394 Matteucci’s Lectures on Living Beings. 
‘There exists, between electricity and the nervous force, an 
analogy which, if it does not possess the same degree of evidence, 
is, however, of the same kind as those analogies which we know 
to exist between caloric, light and electricity. We have seen, 
when speaking of the phenomena present@d by electrical fishes, 
that the faculty which they possess of producing electricity is 
obedient to the nervous system. There is, then, in these ani- 
mals, a peculiar organic structure, such an ‘arrangement of parts 
that by an ae me nervous force, they can develop the electric 
fluid. ‘You remember the identity of causes and circumstances 
which excite aid ‘modify muscular contractions, and this function 
is proper to these animals. You have seen ‘that in them the 
property which they have of giving the discharge, is under the 
immediate dependence of the functions of the nervous system, 
as well, also, as is the faculty which the muscles have of con- 
tractin 
Matteucci’s experiments on induced contraction are highly im- 
rtant. He says—‘I shall commence by briefly stating in 
what this phenomenon consists, and by 
Having prepared a galvanoscopic frog, 
(B) we place its nerve upon one or both 
thighs of a mc es abet in the ordinary 
manner (A); then by applying the two 
poles of a pile to = lumbar plexus of the 
latter, we observe that when the muscles / 
of the thighs contract, convulsions simul- 
taneously occur in the galvanoscopic 
claw, whose ote rest upon the thighs 
in contraction.’ 
‘I have also ascertained that this phe- 
nomenon likewise occurs when we place 
the nerve of a galvanoscopic frog upon 
the muscles of the thigh of a rabbit, and 
make these contract by means of a eurrent acting upon the nerv 
which ramifies in the thigh. Ihave also observed contractions 
of the galvanoscopic frog, without the employment of the elec- 
tric current to excite the contractions of the muscle, producing 
the induced contraction ; the action of some other stimulant, ap- 
ont to the spinal marrow or the lumbar plexuses, being subst 
tut 
‘Lastly, I have repeated these experiments by placing very 
fine layers of deereiee welbianites serween the nerve of the gal- 
vanoscopic frog, and the muscular surface where the induced cou- 
—— is developed. A leaf of gold, or a very thin and insula- 
ing lamina of mica, or glazed paper, being interposed, prevents 
