DUAL CONSCIOUSNESS. 261 



have been ignorant and in those points in which manners 

 depend on training ill-mannered. He would have known 

 only, in this condition, what he had learned in this condition; 

 and as only about a tenth part of his life was passed in the 

 abnormal condition, and presumably that portion of his life 

 not usually selected as a suitable time for teaching him, 

 the abnormal boy would of necessity have been much more 

 backward in all things which the young are taught than the 

 normal boy. As nothing of this kind was noted, it would 

 appear probable that the boy's earlier years were common to 

 both lives, and that his unconsciousness of his ordinary life 

 during the abnormal condition extended only to those parts 

 of his ordinary life which had passed since these seizures 

 began. Unfortunately, Brown-Sequard's account does not 

 mention when this had happened. 



It does not appear that the dual brain theory is required 

 so far as this case is concerned. The phenomena seem 

 rather to suggest a peculiarity in the circulation of the brain 

 corresponding in some degree to the condition probably 

 prevailing during somnambulism or hypnotism, though with 

 characteristic differences. It may at least be said that no 

 more valid reason exists for regarding this boy's case as 

 illustrating the distinctive duality of the brain than for so 

 regarding some of the more remarkable cases of somnam- 

 bulism ; for though these differ in certain respects from the 

 boy's case, they resemble it in the circumstances on which 

 Brown Sequard's argument is founded. Speaking generally 

 of hypnotism, that is, of somnambulism artificially pro- 

 duced, Dr. Carpenter says, ' In hypnotism, as in ordinary 

 somnambulism, no remembrance whatever is preserved, in 

 the waking state, of anything that may have occurred during 

 its continuance ; although the previous train of thought may 

 be taken up and continued uninterruptedly on the next 

 occasion when hypnotism is induced.' In these respects 

 the phenomena of hypnotism precisely resemble those of 

 dual consciousness as observed in the boy's case. In what 

 follows, we observe features of divergence. Thus ' when the 



