448 
Sill B. C. BEODIE ON THE ACTION OE ELECTBICITY ON OASES. 
The iodine formed required for titration 28 cub. centims. of the standard solution of 
hyposulphite, of which 1 cub. centim. was equivalent to 0T082 cub. centim. of 
oxygen. This corresponded to a “titre” of about 3’4 per cent, of oxygen. 1 
The gas was again passed three times through the induction-tube and the ozone again 
estimated, the volume of gas, temperature, and pressure being the same as in the pre- 
vious experiment. 28 cub. centims. of hyposulphite were again required for the titration. 
The gas was now passed five times through the induction-tube, but a comparatively 
small coil was used in the experiment with five of Grove’s cells. The same volume as 
before required for titration 27 cub. centims. of hyposulphite ; that is to say, the “ titre” 
of the gas, after having been passed ten times through the induction-tube, was almost, 
if not quite, the same as the titre of the same gas which had been passed once through 
the induction-tube. 
The gas from the last experiment was again titred after an interval of sixteen hours, 
during which time the quantity of ozone was materially diminished. The same volume 
as before now required for titration 17 *5 cub. centims. of hyposulphite. The gas was 
now passed twice through the induction-tube, the same coil being employed as in the 
last experiment. The same volume of gas as before now required for titration 29 cub. 
centims. of hyposulphite. 
The gas was again passed twice through the induction-tube. The same volume as 
before required for titration 29 '5 cub. centims. of hyposulphite. 
It thus appears that there is a fixed limit prescribed by the conditions of the experi- 
ment beyond which the formation of the ozone cannot pass, and, moreover, that this 
limit is reached at once. 
In this last respect these results differ essentially from those of Von Babo and Claus*, 
who found that for the production of a high percentage, 3T to 5’7 per cent, of ozone, 
the gas required to be submitted for many hours to the action of the electricity gene- 
rated by a powerful coil, and that for several hours the gas thus operated upon under- 
went a regular diminution in volume. A point, however, was ultimately reached at 
which the volume of the gas remained unaltered. 
No difference was detected, by detonation with hydrogen, between the composition, 
of the gas previous to the experiment and its composition after having been submitted 
in the induction-tube to the electric action and passed through the solution of iodide 
of potassium. In the following experiment a bulb containing a solution of iodide of 
potassium was attached to the induction-tube, through which a current of oxygen, pre- 
pared by electrolysis and dried by anhydrous phosphoric acid, was passed direct from 
the generator. The current of oxygen was passed through the tube and solution for 
from four to five hours before turning on the coil, and a portion collected and detonated 
with hydrogen. The numbers thus obtained corresponded to 100 - 06 percent, of oxygen. 
The coil was then set to work without disturbing the apparatus, and after half an hour 
a portion of the gas was again collected and analyzed: it was found to contain 99T 
per cent, of oxygen. 
* Loc. cit. p. 304. 
