¥- of proportion between the two effects, but they enable 
us to separate them from each other. In his second 
dissection of the pile, we havea 1 electrical in- 
“strament, but one ‘which does not* produce galvanic 
‘effects; and the same may be said of his electric co- 
umn, which exhibits*none of the phenomena that we 
exclusively refer'to galvanism. “On the contrary, some 
‘of those combinations which have been made by Mr 
Children, and other er rma aaah od 
darge p were 1 sR ere a di aci 
- ag enon Setaraesr them, may be considered as 
-precisely the reverse of De Luc’s column. Here very 
“slight marks ‘of common electricity were manifested, 
while the most ‘powerful galvanic effects were produ- 
a ‘eed. mt _— : . : 
= ~- Our general conclusion on the subject is, that part 
rica phe of the effects, usually proceeding from the pile, are 
{the pile. purely electrical, and do not, in any degree, depend 
upon a ical e in the state of the metals. We 
conceive it to be a doubtful point in what way this 
electrical action is induced, because, for the reasons 
which we have already given, we do not think that the 
- “experiments of Volta, and the others that have been 
su to coincide with them, are applicable to the 
‘state of things as they exist in the The ; nor do we 
+hink that if we were to admit them, they would ac- 
count for the continued evolution of fresh portions of 
“turbance of the electric fluid, or the electro-motion, as 
% “it'is stiled, is not counteracted by the conductors that 
Jyanic are connected with the metals. As to the proper gal- 
“vanic effects of the pile, we consider them to be always 
immediately caused by the chemical action of the fluid 
upon the metals ; and that, in proportion to the extent 
‘of this action, as depending u the quantity of sur- 
‘face , or the nature of the fluid employed, we 
“obtain the evolution of electricity in greater or less 
iantity, and in a more or less intense state. Our 
_- . + yeaders will perceive, from these observations, that we 
“are, upon 
a ‘thesis; but at the same time that we attach ourselves 
be ‘to this doctrine, we do it with the restriction already 
“referred to, If we conceive that the galvanic 
"phenomena depend upon the chemical chines) we also 
‘admit, thac there are electrical effects produced by the 
"pile, independent of the others, and unconnected with 
tltem. ; 
em. 
wy'shy- | ‘The great discoveries that have been made by Sir 
is. Hy Davy, in his application of galvanism to chemical 
‘decomposition, and the importance which must attach 
‘to all his opinions upon the subject, induce us to in- 
“quire, what view he takes of the question that we have 
‘now been discussing. We have already related the 
‘experiments which he performed on the chemical ac- 
tion of the pile; and it appears that he formerly con- 
sidered it as the primary cause of the phenomena. This 
na however, he afterwards retracted, and adopt- 
“ed an is which he conceived might reconcile 
‘the doctrine of Volta with the experiments of the Eng- 
lish chemists. He supposes, that ‘both electrical and 
chemical actions are necessarily concerned in the pro- 
“duction of the effect ; that the former are the first in 
order of time, and that their tendency ‘is' to disturb 
the electric equilibrium of the different parts of the ap- 
j s, while the chemical chan 
this equilibrium. In the farther detail of the hy- 
esis we shall employ the author’s own words, “In 
>.> ‘the voltaic pile of zine, copper, and solution of muriate 
; a of soda, in what has been called its condition of elec- 
es) 
GALVANISM: 
electricity ; or that they would ‘explain, why the dis- - 
i the whole, advocates for the chemical hypo- - 
te in resto- ~ 
99 
trical tension, the communicating plates of copper and 
zine are in opposite electrical states. And with regard 
to electricities of such very low intensity, water is an 
insulating body ; every copper plate, consequently, pro- 
duces by induction an increase of positive electricity 
upon the opposite zine plate, and every zinc plate an 
increase of negative electricity on the opposite copper 
plate ; and the intensity increases with the number, and 
the quantity with the extent of the series,” 
¥ n a communication is made between the two 
extreme points, the opposite electricities tend to anni- 
hilate each other ; and if the fluid medium could be a 
substance incapable of decomposition, the equilibrium, 
there is every reason to believe, would be restored, and 
the motion of the electricity cease. But solution of 
muriate of soda being composed of two series of ele- 
ments, ssing opposite electrical energies, the oxy- 
gen and acid are attracted by the zinc, and the hydro- 
gen and alkali by the copper. The balance of power 
is momentary only ; for solution of zinc is formed, and 
the hydrogen is disengaged. The negative energy of 
the copper, and the positive energy of the zine, are 
consequently. again exerted, enfeebled only by the op- 
posing energy of the soda in contact with the copper; 
Theory. 
—yo’ 
‘and the process of electro-motion continues, as long as 
the chemical changes are capable of being carried on.” 
See Phil. Trans. for 1807, vol. xlv. ; 
This hypothesis agrees with that of Volta, in-ascri- — 
bing the train of actions to the electric condition of the 
‘metals, yet it differs from it in many essential points. 
It supposes the chemical decomposition of the interpo- 
sed fluid to be a necessary, although not the first step 
in the process.. The conducting power of the fluid is, 
in both cases, taken into account, yet it is regarded in 
“an opposite point of view. According to Volta, the bet- 
ter is the conducting fluid, the more energetic is the 
action of the pile; while the hypothesis of Sir H. Davy 
seems to require the ftuid to possess almost a non-con- 
“ducting property. 
Some of the late speculations of this illustrious che- 
‘mist have led him to deviate still farther from the or- 
dinary hypothesis, not only as it respects galvanism, but 
electricity in general. Those effects, which were for- 
merly attributed to a material agent, capable of being 
added to, or subtracted from a body at. pleasure, are 
‘now conceived, like gravitation, to be inherent qualities 
‘of matter. To these, which are called electric energies, 
all chemical decompositions are. to- be ultimately refer- 
red ; for it is supposed, that chemical attraction, in all 
eases, results from the circumstance of two bodies pos- 
‘sessing opposite electric energies, and consequently ha- 
Electric 
energies. 
‘ving a strong tendency to unite. By means of the gal- 
“vanic combinations, we have it in our power to excite. 
the electric state of a body to an indefinite degree, and 
to induce an electricity contrary to that which is natural 
‘toit. But the farther consideration of the merits of 
‘this theory, belong rather to electricity than to galva- 
nism strictly so called. «To whatever cause we ascribe 
the electric state of bodies, whether to a material agent 
distributed through them in different quantities, or to 
‘some affection of their primary qualities, the states of 
‘positive and negative electricity actually exist; and our 
present business is merely to inquire, what relation 
they bear to the phenomena of the galvanic pile. 
M. De Lue advances an argument, which he con- po {i's 
ceives to be quite decisive, against the +h esis of objections, 
the natural electric energies of bodies producing the 
phenomena of the pile, that'the whole instrument may 
be rendered either positive or negative, by connecting . 
