el 5 — Bx, 
ii. re 
12,4, a 1—z,—y, 
Enig? 
‘ 
1, 
and eet ONE 
a yy tie 
then the substitution into the equation of the envelope yields the 
following formula: 
pre de NG cet 
ee Pe de 7. 
( a, id N oi 1) ( v5 Vs 4 1) 
Ol En C : 7 
L,Y, Lea 
From this follows that the conjugated curve of a nodal envelope 
of liquid phases, is, in the chosen circumstances again a nodal enve- 
lope, with another value of the constant, namely: 
PSP Pr PL 
C'=C (2) a Gales 
Pr Ps 
li <p , ),, the factor of Cis greater than unity and the con- 
Pe Wa À 
jugated curve is therefore to be found nearer the hypothenuse. Only 
in the case that p,=p, we have C’ = C; but then the system is 
only apparently a ternary one, and the envelope degenerates into a 
straight line with the equation: 
elis 
It appears therefore that the conjugated curve in this case always 
coincides with the envelope. 
We might also have considered the nodal envelope for vapour 
phases. Then we consider the projection of the way which we should 
follow, if we descend on the vapour sheet from the point where 
the pressure has the highest value towards the point, where it 
has the lowest value, always moving in such a direction that we 
have the liquid phasis just in front. We find the equation of this 
curve if we express the values of wv, and of y, as functions of «, and 
y, and if we substitute those functions into: 
de, Pes df dy, 
pire De dir 
This is only possible if wx, and uw’, are constant as we have 
already mentioned several times. With the aid of the equations: 
Lv 1 dT nd pe 
ZE ——@ 71 
PS 1 — &,—Y, 
and 41 = Ys a é 
a yy ae 
a 
