From a series of experiments made last summer, the author infers, in confirmation of the results obtained by Young, Berard, and Arago, that the chemical rays of light are subject to the same laws of interference and polarization as its luminous rays.

He found that the two images, produced by the sunbeam, and also by its extreme violet rays, when refracted through a calc-spar prism, quickly produce dark impressions, on being thrown upon photogenic paper, and that the extraordinary ray produces more effect than the ordinary one.