1160 
1 and 2 the points 6, and 6, on YZ in the vicinity of a, and a, 
Then from fig. 1 a diagram arises, such 
as is drawn in fig. 6. 
As the three-phases-triangle now turns 
always its liquid point away from the 
side YZ, the temperature must, accor- 
ding to the previous rule, decrease under 
constant P, viz. when we trace the 
curves starting from their binary termi- 
nating-points. This is in accordance also 
with the first formula (23). 
In the previous communication XX 
Fig. 6. we have deduced the relation: 
es dP 
(AP) ED) (ie da rode anke ek AU 
dl ni) 
Hence appears: when in the invariant (P or 7’) equilibrium 
(which consequently is monovariant) the pressure increases at increase 
of 7, then (dP)r and (d7’)p have opposite signs; when, however, 
the pressure decreases at increase of 7’, then (dP)r and (d7’)p have 
the same sign. We now may express this in the following way: 
we add a new substance to an invariant (P or 7’) equilibrium; 
when in this equilibrium the pressure increases at increase of 
temperature, then the influence on the pressure at constant 7’ is 
opposite to the influence on the temperature under constant P; 
when in this equilibrium the pressure decreases at increase of 
temperature, then the influence on the pressure at constant 7’ is 
the same as the influence on the temperature under constant P. 
It is evident that “influence” means here the sign of the change 
of pressure of temperature. 
Leiden. Inorg. Chem. Lab. 
(To be continued). 
