the horizontal line is drawn according to the well-known law of 
Maxwerr *), then the pressure indicated by that line is what vAN DER 
Waats calls the pressure of coincidence of the mixture and denotes 
by the symbol p.. The volumes at the end of that line we call 
Gc, and vr, 
mixture in equilibrium in the above mentioned way. 
and p, and #, represent pressure and volume of the 
Now the integral f var may be split into three parts: 
Le 
Ye ve 7 
fos | pdr + pdr 
Ver Vn 
Vo 
vo 
For the middle quantity we may write: 
Ve, 
Jae = Pe (Ve — Ve) 
Ve, 
As according to our suppositions the vapour follows the gaslaws, 
we have: 
Pe ve, = MRT. 
For the same reason we may replace p in the third integral by 
1 Through a mistake in the plate this line is drawn much too high here, Also 
the form of the isotherm is imperfectly represented. But the figure is merely given 
as a schemalic representation, 
