Definite Electro-Chemical Action     171
 608.	But admitting that chemical action is the source of
electricity, what an infinitely small fraction of that which is
active do we obtain and employ in our voltaic batteries!    Zinc
and platina wires, one-eighteenth of an inch in diameter and
about half an inch long, dipped into dilute sulphuric acid; so
weak that it is not sensibly sour to the tongue, or scarcely to our
most delicate test papers, will evolve more electricity in one-
twentieth of a minute (595) than any man would willingly allow
to pass through his body at once.   The chemical action of a
grain of water upon four grains of zinc can evolve electricity
equal in quantity to that of a powerful thunder-storm (603,
596).   Nor is it merely true that the quantity is active; it can
be directed and made to perform its full equivalent duty (602,
etc.).    Is there not, then, great reason to hope and believe that,
by a closer experimental investigation of the principles which
govern the development and action of this subtile agent, we
shall be able to increase the power of our batteries, or invent
new instruments which shall a thousandfold surpass in energy
those which we at present possess?
 609.	Here for a while I must leave the consideration of the
definite chemical action of electricity.    But before I dismiss this
series of Experimental Researches, I would call to mind that, in
a former series, I showed the current of electricity was also
definite in its magnetic action (102, 103, 112, 113);  and, though
this result was not pursued to any extent, I have no doubt that
the success which has attended the development of the chemical
effects is not more than would accompany an investigation of
the magnetic phenomena.
December 31, 1833.