and the Laws regarding the Nature of Heatf,.. JQ7 



Table I. Tinim^- € 



We see that the values of C found in both cases increase, like 

 those of A(fl + ^), slowly with the temperature. They bear the 

 same ratio to each other as the numbers of the following series : 



1; 1-13; 1-22; 127; 



1;1-12; 1-17; ISl; 

 and when the ratio of the values of K[a-\-t) (obtained by setting 

 fl = 273) corresponding to the same temperatures are calculated, 

 we obtain 

 m: 1; 1-14; 1-21; 1-39. 



This series of relative values deviates from the former only so far 

 as might be expected from the insecurity of the data fi-om which 

 those are derived : the same will also e:diibit itself further on in 

 the determination of the absolute value of the constant A. 



Such a coincidence of results derived from two entirely differ- 

 ent bases cannot be accidental. Rather does it furnish an im- 

 portant corroboration of both, and also of the additional inci- 

 dental assumption. 



Let us now turn again to the application of equations (IV.) 

 and (V.) ; the former, as regards permanent gases, has merely 

 served to substantiate conclusions already known. For vapours, 

 however, and for other substances to which the principle of Carnot 

 may be applicable, the said equation furnishes the important 

 advantage, that by it we are justified in substituting everywhere 

 for the function C the definite expression Kia + t). 



The equation (V.) changes by this into 



r=^a + t).{s-<T)^', .... (Va.) 



we thus obtain for the vapour a simple relation between the tem- 

 perature at which it is formed, the pressure, the volume, and 

 the latent heat, and can make use of it in drawing still further 

 conclusions. 



Were the law of M. and G. true for vapours at their maximum 

 density, we should have 



ps^^{a + t) . (20.) 



