255 



everything presented to him touched his eye, and still continued to 

 call every object red. 



After couching, the inflammation which followed was not so con- 

 siderable as in the former case ; but this cataract was also fluid, and, 

 from its diffusion through the aqueous humour, occasioned a tempo- 

 rary opacity, which concealed for a time an opacity of the capsule, 

 which rendered the sight permanently imperfect. 



It was not till the end of four weeks from the second operation that 

 the sight was again examined, when it was found that he had ac- 

 quired some knowledge of colours and of the distances of objects, 

 which no longer appeared to touch his eye ; but he could not be said 

 to have acquired any discernment of figure. 



The second opportunity which Mr. Home had of making similar 

 experiments was in a boy of seven years of age, who had been blind 

 from his birth by cataracts in both eyes. His blindness, however, 

 was not so complete as in the preceding case : his pupil contracted 

 considerably when a lighted candle was placed before it, and by day- 

 light he could distinguish many colours with tolerable accuracy, par- 

 ticularly the more vivid ones. The operation of couching was again 

 preferred in this case, with the hope of avoiding inflammation. It 

 gave very little pain, and was attended with the desired success. 



As it was hoped that the eye would be but little disturbed by the 

 operation, Mr. Home was prepared to examine his perception of ob- 

 jects as soon as the operation was over. After the eye had been 

 allowed ten minutes to recover itself, a round piece of card of a yel- 

 low colour was placed about six inches from it. He immediately 

 said that it was yellow ; but upon being asked the shape, he ex- 

 pressed a wish to touch it. Upon this being refused, he continued 

 to look at it, and at length guessed that it was round ; and when a 

 square blue card was put before him, he said that this was blue, and 

 round also. A triangular piece he also called round. With regard 

 to the distance of objects, he could form no judgement, but did not 

 even at first suppose that any of them touched his eye. 



The pleasure which this boy received from receiving his sight was 

 such, that it was found impossible to restrain him from using it. The 

 experiments were consequently repeated, and carried further at the 

 distance of about two hours from the operation. Upon being desired 

 to examine a square card with attention, he after some time said, 

 he had found a corner, and then readily counted four corners ; and 

 in the same manner counted three angles of a triangle, by run- 

 ning his eye along the edges from corner to corner. He was on 

 various occasions deceived, as might be expected, by the different 

 apparent magnitudes of the same body at different distances : a 

 guinea at fifteen inches distance was taken for a seven shilling piece ; 

 but at five inches he thought it a guinea. Upon seeing a cart from 

 a two pair of stairs window, he took it for a wheelbarrow drawn by 

 a dog, and counted the number of horses in other carts, supposing 

 them to be dogs. At the end of a fortnight, when the different 

 pieces of card were placed before him, he could not immediately tell 



