1916-17.] The Adsorption of Sulphur Dioxide by Charcoal. 167 
This was shown by the fact that the rate of leak with stopcock open and 
shut was the same within the limits of concordance of readings taken. 
The quantity of heat measured never exceeded 95 gram calories, and in 
general varied between 55 and 30 calories. 80 per cent, of the effect was 
recorded in the first half-hour and 95 per cent, in the first hour. 
Table I . — Mass of Charcoal = 4*428 gm. in Yacuo. 
V • 
a . 
Aa. 
0 . 
At . 
P. 
0*10 
94*6 
94*6 
165*5 
28*6 
76*1 
(0*48) 0*36 
240*0 
145*1 
219*9 
28*6 
55 
0*92 
387*7 
147*7 
215*3 
29*1 
55 
(1*67) 1*64 
547 
159*0 
213*1 
28*6 
55 
(311) 
705 
157*7 
204*7 
28*9 
76*3 
(5*09) 4*50 
858 
151*3 
186*4 
29*3 
55 
(7-18) 
1003 
144*7 
194*7 
27*9 
95 
(10*32) 
1137 
134*2 
178*5 
27*5 
55 
(14*14) 13*64 
1254 
115*4 
152*6 
27*7 
59 
(24*63) 
1432 
178*6 
226*4 
28*9 
76*5 
(39*73) 
1559 
126*6 
156*5 
29*9 
55 
(54*02) 53*30 
1637 
77*3 
91*9 
30*4 
76*4 
(65*32) 
1711 
74*3 
76*1 
30*9 
55 
. (72*76) 72*05 
1815 
104 T 
106*6 
31*2 
55 
(76*96) 75*50 
1948 
126*9 
120*9 
29*9 
77*0 
(77*73) 76*40 
2065 
114*8 
110*6 
30*5 
55 
Table II . — Mass of Charcoal = 4*428 gm. 
/ 
p . 
a. 
A a. 
0. 
At . 
P. 
0*14 
119*2 
119*2 
197*4 
27*7 
75*9 
0*45 
269*8 
140*2 
208*5 
29*7 
76*5 
(1*06) 1*05 
421*1 
161*3 
223*8 
28*6 
762 
(2*67) 
676 
255*3 
333*6 
28*5 
55 
(5*29) 
923 
246*3 
317*5 
28*4 
76*8 
10*80 
1176 
253*5 
• • • 
... 
59 
(22*10) 
1402 
226*0 
287*5 
29*6 
76*7 
(43*82) 43*60 
1584 
181*8 
226*2 
30*6 
76*6 
(66*32) 
1724 
139*8 
151*4 
29*1 
76*5 
(73*20) 
1837 
113*1 
113*8 
30*5 
>9 
(75*79) 75*41 
1961 
124*6 
118*1 
31*1 
76*6 
77*12 
2104 
143*0 
... 
... 
77*1 
In Table III are given the equilibrium values of p and a, taken from 
Tables I and II. The values of p are referred to —10*1° C., when the 
pressure of the calorimetric dioxide would be 76’0 cm. mercury, using the 
fact that for a given a, p / P is nearly constant. a is referred to one 
gram charcoal. 
