( ») 
when we namely assume that for the critical point the dissociation 
of the double molecules has proceeded so far, that we may practically 
assume that all the molecules have become simple 1 ). As a and b, as 
all the above quantities, refer to double molecular quantities, we 
must write 2 RT C , because for £=1 the factor 1 + ^ (in (1 + £) RT) 
into 2. 
Hence we find with #=2 (gr. cal.) and b = 2b t = »/,: 
or 
T c — 400 (absolute); p c — 400. 
But as we saw on p. 734 of our preceding paper, pv and % are 
now expressed in caloric measure, as R is expressed in gr. cal. So 
to express these quantities in ergs, i. e. p and in dynes per cm 1 , 
the found values of p and «/ e * must still be multiplied by 41,74 X 10 *\ 
or by 41,20, when p and are expressed in atmospheres. 
As now a critical pressure of 400 X 41,2 = 16480 atms. is some¬ 
what too high for an ordinary substance, we may obtain more 
suitable values of pressure without any change in our foregoing or 
following calculations by assuming all values of pressure to be e. g. 
100-times smaller, and all values of volume 100-times larger, retaining 
all values of energy. So instead of b l = lcm*, 2b t = l / 3 cm*, 
— A6==7, cm 8 , we have only to think 6, = 100 cm 9 , etc. In this 
case 270000 must be taken for a instead of 2700, for then the value 
of pressure «/„* becomes 100-times smaller than before, whereas the 
value of the energy % remains the same. 
Now for the low temperature T= 9 (absolute), in consequence of 
which Q becomes — (see p. 774), (3“) passes into 
ft 8 _27 - 
1 —~2 6 
or 
Then the 
b Otherwise the critical data will be determined by the equations (15), (16) 
and (17), derived by me in the Arch. Teyler . (2) T. 11, Troisieme partie, 
p. 235-331 (1909). F ’ 
