HYPNOTISM AND ITS PHENOMENA. 67 



condition of the blood, affecting the vitality of the walls of the 

 vessels ; but more probably it is largely due to sensory reflex action 

 of the nerves.) That this latter seems the commoner mode of action 

 would seem to be shown from the fact that emotional influences of 

 joy and pleasure with their opposites of sorrow and anger, produce 

 their regular effects of heightened circulation in the capillaries in 

 the one case, and pallor from spasmodic contraction of the same ves- 

 sels in the other. We must here add to this the important factor of 

 sympathetic nervous influence directly exerted upon the heart, pro- 

 bably from the vaso-motor centre in the medulla oblongata upon the 

 accelerator ganglion in the one instance, and the depressor ganglion 

 in the other, both of which have their supposed centres in its muscu- 

 lar tissues. 



We now would seem to have sufficient data wherewith to proceed, 

 in our endeavour to explain the phenomena of hypnotism. We have 

 explained the supposed physical conditions tending to produce sleep. 

 Have we the same present in induced hypnotism 1 It seems to me 

 that in a large degree we have. It is perfectly well known that the 

 hypnotic state cannot be produced at will in all persons, and in others 

 only with various degrees of ease. It is true, moreover, that persons 

 in whom hypnotism can be produced are almost invariably those of 

 an emotional tendency, or those in whom the equilibrium which in< 

 health exists between the cerebral and spinal systems is most readily 

 destroyed — certainly those in whom the sympathetic nervous system, 

 is most readily acted upon. Nothing can express our views upon 

 this point more exactly than the quotation of M. Jaccoud's remarks 

 concerning hysteria. He says : " The physiological characteristics of 

 Hysteria depend upon the importance of the opposing relations which 

 exist between voluntary or cerebral innervation, and the involuntary 

 or spinal. The performance of the regular functions of the nervous 

 apparatus depends upon the natural and innate subordination of 

 spinal activity to that of the cerebrum ; this established hierarchy 

 (which demonstrates among other things the experimental study of 

 reflex motility) is the absolute condition of the normal harmony of ' 

 the nervous functions. Now in hysteria this harmonic equilibrium ■ 

 is always broken and always in favour of the spinal cord ; thus is 

 produced a disorder which bears fatally upon the collective functions 

 of innervation — a veritable cerebro-spinal ataxia which constitutes 

 and characterizes the decay of cerebral action, and the predominance 



