553 
Further we assume that Z, is the liquid, which is formed on addition 
of heat. {When this should be the case with Z,, then we should 
have placed £, in the left part of (82) ]. Now we have: 
Tay) =—y,—4,y, and Dax) = a, — Ar. 
za (EE). BRA ME (EE) 
Hence it follows: 
and 
(85) 
Herein AW is the heat, wanted for forming one quantity of the 
liquid £,; AV is the inerease of volume occurring at this formation, 
which can be as well positive as negative. 
Now we shall mean by partition-coefficient of a substance: the 
concentration of that substance in the liquid, which is formed on 
addition of heat, divided by the concentration of that substance in 
the other liquid. x,:2, is consequently the partition-coefficient of the 
new substance, y,:7, that of the component, which does not occur 
as solid phase. 
Consequently we find: 
when in an invariant (P or 7’) equilibrium with 2 liquids only 
components occur as solid phases, then both liquids are situated in 
reaction-opposition. The stratification-temperature under constant P 
by addition of a new substance: 
is elevated (lowered) when the partition-coefficient of the new 
substance is smaller (larger) than that of the component which does 
not occur as solid phase’). 
We may deduce from (35, similar rules for the influence of a 
new substance on the change in pressure at constant temperature. 
We may also give a more simple form to (34) and (35). We have 
viz. expressed the concentrations of the components in the liquids 
in such a way that each liquid contains in all one molecule. 
We may, however, also mean by concentration the quantity of the 
') For some examples of the influence of a third substance on binary equilibria 
see F. A. H. Scureinemakens, Die heterogenen Gleichgewichte von H. W. BaKuHUIS 
Roozegoom III? 160, 
