( 805 ) 
dp sah 
the line “—0. So this point is really a minimum of pressure. Now 
LU 5 
the diagram of isobars has changed in this (fig. 12) that a loop-line 
x 
dp.o 
Vv 
tte tee srogy 
per? teeny 
V 
Wie. 12. 
has made its appearance, as we see immediately from the fact that 
the direction of the tangent of the isobar p= 0, passing through the 
} : Ì dp dp : f 
point of intersection of aap 0 and he 0 becomes indeterminate 
in this point. The two branches of this loop-line start, of course, 
one from the point «=wz,, v =O, the other from the point on the 
line w=w,, where p=O. They pursue their course through the 
double point towards infinity, just as the branches of »=O in 
figure 10. Now too, the positive isobars have the same course as 
indicated there. The negative isobars, however, at least part of them, 
have broken up into two parts, a branch on the left of the mixture 
with minimum eritieal temperature, which has again the same course 
as in fig. 10, and a branch on its right, forming a closed curve round 
; ; ' 4 dp ‘ dp MAD 
the second point of intersection of ena O and 0. Only for isobars 
for a larger negative value than that in the last-mentioned point 
there exists only one branch. 
It is clear what will be the course for intermediate temperatures. 
It follows then again from the given equation that the pressure will 
be negative in the double point lying then at a value of « where 
da db ; : ; 
b—>a =a So we have a loop-line, which itself runs again as a 
