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. Jaccoudhas 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 1 



First, then, in hypnotism the first of Jaccoud's cataleptic postu- 

 lates is present, viz., the suspension of cerebral operations and their 

 externa] 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 stabilite. 



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 



