[B] Recent Experimental Researches, p. 42, &c. Mr. Sturgeon is of
course unaware of the definite production of electricity by chemical
action, and is in fact quoting the experiment as the strongest
argument _against_ the chemical theory of galvanism.

1000. Zinc so prepared, even though impure, does not sensibly decompose the
water of dilute sulphuric acid, but still has such affinity for the oxygen,
that the moment a metal which, like copper or platina, has little or no
affinity, touches it in the acid, action ensues, and a powerful and
abundant electric current is produced. It is probable that the mercury acts
by bringing the surface, in consequence of its fluidity, into one uniform
condition, and preventing those differences in character between one spot
and another which are necessary for the formation of the minute voltaic
circuits referred to (998.). If any difference does exist at the first
moment, with regard to the proportion of zinc and mercury, at one spot on
the _surface_, as compared with another, that spot having the least mercury
is first acted on, and, by solution of the zinc, is soon placed in the same
condition as the other parts, and the whole plate rendered superficially
uniform. One part cannot, therefore, act as a discharger to another; and
hence _all_ the chemical power upon the water at its surface is in that
equable condition (949.), which, though it tends to produce an electric
current through the liquid to another plate of metal which can act as a
discharger (950.), presents no irregularities by which any one part, having
weaker affinities for oxygen, can act as a discharger to another. Two
excellent and important consequences follow upon this state of the metal.
The first is, that _the full equivalent_ of electricity is obtained for the
oxidation of a certain quantity of zinc; the second, that a battery
constructed with the zinc so prepared, and charged with dilute sulphuric
acid, is active only whilst the electrodes are connected, and ceases to act
or be acted upon by the acid the instant the communication is broken.

1001. I have had a small battery of ten pairs of plates thus constructed,
and am convinced that arrangements of this kind will be very important,
especially in the development and illustration of the philosophical
principles of the instrument. The metals I have used are amalgamated zinc
and platina, connected together by being soldered to platina wires, the
whole apparat