being 700 800, averaging near to 750 ; twenty-four 

 compound ingots in all being employed, representing forty-eight 

 ternary alloys. 



Fig. 9 represents these results on the triangular system, the posi- 

 tion of the limiting point L being thence deduced by Stokes' second 

 system, a large-scale plotting giving the values : 



A + A' = 66-25 

 B + B' = 44-5 



whence the composition at the limiting point is : 



