42 



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



On comparing together the relative effects on the solubility of lead 

 in zinc, and zinc in lead, produced hy the presence of tin and silver 

 respectively, it is at once obvious that if 100 parts of zinc can take 

 up m parts of lead in presence of x parts of a third racial (tin or 

 silver), or if 100 of lead can take up n parts of zinc in presence of 

 x of the third metal, then m and n are invariably much greater when 

 the third metal is tin than when silver, even if the solubility in pre- 

 sence of tin be reckoned at only 650 C., or thereabouts, instead of 

 800. 



Thus the following tables are calculated from the mean solubility 

 carves previously described, giving the correlated values of x, m, and 

 n for the three cases tin at about 650, tin at about 800, and 

 silver at about 800 : 



