§ 3. PreUminary results of ineasurtments on the atomic heal of 

 solid Jiydrogen. In connection with our measurements on the specific 

 heat of liquid hydrogen we also carried out some calorimetric expe- 

 riments on solid hydrogen at temperatures which could be reached 

 by reducing the pressure as far as j)ossible. As we have not had 

 an opportunity to calibrate the thermometer-wire at these temj)era- 

 tures we can only give some preliminary results. They are based 

 on the assumption that the linear dependence on the temperature 

 which holds for the constantin wire between 14.16° and 20.48° K. 

 with great accuracy (Comm. N". 143, Oct. 14, Table 1) remains valid 

 for this wire down to 10.5° K. (or at least: down to 11.8° K., if 

 the measurement of Oct. 23 I which is less certain on account of 

 an insufficient vacuum in the calorimeter-vessel is excluded). 



These results are also shown in fig. 2. 



TABLE II. 



Atomic heat of solid hydrogen. Preliminary results. 



Number 





o o <u 

 o o. 



a.n o ^ 



V c 4J 



^^ — -a 

 S^ <« - 



Si CO = 



3:«Siï 



Co ^ OJ 



oj c (i> 



x:"~ 1- 



n fcjo 



CJ OJ OJ 



•- bjOT3 

 E O , 



o 1- ^ 



< >,ci. 



II 



May 11 I 



Oct. 23 I 



II 



10.51 

 9.84 

 8.89 

 6.69 

 8.91 



10.41 



€.87 

 0.89 

 0.83 

 0.68 

 89 

 0.83 



0.73 

 0.68 

 0.55 

 0.45] 

 0.60 

 0.66 



In cooling the solid hydrogen for the object of these measurements, 

 as also in a few special experiments made for this purpose, cooling 

 curves (comp. Comm. N". 149r/ fig. 5) were recorded. In several of them 

 small irregularities occurred ; as these did not show themselves at 

 the same temperatures in all the curves, and even in two of them 

 taken under the same circumstances were completely absent, we 

 ascribe these bends to disturbances (such as changes of thegalvano- 



1) Comp. p. 1002 note. 



