298 Mr Ricleal, On the latent heats of vaporisation 



value of h' — a' gradually decreases and the power of d increases 

 from - I at 0° K. to at the critical point where gas and solid 

 become identical. 



It will be noted that the above expression derived from the 

 latent heat equation and the eflusion formula gives us a general 

 method of calculation of the thermodynamic potential differences 

 or the difference in the fugacities of a substance distributed in two 

 phases and is not necessarily confined to the particular case where 

 one_ phase consists of the material in the zero thermodynamic 

 environment of a perfect gas. 



