fi) 
( 333 ) 
This expression is either positive or negative; that is to say that 
the border curve may be turned with its convex side towards the 
v-axis, while in the p,v, diagram for a simple substance the bor- 
sh ne AD 
der curve is always concave to the v-axis. aa will be positive if m 
and R7",4,,a—m’,, have different signs, and will be negative in 
the other case : 
Vid lian ky, a = ME | RT; hi a me Mr 
ml | figs. 5 and 6 | _ figs. 1—4 | 
Be PSS RO ee 
m,, <0} figs. 41 and 12 | fies!) 7-10 | 
8. The projection of the connodal line on the x, v plane. 
The equation of this curve has been given by Korrrwee *). In 
connection with our preceding formulae it is most easily derived 
from equation (380) by expressing p in terms of # and v by means of 
the equation of state (18). I shall now bring it in a form analo- 
gous to (30). 
The border curve intersects the isothermal of the mixture « at 
two points (p’,, v’,), and (p’,, v’,) which indicate the phases where 
the condensation begins and ends. I again make : 
gote) tm Dee 
(p's + Ps) — pre = IF and 3 (p', — Pp) = 2, 
and consider the four infinitely small quantities ®', gy’, 77’ and a' as 
functions of 2. 
By expressing that the two points are situated on the isothermal 
(18) and on the. border curve (80), I obtain four equations from 
which the relations we want can be derived. In this way I obtain 
to the first approximation, 
1 Rar: ae et ai Amf Mm, 
Ben amat) (SRP NEN mn ihm) [et 
01 
1 [m,, fm’ 2 4m,,m 
a. 5 we - = +. ma, + — Mas, _ Til saan UTk + . . e . (32) 
2M5o| Moir 3 Np 
IT = Ms (LTE nt Oe ne ee Va re) 
and 
RLM (GOTEN Phs ae eee] 
1) Wien. Ber. 98, 1159, 1889. 
