SOME CURIOSITIES OF THINKING. 



723 



disease he did not recognize his surroundings. On going out for 

 the first time the streets of the city no longer seemed familiar ; on 

 coming back he did not know his own house. After a few weeks, 

 however, all his memories had returned excepting those of the let- 

 ters and figures named ; but as the loss of these put a stop to his 

 reading and to all his business life, the small defect of memory 

 was for him a serious thing. Experience has shown that such a 

 defect is due to a small area of disease in one part of the brain. 

 Such cases are not uncommon, and illustrate the separateness of 

 our various memories and their dependence upon a sound brain. 



Among the curiosities of thought which the physician meets 

 with, unexpected perceptions suddenly appearing before the mind 

 with the same vividness as ordinary perceptions, but without any 

 accompanying external excitant, are not uncommon. A person 

 may look at an empty chair and yet see a familiar form seated in 

 that chair, and may even hear remarks made by this imaginary 

 figure and not doubt for a moment that the figure is an actual 

 entity. 



I have seen persons talking with such imaginary individuals, 

 and have had them assure me that they were as sure of their pres- 

 ence and of their voices as they were of my own. I have seen 

 persons manifest the greatest alarm at the presence of animals 

 about them, and refuse to believe from assurance that those 

 animals were not there. 



A young woman, having once been frightened by the sudden 

 presentation to her of a white mouse, has been troubled for years 

 by seeing this mouse running about her, upon her clothing, 

 upon anything she is handling, and even upon her food ; and, as 

 a result, she is in a state of constant agitation and perplexity, 

 though at times convinced that this is the product of her mind. 

 She washes her hands and her clothing frequently because she is 

 convinced that this animal has made them dirty ; and she can not 

 divest herself of the belief that it is real. 



I have sometimes been able to convince persons that such fan- 

 cied figures were not real by asking them to push one eyeball up 

 a little with the finger. This makes all objects about them seem 

 double, as any one can prove to himself, but it does not double 

 the false image the product of the mind. The young woman 

 just mentioned was much comforted by this device. 



Argument alone does not sufiice in such a condition to con- 

 vince one that an impression is erroneous. Thus, a woman who 

 had gradually become totally blind, and was willing to admit that 

 she could see nothing whatever, could not be convinced that she 

 was not surrounded constantly by multitudes of little gnomelike 

 pygmies, whom, she persistently declared, she saw before her, and 

 whom she was afraid that she would step upon or crush by any 



