Colour : a text-book of modern chromatics with applications to art and industry / by Ogden N. Rood.

  • Rood, Ogden N. (Ogden Nicholas), 1831-1902.
Date:
1904
Catalogue details

Licence: In copyright

Credit: Colour : a text-book of modern chromatics with applications to art and industry / by Ogden N. Rood. Source: Wellcome Collection.

    19/352 (page 9)
    MODERN CHROMATICS. CHAPTER I. THE REFLECTION AND TRANSMISSION OF LIGHT. As long ago as 1795 it occurred to a German physicist to subject the optic nerve of the living eye to the influence of the newly discovered voltaic current. The result obtained was curious : the operation did not cause pain, as might have been expected, but a bright flash of light seemed to pass before the eye. This remarkable experiment has since that time been repeated in a great variety of ways, and with the help of the more efficient electric batteries of mod- ern times; and not only has the original result of Pfaff been obtained, but bright red, green, or violet, and other hues have been noticed by a number of distinguished physicists. If, instead of using the electrical current, mechanical force be employed, that is, if pressure be exerted on the living eye, the optic nerve is again stimulated, and a series of bril- liant, changing, fantastic figures seem to pass before the experimenter. All these appearances are distinctly visible in a perfectly dark room, and prove that the sense of vision can be excited without the presence of light, the essential point being merely the stimulation of the optic nerve. In the great majority of instances, however, the stimulation of the optic nerve is brought about, directly or indirectly, by the * B