386 
the critical end-point lies at higher pressure than the three-phase 
line. So two-phase equilibria must be possible at these tempera- 
tures between liquid rich in ether and vapour at pressures higher 
than the three-phase pressure. If, therefore, only one point of end- 
condensation of the ether layer was found to lie higher than the 
three-phase pressure at the same temperature, the intersection would 
have been proved. So we see that in the observation of the two- 
phase equilibria we may find a second decision on the presence or 
absence of the point of intersection in question. 
Now what concerns the observation of the two-phase equilibria 
we have already seen in § 1, that the liquid which is rich in water 
is sometimes not observable in the mixtures. This, however, does not 
Fig. 2. 
affect the decision in question. For every mixture I determined the 
initial and the final condensations of the ether layer in the neigh- 
bourhood of the critical temperature. If in one of the two a layer 
is present, visible or invisible, which is rich in water, the pressure 
must be the same as the three-phase pressure. Now it follows from 
