86 
now ¢alled in question by Mr Nicholson, Dr Wollaston, 
and other English chemists, who were more disposed 
to refer the effects to the chemical action of the fluid 
interposed between the plates in oxidating the metals. 
Volta, however, still adhered to his first opinion ; and, 
in a paper written about this time, he lays it down as 
his decided conviction, that the action of dne of the 
metals upon the other is the sole cause of the excitation 
of the electricity, and that the only use of the inter- 
posed water is to convey the excited electricity from 
one pair of plates to the other. (Nich. Journ. 8vo. 1. 
135.)—Some remarks were, about this time, published on 
Volta’s hypothesis, by Mr Cuthbertson and Dr Bostock ; 
the former objecting to some of Volta’s experiments, 
on which the electric hypothesis of the pile was at- 
tempted to be established, and the latter giving a more 
detailed account of the chemical hypothesis. 
By an ingenious alteration in Bennett’s electrometer, 
it was converted by Mr Pepys into a galvanometer. Mr 
Pepys also confirmed the facts to which we have alread 
alluded, that oxygen is absorbed by the pile, that it 
will not act in azote or in hydrogen, and that it may 
be excited in vacuo, provided acid be interposed be- 
tween the plates. (Philosoph. Mag. x. 38.) About 
this time, Rittersof Jena entered upon his investiga- 
tion of the galvanic phenomena, and both performed 
many new experiments, and entered very zealously into 
theoretical discussions. He conceived that he had ob- 
served a connexion between galvanism and magnetism: 
He says, that if an iron wire be placed in the magnetic 
meridian, the north pole of the wire is more disposed 
to become oxidated than the south pole; when the 
magnetized wire is placed in water, the south pole, on 
the contrary, is most affected. If similar wires be em- 
ployed, but not placed in the magnetic meridian, no 
difference is to be observed in the oxidation of the two 
extremities. See Journ. de Phys. lv. 235. 
In the experiments that had been performed on ani- 
mals, those with cold blood had been generally em- 
ployed, both on account of their being more conveni- 
ent for the operation, and from the greater tenacity 
with which they retain their vitality. It was, however, 
ascertained, that animals with warm blood were equal- 
ly susceptible of the influence; and Creve of Wurtz- 
burg had produced strong contractions in a human leg 
after amputation. Vassali, in conjunction with his 
friends, Giulio and Rossi, performed a more ample set 
of experiments upon the bodies of some criminals 
that were beheaxed at Turin. (Journ. de Phys. lv. 
286.) They pa‘d particular attention to the effect’ of 
the galvanic electricity upon the heart and the other 
imvoluntary muscles, a point which had been the sub- 
ject of much controversy. Volta supposed that the in- 
voluntary muscles could not be made to contract. Fow- 
ler however asserts, that contractions were excited in 
the heart, although with difficulty ; and Vassali con- 
firmed the observations of Fowler, and extended them 
to the stomach and intestines; the same opinion was 
also maintained by Nysten. (Jowen. Phys. lv. 465). 
On the other hand, Aldini, tive nephew of Galvani, 
who now came into notice as an. assiduous experimen- 
aoe asserted that he was unable to act upon the 
Circand’s Circaud announced a discovery, which, if it were 
experiments fully confirmed, would prove of’ great importance in 
en moune. physiology, that the fibrine of the blood, immediately 
after it leaves the vessels, may be made to contract by 
the galvanic apparatus. Delametherie confirms the state- 
ment of Circaud, from his own observations ; but we 
History. 
Pepys’s gal- 
vanometer, 
Ritter’s ex- 
periments. 
Supposed 
connection 
with mag- 
netism. 
Experi- 
ments on 
animals 
with warm 
blood. 
By Vassali, 
Nysten. 
Aldini. 
GALVANISM.. 
have been informed that the experiment has not suc- 
ceeded in this country ; and when we consider the dif- 
ficulty and delicacy of the process, we may be allowed, 
without impeaching the veracity of the narrators, to 
entertain some doubts on the subject. See Journ.. Phys. 
lv. 468; and lv. 161. ae j 
In the year 1803, Aldini published his Treatise on Aldini’: 
Galvanism, a work which contains many curious expe- Pement 
riments, and also some new theoretical opinions. The page S 
experiments which were the most calculated to produce Gad x 
an impression upon the spectators, were performed on by the 
the body of a criminal, who was hanged at Newgate, pile, 18( 
and also on the head and limbs of some of the larger 
warm-blooded animals. A powerful battery being aj 
plied, very strong contractions were excited, the limbs 
were violently agitated, the eyes opened and shut, the 
mouth and jaws worked about, and the whole face was 
thrown into frightful convulsions. These experiments, 
however, were principally remarkable from the subjects 
made use of, and the magnitude of the effect: there 
were others performed, really more curious, in which 
very considerable muscular contractions were excited, Contrac- 
without the intervention of any metal, or other sub- tions pr 
stance which could be supposed capable of disengaging — 
the electric fluid. In some cases the effect was pro- °™ ™ 
duced by bringing into contact the nerve of one animal 
with the muscle of another, and at other times by em- 
ploying the nerves and muscles of the same animal. In 
some of the experiments, there appears to have been the 
most powerful contractions excited, by bringing the 
parts of a warm and a cold blooded animal into contact 
with each other. It does not appear, from any expres- 
sions in this treatise, whether Aldini considered the 
animal electricity, as he calls it, to be of a specifically 
different kind from that excited by the pile, or whether 
he supposes that the different parts of the animal bod 
have the power of generating the same kind of electri- 
city, without the aid of any external agent. He, how- 
ever, deduces from his experiments an inference in fa« 
vour of Galvani’s hypothesis, of a proper animal elec« 
tricity inherent in the body, and not requiring the as- 
sistance of any external agent for its developement. 
There are some points respecting these experiments Re 
that require farther explanation.” The most obvious 4/42 
conclusion that we should draw from them, would be 
that which was formed by Aldini himself, in favour of 
a proper aniinal electricity. But if this be the case, 
they must be regarded as essentially different from those 
of Galvani, where an electricity of the usual kind was 
certainly excited. Perhaps the most probable suppo- 
sition is, that the parts of the body, in these experi- 
ments, acted in.a manner analogous to the pile which 
was constructed by Sir H. Davy, in which electrici 
was developed by the action of two different flui 
upon carbon, There are, however, many circumstan- 
ces wanting to render this analogy complete. 
An important experiment was announced by La- 
grave: he stated, that by placing upon each other al- animal 
ternate layers of muscular Abre and of brain, separated pile. 
by a porous body, soaked in salt water, a pile was form. q 
ed which produced the usual effects of the galvanic | 
apparatus: (Journ. Phys. lvi. 235.) The experiment | 
must be of difficult execution, and we do not know that 'e 
any one has since attempted to repeat it. Should itbe ? 
confirmed, it would throw some light upon the experi- 
ments of Aldini, and would assist in the explanation of 
those facts, where animal electricity seemed to be de- 
veloped, without the intervention of metallic bodies. 
About this time galvanic electricity began to be ex- 
