490 



In these measurements, wliicli aie more accurate than those of 

 July '14 (Comm. N°. 143 § 6), a small deviation from the 7"-law 

 shows itself. Tlie deviation is in the sense thai at decreasing tem- 

 perature the aluniic heat dccrcdsi's iiioi'i' rnp/'i//!/ than follo\vs from 

 the 7"-la\v. 



The deviation becomes still more apparent, if one compares the 

 atomic heat over the wjioie region of the measurements of this paper 

 with Debije's general formula for the atomic heat, cf. fig. 1 and the 

 values of ^ in table HI. 



In tlie liquid hydrogen region and above it, up to 40° K., the 

 values of & decrease continually (fig. 2). In this respect the 



B 



12 



2-1 



— T 



35 



4g 



Fig. 2. 



ED 



72 



E^ 



35 



behaviour of copper differs from that of lead. For the latter metal 

 the values of ^ increase with increasing temperature in the liquid 



