1303 
in which the points m,, /’, and m correspond with the homonymous 
points in fig. 7 (1). 
If now we suppose first that tbe reaction #2 L + @ proceeds 
from the left to the right with increase in volume, the system L+G 
will then appear at lower pressures and the systems F+ Z and 
F+ G at higher ones. Hence, on lowering the pressure, fig. 5 (I) 
will be converted into fig. 6(1) and on increasing the same into 
fig. d(D), which is in agreement with our previous considerations. 
As, on increase of pressure, fig. 5 (I) is converted into fig. 4 (I) the 
pressure for the system F+ L-+ G in fig. 5 (I) is consequently a 
minimum. 
If we had assumed that the conversion F2 L + G took place 
from the left to the right with decrease in volume, the pressure 
would be a maximum. Such a change in volume can only occur 
when the liquid differs but little in composition from /’, and when 
FF melts with contraction of volume. If we imagine in fig. 13 (1) 
the curve Mm, to have shifted so far to the other side of / that 
M, gets situated at the other side of /, this case will occur in the 
system F+ liquid M + vapour /,. 
Let us now take the case mentioned sub B 2, namely when the 
reaction #4 [2G takes place, so that the point G lies between 
the points # and ZL. This is, for instance the case in fig. 9 (I). Let 
us now assume first that the reaction takes place from the left to 
the right with increase in volume. The system “+ Z will then 
appear at a higher, the systems “+ G and L+G at a lower 
pressure. In agreement with our previous considerations fig. 9 (I) 
will be converted, on increase in pressure, into fig. 8 (I) and on 
lowering of the pressure into fig. 10 (I). As on increase of pressure 
fig. 9 (I) is converted into fig. 8(1) the pressure for the system 
F+L+G in fig. 9(1) is a minimum. This is also in harmony 
with the situation of the points m, m, and Fin figs. 11 (U) and 18 (U). 
Let us now just take a system F+ L, + G, in which JL, differs 
but little from Z, and G, but little from G; this system will then be repre- 
sented by a triangle situated in the vicinity of the line Fm m,. As the 
reaction / + £2 G takes place with increase in volume, the conver- 
sion of / + L, into £ + L’, + Gin the infinitesimally differing system 
F+ L,+G, will take place with increase in volume and the 
conversion of “+ G, into £ + L’, + G’, with decrease in the same, 
We have noticed previously that, in this case the three-phase triangle 
must turn in such a manner that, on increase in pressure, the con- 
jugation line solid-vaponr gets in front and that on reduction of 
pressure the conjugation line solid-liquid precedes. This also is in 
85% 
