291 
6’ tor ies , we get: 
Òv / 
dp EE du heads | da. Aa BDE ted 
dv), 2\dv/, | v—b v? (v—b) v 
Now substituting for 4/7, its value from (1), we find: 
(5) 1 #(1—2) RTv—4ah = da A | 
dv}, 2 vb (2—e) RTv Aar (le) A*| vb v(v—b) 
if, (1e) RT Qa 
=~ ~ 25 y = 
(v—b)? ( on v? 
writing simply « ’/,, for Va (see $ 10) and A for Aya; hence also: 
dp 1 a (l—a) (RTv—4ea A) 
(5 Nt 2 (v— mn RTv—4e (1—«) A: 
This must now be =O at the critical point; thus we have: 
@ (1—a) (RTv—4ah)? = [(2—#) RT v— Aw (1—a) APT [(1 Hw) RTv) 16!) — 40°], 
i.e. after some reduction and division of the two members by RTv: 
a (le) RTv — 8e (1\—a) aA = (2e) (14 2) RTv (15!) — 4 (2—2) a? — 
— 4 a (l1—2#’) (1—0’) A’, 
(la) RTv (1 re | 
and from this: 
(2—w) a? — Za (l—a) a A Ha (lr?) (lb!) LZ? 
Re en 
ld Lane 6) 
for which we may also write: 
== (ls (LAME De (A 
En aA had ee 
NER ab) 2 (2) 
This is, therefore, already the expression for R7,, expressed in 
Ve, be, ete. As a check may serve that at A =O this-passes into 
4(2—a)a*® 4(2—.2#)a, (ve — bo) 
Nv, zi N we 
our former expression (Arch. Teyler loc. cit.), derived for the case 
that there does not take place any change in the molecular attrac- 
tion in consequence of the dissociation of the double molecules. 
. If also x= 1 (all the molecules single), then becomes 
Za. (Web) 2 (r—l)’ a 
Si MOE rile re be 
as we also found before. (Cf. among others These Proc. Vol. XVI, 
p.45, and Ibid, p.810). In this the value of r=v,:6, can 
Kle 
RD 
qd? 
of course not be determined until we have also put (4 )= 0. 
Dart 
8 ite 
In ideal substances 6', = 0,7 = 3, hence RT, = 27 a In ordinary 
Yeo 
