452 
SIR B. C. BRODIE ON THE ACTION OF ELECTRICITY OX GASES. 
riment, V 15 that is, Tj -\-V l ; in column VII. is given the difference of the “ titre ” before 
the experiment and the “titre” after the experiment, T— T x ; and in column VIII. the 
T— T 
percentage of ozone destroyed as calculated from the equation, #=100 ■ ^ ] , where 
x is the percentage referred to, and T and T — T 1 are the numbers belonging to the 
experiment in columns II. and VII. 
I. 
II. 
III. 
IV. 
V. 
VI. 
VII. 
VIII. 
Temperature. 
T. 
V. 
V- 
T+Y. 
V+V- 
T— T r 
-100^ 
no°C. 
14-48 
273-64 
13-63 
288-12 
286-21 
0*85 
5*87 
150° C. 
14-43 
272-96 
11*59 
287-39 
287*08 
2*84 
19*68 
200° C. 
14-43 
273-50 
0-41 
287*93 
287*08 
14-02 
97*15 
If the experiments were made with perfect accuracy, the numbers in columns V. and 
VI. should be identical. In the first experiment the difference between these numbers 
is beyond the usual error of experiment. This, however, does not affect the “ titre ” of 
the gas, which is quite independent of any accidental error of measurement. It thus 
appears that by merely passing the electrized gas through a tube heated to 200° C. 97 T 5 
per cent, of the ozone is destroyed. 270° C. is the temperature given by Andrews and 
Tait as that at which the ozone is “rapidly destroyed;” the point of rapid decomposition 
of the ozone lies, however, considerably below this temperature. 
The change in volume which the electrized gas undergoes when brought in contact 
with metallic silver and certain other substances is closely related to the expansion 
of the gas at an elevated temperature ; I have made some experiments on this point 
also. 
When the perfectly dry electrized gas is passed through a tube containing silver leaf, 
the silver leaf becomes dark in colour at the place where the gas enters the tube, the 
change in colour appearing as dark specks and also as a transparent film of a purple hue 
on the surface of the silver. This change in appearance extends, however, but a very 
little way into the tube, which becomes intensely hot where the gas enters ; not a trace 
of ozone passes out of the tube, and the gas measured in the aspirator is found to have 
undergone an increment of volume. The silver leaf and other substances employed in 
the following experiments were contained in small tubes of thin glass. The tube was 
kept during the experiment at the temperature indicated in column I. of the following 
Table : in which Table T is the “ titre ” of the gas ; V is the volume of the gas before 
the experiment; V x is the volume of the gas after the experiment; T-f- V is the sum of 
the “titre” of the gas and the volume of the gas before the experiment. 
