Lectures on the parts concerned in the operations on the eye, and on the structure of the retina : delivered at the Royal London Ophthalmic Hospital, Moorfields, June 1847 : to which are added, a paper on the vitreous humor; and also a few cases of ophthalmic disease / by William Bowman.
- Sir William Bowman, 1st Baronet
- Date:
- 1849
Licence: Public Domain Mark
Credit: Lectures on the parts concerned in the operations on the eye, and on the structure of the retina : delivered at the Royal London Ophthalmic Hospital, Moorfields, June 1847 : to which are added, a paper on the vitreous humor; and also a few cases of ophthalmic disease / by William Bowman. Source: Wellcome Collection.
Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.
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![] 02 MODIFICATION OF BItfJCKE's very fine, delicate, and closely arranged, so as hardly to be visible with- out the aid of a pocket-glass (see fig. 8). The difficulty of making a clean section at this part, even with a sharp knife, in consequence of the tendency of the structure to be drawn before the blade, caused some uncertainty with regard to the ultimate destination of these lines in the ciliary region. However, after examination of many specimens, I was enabled to feel assured that they passed up to the hyaloid at or in front of the ora serrata, and did not pass round at the back of the lens, in parallelism with the anterior surface of the vitreous body. This being the general arrangement, I noticed in some specimens, of which fig. 9 was the best marked, white layers of irregular character behind the lens at c, and others obviously dipping backwards from the side of the lens, behind the canal of Petit, into the central portion of the vitreous, and there breaking up into fine layers, d. Others, again, followed the posterior wall of the canal of Petit from the ciliary body to the lens. It will be observed that the layer marked d corre- sponds nearly in direction with those which diverge from the ciliary body, and run up to the lens in figs. 1 and 2 from the human eye. In one section through the close and fine lines near the ora serrata I found the appearance delineated in fig. 10, where the lines c are inclined at an angle to those at b. In the specimens thus pre- pared there was usually a disposition to tear in the direction of the white lines, especially behind, where the lines were more opaque and wider apart. There can be no doubt that the white layers now described are composed of a precipitate of the lead. Examined with a high power the grains of precipitate are obvious enough. They, are scattered irregularly in the transparent tissue of the vitreous wherever the solu- tion has penetrated, but in the white layers they are infinitely more abun- dant. Still no sudden bounding line can be distinguished which would warrant the belief that any membrane like the basement mem- brane of other parts had intercepted the precipitate. In some parts the grains of the precipitate had arranged themselves on the surface of the more opaque layers in something of an areolar form. It is easy to understand how an accumulation of a multitude of pre- cipitated particles in a certain plane would, so far as their presence extended, serve to break up the continuity and strength of the vitreous substance in that direction; therefore the splitting or tearing of](https://iiif.wellcomecollection.org/image/b21043140_0118.jp2/full/800%2C/0/default.jpg)
