( 893 ) 
: Bu - : ; 
coincide, in which case the part of (re =0 which runs from the 
av 
Pp 
double point towards smaller values of v, forms a closed curve — 
this coinciding depends on the shape of the line v= 5. If the latter 
is a straight line, as we have assumed in our calculations for the 
sake of simplicity, coincidence is either excluded or at least very 
d*b ~ 
doubtful. But if, what is really more probable, oe should be positive, 
TL 
the whole p-line over its full width turns its convex side to the 
| ï dv 
z-axis for po, and it no longer intersects the line (a) == 
\da* }), 
2 
a 
v 
d’ 
We then conclude that the part of = = 0 which runs from the 
double point to smaller volumes, is closed, and that the whole curve 
dv 
(5 -}=0O forms one continuous curve, with a double point in the 
2 
p 
above mentioned point. With rise of the temperature this curve 
undergoes a change of shape, which it is not necessary for our 
present purpose to examine in details. 
2 
. & . Vv . ‘ 
Let us in the same way describe the course of (=) == (Qin ig 
a 
q 
general features. Also for the course of this curve the presence of 
d, 
zl =0 is of the highest importance. If this line is present, and 
& Ë 
2 
d 
intersects e = 0, which then takes place in two points, the 
v 
: ce aor d*v 
lefthand point of intersection is again double point for G :) == () 
9 
ve 
From this double point two branches start, which remain in the 
d 
| is negative. So the lefthand branch, which 
v 
region in which ( 
wv 
runs to the high values of v7, continues on the righthand side of 
dp ave 
(=) = 0, and moves further apart from this line, and the righthand 
v 
d* ; 
branch passes through that point of (3) == 0, in which this latter 
a? 
curve has maximum volume, and continues to follow the line 
d, imei 
(2) = 0 in its course at a certain variable distance. The two other 
ax v p 
dv 
da 
branches, which start from the double point of ( ) = 0, again 
q 
