392 PEOFESSOE BXmSEN A^T) DE. H. E. EOSCOE’S PHOTO-CHE^HCAX EESEAECHES. 
effervescence, or diffuses through the liquid by virtue of molecular attractions and thus 
makes room for new, not yet decomposed molecules, a certain amount of force is expended, 
which corresponds to that exerted by the catalytic action. From this point of '^iew these 
catalytic phenomena are not to be regarded as manifestations of a peculiar force, but as 
actions which must always occur as necessary consequences of affinity, when a mass in 
the state of chemical action undergoes an essential alteration of its constituent parts. 
The quantitative estimation of the relations which exist in these phenomena of con- 
tact between the mass of the substance, the time and other modifying conditions, has as 
yet not been possible, owing to the absence of any case in which these relations were 
exhibited in their simplest forms. Our method of photo-chemical measurement points 
out a direction which promises to afford interesting results concerning these quantitative 
relations. 
As we intend at a future time to consider these relations more fully, we shall here 
merely enter into the subject as far as is necessary for the due understanding of the phe- 
nomena of induction. The following conclusions may be drawn from the foregoing 
experiments with excess of hydrogen : — 
(1) That the maximum of the induction of the normal chlorine mixture is reduced 
from 100 to 37 ’8 by the presence of hydrogen. 
(2) That this diminution of the action does not arise fi’om the dilution caused by the 
addition of the hydrogen, but from a catalytic action proceechng from its particles. 
Still more remarkable than in the case of the hydrogen, is the effect produced by the 
admixture of other foreign gases on the combining power of the normal chlorine and 
hydrogen. This is most distinctly seen for oxygen gas in the following Table : — 
Series of Experiments VII. 
Temp. 15°‘4 C. Barometric pressure =0“'7550. 
I. 
11 . 
111 . 
IV. 
V. 
VI. 
Time of 
observation 
in minutes. 
Normal gas, 
alone. 
Ditto, with 
5 
10 0 0 
of oxygen. 
Ditto, after 
longer 
saturation. 
Ditto, with 
1 3 
lOOO 
of oxygen. 
Normal gas, 
alone. 
0 
1 
5-2 
1-0 
4-0 
1 - 0 * 
15-6 
2 
7-3 
2-0 
5-0 
2-0 
24-0 
3 
9-4 
4-0 
3-0 
1-0 
27-1 
4 
11-5 
3-0 
3-0 
1-0 
29-9 
5 
13-5 
3-0 
5-0 
DO 
38-5 
6 
15-6 
4-0 
6-0 
1-0 
38-5 
7 
20-3 
4-0 
3-0 
2-0 
44-7 
8 
24-3 
5 - 0 * 
3-0 
1-0 
p 
9 
30-4 
5-0 
3-0 
1-0 
47 - 0 * 
10 
36-9 
4-0 
4 - 0 * 
1-0 
45'0 
11 
40-0 
4-0 
5-0 
1-0 
47-0 
12 
48-0 
5-0 
6-0 
1-0 
13 
53 - 0 * 
5-0 
5-0 
1-0 
14 
53-0 
5-0 
4-0 
2-0 
15 
• • • . . • 
5-0 
5-0 
2-0 
16 
5-0 
