SIR B. C. BEODIE ON THE ACTION OF ELECTRICITY ON GASES. 
453 
Temperature. 
T. 
V. 
Yj. 
T+V. 
i4°-7 C. 
14-43 
273-17 
287*38 
287-6 
10° C. 
9-33 
273*22 
282-45 
282-55 
9*1 
272-97 
282-05 
282-07 
8-98 
272-23 
280-39 
281-21 
It hence appears that the electrized gas when thus passed over metallic silver undergoes 
an expansion equal to the “ titre” of the gas, precisely as though the gas were passed 
through a heated tube. The difference between the numbers in columns IV. and V. 
falls within the unavoidable errors of experiment, and is inappreciable, except perhaps 
in the last experiment. The quantity of oxygen retained by the silver must therefore 
in these experiments have been excessively minute. That this oxidation of the silver is 
nevertheless an integral part of the action, and although minute is still capable of 
estimation, appears from the following experiment, which was made with every precau- 
tion and with a special view of determining this point. The two experiments were 
made consecutively, without detaching from the apparatus the tube containing the 
silver. 
T. 
V. 
T+V. 
9-68 
9-68 
270-27 
269-67 
-A GO 
279-95 
279-35 
Regarding these two observations as constituting a single experiment, the total volume 
measured in the aspirator after the experiment, namely the sum of the volumes in the 
two experiments headed V 1? is 556*38, whereas the sum of the volumes in the two 
experiments in the column headed T+V, column V., is 559*30 ; the difference between 
these volumes is 2*92 cub. centims., which, if the experiment be correctly conducted, 
represents the oxygen retained by the silver. 
The tube containing the silver was now heated by means of a spirit-lamp, and the 
gas evolved measured in the aspirator; this gas amounted to 2*5 cub. centims., the 
difference between this number and the previous deficiency 2*92 cub. centims., that is 
0*34 cub. centim., being the total amount of oxygen unaccounted for. 
The oxide of silver here formed appears to be a peroxide of silver ; for if a tube in 
which such an experiment has been made be washed out Avith a solution of iodide of 
potassium iodine is formed. That the minute quantity of the peroxide of silver thus 
formed is really an effective agent in determining the decomposition of the ozone, is 
rendered probable from the circumstance that the binoxide of manganese produces a pre- 
cisely similar change (as to the decomposition of the ozone and the expansion of the gas) 
to that produced by silver, a small amount of oxygen being here also (if one experiment 
may be trusted) retained by the agent by which the decomposition of the ozone is 
effected, Avhile the contact of the metals copper, gold, and aluminium produces no 
change whatever in the gas ; these points are evident from the following experiments. 
9 9 
O Q -j 
