De la Double Refraction elliptique et de la Tétraréfringence du Quartz dans le Voisinage de l'Axe

Abstract

THE peculiar phenomena exhibited by quartz in directions slightly inclined to the optic axis were explained by Airy in 1831 on the hypothesis that in any such direction two streams of permanent type can be propagated, these streams being oppositely and elliptically polarised with their planes of maximum polarisation respectively parallel and perpendicular to the principal section. With the aid of these assumptions, he calculated the forms of the interference patterns displayed in plane and circularly polarised light by plates of quartz perpendicular to the optic axis, and also discussed the remarkable phenomena that are observed when two such plates of equal thickness but of opposite rotations are superposed and traversed by a convergent stream of polarised light that is subsequently analysed. The close agreement between these calculated results and the experimental forms of the curves led to a general acceptance of Airy's views, and the conviction of their correctness has since been strengthened by experimental investigations of a more direct character.

De la Double Refraction elliptique et de la Tétraréfringence du Quartz dans le Voisinage de l'Axe.

Par G. Quesneville. Pp. xiv + 361; avec 4 planches. (Paris: Gauthier-Villars et Fils, 1898.)