22 Faraday's Researches

three inches into the wet soil of the ground. This battery
thus arranged produced feeble decomposing effects, as nearly
as I could judge answering the description Mr. Barry has given.
Its intensity was, of course, far lower than the electricity of the
kite-string, but the supply of quantity from the discharging
train was unlimited. It gave no shocks to compare with the
" usual shocks " of a kite-string.

78. Mr. Barry's experiment is a very important one to repeat
and verify. If confirmed, it will be, as far as I am aware, the
first recorded case of true electro-chemical decomposition of
water by common electricity, and it will supply a form of elec-
trical current, which, both in quantity and intensity, is exactly
intermediate with those of the common electrical machine and
the voltaic pile.

III. Magneto-Electricity

79. Tension.—The attractions and repulsions due to the
tension of ordinary electricity have been well observed with
that evolved by magneto-electric induction. M. Pixii, by using
an apparatus, clever in its construction and powerful in its
action,1 was able to obtain great divergence of the gold leaves
of an electrometer.2

80. In motion : i. Evolution of heat.—The current produced
by magneto-electric induction can heat a wire in the manner
of ordinary electricity. At the British Association of Science
at Oxford, in June of the present year, I had the pleasure, in
conjunction with Mr. Harris, Professor Daniell, Mr. Duncan,
and others, of making an experiment, for which the great magnet
in the museum, Mr. Harris's new electrometer and the magneto-
electric coil3 were put in requisition. The latter had been
modified in the manner I have elsewhere described,4 so as to
produce an electric spark when its contact with the magnet was
made or broken. The terminations of the spiral, adjusted so as
to have their contact with each other broken when the spark was
to pass, were connected with the wire in the electrometer, and
it was found that each time the magnetic contact was made

1 Annales de Chimie, 1. p. 322. 2 Ibid. li. p. 77.

3 A combination of helices was constructed upon a hollow cylinder of
pasteboard: there were eight lengths of copper wire, containing altogether
220 feet; four of these helices were connected end to end, and then with
the galvanometer; the other intervening four were also connected end to
end, and the battery of one hundred pairs discharged through them.

* Phil. Mag. and Annals, 1832, vol. xi. p. 405. appa-