384 PEOFESSOE BUNSEN AND DE. H. E. EOSCOE’S PHOTO-CHEMICAE EESEAECHES. 
Series of Experiments II. A. 
Tube r. 
Cylinder 1. 
Cylinder 2. 
Cylinder 3. j 
a 
0-002487 
0-002487 
0-002487 
0-002487 1 
n 
1 
6 
4 
1 1 
t 
78-6 
70-0 
70-0 
70-0 
^1 
3-9 
6-8 
41-0 
28-0 
( 
The calculation from these numbers shows — 
Exp. 1. 
Exp. 2. 
Exp. 3. 
Cylinder 1. 
Cylinder 2. 
Cylinder 3. 
Chlorine mixture at 0° and 0™-760 
before insolation 
180-1 
107-0 
69-5 
Ditto, after insolation 
180-4 
104-4 
18-3 
Hydrochloric acid in 100 vols. gas 
0-0 
2-4 
73-7 
If the gas consisted of equal volumes of chlorine and hydrogen, the tube r, whose capa- 
city at T° and P pressure was found to be C, must, according to calculation, have con- 
tained I6'4 cub. cent, of chlorine at 0° and 0“‘76 ; as the amoimt of chlorine found by 
analysis was I6’3 cub. cent., it may be concluded that the gas was pure. The great loss 
of 73-7 per cent, in cylinder 3 could not arise from leakage, as a mixtm-e of chlorine and 
hydrogen preserved in the dark in this cylinder showed on analysis no perceptible change. 
Experiment II. The tube r, with cylinders I and 2, were exposed to the diffuse light 
of a cloudless sky for three hours, and gave the following elements for calculation ; — 
T=12°-9, P=0"'-752I. 
Series of Experiments II. B. 
Tube r. 
Cylinder 1. 
Cylinder 2. | 
i 
a 
0-002487 
0-002487 
0-002487 
n 
1 
5 
1 
t 
79-9 
79-0 
79-7 
^1 
5-2 
32-0 
48-5 
These values give — 
Exp. 1. 
1 
Exp. 2. 1 
Cylinder 1. 
Cylinder 2. ; 
j 
Mixture at 0° and 0“-76 before insolation. 
179-8 
106-8 
Ditto, after insolation 
160-3 
13-2 ! 
Hydrochloric acid formed in 100 gas ... 
10-8 
87-6 j 
As the analysis of the tube r gave I6‘3 chlorine to I6'5 hydrogen, we may conclude that 
in this experiment also the gas had the normal composition. 
In order to determine more accm'ately the influence which the volume of gas exerts 
upon the duration of the induction, we employed an arrangement similar in principle to 
the instrument represented in flg. 2 of Part I., but having a peculiar insolation-vessel 
