34 
Proceedings of the Royal Society of Edinburgh. [Sess. 
T - 
T 
+ p'V 
,da 
da 
(17) 
=v 
+ * v ( T (l), 
1 0A 
A da 
n - g 
1 
a 
+/V'| 1 -(w-a)i . 
_ d log j? _ rt+I - — 
d log a l dg 
0Y dp\ 
dp da) 
aY 
Kl), 
_1 0A 
A da 
assuming pY = RT. 
The value of the second term is shown in Table i V. below. It evidently 
tends to reduce the discrepancy, but does not remove it. The value of the 
term was calculated assuming the volume of the gas in the adsorption 
chamber to be 20 c.c. Titoff gives the volume of the smaller bulb employed 
as circa 25 c.c., containing 4-10 grm. charcoal, density 1*8. Hence 
n-ga 0 lo gp RT 20 p 01ogp - 094 . 
ga 0 log a 22,400 ga 76 0 log a 
Table IV. 
p. 
ga. 
0 log p 
0 log a ‘ 
a. 
A. 
Correction. 
NH S { 
0 - 3 cm. 
20 c.c. 
1*4 
5-5 
0-44 
o-oooi 
76 
510 
7 
135 
•38 
•007 
CO, { 
0*2 
25 
1-3 
2-3 
0-35 
•0001 
73 
690 
3 
65 
•28 
•002 
N 2 { 
1-0 
27 
1 
0-26 
0-29 
•002 
76 
140 
1*3 
13 
•31 
•004 
' Since the second term does not remove the discrepancy, we must con- 
sider it mainly due to the third term, which represents the change in 
energy due to an alteration in the extent of the adsorbing area per grm. 
The third term is 
0E 
dg 
«v|t 
(cp\ 
\0T7 
A 
1_0A 
A da 
-A 
+ apY 
1 0A 
A da 
from (10) 
cr + T 
0<X 
0T 
a 
A 
V T \ . 
• \df) A J da 
We may derive an estimate for the value of — j.V.T 
dp\ 
0T / A 
0A 
da 
as 
% 
follows : — 
