William Hyde Wollaston

William Hyde Wollaston 1766-1828, English scientist, M.D. Cambridge, 1793. His wide-ranging scientific achievements include the discovery (1802) of the dark lines (Fraunhofer lines) in the solar spectrum; invention of the reflecting goniometer (an instrument by which the angles of crystals are measured) and of the camera lucida; a method of making platinum malleable; the discovery of the elements palladium (1803) and rhodium (1804); and establishment of (1801) the equivalence of galvanic and frictional electricity. He created an endowment with the Wollaston medal to be awarded annually by the Geological Society, London, for outstanding research. Wollastonite, a mineral compound of calcium, silicon, and oxygen, was named in his honor.

Wollaston prism A device used for analysing and producing polarized light, used in some designs of polarimeter. It consists of two prisms of either quartz or calcite cemented together. The Wollaston prism divides incoming light into two linearly polarized beams with perpendicular planes. It is named after the British scientist William Hyde Wollaston (1766–1828).