454 
SIR B. C. BRODIE ON THE ACTION OE ELECTRICITY ON GASES. 
An experiment thus made with hinoxide of manganese gave the following result : — 
T. 
V. 
y 
Vr 
T+V. 
13*45 
276-98 
288*84 
290*43 
The difference between the numbers in the fourth and third columns, namely T59 
cub. centim., represents the oxygen retained by the manganese. 
The three following experiments were made in a precisely similar manner with the 
metals copper, gold, and aluminium, with the exception of a bulb containing iodide of 
potassium being placed immediately after the tube containing the metal; the “titre” 
of the gas after the experiment, T 1? as estimated in this bulb, is given in the last column. 
T. 
V. 
v r 
T* 
Copper 
14*55 
276-48 
276-07 
Gold 
14*36 
276*10 
275*81 
14*27 
Aluminium... 
14-17 
275*52 
274*61 
14*20 
It appears from these experiments that the “ titre” of the electrized gas is precisely 
the same after the passage of the gas over these metals as before the experiments, and 
also that the volume of the gas is unaffected, the results being the same as though the 
gas had been passed through the solution of iodide of potassium alone. 
When the electrized gas is passed through a solution of binoxide of sodium the ozone 
is destroyed, and a certain portion of the binoxide of sodium also is decomposed. This 
reaction is constantly referred to as an ascertained fact, but has never been really 
investigated. It was of great importance, in relation to the theory of this reaction, to 
ascertain by experiment the relation which exists between the two decompositions. 
The points to be ascertained were : — the “ titre” of the electrized gas, the oxygen lost 
by the binoxide of sodium, and the ratio of this oxygen to the “ titre,” also the expan- 
sion undergone by the electrized gas, the difference, that is, of the volumes of the gas 
after and before the experiment, and the ratio of this difference to the “ titre” of the gas. 
The oxygen lost by the binoxide of sodium was determined by titration of the solu- 
tion of the binoxide of sodium before and after the experiment with a standard solution 
of permanganate of potash, according to the method described by me in a former paper*. 
From the difference between these two titrations the amount of oxygen lost by the 
binoxide of sodium may be calculated. 
Since ozone is decomposed when brought in contact with a solution of caustic alkali, 
which substance is always present in the solution of binoxide of sodium, and, indeed, is 
a product of the decomposition of it by ozone, it was possible that errors in the exact 
estimation of the reaction might arise from this circumstance, as also from the spon- 
taneous decomposition of the peroxide of sodium, which is especially rapid in a strongly 
alkaline solution. To guard against such errors, the binoxide of sodium in the first 
experiment was dissolved in water saturated with carbonic acid. Ozone, although 
'* Philosophical Transactions, 1862, vol. clii. p. 840. 
