Notes on the applications of polarized light in microscopy

Brewster (1830a) points out that beautiful color effects will be seen if metallic salts are allowed to crystallize from solution under a microscope in polarized light. For this he recommends a glass-plate polarizer and a thin plate of agate or tourmaline as analyzer. The first one to equip a microscope with Nicol prisms was probably Talbot (1834a, 1837) who describes various observations with this equipment. Polarizing prisms for microscopes were sold as early as 1836 by the optician Andrew Pritchard in London: they are included in an advertisement in The Quarterly Literary Advertiser. Use of these as well as of tourmaline plates is mentioned by Goring and Pritchard (1837) and in a Watkins & Hill catalog in 1838. Powell & Lealand in London made microscopes with optional Nicol prisms in 1840-41 (Turner 1989, p. 120-122, Fig. 1). A new microscope by Ross (1843) also has polarizing and analyzing prisms among its accompanying apparatus, and so has one by Smith & Beck in 1848 (Turner 1989, p. 174-175, Fig. 1).