800 

 p n dloffo) a 7i^ 



A—V-2 heilig very siiicall with respeot to the other factors, we may 

 iieo-lec't its influence in il' '). The equation of state has the same 

 form as nan dv.r Waals' equation. However, the correlation is sensible 

 in the accidental deviation; for it changes the value of t' ; and 

 tW,, which vanish if tiio correlation is neglected, obtain values 

 deviating from zero. 



Denotin» bv A-, and by A^- the minors of the discriminant, 



we have 



— A„ 



where /.• is the number of elements into which the volume is divided. 



dp 

 The condition A =: is equivalent to the condition -— = 0. For 



ar 



if we write down the determinant in some arrangement, and if we 

 add all rows to the tirst row, we get a determinant of which all 

 terms of the tirst row have the form 



1 1 (/ db/w 1 _ 



1? 1' da da &dr 



Strictly speaking, this is not true for some terms at the end of the row, 

 but as we have neglected the action on the boi-ders, we may neglect 

 this fact too. In reality our considerations are ojily true for an infini- 

 tely great volume, where this difficulty disappears, as A is then an 

 infinite determinant. 



Now if 



then A = 0. 

 Or if A =*0 



1 1 dfay 1 _ 



- + - a* ~ \ 2 (f,,= 



I' V dfi Gdv 



d dfoi a 

 da da & 



dp 

 which therefore agrees with — 



dv 



1) Of. 1. c. p. 129. 



~) Gf. Ornstein, Accidental deviations in mixtures. These Proceedings 15, 

 p. 54 (1912). 



