( 1262 ) 
complex is considered as a compound molecule, the number of com- 
pound molecules amounts to the xk part of this value of z. The 
number of simple and the number of compound molecules is then 
to each other as 1— 2 is to 
n 
ig 
4 T dv 
In conclusion a remark on the valne of ec; for the saturate 
(2) 
IU 
vapour phases. Let us write nn é, in which ¢ is the value obtained 
when unity is divided by the values from SrpNey Youna’s last table. 
At very low temperatures this value is only very little smaller than 
1, e.g. for ether of O° about 1 — 0,028. With rise of temperature e 
U 
1 
decreases, and for 7), it has descended to —. From 
== Ewe 
Ss 
derive: 
Tdp Tar Tde 
p dT ' vdl edT 
from which follows: 
Tdv hy dp 7. de 
vdT p aT a 
L Dade ‘ T de . ; 2 
Now ——. is negative, and — ——— is exceedingly small for very 
e dl edt ‘ F 
low temperatures. At the zero-point of the temperature the value 
1 
would be equal to 0, and even for m iy, it is still smaller than 
e.g. —. But it rises continually, and for 7, for which en 
4 ; v dl 
is infinitely great, it will also have to be infinitely great. So there 
is also a temperature for which it is equal to 1. We can calculate 
from SypNey Youne’s table at what temperature this takes place, 
T dv Tdp 
v dl par 
responds to m==0,79. For the different substances m varies only 
little. We shall discuss this temperature again, when we shall con- 
sider it as the temperature at which the product pv has maximum 
value. 
and so at what temperature This temperature cor- 
T dv 
So below this temperature the quantity — — aT is smaller than 
v d 
LT dp set ze 
DT’ but it is greater in the interval m==0,78 to m =—=1, rapidly 
P f 
increasing as it approaches to 7%. 
