1114 



tried, partij' l^ecause they do not refer to these low teuiperatures, 

 partly because we have not, as far as they have been derived from 

 the ciuantiim theory, enough data, at least not for crystalline antimony. 

 Fig. 1 shows the curve /t//?„ ; except at — 32.9° it comcides 

 very well with the experimental curve. 



0,<l jfZ- (1^- ,()?)- ,(is- ,«i(»l- ,uci „iivl- Ji'.il jisi- J)nc- 

 Fig. 1. 



The values have been collected in table 1. The ditferences between 

 the observed values and those calculated from the above mentioned 

 formula with two coefficients are about V/^ ; it would be possible 

 to get better agreement with a formula containing more coefficients 

 but this was of no value since on account of the indefiniteness of the 

 soldered joints an accuracy of 1 Vo i« as much as can be expected. 



The values in table I have been calculated with the formula : 



R =zR,{l-\- 0,00511 1 <9 + 0,000005654 6»^). ... (1) 



The linear coefficient of expansion is therefore somewhat greater 

 in the basic plane than in other directions. 



The ''Recueil de Constantes Physiques" gives a 0,0039 '). This 

 agrees with the measurements of Eucken and Gehlhoff ^), who find 

 for the electric conductivity of a cast stick of antim.ony at 

 0° — 79° — 190° 



2,565.10^ 3,568.10^ 9,56.10^ 



1) Recueil de Const. Phys. p. 584, 1913. 



2) A. Eucken und G. Gehlhoff, Verb. d. D. Phys. Gesellsch. 14, p. 169, 1912. 



