Faraday's Researches

which would have been supplied by decomposed water, whilst
the nitrogen had no certain or constant relation whatever.
When; upon multiplying experiments, it was found that, by
using a stronger or weaker solution, or a more or less powerful
battery, the gas evolved at the anode was a mixture of oxygen
and nitrogen, varying both in proportion and absolute quantity,
whilst the hydrogen at the cathode remained constant, no doubt
could be entertained that the nitrogen at the anode was a
secondary result, depending upon the chemical action of the
nascent oxygen, determined to that surface by the electric
current, upon the ammonia in solution. It was the water,
therefore, which was electrolysed, not the ammonia. Further,
the experiment gives no real indication of the tendency of the
element nitrogen to either one electrode or the other; nor do I
know of any experiment with nitric acid, or other compounds
of nitrogen, which shows the tendency of this element, under
the influence of the electric current, to pass in either direction
along its course.

484. As another illustration of secondary results, the effects
on a solution of acetate of potassa may*be quoted. When a
very strong solution was used, more gas was evolved at the
anode than at the cathode, in the proportion of 4 to 3 nearly:
that from the anode was a mixture of carbonic oxide and car-
bonic acid; that from the cathode pure hydrogen. When a
much weaker solution was used, less gas was evolved at the
anode than at the cathode ; and it now contained carburetted
hydrogen, as well as carbonic oxide and carbonic acid. This
result of carburetted hydrogen at the positive electrode has a
very anomalous appearance, if considered as an immediate con-
sequence of the decomposing power of the current. It, how-
ever, as well as the carbonic oxide and acid, is only a secondary
result; for it is the water alone which suffers electro-decom-
position, and it is the oxygen eliminated at the anode which,
reacting on the acetic acid, in the midst of which it is evolved,
produces those substances that finally appear there. This is
fully proved by experiments with the volta-electrometer (442);
for then the hydrogen evolved from the acetate at the cathode
is always found to be definite, being exactly proportionate to
the electricity which has passed through the solution, and, in
quantity, the same as the hydrogen evolved in the volta-elec-
trometer itself. The appearance of the carbon in combination
with the hydrogen at the positive electrode, and its non-appear-
ance at the negative electrode, are in curious contrast with thewhich opinion it appears, from that time, Davy coincided