974 
the factor p will indeed be somewhat greater than 1, but differ 
only little from 1. 
If we confine ourselves to that part of the whole region where 
no quasi-association worth mentioning is to be expected, to which 
part the critical point also belongs, the last equation will hardly 
b 
change, if we put unity in it instead of « a And then a rule 
k 
follows from this holding for all normal substances, so for not really 
Ter v 
associating substances, viz. for given ar and m, —————— has the 
same value. For substances with the same value of f—1, p is 
therefore also the same and with different value of #—1 we have 
Y Y 
aoe 1 SE Vee 1 
8 3 
or according to results obtained in These Proc. p. 903. 
! 
Y Y 
ints “ bg a7 = 
ca biim Bhim. 
Not rigorously valid for the whole region, however. To equal 
reduced pressure and temperature corresponds a volume which in 
b 
reduced measure is different for the different substances, when ace 
lim 
. » . . v . 
differs. But if we write the value BE for v, and the value 
REE 
blim 
for v',‚ we obtain: 
4 = a= 
Fa eee 
tum 
b, 4 b, 
a Va Sn AE) 
And as we have concluded to the approximate equality of 3, 
h LEN : 
pete al 1) ete. we find as approximate rule: At the same 
Dim Bhim 
reduced temperature and pressure the same volumes are for all 
substances the same number of times the molecular volume viz. by. 
If, therefore, we had expressed the law of corresponding states in 
