MOLECULAR ATTRACTION.* 



(THIRD PAPER) 



BY J. E. MILLS. 



In a preceding- paper 1 , making use of the measurements of 

 Profs. Ramsay and Young and of Prof. Young, we applied 

 the theoretically derived equation, 



fT-rn = constant ' 



to twenty-one substances, and called particular attention to 

 variations in the constants obtained and to the range of tem- 

 perature covered by the measurements. (In the above equa- 

 tion, L denotes heat of vaporization, E, is energy spent in 

 overcoming external pressure, and d and D denote density of 

 liquid and vapor respectively.) In this paper making use of 

 the same measurements and the results there derived we wish 

 to point out some further applications of the theory. But 

 first we call attention to several points bearing more directly 

 upon the results of the last paper. 



The constant given by equation 1 above, as will appear 

 later in this article, is an important property of a substance, 

 and depends upon the attraction of one molecule for another. 

 We have to refer to this constant so often that a more specific 

 designation is desirable. We have hitherto called the abso- 

 lute attraction at unit distance from a molecule /x. The above 

 constant we will call //. (Therefore /x = c fi^~m). We call 

 the internal latent heat of vaporization A. and therefore have, 



[2] A = y! &T — f"B). 



* Reprinted from the Journal of Physical Chemistry, Vol. 8, No. 9, Dec. 

 p. 593 (1904). 



1 Jour. Phys. Chem., June, 1904. Referred to in this article as "sec- 

 ond paper." * 



1904) 146 



