865 
From a consideration of fig. 5 it immediately follows that the 
vapour lines appertaining to the curves a/b of figs. 8 and 2 are. 
exphased and may. or may not, intersect the saturation line. 
If we still increase the temperature a little, the point /’ gets above 
the liquidum surface and the saturation line of / under its own 
pressure becomes exphased. We then obtain fig. 12 (I) in which the 
vapour line may. or may not. intersect the saturation curve under 
its OWn Vapour pressure. 
If we increase the temperature still a little more, the saturation 
and the liquidum surface come into contact in a point; it is evident 
that on the saturation surface of /° this point does not coincide with 
/, but is shifted towards the gas surface. We now have the highest 
temperature at wliich the system #+ + G exists. In fig. 12 (1) 
both lines contract to a point; both points lie with / on a 
straight line. 
V <v. We now imagine the saturation surface of fig. 7 to have 
been introduced in fig. 5 and in such a manner that the point / 
is situated above the liquidum surface. The section is then again a 
saturation line of the substance /’ under its own vapour pressure, 
which surrounds the point /. In projection we, therefore, again 
obtain fig. 7(1) or 11(1) with an exphased or circumphased correlated 
vapour line which has shifted towards the side of the vapour surface. 
On increasing the temperature the liquidum and vapour surface 
shift in an upward direction but the saturation surface of /” shifts, 
however, downwards. At a definite temperature, the minimum melt- 
ing point temperature of / (point /’) arrives at the liquidum side: 
and it is now evident that the saturation line under its own vapour 
pressure has: shifted, starting from /’, from the gas surface. In pro- 
jection we thus obtain the curves a Fb of fig. 3 or 4. The corre- 
lated vapour line has, of course, shifted towards the side of the 
gas surface aud may be either exphased or circumphased. 
What will happen at a further increase of temperature will now 
he readily understood. 
In order to find the boiling point line: 
of the solutions saturated with /’, for a 
definite pressure /?, we take the vapour 
surface and the liquidum surface for this 
pressure P; we then obtain fig. 8 in which 
the temperature axis is taken perpendicu- 
larly to the component triangle ABC. The 
liquidum surfare is represented by the drawn, 
the vapour surface by the dotted lines. In 
