870 
as the saturation line of /. Hence, at these pressures only unsatu- 
rated vapours and those saturated with solid /# can occur in the 
stable condition. 
From a consideration of the equilibrium + ZL + @ it appears 
that the saturation curve of / under its own vapour pressure is a 
curve surrounding the point /, on whieh however, now occur two 
points with a maximum vapour pressure. The same applies to the 
correlated vapour curve surrounding the former curve. Each maxi- 
mum or minimum point of the one curve lies with the correlated 
maximum or minimum point of the other curve and the point # 
on a straight line. 
We have assumed above that when the liquidum and the hetero- 
geneous region disappear in a point within the saturation line of 
F two three-phase triangles, as in fig. 2. appear. We may, however, 
also imagine that the liquidum line of the heterogeneous region LG 
in fig. 1 contracts in such a manner that it intersects the saturation 
line of # in two points only; only two three-phase triangles are 
then formed. 
The saturation line of / under its own vapour pressure and the 
correlated liquidum line are then both circumphased and exhibit one 
point with a maximum and one with a minimum vapour pressure. 
When the hquidum region disappears at one temperature within and 
at another temperature without the saturation point of -/’, it will, 
at a definite temperature disappear in a point of the saturation line. 
Among all solutions saturated at this temperature with /’ and in 
equilibrium with vapour there will be one which is in equilibrium 
with a vapour of the same composition. The saturation line of F 
under its own vapour pressure and the correlating vapour line then 
meet in the point with the minimum vapour pressure. 
We have noticed above that there exist saturation lines of /’ under 
their own vapour pressure which exhibit two vapour pressure maxima 
and two minima. Sueh enrves must. of course, be capable of con- 
version into curves with one maximum and one minimum; this 
takes place by the coincidence of a maximum and a minimum of the 
first curve causing the part of the curve situated between these two 
points to disappear. The two other parts then again merge in each other. 
We have deduced above the saturation line under its own vapour 
pressure with two maxima and two minima in the assumption that 
the liquidum region disappears somewhere within the saturation line 
of F. We may also however, imagine similar cases if this disappear- 
ance takes place in a point outside the saturation line of /. We 
have only to suppose that in fig. 1 the liquidum line of the hetero- 
