( 142 ) 



we suppose the volume of the molecules to be in variable, llie follo- 

 wing approximated equation 



a 

 he——— ^' 



M RT 



In this formula M denotes the pressure of the liquid phase i. e. 



the molecular pressure, and -- the heat required for the transfor- 







mation. 



The following api)roximated equation holds for molecules of 



variable volume: 



a 



^'^m = -Rf' 



where again — denotes the heat required for the transformation, which 



is greater if the molecules in the licpud i)hase are smaller, as well in the 

 case that this diminishing of the volume is real, as in the case that it 

 is only fictitious. Again the molecular pressure is also higher. But 

 the molecular pressure is now pro\ idcd with the factor K. If 

 it is a real diminishing then the signilication of this factor can be 

 sharply defined. The factor is in this case at least approximately 



equal to ^ -, its signification can be derived from tlie following 



equations, (comp. my paper: "The ecpuilioJi of slate and the Theory 

 of cyclic Motions") : 





(h,,-h,) = RT 



So we find for it 



0/ 



i1/ + , ^ , 



The quantity f ^r— ) in this equation represents Ihc atomic forces, 



which keep the molecule intact or at least contribute to the causes 

 which keep the molecule intact. Making use of this value of K we 

 find : 



