luid to the gaseous state, and in doing so expands to 1,696 times
its bulk. Now if the steam so developed be confined under a pressure
of 105 pounds to the square inch, the water will not vaporize until a
molecular velocity is attained indicated by a temperature of 312 deg. F.
(Spons' "Engineering," D2, page 418), and then the expansion is only
253 times its bulk. By using this steam, in a steam engine, the
caloric in the steam tends to push the molecules of which it is
composed into an ultimate expansion of 1,696 times the bulk of the
water from which it was generated, and this force acts upon the piston
and does the work. Thus we see that the steam engine is driven by the
same force which produces the phenomena accredited to electricity.

I have already shown that in what we term combustion not a particle of
the ponderable matter is annihilated. Combustion is but a phenomenon
resulting from a rearrangement of the particles, and so it is with the
imponderable physical force caloric; it is not consumed when light and
heat are produced, nor converted into power, as we are sometimes told.
But whatever the phenomena produced, the aggregate amount of static
and dynamic caloric is always and ever the same.

If we consider the Ritter-Plant-Faure-Battery, which is mentioned as
storing electricity, we find that the phenomena exhibited by the use
of this apparatus are produced by the same factor. The battery is
composed of two sheets of lead, which are covered with a layer of
minium (Pb3O4). The sheets are laid one upon the other with an
intervening layer of felt. The pack is then rolled up in a spiral form
and placed in a vessel containing acidulated water. One of the plates
is connected with the positive, and the other plate with the negative
pole of a battery or generator.

When the current of electricity enters the battery, the Pb3O4 on the
positive plate is reduced to Pb, and the oxygen so set free attacks
the Pb3O4 on the negative plate, and oxidizes it to PbO2. In this
chemical action, caloric is occluded in the Pb and unlocked in the
PbO2, but a much greater amount of caloric is locked up than is
unlocked, although the amount of oxygen used in both cases is
precisely the same, which has been fully explained in the oxidation of
carbon.

Now after the battery has been thus charged and the wires disengaged,
the chemical action ceases for want of the reducing agent (_dynamic
caloric_), and the apparatus may be held at re