4 6 



ENERGY CHANGES INVOLVED IN DILUTION OF AMALGAMS. 



THE POTENTIAL BETWEEN CADMIUM AMALGAMS. 



The study of cadmium was now taken up, in the same general manner as 

 that just described. Four amalgams were made from the first sample of 

 pure electrolyzed cadmium, and bottled up in pipettes exactly as in the case 

 of zinc. 



The very dilute amalgams, 5, 6, 7, and 8 were made inside the cells by 

 dilution with distilled mercury in hydrogen. 



Concentration Ratios of Cadmium Amalgams. 



From these amalgams two quadruple cells were made up, and their electro- 

 motive forces measured with all possible care. 



The first cell contained amalgams 1 and 2 as well as 5 and 6. Its tem- 

 perature was 23.03 . The potential of the i-volt cell was 0.9926 volt. 



The sum of (1-6), (5-2), and (2-6) is 0.026875 ; the direct measurement of 

 (1-6) gives 0.02687; other similar checks are equally satisfactory; hence 

 the potentiometer readings are still reliable. 



63 This value is corrected for the small amount of cadmium dissolved by ammonia 

 during amalgamation. The amalgam contained 2.9553 P er cent of cadmium. 



