and one of zinc,
each one-eighteenth of an inch in diameter, placed five-sixteenths of an
inch apart, and immersed to the depth of five-eighths of an inch in acid,
consisting of one drop of oil of vitriol and four ounces of distilled water
at a temperature of about 60 deg. Fahr., and connected at the other extremities
by a copper wire eighteen feet long, and one-eighteenth of an inch in
thickness, yielded as much electricity in little more than three seconds of
time as a Leyden battery charged by thirty turns of a very large and
powerful plate electric machine in full action (371.). This quantity,
though sufficient if passed at once through the head of a rat or cat to
have killed it, as by a flash of lightning, was evolved by the mutual
action of so small a portion of the zinc wire and water in contact with it,
that the loss of weight sustained by either would be inappreciable by our
most delicate instruments; and as to the water which could be decomposed by
that current, it must have been insensible in quantity, for no trace of
hydrogen appeared upon the surface of the platina during those three
seconds.

861. What an enormous quantity of electricity, therefore, is required for
the decomposition of a single grain of water! We have already seen that it
must be in quantity sufficient to sustain a platina wire 1/104 of an inch
in thickness, red-hot, in contact with the air, for three minutes and three
quarters (853.), a quantity which is almost infinitely greater than that
which could be evolved by the little standard voltaic arrangement to which
I have just referred (860. 871.). I have endeavoured to make a comparison
by the loss of weight of such a wire in a given time in such an acid,
according to a principle and experiment to be almost immediately described
(862.); but the proportion is so high that I am almost afraid to mention
it. It would appear that 800,000 such charges of the Leyden battery as I
have referred to above, would be necessary to supply electricity sufficient
to decompose a single grain of water; or, if I am right, to equal the
quantity of electricity which is naturally associated with the elements of
that grain of water, endowing them with their mutual chemical affinity.

862. In further proof of this high electric condition of the particles of
matter, and the _identity as to quantity of that belonging to them with
that necessary for their separation_, I will describe an experiment of
great simplicit