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Albert P. Mathews 



perature, since as we go to lower temperatures "a," computed 

 by this formula, becomes steadily larger. This is owing to 

 the fact that some of the latent heat is consumed in doing other 

 things than in overcoming molecular cohesion, a part probably 

 being rendered latent by an actual expansion of the molecules. 

 H is the latent heat used in increasing the intramolecular 

 energy. It vanishes close to the critical temperatures. I 

 have, therefore, computed "a" by this formula within a degree 

 or so of the critical temperature. At temperatures lower than 

 this "a" by this method will be found too large, but within a 

 fraction of a degree of the critical temperature the change 

 in the size of the molecules is probably negligible. To find ^ 

 at this temperature I have computed it from S. Young's 

 recently published data of the liquid and vapor densities 

 using Mills' 1 formula for the computation of X, namely, 



7 COMPUTATION OF "a" FOR ONE GRAM MOL FROM INTERNAL 

 HEAT (NEGLECTING //) 



1 Mills: Phil. Mag., 21, 85 (1911). 



