Biot, Jean Baptiste (1774-1862), a French physicist, conducted research on magnetic fields and the effect of gas on light rays. A magnetic field is the influence that a magnet or an electric current creates in the region around itself. Biot also helped develop a measurement technique known as saccharimetry. That technique uses a form of light called polarized light to measure the concentration of sugar in a solution. Biot was also an expert on the application of physics to astronomy, and he studied the composition of meteorites.