aL 
phase equilibrium /’-+ + G@ the three-phase triangle is very narrow 
and as noticed previously, we can distinguish many cases. From a 
“consideration of these cases appears the following. 
We represent, as before, the liquid with the maximum pressure 
by J the correlated vapour by M, the liquid with the minimum 
pressure by mm and the correlated vapour by m,. The complex 
distillation curves have, in the vicinity of the line FM (Fm a 
direction about parallel to this line from /’ towards M(m) or reversedly 
so. If, however, the vapour point M, (m,) is situated between and 
M(m) they: proceed from F and M (m) towards the point MW’ (m,) 
or reversedly so, and in the vicinity of this point they inflect in 
definite direction away from the line Mm) or towards that line. 
Let us take the case of a distillation temperature lower than the 
maximum sublimation point of the solid substance #’; the saturation 
line of # under its own vapour pressure and the correlated vapour 
line then possess a form as in fig. 11 (I). In fig. 4 a part Mdhm of 
this saturation line has been drawn but the correlated vapour line 
has been omitted. From a consideration of the three-phase triangles 
we can readily deduce the course of the complex saturation curves ; 
the arrows indicate the direction in which the complex moves on 
distillation. If these complex distillation curves are intersected by 
a straight line passing through the point /’ the tangents and curva- 
tures in these points of intersection must then satisfy the conditions 
deduced therefor. 
M A 
Fig. 4. 
If in the vicinity of the line Fm‚m we imagine a three-phase 
triangle so that the vapour point is adjacent to m, and the liquidum 
point adjacent to m, we notice that a part of the complex distilla- 
tion curves must proceed towards the point fand another part 
towards the point m, whilst there is one that, without bending 
