On the laws which regulate the Absorption of polarised Light by Double Refracting Crystals. In a Letter addressed to . Sir Joseph Banks. read November 12, 1818.

(London, W. Bulmer and Co., 1819). 4to. No wrappers as extracted from "Philosophical Transactions" 1819 - Part I. Pp. 11-27, 1 textillustr. First appearance of one of Brewsters importent paper in the field of optical mineralogy, a field he himself created. In the paper he investigates the polarization-force of double refracting crystals. In 1819 he was able to group all but a few of hundreds of minerals and crystals into mutually consistent optical and mineralogical categories: the primitive form determined the number of axes of double refraction."He regarded "all the various phenomena of polarisation of light by reflexion and refraction as brought under the dominion of laws as well determined as those which regulate the motions of the planets." In 1816 he received the Copley Medal, in 1819 two Rumford Medals, and in 1831 a Royal Medal for the papers in which he announced these discoveries. On the popular level, Brewster?s reputation was established in 1816 by the fad for his kaleidoscope. Its invention was a direct result of his studies of the ory of polarization by multiple reflections."(DSB).