1157 
in the case of the new figures 3 and 4 the boiling-point is raised 
under constant P and at constant 7 the vapour-pressure is lowered; 
in the case of fig. 5 under constant P the boiling-point is lowered 
and at constant 7’ the vapour-pressure is raised. 
Kasily we see that this all is also in accordance with the deduc- 
tions from formula (12). In fig. 3 the vapour « has a mediate 
composition and ¢ in formula (12) is, therefore, positive. In figs 4 
and 5 the vapour has a not-mediate composition but e is in fig. 4 
still positive, but negative in fig. 5. 
The previous considerations are valid still also, when also one of 
the components of the binary equilibrium H= L, + L,+ G is not 
volatile. When Y is this component which is not-volatile, then in 
the figs 1-—5 point a coincides with Z When also the new sub- 
stance is not-volatile, then the vapour remains always represented 
by point 7; when the new substance is volatile indeed, then the 
vapour proceeds along the side ZX. Also in those cases, the boiling- 
point shall be raised or lowered under constant P and the vapour- 
pressure shall be lowered or raised at constant 7’, dependent on 
the situation of the three-phases-triangle. 
In a similar way we may deduce also the influence of a new 
substance on the ternary, equilibrium H=—1,+ L, + L, + G. 
When we represent the reaction by: 
Ni li teh be ct Alacer. oreleiai ial (18) 
then is: 
= (A#) = 2 — 1,2, — 1,4, — 1,2, 
and À, 4, and 2, are defined by: 
4,+4,+4,=1 Aven allan delle =y » … (19) 
dz tthe Agta at Avene 
When. we take a regular tetrahedron for concentration-diagram, 
then the phases of the ternary equilibrium / are represented by 
four points on the side-plane YZU; we shall call those points a, 
a, a, and a. When, at constant P, we add a new substance X, 
then each phase traces a four-phases-curve; we call those curves 
orbi en AS OE C4 sd, O, C,,jand.,a.be. 
The four-phases-tetrahedron 6, 6,6, 6 turns now its vapour-point 
b either towards the side-plane YZU or away from that plane. 
Easily now we find the rule: 
when we follow the four-phases-curves of the quaternary equili- 
brium L,+ 4,+ Lig + G starting from their ternary terminating- 
points, then 
under constant P the temperature decreases and at constant 7’ 
