50 



Hg 



40 



i 



10 



20 



30 



^0 



J180 



generated by maintaining at 20° sorne 

 cadmium which had been electrolytically 

 deposited on a platinum spiral. 



According to Getman's measurements 

 for these f?-cells our formula (i>) holds good 

 between 0° and 35". On the other hand, 

 Getman investigated similar cells above 

 40°, but the Cd-^? which they contained 

 had been formed by heating «- (or y-) cells 

 at a temperature of 95° for several days, 

 the cadmium thus being in contact with 

 a solution of cadmium sulpliate. 



According to Getman's measurements 

 above 40° oui- formula (D) holds good 

 for these cells. 



Whereas the elements contained the 

 heterogeneous amalgam as long as they 

 were at temperatures below 40°, they 

 contained the koinogeneous liquid phase 

 above this temperature. The temperature 

 at which the e. m. f. of these two types 



At Proc Cd 

 Fig. 1. 



of cells become identical, corresponds to the temperature at which 

 the heterogeneous phase of the 8 7o amalgam changes into the 

 homogeneous liquid state. 



If the electrical measurements of Getman are accurate, the point 

 of intersection *S, (Fig. 2) of the curves B and D should to be found 

 at the temperature indicated by Bui.'s diagram, viz. 40°. 

 From Getman's equations : 



0.04862—0.000200 {t—1b) = 0.04280 -f 0.000170 (^—25) 



20* 30° 40° 80° 60* TO 



l^ig. 2. 



