26o ROUGH WAYS MADE SMOOTH. 



bear very forcibly on the question whether Holland's theory 

 of a dual brain is correct. I propose briefly to describe and 

 examine this case, and some others belonging to the same 

 class, two of which were touched upon in my former essay, 

 but slightly only, as forming but a small part of the evidence 

 dealt with by Brown-Sequard, whose arguments I was then 

 considering. I wish now to deal, not with the question of 

 the duality of the brain, but with the more general question 

 of dual or intermittent consciousness. 



Among the cases dealt with by Rrown-Sequard was that 

 of a boy at Notting Hill, who had two mental lives. Neither 

 life presented anything specially remarkable in itself. The 

 boy was a well-mannered lad in his abnormal as well as in 

 his normal condition, or one might almost say (as will 

 appear more clearly after other cases have been considered) 

 that the two boys were quiet and well-behaved. But the 

 two mental lives were entirely distinct. In his normal con- 

 dition the boy remembered nothing which had happened in 

 his abnormal condition ; and vice versa, in his abnormal 

 condition he remembered nothing which had happened in 

 his normal condition. He changed from either condition to 

 the other in the same manner. ' The head was seen to fall 

 suddenly, and his eyes closed, but he remained erect if 

 standing at the time, or if sitting he remained in that position 

 (if talking, he stopped for a while, and if moving, he stopped 

 moving) ; and after a minute or two his head rose, he 

 started up, opened his eyes, and was wide awake again/ 

 While the head was drooped he appeared as if either sleeping 

 or falling asleep. He remained in the abnormal state for a 

 period which varied between one hour and three hours ; it 

 appears that every day, or nearly every day, he fell once 

 into his abnormal condition. 



This case need not detain us long ; but there are some 

 points in it which deserve more attention than they seem to 

 have received from Dr. Brown-Sequard. It is clear that if 

 the normal and abnormal mental lives of this boy had been 

 entirely distinct, then in the abnormal condition he would 



