( 624 ) 
When the plane is rolled further the binodal curve passes the part 
DE' on the left side and the part D'# on the right side, where the 
spinodal curve is again met with. For this part there is a maximum 
pressure, while there is now a cusp in #’. And finally this plait, 
which has its top in Q, is closed by the portion /’ RE of its binodal 
curve. If we consider also unstable phases as realisable, states between 
KF! and R coexist with conjugate ones between Hand RF on this part. 
The point A closes this branch plait as unrealisable plaitpoint. 
There is not the slightest doubt that for the above mentioned 
mixtures of ethane and alcohol just above 7, the newly appearing 
plaitpoint Q on the alcohol side leads to the diagram of fig. 1 and 
that Q is then the top of a branch plait. If the points A and A" are 
still very close together, then the distances from these points to points 
of the spinodal line must, a fortiori, be extremely small, and we 
have justly assumed that the tangent plane in A’ A” when rolled 
further, passes through the spinodal curve on the side of A”. 
That on the other hand at temperatures just below 7’, the plait 
the top of which is P, must be considered as a branch plait, is 
beyond doubt for the same reasons. Above 7’, namely, only the top 
QQ is found, and the whole plait does not present the slightest com- 
plication. Only with decrease of temperature below 7, an extremely 
small bulging out appears in the beginning at P (i. e. in the position 
which that point has at that temperature) and the same reasons 
which led us to consider the point Q as top of a branch plait 
just above 7’, must lead us now to consider Pas top of a branch 
plait. Fig. 3 represents the binodal lines in this case. Only we have 
assumed there that the temperature has fallen already so much below 
T,, that the branch plait has got such an extension, that at first 
sight it is not to be distinguished from a part of a main plait. 
Both in fig. 1 and in fig. 5 there is asymmetry between the two 
binodal curves of the tops P and Q. But when 7’ is gradually 
changed from 7, to 7, or vice versa, fig. 1 will gradually pass into 
fig. 3 or vice versa. This transition requires a value of 7, at which 
the asymmetry between the two tops P and Q has vanished. What 
the shape of the binodal curves must be at the transition temperature, 
is represented in fig. 2. Then we have one plait with one base, but 
with two heads. 
If we compare fig. 1 and fig. 2, the only difference is that the 
points B’ and £' have coincided, which involves that the node 
belonging to B' and that belonging to //’, so the points B and Z, 
also coincide. From fig. 2 we derive fig. 1 by separating again the 
parts which have run together, at the points which have coincided, 
