ABSTRACT
In 1811, Arago discovered that the plane of polarization of linearly polarized light was rotated when a beam of light propagated through quartz in a direction parallel to its optic axis. This property of quartz is called optical activity. Shortly afterward, in 1815, Biot discovered (quite by accident) that many liquids and solutions are also optically active. Among these are sugars, albumens, and fruit acids, to name a few. In particular, the rotation of the plane of polarization as the beam travels through a sugar solution can be used to measure its concentration. The measurement of the rotation in sugar solutions is a widely used method and is called saccharimetry. Furthermore, polarization measuring instruments used to measure the rotation are called saccharimeters.
