The structure and physiology of the eye, as affording evidences of design, with illustrations : being the substance of a lecture delivered before the Loughboro' Literary and Philosophical Society, March 6th, 1855 / by B.W. Brown [sic].

  • Browne, Benjamin Webster.
Date:
[1855]
Catalogue details

Licence: Public Domain Mark

Credit: The structure and physiology of the eye, as affording evidences of design, with illustrations : being the substance of a lecture delivered before the Loughboro' Literary and Philosophical Society, March 6th, 1855 / by B.W. Brown [sic]. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Now, look at the Crystalline Lens. In an attentive exami- nation of the Eye, you will perceive the three Humours are all exquisitely transparent; but, different in size, shape, and consistence ; but, the most important is the beautiful Lens. In the inhabitants of the mighty deep,—there being so very small a quantity of Aqueous Humour, the Lens is large ; in Reptiles, however, it is small, there being a larger quantity of the Aqueous and Vitreous fluids ;—in the Eye of birds, as well as in that of man, this is remarkably the case ; and what is very singular, it varies in shape according to its size :— in the human species, it is rather flat and small,—at the same time the Aqueous and Vitreous Humours are large in quantity ;—again, we perceive admirable design in the strict relation which exists between the size and conformation of the several humours of the Eye, according to the circumstances and situation of the creatures to which they belong. The Crystalline is a solid body, which varies in density;—it is found to be much firmer towards the centre, and more so in old age, than in early life ;—it is much flatter at that period, than during infancy;—of course I am now confining my remarks to the Human Eye. The Lens then, consists of concentric layers, and those of Radii,—you are aware, it is placed beyond the Iris, in a depression of the Vitreous Humour, and exactly opposite the Pupil,—it possesses its own capsules or investing membranes of an exquisitely delicate structure. Carefully remove the Lens from the fresh Eye of a bullock, as a simple means of examining this beautiful body, and then try to compare anything to its transparency!—there is nothing to equal it in beauty or transparency. You will be ready to exclaim,—what are all the Lenses which the Optician constructs, when compared with this ? The Lens of the Optician is a solid piece of glass, transparent and beautiful to a degree, certainly; but, far excelled by the Crystalline of the Eye. It is impossible he should be able to construct a Lens like that of the Eye—which varies in