(4) 
that we therefore might superficially think, that the introduction of 
Tr is of no use; but in the first place in very many cases the 
critical temperatures, found experimentally, do not differ much from 
this quantity and in the second place even the simple assumption, 
that this quantity varies fluently with the composition, will yield 
many conclusions, confirmed by the experiments. As an instance | 
mention the connection of the fact, that if a mixture has a minimum 
critical temperature, a maximum-pressure is found on the connodal 
curve. A closer investigation of the signification of the quantity wu 
itself will however enable us to give a still more exact form to all 
further conclusions which have been deduced in this way, and to 
all further deductions which are important for the theory of mix- 
tures. For the present I shall occupy myself only with the case 
that one of the coexisting phases is a rarefied gas-phasis. In this 
case wr, and «w',, may be neglected. For in the equation: 
MRT u =| vdp 
MRT 
P 
rare, and this holds for every mixture whatever its composition may 
be. Therefore we get by integration : 
the value of v may be represented by if the phases are very 
MRT u = MRT Ip + gp (T) 
In order to remain in accordance with the form of p. 450, | 
will determine g(7’) such, that we may write: 
f= log, zi pent 
This signifies in fig. 1 that the vapour branches coincide, whatever 
the value of x, y and 1—«—y may be. 
In all such cases the equations (1) and (2) may be simplified as 
follows : 
Dey, Peg ey 
1 U u! 
and vds = eee en 
leg, leg, 
If the pressure increases mw’, and w', begin to differ from zero, and 
properly speaking these quantities always differ from zero. This is to 
be aseribed to the deviation from the law of Borre which occurs 
in a different degree for different mixtures. But just as we do not 
commit considerable errors if we neglect the deviation from the law 
