DREAMS AND ILLUSIONS. 279 



image. Whatever may be the genesis and primitive 

 character of the idea of space, and its psychical and 

 physiological relations to actual space a question 

 which has been the theme of so much discussion in 

 our time it is certain that first habit and then 

 hereditary influence cause us to have the sensation 

 and apprehension of a psychical space, which may 

 be termed artificial and congenital, and upon which 

 the various impressions of the senses are spon- 

 taneously projected. Of this there is an evident 

 proof in the fact that if we look at the sun or any 

 bright object, such as the windows of a room in the 

 day time, and then close our eyes, so as to make the 

 vision of external space impossible, the image of 

 the sun, sometimes of a different colour, or of the 

 window, is projected into the darkness at some distance 

 from us, and moves about this psychical space. This 

 phemonenon also occurs in the subjective sensations 

 of hearing, since the sounds do not appear to be close 

 to the ear, but at a distance. We are not here called 

 upon to discuss the causes which generate the 

 appearance of this psychical space, but the fact is 

 indisputable ; so that conversely it becomes intelligible 

 how the internal image may be projected in the same 

 way, or may at least appear to be externally projected 

 in hallucinations. This surprising phenomenon is 

 only a modification of the ordinary exercise of the 

 psychical and physiological faculties in the projection 



of images ; of which, after the idea of space has been 

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