SIE B. C. BEODIE ON THE ACTION OF ELECTEICITT ON OASES. 
97 
I. 
II. 
in. 
IV. 
Degree of concentration of the solution of 
T. 
s. 
R=|. 
hydriodic acid employed. 
T 
1 gramme of Iodine in 3 cub. centims. ... 
26-2 
41-5 
1*54 
1 gramme of Iodine in 6 cub. centims. ... 
26-2 
38*8 
1-47 
26*2 
39-2 
1-48 
„ 
26*2 
40 
1-52 
1 gramme of Iodine in 12 cub. centims. ... 
26-2 
38-7 
1-47 
„ 
26-2 
37-5 
1’42 
20 
28-7 
1-4 
14 
21-5 
1-53 
14 
22-5 
1-6 
27-7 
42 
1*51 
Mean=l*49 
The oxidation, therefore, of the hydriodic acid effected by the ozone, when thus largely 
diluted with carbonic acid, is exactly intermediate between the oxidation effected in the 
case of neutral iodide of potassium and the oxidation effected in hydriodic acid of the 
same concentration by undiluted ozone. When, in the case of the experiments with 
electrized oxygen, the concentration of the solution of hydriodic acid is less than that 
indicated by one gramme of iodine in 16 cub. centims. of the solution, the oxidation 
effected is very appreciably diminished, and appears (for the experiments do not enable 
us to pronounce with certainty on the point) to pass continuously through all the inter- 
mediate stages until an oxidation is reached closely approximating to (but still in no 
case reaching) the oxidation effected in neutral iodide of potassium, the smallest oxida- 
tion obtained in my experiments by an excessive dilution being 1 yjj that oxidation ; 
but in the present case the reaction is of a different character, being perfectly definite 
and not subject to variation, with the variation of those conditions by which it is affected 
in the other instance referred to. We need not conclude that these conditions are here 
altogether inoperative, but only that the influence of the dilution of the ozone is so 
predominant as to render these causes insignificant as regards the total result. The 
experiments were made with a gas of which ^ consisted of oxygen, the rest being 
carbonic acid; and this proportion was constant in the several experiments. In the 
case, however, of two experiments with gas derived from the decomposition of pure 
s 
carbonic acid, T71 and 1-79 were obtained as the value of the ratio and it is quite 
likely that the reaction may vary with the degree of dilution of the ozone and the pro- 
portion of the several gases present, just as it varies with the degree of dilution of the 
hydriodic acid. Using the notation employed in my previous memoir* (to which the 
reader is referred for explanation) in addition to the two forms of the decomposition of 
ozone by hydriodic acid there mentioned, namely, r=f, in which the unii of ozone is 
* Philosophical Transactions, loc. cit. p. 482, and 1866, pp. 792, 805, 810. Journ. Chem. Soc. 1868, 
vol. vi. p. 367. 
MDCCCLXXIV. 0 
