( 528 ) 
second straight part, where A assumes the final value A, (all 
molecules have become single), lie wholly on the right of OM. The 
plait will consequently be identical with that of the preceding case 
— only with this difference, that the point A lies below — 90°C., 
where the dissociation of the double molecules begins, so that this 
point lies wholly beyond the region of attainable temperatures. 
ce. As soon as the value of A’ increases a little, we get the case 
of transition of fig.3. The curve A= f(T') touches now the line 
OM in B,C, and from this moment the ¢solated plait will begin to 
appear, extending itself above the just regarded normal plait, which 
lies in unattainable depth. Here it is only two coinciding critical 
points in the one point B,C. 
d. When the value of A, is still a little greater, the case of fig.4 
will present itself, where the line OJ is intersected, besides in A, 
in still two other points B and C. The isolated plait above the 
normal one is formed now, with two critical points, a lower one 
in B and an upper one in C. Everywhere between B and C 
K is > 7, just as below A, so that we are, in consequence of 
0°Z ; : : Hee 5 : 
rede in the unstabie region, i.e. within the spinodal line of 
the plait. 
This case — or the case of fig. 6 — is realised by a great 
number of substances, also in the case of #vo anomalous substances *). 
a. In some cases the wpper critical point is found, as in the 
CH, 
case of water and COG i} 
(Rorumenp), and of H,O and #sobutyl- 
alcohol (Aurexerew); propably also in the case of water and ether 
(Kiopsm and Arexesew), of HO and CO (C,H,), (Rorumunp), of 
H,O and ethyl-acetate (Arexerew), and of H,O and amyl-alcohol 
(ALexesew), in which latter cases, however, the point C was not 
reached. As to water and ether e.g., Kropper has already found, 
that the values of « of the two coexisting liquid phases reapproach 
each other, when the temperature is lowered. That is an indication 
for the existence either of a lower critical point, lying still more 
down or of a contraction as in fig. 6. 
8. In other cases it is only the /ower critical point, that is observed, 
as in the case of water and triethylamine (RoTHMUND), water and 
diethylamine (Germ), and of water and g-collidine (RoTHMUND). 
1) Many anomalous substances namely can be regarded as normal ones, because 
the variation of v is so small; only in the case of water this variation is excep: 
tionally great. 
