1201 
(Therefore, it does not extend itself, as is drawn in fig. 3 overa/|. 
When an equilibrium ZR exists [this is the case when the 3 
phases in the concentration-diagram are situated on a straight line | 
then also a turning-line ZR exists, this is represented in fig. 3 by 
ef. This point of contact f represents the equilibrium ER4—). 
The region EZ is now two-leafed, a fe is the one, de fe is the 
other leaf. 
When we consider the equilibrium “= /+ 71 + Gata constant 
T, lower than 7, then the pressure on the turning-line ef is a 
maximum; when the turning-line was represented by gh, then the 
pressure would be a minimum. 
Fig. 3. 
On curve acd is situated in the vicinity of c a solution s, which 
has the same composition as the compound /. When /’ melts with 
increase of volume, then s is situated on branch dc, as in fig. 3. 
It is apparent from formula 17 of the communication on ‘Equi- 
libria in ternary systems XI”: when we enter at constant 7'starting 
from the point s the region H=#+ L +4 G, then the pressure 
must increase. 
Hence it follows, that the point of contact h of curve gh must 
always be situated on branch ds and that of curve ef always on 
branch as. In the latter case the point of contact may, therefore, 
also be- situated between s and c e.g. in f,; then we get a limit- 
curve like ef. The equilibrium “= + L + G then still exists 
at temperatures above 7, the highest temperature at which the 
equilibrium HL4—o may occur. 
Let us now consider the equilibrium ZB L+G of the 
