EXPLANATION OF VISION. 



f .. .1 .', 



APPARENT DIRECTION. 



that an eye in any place to which the reflected rays come, 

 it' turned toward the mirror, would have an image of the 

 candle formed within it by means of a different beam, and, 

 of course, the candle would appear to each observer in a 

 different place behind the mirror, namely, in a place cor- 

 responding to the course of his own particular beam. 



Thus, if there were twenty persons looking at the reflec- 

 tion of the same candle in the same glass, there would be 

 twenty images, distinct from each other in this sense, name- 

 ly, that each would be seen reflected in a different part of 

 the glass from the other, and would be produced by a dif- 

 ferent beam of light. 



You must remember, then, that the mental perception 

 we have of any object, formed by the image of it in the 

 eye, depends entirely upon the manner in which the light 



