1884.] on the Physiological Aspect of Mesmerism. 41 



the appropriate muscles ; give a slight tap on the arm, and it relaxes. 

 Braid observed in some subjects that if a limb was made rigid by- 

 passing the hands over it, and if it was left extended for a short time, 

 then the repetition of the same act of passing the hands over the limb 

 caused the rigidity to disappear. It is unnecessary, I think, to con- 

 sider in detail the corresponding states in the narcotised dog and the 

 mesmerised man ; enough has been said to show that in both certain 

 slight stimuli produce, sometimes excitation, sometimes inhibition. 



It must, however, be noted, that our conception of inhibition is not 

 rendered clearer by these facts ; for it would appear from them that a 

 nerve centre may be excited or be inhibited by the same nerve impulse, 

 the result depending upon the condition of the nerve centre. This 

 is not a necessary inference, but it is perhaps at present the most 

 convenient working hypothesis. A certain group of facts, indeed, may 

 be held together and receive a provisional explanation by saying that 

 in some conditions of the central nervous system, a stimulus excites a 

 nerve centre if it is quiescent, and inhibits it if it is active. 



It seems to me probable that what is called the " transference of 

 contracture " and the " transference of sensation " are of the same 

 order of facts. These phenomena are exceedingly curious. Suppose 

 that the left biceps of a mesmerised person be gently stroked or pressed, 

 so that it contracts and remains so. The continuous contraction of 

 the muscle is called contracture. In consequence of the contracture, 

 the arm is kept bent. Suppose that the biceps of the other arm be gently- 

 stimulated, we may get a transference of the contracture, i. e. the right 

 biceps becomes contracted and the right arm bent, whilst the left arm 

 which previously was bent, falls flaccid. Similarly there may be a 

 transference of sensation ; thus the right arm say is rendered insensi- 

 tive, so that pricking it with a needle does not give rise to any sensa- 

 tion ; on the back of the right hand, a piece of metal, such as a two- 

 shilling piece, is now placed, and left for a short time. On removing 

 it, it is found that the spot of skin which was in contact with the metal 

 has become sensitive, so that the prick of a needle is at once felt, but 

 that the corresponding part of the other hand has become insensitive, 

 so that pricking it with a needle produces no sensation. 



The observations of this kind have hitherto been made almost, 

 though not quite exclusively, upon patients suffering from certain 

 diseases of the nervous system, and the facts have been described as 

 occurring both in the wakeful and in the mesmeric state. The 

 proximate explanation appears to be, to take the case of transference 

 of sensation just mentioned, that the gentle tactile stimuli caused by 

 the pressure of the coin on the skin, reaching an inhibited centre 

 sets it in activity, and the sensibility of that part of the skin is 

 restored, but the stimulus passes on to the corresponding and hitherto 

 active centre of the opposite side of the body, and this is inhibited. 



Here I must leave the subject. I have not attempted to give 

 an account of all the phenomena of mesmerism ; I have taken 

 those phenomena which seemed to me to be the least easy to 



