Cuap. VII, § 2.] 
ability shown by the author in discussing them. 
There was no part of Europe in which Galvani’s ob- 
servations were not held to bear out his theory; and 
the warmest. eulogy of them is to be found in the 
writings of Volta himself, who soon advocated a dif- 
ferent explanation. Volta calls animal electricity “a 
great and luminous discovery which forms an epoch 
in the annals of physical and medical science,” and as 
ELECTRICITY.—GALVANI—NOBILI—VOLTA. 
961 
direction already mentioned, which continued for se- 
veral hours after death. Strange to say, Nobili mis- 
apprehended the nature of the phenomenon, ascrib- 
ing it to Thermo-Electricity, though he ought to 
have been undeceived by the singular intensity of 
the animal current, which, feeble as it is, can force 
its way along thousands of feet, or even some miles of 
fine wire.” 
These experiments were renewed in 1837 by M. 739.) 
Matteucci of Pisa, who has the merit of reviving the MM. Mat- 
original and correct opinion of Galvani as to the vital ime x 
source of this electricity. To his researches, and the Reymond. 
“ proved to demonstration (ad evidenza) by many ex- 
periments well contrived and accurately executed.” ? 
Had there been as little novelty as has sometimes 
been alleged in Galvani’s observations, they would 
— —_ - —_—s 
not have been heard of at once, and repeated in every 
civilized country, nor have given birth to a new and 
splendid science. Nothing then in progress, either 
in the hands of Volta or of any one else, gave the 
slightest clue to the invention of the Pile, which, but 
for Galvani, might have been yet undiscovered. 
still later ones of Dr Du Bois Reymond of Berlin, we 
owe the knowledge of most of the facts as yet ascer- 
tained in this most difficult and obscure branch of 
enquiry, where the sources of error are so numerous 
as only to be eluded by consummate skill on the part 
of the experimenter. It appears to be established 
} (738.) Revival of Experiments on Animal Electricity. that the vital electricity exists both in the muscles 
‘Revival The grand discovery of Oersted, which gave a fresh im- and in the nerves of many, probably of all animals 
shes pang ulse to so many branches of science, revived likewise when living or recently dead ; that therefore the frog 
animal the subject of the proper electricity of the animal tis- current of Nobili is only a single case of the general 
electricity 
—Nobili. 
= 
me 
sues, which had been well-nigh forgotten since the 
death of its discoverer Galvani. Twenty-nine years 
later, in 1827, Nobili of Florence demonstrated the ex- 
istence of what has been termed “ The current of the 
frog.” We have seen that a momentary spasm is 
produced when a circuit is completed, including the 
muscle and nerve of the recently dead animal. But 
by the aid of that admirable instrument the Galvan- 
ometer, Nobili succeeded in showing that a continu- 
ous current of positive electricity constantly passes 
from the feet to the head of the frog. This he de- 
tected by placing the feet of the animal in connec- 
tion with one end of the galvanometer wire, and its 
spine with the other (the whole being properly insu- 
lated), when the needle of the instrument was per- 
manently deflected to the amount of 5° or more— 
indicating the passage of a stream of electricity in the 
muscular current, and that the latter arises from the 
electro-motive action of even the minutest fibres of 
which a muscle is composed—the general law being 
(according to Dr Du Bois Reymond) that positive elec- 
tricity moves from the transverse section to the longi- 
tudinal section of a muscle or a nerve, or any portion 
of either. Finally, the last-named writer has- shown, 
to the satisfaction of many eminent men who have 
witnessed his experiments, that powerful muscular 
contraction, whether induced by stimuli or the result 
of volition, tends to diminish the force of the natural 
muscular current. This he demonstrated first on the 
frog poisoned by strychnine, but afterwards on the 
muscles of his own arm, in which by voluntary con- 
traction he could diminish at will the force of the 
natural current, which in the state of rest is directed 
from the shoulder to the hand, 
§ 2. VotTA.—Progress of Discovery in Common and Atmospheric Electricity—The Electro-motive 
Theory—Voltaic Pile—Ohemical Analogies and Decomposition—Fabbroni; Nicholson and 
and Apinus, Beccaria and Wilke, Cavendish and 
Coulomb, gave it only ashare of their attention ; but 
Volta was from boyhood exclusively an electrician. 
Such devotion deserved success, and he achieved it. 
He was already famous, and an honorary fellow of 
the Royal Society, long before his principal discovery 
of the Pile. A review of his career may therefore 
be conveniently divided into two parts—what con- 
Carlisle. 
(740.) Vorra was the first among philosophers whose cerns ordinary and atmospheric Electricity ; and the 
Volta. _ career Jay solely in the study of electricity. Franklin new doctrine of Galvanism and the Electro-motive 
force. 
I. Atessanpro Vorta was born at Como, of a noble 
(741.) 
His early 
family,in 1745. His first paper on Electricity was ad- experi- 
dressed to Beccaria at the age of eighteen. But it was ments— 
not till 1775% that he published a description of the bis Electro- 
Electrophorus, an ingenious instrument in which a 
conducting body becomes electrified an indefinite num- 
ber of times in succession by being brought near to an 
1 Opere del Volta, ii., p. 13, 14. 
2 The galvanometer of Du Bois Reymond contains 3-17 English miles of wire, in 24,160 coils. 
3 See the letter to Priestley in the First volume of Volta’s Works. 
VOL. I. 
6F 
phorus and 
Condenser, 
