SOME PHYSIOLOGICAL ASPECTS OE HYPNOTISM. 529 



material world altogether ; who holds conversations with 

 disembodied spirits, and is daring enough to project him- 

 self into a future which is, from the nature of things, non- 

 existent. There is no known physiological basis even for 

 telepathy, apart from sense-organ impressions, and ex 

 fortiori none for such phenomena as the above. It may 

 be that the nervous system will be subsequently found 

 to react to physical changes in the surroundings which are 

 at present unknown, but it is inconceivable that it should 

 do so without such reaction being a response to a definite 

 stimulus. 



To a physiologist, with all the details of his science fresh 

 in his mind, every response to an external stimulating agency 

 must be one which involves a peripheral sense-organ and 

 its afferent nerves. If telepathy cannot be explained by 

 means of existing sense-organs, but demands a new sense, 

 then the discovery of such a new sense-organ would alone 

 furnish an adequate physiological basis. To suppose that the 

 processes in one brain can, by a process akin to electrical 

 induction, evoke analogous states in the brain of a distant 

 separate individual is a supposition so opposed to the whole 

 of physiological science as at present constituted that its 

 conceivability demands a mental somersault on the part of 

 the physiologist. ' 



A great gulf thus divides the phenomena due to sugges- 

 tion from those which are held by superficial observers to 

 be of the same class, but which are in reality widely 

 different, and the evidence for which, is so bound up with 

 cases of imposture and fraud, as to be, in my opinion, un- 

 reliable. 



I have endeavoured to show that the inhibition theory 

 of Heidenhain and the fatigue theory of Preyer may be 

 extended in the light of modern neurology so as to com- 

 prise the phenomena due to suggestion, and thus to afford 

 a physiological hypothesis of the main features of hypnotic 

 phenomena. In this endeavour special stress has been laid 

 upon the part played by the little known substance which 

 intervenes between the terminal processes of different nerve 

 cells. It is not too much to say that the more precise 



