( 338 ) 
b. K>O; the border curve and the connodal line are hyper- 
bolae; the asymptotes are: 
p= +(p—pri)V K(bordercurvejandy'= + m, ,(«—« 7.) V K(connodal line). 
If T>T;, p (or g’) is the real axis; only that branch of the 
hyperbola which lies above the axis p= pry can be observed as 
border curve; in the case of the connodal line it is only the branch 
lying above the axis r= em which can be observed; again two 
plaitpoints are found of which only one can be observed, and the 
coordinates of which can be expressed by the same terms as used 
for the ellipse. If 7 =—=7}, the border curve and the connodal line 
consist of two straight branches meeting at the critical point of the 
pure substance, which is therefore a double plaitpoint. Lastly, if 
T< Ty, there is no longer a plaitpoint; we observe two branches 
of the border curve and the connodal line lying to the right and 
the left of the point prz, vr; each phase on one branch co-exists 
with a phase on the other. 
11. The border curve in the p, v, T diagram for a mixture 
of composition «. 
In equation (86) of the projection of the connodal line on the 
a, v-plane, if we consider «© as constant and 7’ as variable, that 
equation will express how the volumes of the phases, where the 
condensation begins and ends depend for the same mixture on the 
temperature. It therefore may be considered as the projection on the 
v, T-plane of the border curve on the p,v, 7-surface for the mixture 
of composition «. 
This projection, can be written in the following form, corresponds 
to (36) 
0 = (vv)? — 2 ©" (var) + B'?—g'?, . . . (44) 
where 
1 
Dii En (v',+0',) — vak = DH org vor = (to a first approximation) 
<i LE m* 4, xi 2 mo 4m,, my, 
—— Mm, ora ae jee as ‘p =F . TE = & + 
RT; Ree SATE aa, be ee 
we = m,,(m*,, 2 
a le) = on ne En + Mo |H 3 Mei — 
A mms | T—Tx 45 
DT, ET ee 
and 
ih 2 m,, T—T x, 
dr “ep? ZE ak ai ara 46 
f 4 e, ) 4 RT rme, Ma GTE en 
