( 546 j 
As soon as the pressure has increased to pc (the maximum tension 
of the first component) the vapour branch has moved so far upward 
that it has reached the liquid branch on the left side of the figure. 
For the right side this would take place for p=py# (maximum 
tension of the second component). And for pressures between pc 
and pp the gas- and liquid branches have a double point on the 
left of zp — in the same way for pressures between py and pp 
a double point on the right of « . 
For pressures above Pp the gas-branch has moved above the 
liquid branch; for p= Pp these two branches touched each other. 
If the pressure is made to draw near to pq, the gas-branch and 
the branch of unstable phases form a closed curve, which has a 
cusp right and left, which curve is reduced to a point for p — pa, 
and for still higher values of p also this point has hein dae and 
only the liquid branch remains. 
We shall be brief in the discussion of the value of ¢ at different 
pressure at the temperature assumed in fig. 8. The ¢-curve for the 
pressure p=pc is represented in fig. 11; the four cusps lie at 
vp, xy, ty and zy. For a somewhat lower pressure p= px the 
right crest has disappeared, and for a still lower pressure p = ps 
(plaitpoint pressure) the right part of © is curved continuously. So 
we have here between S and £ retrograde condensation of the 
second kind. I shall leave the modification of ¢ for pressures 
greater than po undisenssed. 
— 
Fig. 11. 
For a binary mixture I have pointed out that there is a connec- 
tion between the circumstance that two phases of equal concentra- 
tion can coexist, and the circumstance that for a mixture of the 
two components of that system a minimum critical temperature 
