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XXXI. Electro-Physiological Researches. On Induced Contraction. — Ninth Series. 
By Signor Carlo Matteucci, Professor in the University of Pisa, Sfc. 
Communicated hy W. R. Grove, Esq., F.R.S. 
Received May 13, — Read June 20, 1850. 
It is not without considerable regret that I am compelled to depart from my esta- 
blished rule of never publishing any facts relating to electro-physiology without having 
previously endeavoured to connect them with those already discovered, and without 
having succeeded in reproducing them in such a constant and unvarying manner as 
to remove the slightest doubt of their truth. The announcement, however, just made 
to the Academie des Sciences by M. nu Bois Raymond of a work “O;? the Law of Mus- 
cular Current, and on the Modification which that law undergoes hy the effect of Con- 
traction,''' obliges me, though unwillingly, to transmit to the Royal Society the con- 
tinuation of my researches on induced contraction, confining myself, for the present, 
to some fundamental experiments, made a long time since, for the publication of 
which I should have wished to await a more favourable moment. 
In the Third and Fifth Series of my Electro-physiological Researches*, I studied, 
with all possible care, and in its minute details, the fact of induced contraction, in order 
to deduce the law of this phenomenon, and from thence to be led to the discovery of 
its cause. In the Fifth Series, principally, I was led to conclude, that, according to all 
the analogies, and without being in opposition to the experiments, induced contrac- 
tion might be considered to be the effect of an electric discharge which takes place 
during the act of muscular contraction. 
In a memoir published in the Annales de Physique et de Chimie, Octobre 1847, 
after having given an exposition of the laws of the electrical discharge of fish, and 
demonstrated all the analogies existing between this function and muscular contrac- 
tion, I declared still more explicitly, that experiment leads to the admission that in 
muscular contraction there is a phenomenon analogous to that of the discharge of 
the Leyden phial, and which was the cause of induced contraction. Nevertheless it 
has been my wish that this conclusion, which I have always studiously announced with 
extreme reserve, should be demonstrated by direct experiment, and this object I have 
vainly endeavoured to attain in making use of the galvanometer. 
In the memoirs above cited, are to be found a description of all the efforts made to 
this purpose ; by forming piles with muscular elements of the frog and making these 
elements contract, I endeavoured, but always without satisfactory result, to obtain 
* Philosophical Transactions, Part II. 1845, 1847. 
