A critical inquiry respecting a new membrane in the eye, discovered by Mr. George Hunsley Fielding / [William Gordon].

  • Gordon, William, 1800-1849.
Date:
1832
Catalogue details

Licence: Public Domain Mark

Credit: A critical inquiry respecting a new membrane in the eye, discovered by Mr. George Hunsley Fielding / [William Gordon]. Source: Wellcome Collection.

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    that of rays reflected from the Membrana Versi¬ color, or from any other membrane ;—and lastly, that the Pigment sun Nigrum of the Choroides, bv absorbing and stifling the light as soon as it has done its office of exciting the Retina, prevents internal reflection and confused vision. I have now to consider the theory of undulation, which, we are informed, is borrowed from that of D e la Hire. It supposes that “the image of the object is projected through the Transparent Retina upon the Reflecting Membrane which is placed behind and in contact with the Retina.— Upon this sensible surface the stimulus of the rays produces certain undulations which are communicated to the Retina, in which similar undulations are excited, which are propagated in a series of vibrations along’ the Optick Nerve to the Sensorium.”# According to this theory, it appears that the light which enters the eye acts only on the Membrana Versicolor, and not at all on the Retina ; and that the latter derives all its sensations, from those undulatory movements of the Membrana Versicolor, which are produced in it by the stimulus of the luminous moleculse, that fall upon its surface. This theory repre- * Vid. Mr. F.’s L(;ct. p. 26.
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