VOL. XLVm.] PHILOSOPHICAL TRANSACTIONS. 415 



SO as to see tolerably well, am, on one eye only, with which he already sees 

 very well, ae had it performed on both ; one of which was lost, and the other 

 recovered ; but continued inflamed, and could not bear nmch light, ab had it 

 done on one eye only, which was lost. 



Both the eyes, in which the operation failed, were destroyed by the subse- 

 quent inflammation ; but in the case of ab, the ill success was partly owing to 

 the imperfection of the instrument ; a disadvantage that must frequently attend 

 on the execution of new attempts. It was the first operation he had performed, 

 and he had provided a knife with so thin a blade, that after he had passed through 

 the cornea into the anterior chamber of the eye, the point was so blunted, that, 

 on endeavouring to carry it through the cornea out on the other side, the blade 

 bent, and he was apprehensive it might break : however, withdrawing it a little, 

 he made 2 or 3 efl^brts, and succeeded in the incision, and the removal of the 

 cataract. During this operation, the aqueous humour being discliarged, and the 

 patient struggling, he wounded the iris ; which bled profusely, and continued 

 for several days to discharge a great quantity of blood, and bloody ichor : and 

 to this accident was imputetl the miscarriage of the operation ; though Mr. Da- 

 vid aflirnis, that wounds of the iris had been very seldom followed with bad 

 eflects in his practice. 



He had reserved the mention of ak's history to the last, because of its singu- 

 laritv. She was altogether as blind as those whose cataracts are ripe ; but her's 

 had the appearance of a beginning cataract, being of a light blue, and but little 

 opaque. On making the compression, the crystalline did not advance through 

 the pupil, as in the other instances : and he found, that if he exerted more 

 force, he should soon evacuate all the vitreous humour. It was evident, by the 

 great distance of the cataract behind the iris, that this disappointment did not 

 arise from an adhesion to the iris : however, he had immediately recourse to the 

 experiment of cutting through the capsula with the point of his knife ; hoping by 

 that means to have set free the crystalline, but it gave him no assistance. He 

 then passed the curette (a little scoop) through the pupil, and turned it several 

 times round, in expectation of breaking the capsula; but found not the least re- 

 sistance to his instruments ; so that both operations proved ineffectual ; the cir- 

 cumstances being exactly the same in each eye. He had, in couching, met with 

 cataracts of this nature ; but had no apprehension that he could not have dis 

 charged, by the wound of the cornea, the matter of a cataract, in however fluid 

 a state it might prove. 



* Some weeks after this paper was read, Mr. Sharp received an account, that tlie pupils of both 

 eyes had contracted so much, as hardly to leave room for the admission of light; and it was appre- 

 hended the patient would soon become blind. — Orig. 



