396 Matteucci’s Lectures on Living Beings. 
‘From all this it appears, that there is no experimental evi- 
dence in favor of the explanation of the phenomenon of induced 
contraction, by the assumption of the development of electricity 
uring muscular contraction.’ ; 
‘We are, then, still ignorant of the coullot muscular contrac- 
tion, and all that we know of this phenomenon are the following 
particulars: it is produced, even when acting at great distances 
from the muscle upon the nerve, whose ramifications it receives; 
the integrity of the nervous filament from the pomt where the ex- 
citation takes place to the muscle itself, is indispensable; this 
transmission is effected with such rapidity, that we are compell 
to compare it to that of electricity, light, and radiant caloric, prop- 
agating itself through various media; what modifies, augments 
or destroys the accomplishment of the chemical physico-phenom- 
ena of the nutrition of the muscle, has an analogous action upon 
its contractibility, provoked by any influence acting upon the 
nerves; and lastly, in the laws of the contraction of a muscle, 
we find an analogy with the physical laws of elasticity. The 
fact of induced contraction will, then, be a phenomenon of in- 
duction of this unknown force, which circulates in the nerves 
and produces muscular contraction.’ 
The following views are presented on the production of ner- 
vous force-—‘In conclusion, let us say a few words on the pro- 
duction of the nervous force. Although it be true that we pos- 
sess no knowledge of it except in living animals, and consequently 
want the apparatus to accumulate it and study its laws, out of 
the animal itself, yet we should not abandon all physical analo- 
gies in the investigations which we make relative to its mode of 
production. Whenever a movement occurs, or the effect of foree 
is manifested, we are certain that some transformation of matter 
a loss of power, and as we see the animal machine recover its ap- 
titude for exercise after having obtained food and rest, we 
admit that the force necessary to muscular action may arise 
