1219 
we notice that the latter, besides the point of contact /’, has another 
two points of intersection in common with curve ab, which both 
appertain to a lower temperature than 7’. The horizontal line in fig. 2 
corresponding with the pressure Pp must therefore intersect the curve 
XFY, besides in F, also in two other points to the left of point 
F; the one point of intersection must lie on the branch XF, the 
other on the branch )/. 
If now we take the boiling point line of a somewhat lower pres- 
sure P’, this will be intersected in fig. 2 (II) in two points by the 
line XYF'Y. Hence, the horizontal line in fig. 2 corresponding with 
this pressure P’ must intersect curve \/} in two points. 
The boiling point line of a somewhat higher pressure ?" is inter- 
sected by the line Y/')’ in four points, of which two lie on the 
part YF and two on the part VF of this line. The horizontal line 
corresponding with this pressure /" in fig. 2 intersects therefore 
each of the branches XN and FF in two points. 
If in fig. 2 (II) we take a straight line ZFZ, whose direction 
differs but little from the tangent X/Y this will intersect the boiling 
point line of the pressure Pp not only in /’ but also in three other 
points namely two on FZ, and another on /Z. The horizontal line 
in fig. 2 corresponding with the pressure Py, therefore, intersects 
the curve ZFZ, in F and further the branch ZF in one and the 
branch ZF in two points. Hence, on branch ZF must occur a 
point with a maximum and another with a minimum vapour pressure 
V > v therefore A >0 and 2>0; Q—-AS>0; Q—-uS> 0. 
) 
Zi B 
From (20) follows : — positive and greater than Be. from (9) and 
also from (18) and (19) follows dP and 7 positive. The curve XP Y 
must therefore have a form as drawn in fig. 3 wherein d,/d again 
represents the tangent in the point / at the omitted melting point 
line; the dotted line passing through / represents the tangent in the 
cusp F at curve XFY. 
The fact that curve X/'Y in 
fig. 3 must proceed from # towards . 
higher temperatures and pressures 
q@ is again evident from a considera- 
tion of the saturation line of the tem- 
perature 7'p under its own vapour 
pressure, and of the boiling point 
line of the solutions saturated with 
F of the pressure Pp. For both 
curves have in this case a form 
