38 Mr. J. 'N. Langley [March 14, 



soon brotiglit back by the inhibitory impulses streaming to them from 

 other nerve centres. 



The extent to which the torpid condition develops itself, varies in 

 different individuals. It depends upon the condition of the nervous 

 system, upon the relative intensities of the inhibitory and exciting 

 impulses. As far as our present knowledge goes, it would appear 

 that a few only of those who can be mesmerised, can be made to pass 

 into a condition of complete anaesthesia. It is possible, however, 

 that this may be due to the passes which give rise to inhibitory 

 impulses not being continued long enough. Dr. Esdaile, who in 

 India was accustomed to mesmerise his patients before performing 

 surgical operations upon them, used to continue the passes for one to 

 two hours, and often to repeat this for several days in succession. 



In different people the order in which different centres are 

 inhibited varies, as we should expect from the unequal development 

 of different centres in different people. This is no doubt of influence 

 in determining whether the general state is cataleptic, somnambulistic, 

 or lethargic, and here probably the method used to mesmerise is also 

 of considerable importance ; it would seem that the cataleptic condi- 

 tion is more likely to be developed when the process of mesmerisation 

 involves a strain on the eyes of the subject, than when he is mes- 

 merised by passes. Not much attention, however, has as yet been 

 directed to this point. 



There can, I think, be no doubt that mesmerism may help, 

 and sometimes cure, persons suffering from certain diseases of the 

 nervous system. It is not in our power to make any accurate state- 

 ment of the way in which this is brought about ; but since disease 

 may be the result of either an over-activity or of an under-activity of 

 any part of the central nervous system, it is reasonable to suppose 

 that a beneficial effect will follow the employment of a method 

 which allows us to diminish or increase these activities as we will. 

 This is a side of the question which is of the greatest interest both 

 to physicians and to physiologists — to physiologists, since it bears 

 directly upon the problem of the influence of the nervous system on 

 nutrition. There is good reason to believe that by directing attention 

 strongly to any particular part of the body, the nutritive state of 

 that part of the body may be altered. The determination of the 

 actual way in which this is brought about is full of difficulties, but 

 the following way is at least theoretically possible. It may be that 

 the nerve centres connected with the tissue in question are made 

 unusually active, and that they send out nerve impulses of a trophic 

 nature, that is, impulses which directly control the nutrition of the 

 tissue. The alteration in the tissue caused by its changed nutritive 

 state — its changed metabolism — may conceivably be either beneficial 

 or detrimental to the whole organism ; it may give rise to a diseased 

 state, or get rid of an existing one. 



The modern miracles of healing, wrought in persons in a state of 

 religious enthusiasm, offer a field for investigating this problem ; the 



