SIR B. C. BRODIE ON THE ACTION OE ELECTRICITY ON GASES. 
467 
The value of the ratio II is essentially the same as that previously arrived at. AVe 
may conclude, therefore, that while the oxidation effected by pure oxygen is raised from 
1’7 at 18 3 C. to 4‘6 at 55° C. (that is, nearly in the proportion of 1 to 3), the oxidation 
effected by the ozone is not appreciably altered by the same variation of conditions. 
At the temperature of 0° C., however, exactly the reverse occurs ; for while, as has 
been shown, the oxidation effected by pure oxygen at 0° does not sensibly differ from the 
similar oxidation at 18° C., the oxidation effected by the ozone is materially increased, 
as appears from the following experiments. The correction for the effect of the asso- 
ciated oxygen is here made by deducting 1*9 cub. centim. from the total oxidation. 
Experiments with Hydriodic Acid at 0° C. 
I. 
Degree of concentration of the solution of 
hydriodic acid employed. 
II. 
T. 
III. 
S. 
. oo & 
>■ ii 
2 grammes of Iodine in 2 cub. centims. ... 
31*4 
78-2 
2-49 
55 55 55 
31-4 
77*7 
2-47 
55 55 55 
27*1 
63-2 
2-33 
55 55 55 
14-9 
34-6 
2-32 
55 55 55 
8-78 
Q-Q-l 
2*52 
Mean ... 2*43 
When the electrized gas is passed through a solution of hyposulphite of soda, a certain 
oxidation of the hyposulphite is effected, and the gas undergoes a diminution in volume. 
These effects differ in neutral and alkaline solutions of the hyposulphite, and in the latter 
case vary with the amount of the alkali (carbonate of soda) contained in the solution. Of 
the action on neutral and slightly alkaline solutions I shall speak hereafter. The experi- 
ments of which the results are given in the following Table were made with a solution 
of hyposulphite of soda rendered strongly alkaline with carbonate of soda. The gas 
before the experiment was measured in the gas-pipette, and thence drawn through ti 
bulb containing in most cases about 30 cub. centims. of the alkaline hyposulphite of 
soda into the aspirator, where the gas was again measured, the experiments being con- 
ducted precisely as described in Section II., p. 446. 
In column I. of the following Table the relative strengths of the solutions of hypo- 
sulphite of soda are given in terms of the cub. centims. of oxygen at 0° C. and 760 
millims., equivalent to the iodine employed for the titration of 1 cub. centim. of the 
solution, that is, in terms of the volume of oxygen required to effect the oxidation to 
tetrathionate of the amount of hyposulphite contained in 1 cub. centim. of the solution. 
In column II. is given the “ titre” of the gas, T ; in column III. the volume before the 
experiment, Y ; in column IV. the volume after the experiment, Vj ; in column V. is 
given the contraction, V — Y l ; in column VI. is given the ratio of the contraction to the 
“ titre ” of the gas, V ~- 1 . The temperature at which the experiment was made is also 
given. 
MDCCCLXXII. 
