358 PEOFESSOE BUIS'SEN AJST) DE. H. E. EOSCOE’S PHOTO-CHE^nCAE EESE A ECHES. 
The amount of chlorine, C, subtracted from the total volume of gas, Cj, gives the volume 
of the hydi-ogen contained in the gaseous mixture. The results of a series of experiments 
conducted according to this method are given in the following Table : — 
Series of Experiments I. 
i 
Capacity of 
vessel. 
Tempera- 
ture. 
T. 
Barometer. 
P. 
n. 
t. 
f. 
a. 
Cl. 
Chlorine 
found. 
C. 
Chlorine 1 
calculated- j 
.Cl. 1 
i 
Exp. 1. 
34-81 
ii-3 
0-7363 
2 
66-1 
57-7 
0-002443 
32-385 
16-02 
16-19 i 
Exp. 2. 
34-81 
11-6 
0-7415 
2 
67-0 
58-3 
0-002443 
32-580 
16-27 
16-29 
Exp. 3. 
190-24 
11-5 
0-7518 
6 
79-6 
66-6 
0-0024869 
180-590 
89-96 
90-28 
Exp. 4. 
61-01 
12-9 
0-7393 
2 
71-9 
15-2 
0-0024869 
56-672 
28-15 
28-34 ■ 
Exp. 3. 
64-27 
12-9 
0-7393 
2 
77*4 
19-5 
0-0024869 
59’700 
29-61 
29-85 
Exp. 6, 
51-60 
12-9 
0-7393 
2 
76-7 
45-7 
0-0024869 
47-931 
23-57 
23-96 , 
The two last vertical columns show that the electrolytic chlorine and hydrogen gas 
invariably contains equal volumes of its constituents, and that the small variations from 
this proportion, which occur in these experiments, do not exceed in amount the errors of 
observation to which even the most accurate analytical processes are necessarily subject. 
These analyses show also that the gas under examination did not contain any free oxygen, 
for if a decomposition of the water as well as the hydrochloric acid had taken place, by 
which two volumes of hydrogen are disengaged for every volume of oxygen, the volume 
of hydrogen could not have stood to the volume of chlorine, nor to the volume of clilo- 
rine and oxygen, in the simple relation of equality ; especially as the free oxygen is not 
estimated by the volumetric method employed. The absence of all oxides of chlorine 
which might have been formed by secondary action may also be deduced from the 
following considerations. In the electrolysis of hydrochloric acid, the liberation of every 
two volumes of hydrogen is accompanied by an evolution of two volumes of chloiine ; in 
the electrolysis of water the same two volumes of hydrogen are accompanied by only one 
volume of oxygen. This oxygen, combined with two volumes of chlorine, gives two 
volumes of hypochlorous acid gas. As soon as the equihbrium between the electrolytic 
liquid and the evolved gas has been established, the liberated gas would contain, 
supposing this decomposition to occur, in six volumes, four volumes of hydrogen and 
two volumes of hypochlorous acid gas. These two volumes, CIO, liberate, however, 
just as much iodine as four volumes of chlorine. Hence the analysis would have ghnn 
four instead of three volumes of chlorine, on the supjjosition that the whole of the 
chlorine combmed with oxygen to form hypochlorous acid. If only small quantities of 
hypochlorous acid were present, a slight excess of chlorine above the normal amoimt 
would have been found, whereas experiment always gave a slight loss of chlorine. By 
similar reasoning, it may be proved that none of the higher oxides of chlorine can be 
contained as admixtures in the gas. 
The perfect purity of the electrolytic gas haring been thus established beyond doubt, 
a question of no less importance presented itself ; namely, does the combination of chlo- 
