(547 j 
occurs. The existence of such a connection having since been perfectly 
confirmed by the experiments of KurNEN and QUINT, we are naturally 
led to investigate whether a minimum-critical temperature can occur 
also for a mixture of three substances — and what are the conditions 
for the existence of such a minimum critical temperature. That 
connection could however not follow and could not be derived simply 
from the principle of continuity, but considerations of a molecular- 
theoretical nature were required to conclude to the existence of such 
a connection. Therefore I shall at the moment, as we consider it 
only our task to examine what follows for a ternary system from 
the assumption of continuity, refrain from seeking the conditions 
which the components. must satisfy in order to be able to form a 
mixture which possesses maximum pressure and assume only that 
a mixture can really be formed from the three chosen components 
for which liquid and vapour are composed in the same way and 
whose coexistence pressure is therefore maximum. 
If we take the pressure somewhat smaller than that maximum 
pressure, so that we get a section of vapour and liquid sheet as 
drawn in fig. 10 for every section normal to the zy-surface passing 
through the point representing that special mixture, the: connodal 
curve will consist of two closed curves, of which the inner curve 
indicates the vapour phasis. If p is equal to that maximum pressure, 
the two closed curves have been reduced to one point, the point 
where the two sheets touch each other. Under a still greater pressure 
the vapour sheet will have risen quite above the liquid sheet. With 
decreasing pressure the two closed curves extend, and if we took 
only the principle of continuity into account, a great many cases 
would be possible. For instance the extending closed curves might 
reach the sides of the triangle which represent the pairs of which 
the ternary system consists, and cut them in two points, either one 
side or two sides, or all three the sides. In the last case the three 
pairs which compose the ternary system, would possess all three the 
properties of maximum pressure. But an extension is also possible, 
at which the second and the third side is never cut twice — and 
even one at which none of the sides is cut twice, and at which 
therefore the closed curve which extends and which is changing its 
shape, reaches the sides of the triangle for the first time in one of the 
angles, In this case the ternary system would have maximum pres- 
sure, without this being the case with any of the pairs of which 
it consists. The investigation of conditions which are required for a 
minimum critical temperature will probably be able to decide the 
