PROFESSOR MATTEUCCI’S ELECTRO-PHYSIOLOGICAL RESEARCHES. 
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hempen thread soaked in water, and a very fresh nervous filament, both being as 
nearly as possible of equal dimensions, presented resistances to the electric current in 
the proportion of 12 to 15. But the main object which I had in view in studying 
the relative conducting power of muscles and nerves, was to ascertain whether, when 
a current was impelled through a mass of muscle, any part of the current might 
have passed through the nervous filaments spread throughout that muscle. For this 
purpose I took a piece of muscle from the thigh of a rabbit, a dog, or a fowl which 
had been dead for sufficient time for muscular irritability to have ceased ; I cut this 
mass of muscle with a knife, and introduced into the opening thus made the nerve 
of a highly sensitive galvanoscopic frog ; I covered over the nerve and a part of the 
leg, endeavouring to envelope them perfectly in the piece of muscle. When the con- 
tractions, which often occur in the galvanoscopic frog itself immediately after it has 
been prepared, had ceased, 1 passed an electric current of from 25 to 30 elements of 
Faraday through the mass of muscle, applying the poles to different parts of its 
surface. In whatever way I varied this experiment, provided I did not touch very 
close to the nerves of the galvanoscopic frog, this frog never entered into con- 
traction, although a very powerful electrical current traverses in all directions the 
mass of muscle in which the nerve of the frog was contained. I have remarked 
already that in this experiment a mass of muscle must be employed in which all 
irritability is extinct, because if muscles are made use of which contract on the 
passage of the electric current, the galvanoscopic frog exhibits phenomena of induced 
contraction ; we are convinced of this by observing that they cease when the mus- 
cular irritability has disappeared. We may therefore conclude fi-om this experiment, 
that when the poles of a pile of 25 or 30 elements are applied to the surface of the 
muscles of a living animal, the phenomena produced by the passage of the current 
must depend either on the direct action of the current on the muscular fibre, or on 
the indirect action or influence of the electric current transmitted by the muscular 
fibre on its own nervous filaments, or, to express it more clearly, on the nervous force 
existing in these filaments. 
Convinced of the great importance of this conclusion, I have varied these ex- 
periments in order to confirm them in different ways. I have already, in the 
commencement of this memoir, spoken of the difference of excitability produced in 
a nerve by an electric current according to its direction. This electro-physiological 
law is easily demonstrated by an experiment which I have detailed at some length 
in my memoirs*, and which is made by preparing the frog in the ordinary manner, — 
cutting it at the junction of the two thigh-bones, and then placing it astride between 
two glasses of water with one foot in one glass and one in another. When the two 
poles of the pile are plunged into the liquid (pure water) contained in the two 
glasses, it is obvious that one of the limbs is traversed by the electric current in the 
same direction as the ramification of the nerve, and the other in a contrary direction. 
* Philosophical Transactions, 1846. 
MDCCCL. 2 P 
