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,15. In ih: hr.-murs of the eye. By their defeAive quantity ; 

 ty the tiirbid Hate, or imperfeclly traiifparent condition, of 

 the iur-no'-irs ; by the lofs of any one of them, through acci- 

 dent or violence ; by an altered figure of the cryilalline 

 lens. 



4. //; the brain or optic nerve. By comprelTion, producing 

 palfyorGuTTA Serena (which fee); by a Itate of debihty 

 or inertnefs in the vifnal organ, fo as to require an uncom- 

 monly ftrong light ; by too great fenfibility in the optic 

 nerve, eiiduring but a very feeble imprcffion from the hght, 

 and tranfmitting only a confnfed perception of vifible objecls 

 to the mind ; by fome unknown change in the nervous 

 powe'-, caufing depraved vilion, and exciting imaginary 

 fcenes. which no perfon can obfcrvc befides the patient 

 himfclf. 



It Ikis been generally fuppofed, that blind perfons have not 

 any idea of vifible obje'fts, though they can dillinguifh them 

 by the touch : thus the gentleman couched by JSIr. Chcfel- 

 den, though he knew the colours afunder in a good light 

 during his blind (late ; yet when he faw them after couch- 

 ing, the faint ideas he had of them before, were not fufficient 

 f M- him to know them by afterwards. Fliil. Traiif. N" 403. 



P-4+7' 

 It was even a confiderable time before he could remember 



which was the cat and which tlie dog, though often intormed, 

 without feeling them. Add, that he had no idea of diftance; 

 but thought all the objefts he fuw touched his eyes, as wiiat 

 he felt did his n<in. 



But a cafe is recorded by J.Ir. Ware in the Philofophical 

 Tranfadions (read to the fociety June nth, 1801), which 

 does not accord with Mr. Chefelden's obfervation on this 

 fubjeft. It was the cafe of a young gentleman, who (by a 

 furgical operation) recovered his fight when leven years of 

 age ; after having been deprived of it by catarails, before he 

 was a year old. Mr. Ware gives the following account of 

 the fads in queftion : " I performed the operation on the 

 left eve, on the 29th of December hH, in the prefencc of 

 Mr. Chamberlayne, F.A.S. Dr. Bradley, of Baliol college, 

 Os;ford, and Mr. Piatt, furgcon, in London. It is not ne- 

 celTary, in this place, to enter into a dcfcription of the opera- 

 tion. It will be fufficient to fay, that the child, during its 

 performance, neither uttered an exclamation, nor made the 

 fmalleft motion, either with his head or hands. The eye was 

 jiimediatcly bound up, and no inquiries made on that day 

 with regard to his fight. On the 30th, I found that he had 

 experienced a (light licknefs on the preceding evening, but 

 had made no complaint of pain, either in ins head or eye. 

 On the 31ft, as foon as I entered his chamber, the mother, 

 with much joy, informed me that her child could fee. 

 About an hour before my vifit, he was Handing near the fire, 

 with a h.mdkerchief tied loof,-ly over his eyes, when he told 

 her that under the handkerchief, which had flipped upward, 

 he could dilUnguifh the table by the fide of which (lie was 

 litting : it was about a yard and a half from him ; and he 

 obferved that it was covered with a green cloth (which was 

 really the cafe), and tl-.at it was a little farther off than he 

 was able to reach. No further qiiellions were alked him at 

 that time ; as his mother was much alarmed, lc(l the ufe 

 thus made of his eye might have been premature and inju- 

 rious. Upon examinption, I found that it was not more in- 

 flamed than the other eye ; and the opacity in the pupil did 

 not appear to be much diminidied. Dehrous, however, to 

 afccitain whether he was able to dillinguilh objeAs, I held 

 a letter before him, at the dillance of about twelve inches, 

 when he told me, after a (hort hefitation, that it was a piece 

 of paper ; that it was fquare, which he knew by its corners ; 

 and that it was longer in one dirctlioii than it was iu the 



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other. On being defired to point to the corners, he did it 

 with great precifion, and readily carried his finger in the line 

 of its longell diameter. I then (hewed him a fmall oblong 

 band-box covered with red leather, which he faid was red and 

 fquare, and pointed at once to its four corners. After this, 

 I placed before him an oval filver box, which he faid had a 

 (hiniug appearance ; and, prefently afterwards, that it was 

 round, becaufe it had not corners. The obfervation, how- 

 ever, which appeared to me mod remarkable, was that which 

 related to a white (lone mug ; which he firll called a white 

 bafon, but, fooi^ after, rccollefting himfelf, faid it was a mug, 

 becaufe it had a handle. Thefe experiments did not give 

 him any pain ; »nd they were made in the prefence of his 

 mother, and of Mr. Woodford, a clerk in his majefty's trea- 

 fury. I held the objefis at di{rerent dillances from his eye, 

 and inquired very particularly if he was fcnfible of any dif- 

 ference in tlieir iituation ; which he always faid he was, in- 

 forming me, on every change, whether they were brought 

 nearer to, or carried further from him. I again inquired, 

 both of hismotlicr and himfelf, whether he had ever, before 

 this time, dillinguilhed by light any fort of objeft ; and I 

 wa-; alTured by both that he never had, on any occafion ; and 

 that, when he wiflied to dil'cover colours, which he could 

 only do when they were very (Irong, he had always been 

 obliged to hold the coloured objeft clofe to his eye, and a 

 little on one fiJe, to avoid the projection of the nofe. No 

 further experiments were made on that day. On the ill of 

 January, I found that his eye continued quits free both from 

 pain and inflammation, and that he felt no uneafinefs on the 

 approach of light. I (hewed him a table knife; which at 

 firll lie called a fpoon, but foon redified the millake, giving 

 it the right name, and dillinguilhing the blade from the 

 handle, by pointing to each as he was defired. He after- 

 wards called a yellow pocket-book by its name, taking notice 

 of the filver lock in the cover. 1 held my hand before him ; 

 which he knew, but could not at fird tell the number of my 

 fingers, nor dillinguilh one of them from another. I then 

 held up his own hand, and defired him to remark the di3er- 

 ence between his thumb and fingers ; after which, he readily 

 pointed out the diftinftions in mine alfo. Dark-coloured 

 and fmooth objetls, were more agreeable to him than thofe 

 which were bright and rough. On the 3d of January, lie 

 faw, from the drawing-room window, a dancing-bear in the 

 llreet ; and diilinguiihed a number of boys that v.-ere (land- 

 ing round him, noticing particularly a bundle of cloths which 

 one of them had on his head. On the fame evening, I placed 

 him before a looking-glafs, and held up his hand : after a 

 little time he fmilcd and faid he faw the (hadow of hlshant', 

 as well as that of his head. He could not then dillinguilh 

 his features ; but, on the fDllowlng day, his mother iiaving 

 again placed him before the glafs, he pointed to his eyes, 

 nofe, and mouth, and feemed much gratified with the 



Having thlis 'lated the principal obfervations that were 

 made by Mailer W. I (liall now make a brief comparifon be- 

 tween this ilatemtnt, and that which is given in the XXXVth 

 volume of the Philofophical Tranfaflions, of M. Cheleldtn's 

 patient, who was fuppofed to be born blind, and obtained 

 his fight when he was between thirteen and fourteen years 

 old. 



It fliould be obferved, that though Mailer V/. was fix 

 years younger than Mr. Chefelden's patient, he was renl:irk- 

 ably intelligent, and gave the moft diredt and fatisfaclory 

 anfwers to es-ery qucllion that was put to him. Both of 

 them, alfo, if not born blind, lol^ their fight fo very early, 

 that, as Mr. Chefelden exprelFes it, " they had not any re- 

 coUee'lion of having ever feen." 



My 



