( 26 ) 
Physics. — “On the solid state II. By J. J. van Laar. (Com¬ 
municated by Prof. H. A. Lorentz.) 
(Communicated in the meeting of April 23, 1909). 
b. In the foregoing Paper *) the expression (see p. 770): 
y+ l —— -P±^.Ab 
«■ .r . RT. RT 
was found for the dissociation of the double molecules of an arbitrary 
substance. With 
. l +h 
~r (-Lb) = (-Lb) = tp 
%(-Lb) = X 
(see p. 773) it was reduced to 
( 3 ) 
when y = 7, was assumed. For as y = - (— k l + 2 & 2 ), k, will be 
e. g. for a tri-atomic molecule about 6 (gr. cal.), and k x will be 
about 9 for the six-atomic double molecule. For y we find then the 
value V, ( 9 -J- 12) = •/,. But in other cases the exponent y will, 
of course, possess other values. In order to be able to carry out 
some numerical calculations, we are at any rate justified in assuming 
an imaginary substance, the determining quantities of which are given 
by arbitrary, but possible values. 
Thus we imagined a substance, for which (see p. 773) 
c “ 2 (gr. cal., c.M- 3 ) ; ?0 — 3200 (gr. cal) ; y = 7* | 
« as 2700 ; b, — 1 ; 2b, = 7, ; - Lb = — (_ b x -f 2b,) = 7 . I ’ 
Which caused equation (3) to pa® into (R = 2 gr. cal.) 
j— = 32000 <?’/’ e ~ - .(®°) 
On the supposition a and b constant, the critical data of this 
substance will be determined by 
2RT c = —i ■ _ __LiL 
___ 27 b Pe 27 b * ' 
1} These Proceedings, March 27th 1909, p . 76B . 
