clxviii Journal of Comparative Neurology. 



Somnabulists have two different psychological existences which are 

 alternately successive. They do not know what occurs during the at- 

 tack of the disorder. The most simple somnambulism ought to be con- 

 sidered as identical with the great phenomena of double existence 

 which are sometimes so manifest ; it is always the result, the mani- 

 festation of dualism of personality. 



This state is produced in different ways. Sometimes the first 

 personality, the first group of psychological phenomena disai)pears by 

 sleep, by the exhaustion of attention, and the second group is easily 

 developed. 



In other cases a sort of periodic alternation is established by habit 

 and the second group is regularly reproduced when the first has en- 

 dured for a length of time. 



More often still, some little fact; e.g., a definite sensation, is 

 found associated with the group of phenomena which constitute som- 

 nambulism, and when this sensation is provoked it introduces auto- 

 matically all the systems of which it is a part. 



M. Charcot has established the fact that definite relations exist 

 between the somnambulistic state and the hysterical attack. 



He has shown that the attack included often phenomena of a 

 somnambulistic nature, and that on the other hand natural or provoked 

 somnambulisms were often preceded, or even accompanied by a great 

 number of symptoms belonging to the attack. 



Sometimes the attack is spontaneous. But most frequently it is 

 provoked by a psychological phenomenon associated with the emotic 

 state, the fixed idea. 



An hysterical patient who, in his attacks, is a pray to dispair 

 caused by the death of his child or to terror produced by a conflagra- 

 tion, if he think only of his child, or even of some other child, if he 

 watches a little flame or simply a piece of red paper, it is sufficient to 

 cause an attack. 



Touching hysterogenic points, i.e., provoking a definite sensation 

 belonging to a group of psychological phenomena of the crisis, is suffi 

 cient to bring about the attack of convulsions. 



That which strikes most observers in the development of the at 

 tack is the absolute, mathematical, regularity of the attacks in the 

 same patient. Here always the same movements, gestures, cries, 

 words. 



We can predict every minute what is about to take place. The 

 automatic regularity characteristic of all these stated can be easily ex- 

 plained, according to Janet. The second existence is often a rudi- 



I 



