( 826.) 
Tr = Ty, (A — 1,17 we + 1,58 «*) 
par = pe (W— 1,624 42,4507). 2 2. . (16) 
vp ==. vy (14-0022 —.0/95 2"), 4) 
while from (14) would follow: 
var = vy (1 + 0,45 « + 0,08 z°). 
Although the agreement between the two expressions for v‚j is 
not quite satisfactory, it yet by no means indicates that the law of 
corresponding states does not hold; it may very well be a result of the 
uncertainty of the critical data of the homogeneous mixtures, chiefly 
of the v,,’s. Besides from the second formula for v,; I find: 
for 2 = 0,05 vr = 0,00432 and for # == 0,1. 9,;= 000483 
and these values deviate from those determined directly (0,00434 and 
0,00444) not more than the amount of the error that can be made 
in these determinations. Besides, since the law of corresponding 
states does not hold entirely with pure substances, it is not likely 
to do so for mixtures. 
3. The p, v, 2, diagram for martures with a small value of a, 
at a temperature differing little from Ty. 
We shall now consider different mixtures at the same temperature 
T'; the system of isothermals in the p, v, 2 diagram, at that tem- 
perature is represented by the equation of state (13), where, however, 
T must now be taken as constant and w as variable. We will now 
put this equation in another and more suitable form. 
Among all the mixtures there is one for which the critical tempera- 
ture would be 7’ if this mixture remained homogeneous; the com- 
position «7; of this mixture, and also the critical elements py, and 
vr; are determined by equation (14). (In this equation we must put : 
Vr PRS bii Dak = pTt and vr == V7}). 
Hence we find to a first approximation 
Kian eae 14 BT AE De (IT), oT = ae 
It will be seen that to a first approximation the value vz is 
either positive or negative according as 7'— 7), and «a have the same 
or opposite signs, that is to say 
a >> 0 eg |) 
T>T,| em >; figs. Land? | em <0; figs. 3, 5, 9and11 | 
| | 
| | 
T<Te vre <0; figs. Zand8 \ wr >0; figs. 4, 6, 10 and12 | 
(T-T;).(17) 
2) Comp. also Krrsou, luc. cit., p. 12. 
