HYPNOTISM. 365 



of some mental phenomenon : e.g. the perception of a colour, 

 or the impulse to make a movement. Inhibitory suggestions 

 are those which cause the cessation of some mental pheno- 

 menon ; e.g. the loss of the power of seeing blue, or the 

 impossibility of bending the arm. 



Unconscious suggestion. — It is very easy to draw erro- 

 neous conclusions in making experiments on hypnotised 

 persons, owing to the difficulty there is of being sure that 

 the result obtained is due to the given suggestion only, and 

 that it may not have its origin in other unintentional 

 suggestions as well. For, in accordance with the law of 

 expectant attention, it is difficult not to give some hint, 

 consciously or unconsciously, as to the expected result. 

 This is perceived by the subject, who reacts correspondingly. 



To this source are due many errors in the statements of 

 Heidenhain and of the Salpetriere school as to the physio- 

 logical characteristics of the hypnotic state. Thus it was 

 asserted that, if the right arm of a " subject " be paralysed 

 by suggestion, and a magnet be then brought into contact 

 with it, the paralysis is transferred to the opposite arm. It 

 has, however, been shown that if a piece of brass were used, 

 the " subject " believing it to be a magnet, the transference 

 took place ; and, conversely, if the person were led to believe 

 that the magnet was a piece of brass, the transference did 

 not take place. The results, then, were due to the hypnotiser 

 thinking that a magnet would effect such a transference, 

 and unconsciously betraying this belief to the " subject." 



Voluntary muscular system. Without suggestion. — If no 

 suggestion be made, a hypnotised person may either move 

 freely (so-called " active hypnosis ") ; or, on the other hand, 

 present the aspect of being asleep, with infrequent or no 

 spontaneous movements (" passive hjrpnosis ") ; or, as is 

 usually the case, be in one of the many states between these 



