30 



Dr. Alder Wright and Mr. C. Thompson. [May 8, 



(averaging near 650), described in Part I, being represented by 

 No. 2, in each, case equal quantities of lead and zinc and varying 

 proportions of tin being employed for the mixtures originally fused. 

 The effect of the higher temperature is apparently to give a curve 

 somewhat underlying that obtained at the lower temperature, and 

 crossing the base line sooner ; but the difference is not extremely great, 

 and is probably at least partly due to the circumstance that the 

 greater volatilisation of zinc at the higher temperature causes the 

 proportion of lead relatively to zinc in the entire mass to rise higher: 

 as shown in Part I, the tin distribution curve obtained with two parts 

 of lead to one of zinc in the original mixtures underlies that obtained 

 with equal proportions of the two metals, and crosses the base line 

 sooner. 



When the percentages of tin and zinc in the heavier alloys are 

 plotted as abscissae and ordinates respectively, a curve is obtained 

 sensibly overlying that previously obtained at about 650 ; and 

 similarly with the curve obtained by plotting the percentages of tin 

 and lead in the lighter alloys as abscissae and ordinates respectively. 



The following tables exhibit the solubility values deduced from the 

 mean curves thus graphically obtained, the corresponding values for 

 650 being annexed for the sake of comparison : * 



Solubility of Zinc in Lead-Tin. 



* By inadvertence, some numerical inaccuracies exist in the table of solubility of 



