electromagnetic theory of light

A theory propounded by J. Clerk Maxwell, that light is an electro-magnetic phenomenon. Though the theory has found able advocates, it has not received general acceptance among physicists. The discovery of the Roentgen rays tends to establish the correctne of the theory. Certain phosphorescent light has, like the X-rays, the power of penetrating bodies opaque to ordinary light, which seems to furnish a connecting link between ordinary light and the Roentgen rays, and the discovery by Mr. Marconi, an Italian electrician (in February, 1897), that electric vibrations can be projected through space in straight lines, and be reflected and refracted like light-indeed, made to conform to all of the manifestations characteristic of light seems to leave little room to doubt that electricity and light have a common origin. electro-magnetic units, s. pl. [UNIT.]