HYPNOTISM. 373 



rarely accept suggestions regarding the senses, unless they 

 are in the somnambulistic state. 



As to the alterations which may be so produced, we maj-, 

 in the first place, heighten or lessen the acuity, produce 

 a hyperesthesia or anaesthesia, of £iny sense. Thus we may 

 suggest an increased visual or tactile acuity, and then find 

 that the " subject " reacts to much smaller stimuli than he 

 does in the waking state. Probably many of the pheno- 

 mena of so-called " clairvoyance " and " transposition of the 

 senses " are really due to this suggestive hyper^esthesia. 

 Similarly we may heighten the power of smell. Thus a 

 ^'' subject " of Carpenter's was able to pick out the glove of 

 a certain person from sixty others, though he was not able 

 to do this when his nostrils were plugged with cotton-wool. 



Conversely, we may produce anaesthesia by suggestion. 

 Thus numerous surgical operations have been done on 

 persons in this state of suggestive anaesthesia of general 

 sensibilit}'- ; for instance, by Elliotson, in India, in 1845-6, 

 i.e. in pre-chloroform days. 



The suggested loss of the muscular sense is very interest- 

 ing ; thus, suppose a person be told that he is ignorant of 

 the position of his right arm, though he can move it freely 

 and feel when touched. It will be found that, as long as 

 his eyes are open, he knows the position of his arm {i.e. 

 because he can see it), but that if his eyes be closed, he does 

 not ; e.g. if he be told to touch his opposite hand, he passes 

 his right hand across his chest and down the left arm to 

 the hand, i.e. guiding himself by the sense of touch (in 

 technical language, his arm is '' ataxic "). 



These suggestive anaesthesias, it may be remarked, present 

 the closest analogies to those which may occur in hysteria. 



We may, however, produce by suggestion not an increased 

 or lessened acuity, but hallucinations, of the senses. Since 



