[Skip to Content]
[Skip to Content Landing]
May 4, 1895


JAMA. 1895;XXIV(18):665. doi:10.1001/jama.1895.02430180011002d

This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.


These eighteen propositions will assist the beginner to more readily understand the many pages treating of the same subjects in all our text-books.

With a second lecture on the lenses which correct the errors of refraction, and a third lecture on the frames which hold the lenses which correct the errors of refraction, we will have completed the "House that Jack Built."

  1. Three essentials to sight—Lighty; eye; brain.

  2. Three characteristics of light; it proceeds—From every point; in every direction; along straight lines called Rays.

  3. Three directions to rays of light—Parallel; divergent; convergent.

  4. Three destinies for light—Absorbed; reflected; refracted.

  5. Three varieties of forms of glass reflect light— Plane; prism; curved surfaces.

  6. Three combinations of curved surfaces converge rays of light—Convex spherical; convex cylindrical; convex sphero-cylindrical.

  7. Three combinations of curved surfaces diverge rays of light—Concave spherical; concave cylindrical; concave sphero cylindrical.

  8. Three refracting surfaces in the eye—Anterior surface of cornea; anterior surface

First Page Preview View Large
First page PDF preview
First page PDF preview