70 Mr Ozaley, Magnetic Susceptibslity with Temperature. 
As the critical temperature is approached 8,— 1, therefore 
he 
ae (OY — })r-1 O= Si | 
Toes CO". 3%. (vu — b)? .e Je FS, 
1 _2.Ab, Ae 
and ——~— = ('.9% (v—b).e @-9.¢ *, 
1 — Bp 
We shall assume that the amount of heat absorbed in the 
change of molecular complexity increases as the complexity 
increases, and that, further, the change of specific heat, Ry,, and 
the alteration of volume which accompanies association, Ab,, also 
increase numerically with the degree of complexity. Referring to 
the numerical values * of (v—b), qo, RS, Ab, it is seen that the 
ratio 
on these assumptions. 
Therefore near the critical temperature 6, > A». 
From (6), differentiating with respect to S$, we find 
0B, p(1— By"). Bp? + 2By?** 
GSS (1— By)? 
Qo, 
=O yy. 3%. (u — b)PO. ea (ItP—1 Bp) Abp | eo BS 
, p—l : 
ZG. aa Nesta (OS) 2g (+9-1.B,) .Abp  @ BS ae 
‘ — OC’. 3% (y—b)?4.€ (141 Bp) Ady Gop . = 
RY 
neglecting the change in the value of Ab, due to an infinitesimal 
change in 5. 
08 pu 
If a =0, Yysut%e = var : Roe 
and therefore Sn = a PERRO PE Sen Sb0000- (7). 
Again 
By? _(#(p=1). Bp) Abe _ quo 
Io" =C".S% (u— b)? +.e Ce .e #3, 
— Pp 
* (v—b)>1, qo.=5000 gm. cals., R3=1380 gm. calories for the critical temp. 
Ab, = — 8:26 c.c. if v=18'0 c.c. These values are taken from the paper referred to 
at the foot of p. 68. 
+ Sz, is the temperature at which the association is greatest. 
+ It should be noted that 3), is not independent of p, for qo) and Ry, are each 
functions of the molecular complexity. Hence the additional remarks concerning 
the positions of the minima. 
