76 PROCEEDINGS OF THE CANADIAN INSTITUTE. 
rigidly adequate to it, and arrests the muscles exactly in the position 
which one gives to them. Benedikt notes, concerning this point, 
that according to the researches of Volkmann the contractile capacity 
of muscle augments or diminishes according as it is shortened or 
elongated by traction.” Evidently, we think, M. Jaccoud has thrown 
much light on the pathology of the symptoms of catalepsy ; but as 
he says, the causation of the malady is yet obscure ;—or, how are 
produced those opposed states of the cerebral and spinal centres, and 
why are the symptoms limited to the muscles of animal life? 
Referring again to the cataleptic condition associated with the 
hypnotic state, we ask what changes take place in the system, which 
by the simple raising of an eyelid effect the change into what M. 
Jaccoud says is, one of increased spontaneous and reflex tonicity ? 
First, then, in hypnotism the first of Jaccoud’s cataleptic postu- 
lates is present, viz., the suspension of cerebral operations and their 
external manifestations. How has it been possible for light to pro- 
duce all these changes! We have already noted the hyper-excita- 
bility of the muscular nerves present in hypnotism, causing muscular 
contractions when subject to the slightest irritation. We have 
further supposed that light has been the excitant or irritant inducing 
sleep with cerebral force in abeyance. Again we must remember 
the muscular relaxation taking place when hypnotism is induced. 
Evidently then our assumed nerve spasm has here passed off. But 
on opening the eye of the patient the excitant is again present with 
cerebral operations wholly in abeyance ; hence we may suppose that 
the irritant affecting the optic nerve not only renews the spasm 
previously present and setting out from the sympathetic nerve cells 
residing in the medulla oblongata, thereby not only making the 
cerebro-spinal ataxia more complete, but also as a consequence 
leaving the spinal cord perfectly separated from cerebral influence ; 
and, moreover, having an irritant in the form of light constantly 
producing a central influence upon it, we have it held in a state 
accurately defined by M. Jaccoud as innervation de stabilité. 
But, gentlemen, our already too long paper must be brought to a 
close. These hypotheses and suggestions are only made by us as 
possible explanations of a series of phenomena both strange and 
unusual. It will indeed afford us a real pleasure when advancing 
medical science will have rescued many of these questions from the 
mists still enveloping them, and when the pure light of day will be 
