116 . On Chemical Philosophy. 
as free from moisture of any kind as possible; in fact, from every: 
thing readily soluble in beat or in this power. I would there-: 
fore define Electricity to be “ the object of science which treats: 
of the mechanical and natural means ef separating this GRAND 
AGENT from some of iis combinations, and of ascertaining its 
actions in this state.’ In galvanism, on the cther hand, this 
solvent power, this electric fire, is produced in circumstances in’ 
which it has substances to act upon; substances which are most 
readily dissolved in it ; substances, in fact, which seem to form. 
the grand medium of communication between this PowER and 
PASSIVE SUBSTANCES; and which are partially dissolved in it. 
And hence I have defined Galvanism as the electric fire or the 
GRAND AGENT, ‘only partially separated from its combina- 
tions;” by which I refer principally to oxygen and to hydrogen, 
With this in view, we may answer such questions as the 
following, which have often. been stated but never answered: 
“Why does galvanism exist in a lower state of intensity than 
electricity in producing shocks?” Because its active energies 
are less, being in part occupied by holding other bodies in solu- 
tion; from which cause it is also less attenuated, consequently less 
rapid in its movements, or passes through substances with greater 
difficulty. But ‘* Why again is its power in producing chemical 
effects greater than electricity?” First, because its quantity pro- 
duced in a given time is so much greater; but chiefly, because 
it is combined with substances which have a powerful tendency 
to direct and fix its actions, and which are as it were the grand 
medium of communication between this PowER and PASSIVE 
SUBSTANCES; whence has arisen the proverbial fact,—that when 
such substances are employed in the galvanic apparatus as least 
produce this decomposition and solution of oxygen and hydrogen, 
the electrical effects are then greatest, and the chemical effects 
slightest, and not perceptible at all when there is no fluid or 
moisture present. In this way we would explain why De Luc’s 
column, which is excluded from air and moisture, produces no 
chemical effect; and why the electric machine produces so 
much less than that produced by the galvanic means. Hence 
too galvanism burns charcoal with such intense brilliancy ; and 
yet the charcoal is scarcely consumed, because the oxygen and 
hydrogen held in solution produce, in part, this effect: hence 
a wire heated by galvanism continues so longer than when 
heated by electricity; and hence we perceive the explanation of 
a very singular fact,—that the chemical effects of, galvanism are 
increased by increasing the surface or size of the plates to a 
certain extent, beyond which it ceases to have these effects. 
The explanation of this last circumstance I conceive is this : 
By increasing the size of the plates we increase the chemical 
action 
