Successive refractions in doubly-refracting prisms. Special properties of the two rays emerging from the first doubly refracting crystal. Polarization by double refraction.
Reflection from transparent media polarizes the light partially or wholly according to the incidence. Brewster’s law. Reflection of polarized light from a transparent medium.
Simple refraction partially polarizes the light. Many successive refractions polarize it almost totally. Piles of glasses.
Different methods to obtain a ray of polarized light, 1st, by reflection; 2nd, by simple refraction; 3rd, by double refraction, by eliminating one of the refracted pencils;—by a screen,—by total reflection, Nicol’s prism, by absoption, tourmaline.
Distinctive characters of light completely or partially polarized.
Lessons 32–34. Theory of Undulations.
Hypothesis of luminous undulations.
Vibratory state of a simple ray of homogeneous light. Vibratory state at the inter of two simple rays of homogeneous light intersecting at a very small angle.
Experimental proofs in support of this hypothesis:
1st. Experiment with interferences, fringes. Their breadth is different for different colors; they give the various colors of the prism in white light. The alternately bright and dark sheets are hyperboloids of revolution. The measure of the fringes give the means of estimating the lengths of the undulations corresponding to different colors.