MAGNITUDES AND DISTANCES OF OBJECTS. 171 



one object to another ; and how much we are indebted 

 to examination by the touch, for our knowledge of their 

 forms, or how much our judgment of their magnitudes de- 

 pend on comparisons, perhaps with our own persons, we 

 are unable to determine. These cases show that we are 

 dependant for this kind of knowledge, in a great measure, 

 on former experience. 



515. Chesselderfs Case. This was the case of a young 

 gentleman who was bora blind, or lost his sight so early 

 and so entirely, that he had no remembrance of ever hav- 

 ing seen any object whatever, until he was fourteen years 

 of age. His disease was a cataract in each eye, and at 

 this age it was couched, as the operation is called, and 

 by which his sight was restored. 



516. " When he first saw," says Chesselden, " he was 

 so far from making any judgment about distances, that he 

 thought all objects whatever touched his eyes (as he ex- 

 pressed it), as what he felt did his skin, and thought no 

 objects so agreeable as those which were smooth and 

 regular, though he could form no judgment of their shape, 

 or guess what it was in any object that was pleasing to 

 him. He knew not the shape of anything, nor any one 

 thing from another, however different in shape or magni- 

 tude ; but upon being told what things were, whose forms 

 he knew before, from feeling, he Would carefully observe, 

 that he might know them again ; but having too many 

 objects to learn at once, he forgot many of them ; and 

 (as he said) at first, he learned to know, and again forgot 

 thousands of things in a day. At first, he could bear but 

 very little light ; and the things he saw he thought ex- 

 tremely large, but upon seeing things larger, those first 

 seen, he considered less, never being able to imagine any 

 lines beyond the bounds which he saw ; the room he was 

 in, he said, he knew to be but a part of the house, yet 

 he could not conceive that the whole house could look 

 larger." His cat, which, of course, he knew perfectly 

 well by feeling, he did not know by sight, and being told 

 what it was, closed his eyes, to ascertain the truth in his 



usual manner." 



. 



517. Mr. Wardrop's Case. A case, in many respects. 



