( 895 ) 
v dx 
And this occurs in the case which has long been known of minimum 
plaitpoint temperature for perfectly miscible substances. That also the 
spinodal line can pass through this point of intersection, and so the 
p-lines and the g-lines can touch each other, we see when we consider 
that in that point the g-lines run almost vertically, and that the 
d d 
the upper branch of €) =— 0 on the righthand side of ( 4 = 0; 
p-lines in the neighbourhood of i) = 0 also run almost vertically. 
Vv) x 
But also for not perfectly miscible substances this case occurs, viz. 
in the case of the preceding contribution represented by fig. 43. By 
assuming a great value of ” in connection with ¢, and €, below 
certain limits, we had non-perfect miscibility, while further minimum 
value of 7% was assumed. I have already pointed out, that the figure 
given there might undergo some modification according as the com- 
ponent with the smallest value of 7% was also that with the smallest 
size of the molecules or the reverse. The given figure remains 
unmodified if the substance with the smallest value of 7), is that 
which possesses the largest molecule, and might, therefore, serve for 
mixtures of ether and water. As with increase of the size of the 
molecules the value of 7), decreases, we must choose from fig. 1 a 
region lying to the left and as we still assume minimum 7%, we 
have to put it at a value of # which is only little smaller than 1. 
da 
gets very near to the component with the smallest value of 7. Let 
us take ether for this. The splitting up then takes place in such a 
way, that, as is drawn in fig. 43, the small portion that has got 
detached contracts into the axis (c= 1) with increase of 7. So the 
double point now too almost coincides with the # at which 7% is. 
minimum and lies near the value of v‚ for that mixture. Accordingly 
it would have been better if I had omitted the words (Contribution 
XIV p. 829) “but for-~ other value of 7’ and x’. It is noteworthy 
; ; ef : Sou dv 
Then the discussed point of intersection of ( Jet and (3)=0 
v p atv q 
at 
back to the neighbourhood of z=1, the closed detached portion of 
dv me dp RE 
the line = = 0 lies far apart from G ) = 0; it lies vin at 
q v 
dp 
that in this case, in which the line ze) = 0 has been quite forced 
a“ Md 
: ay 
small value of #, because the curve erick must be found in the 
av 
tik : be fds dv 
lefthand half. So a point of intersection of | — |= 0 and {| — |=0, 
dx* }, dax? 9 
