Abstract
ON November 30, 1812, just above 100 years ago, the French physicist Biot communicated to the Institute of France a memoir “on a new kind of oscillation which the molecules of light experience in traversing certain crystals.” In this paper, which extends over 371 pages of the printed memoirs, the phenomenon of “rotatory polarisation” was described for the first time. This phenomenon depends on the property which certain substances possess of taking a beam of polarised light and imparting a twist to the plane of polarisation: the beam of light enters with all the vibrations compressed, say, into a vertical plane; it emerges apparently unchanged, but careful examination shows that the component vibrations are no longer vertical, but inclined either to the right or to the left. The importance of this discovery to physicists and to crystallographers was immediately obvious. In our own generation its fertility has been realised also by chemists, who have found in the polarimeter an instrument which promises to render to the science services not less notable than those which have been accomplished with the help of the spectroscope.
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Applications of Polarised Light . Nature 91, 542–546 (1913). https://doi.org/10.1038/091542a0
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DOI: https://doi.org/10.1038/091542a0