480 SIR B. C. BRODIE ON THE ACTION OF ELECTRICITY ON GASES. 
sulphite of soda ; a similar estimation was made with the solution after the experiment. 
From the difference between the amounts of hyposulphite respectively employed in the 
two cases, the oxidation effected in the tin solution was calculated in cub. centims. of 
oxygen. 
The volume of the gas before the experiment was measured in a small gas-pipette ; 
the gas after the experiment was collected and measured in an ordinary graduated jar. 
In the following Table S is the oxidation effected in the protochloride of tin as expe- 
rimentally determined, T, V, V 2 have their previous signification. 
T. 
V. 
W 
V-V r 
S. 
v-v, 
T ‘ 
S 
T' 
3-86 
90-40 
80-02 
1038 
15-31 
2-69 
3-93 
3-24 
89-24 
81-30 
7-94 
11-75 
2-45 
3-63 
2-92 
88-37 
80-25 
8-12 
11-09 
2-78 
3-78 
If the experimental results absolutely coincided with the view above given, we should 
S V — V 
have ?p = ld — 1 * 
Also, if we deduct the “titre” of the gas from the total oxidation, the difference 
gives the oxidation due to the gas which disappears in the contraction, and the ratio 
of this difference to the contraction gives the density of this gas as compared with the 
density of oxygen. Calling this density A, we have in the three experiments successively : 
(1) A = ibbs ~ I®* 
(2) A=||i=l-07. 
(3) A=|h=l-0°. 
We may conclude from these experiments that, by the oxidation of the solution of 
protochloride of tin, nothing whatever is removed from the electrized gas, except the 
quantity of oxygen estimated in the “ titre” of the gas, together with a certain volume 
of gas of the density and properties of oxygen. 
In the two following experiments I attempted to discriminate between the oxidation 
effected by the ozone and the oxidation due to the oxygen associated with it ; this was 
done by causing the gas, after being deprived of ozone by its passage through the bulb 
of protochloride of tin, to pass through a second bulb of the same solution, in which also 
the oxidation was afterwards estimated. The oxidation in the second bulb was taken as 
the measure of the oxidation due to the oxygen associated with the ozone, and the 
difference between the oxidation effected in the two bulbs respectively was assumed to 
be the true oxidation effected by the ozone. In this mode of operating the two oxida- 
tions were effected under precisely similar circumstances as regards the temperature and 
rate of passage of the gas, and are strictly comparable. 
Before the experiment the oxygen required to effect the complete oxidation of the 
