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VIIT. Account of a new Operation lately performed with Sue-; 

 ce/'s in France, for rejhring Sight in certain Cajes of 

 Blindncfs. Bj C.Dkmours. 



c 



DEMOURS, who performed this new and inge- 

 nious operation, prefented a memoir on the fubjecl: to the 

 National Inftitute, which was read on the 15th of June laft. 

 From this memoir the prefent account has been extracted. 



The eye is a ball or globe fdled with different transparent 

 humours, which are contained in feveral membranes. The 

 outernioft of thefe membranes is called the cftrnea; it is 

 tranfparent, and placed before the iris, which is the coloured 

 part of the eye, and which itfclf forms a fecond membrane; 

 but the latter is not tranfparent, and would prevent the rays 

 of light from penetrating to the hind part of the globe of 

 the eye, were it not pierced with a round hole, called the 

 pupil. A little beyond this hole is the cryllallinc humour, 

 forming a kind of lens, through which the ravs of light are 

 obliged to pals ; and by means of which they form dillinct 

 images on the retina at the bottom of the eye. The humour 

 contained in the infide of the globe is called the vitreous hu- 

 mour ; it is perfectly tranfparent, as is alio the aqueous hu- 

 mour, which is placed between the tranfparent cornea and the 

 crystalline. 



C. Sauvages, on whom C. Dcmours performed the opera- 

 tion which is the fubject of this article, had for feveral 

 years an abfeefs in the cornea, in confequence of which the 

 aqueous humour was entirely wailed, and the tranfparent 

 part of the cornea had become totally white and opake in 

 the right eye, and for about four- fifths in the left eve. This 

 eye is represented in the annexed engraving (Plate V. 

 fig. 5). The tranfparent cornea, C, fuffcrs to be ken to- 

 wards the upper part but a fmall portion of the iris. The 

 white fpot covers entirely the round hole or pupil, which 

 exilts in the centre of the iris, and through which alone the 

 rays of light can pafs. 



C. Demours, taking advantage of the tranfparencv which 

 fill ! exitted towards the upper part of the cornea, made there 

 a fmall aperture, denoted by the letter A ; and having in- 

 troduced 



