1181 

 we find in perfect agreement with Bijl's results: 



9. We liave now to looit at the meaning of the temperature of 

 37°. 49 found by Getman, which he considers to be the transition 

 temperature of the transformation of Cd^ into Cd^g. At 37°. 49 the 

 curves A and D intersect, viz. this is the temperature at which 

 the cells 



Cd-amalgam 8 "/o bj weight 

 {heterogeiieotis) 



Cd-amalgam 8 7o bj weight 

 homogeneous liquid 

 have the same e. m. f. 



From our diagram (Fig. 2) we see that this temperature must be 

 lower than that (40°. 7) at which the Iteterogeneous amalgam changes 

 into the homogeneous liquid state. 



As a matter of fact it was found by Getman 3° lower. Evidently 

 it does not correspond to the transition temperature of the trans- 

 formation of Cdj. into Cd^s- The same may be said with regard to 

 the point of intersection S^ of the curves C and D. According to 

 our diagram (Fig. 2) this point is to be found at a temperature 

 above 40°. 7. From Getman's measurements we find 43 .5. 



10. Getman considering 37°. 49 as the transition temperature of 

 Cdj, into Cd,3 next points out that our dilatometric experiments are 

 open to objection. He says: "It must be borne in mind, however, 

 that in each of these dilatometric measurements nexer less than 

 300 g. of cadmium were used, and it is a foell established fact 

 that lohen so large a. mass of a metal undergoes molecular transform- 

 ation the true transition tempei'atnre may be far removed from 

 that at tnhick the transformation actually takes place." 



Here again a mistake has crept in. Get. par. the accuracy of 

 dilatometric measurements as carried out by ourselves increases with 

 the quantity of material used, as the change of the level in the 

 capillary tube at coristant temperature increases with this quantity. 

 Moreovei-, the fact that the direction in which the oil moves shows 

 a reversal of sign ') if the temperature increases only 0°.5, proves 

 that any i-etardation of the transformation has not taken place. It 

 must be borne in mind that our metal had always been treated 



1) These Proceedings 17, 54 (1914). 



