398 
and at these temperatures only the appearance of the other compo- 
: ; : ; dp 
nent as solid phase is possible. So again supposing oz to be posi- 
B), 
tive, only the first component can appear as solid substance because 
then the second component will generally possess the lower critical 
temperature. We know that in this case a transformation in the 
connection of the plaits takes place, as is indicated in fig. 3. We 
must now suppose that at low temperatures the behaviour does not 
6 
—_ 
Fig. 3. 
a et 
bi 
differ from what was discussed in §3 (lines a, 6, and c of fig. 1) 
that then, however, the transformation of fig. 8 makes its appearance. 
If this takes place before the condition g of figure 1 has been 
reached, it is clear that the liquid points of the three-phase line 
SHL, + L, lie on the longitudinal plait at low temperature, but 
that when the transformation takes place the branch on which L, 
and L, lie gets into connection with the vapour branch. Hence on 
rise of temperature the three-phase line S + L, + L, merges conti- 
nuously into S+ L,-+ G. Then the points L, and G of the three- 
phase line 5+ L,+G which lie on the transverse plait at low 
temperature, are both found on the closed portion in the trans- 
formation; hence the three-phase line 5 + L, + G terminates in the 
hidden plaitpoimt ?,, where the line for fluid by the side of solid 
touches the closed portion. Without our entering into any further 
particularities, it will be clear in my opinion, that fig. + indicates 
the P,7-projection holding for this case. That again a transition takes 
place by means of an unstable ridge, can be shown in perfectly 
analogous way as in the transition described in $ 3. 
