Jean-Baptiste Biot (; ; 21 April 1774 – 3 February 1862) was a French physicist, astronomer, and mathematician who co-discovered the Biot–Savart law of magnetostatics with Félix Savart, established the reality of meteorites, made an early balloon flight, and studied the polarization of light. The biot (a CGS unit of electrical current), the mineral biotite, and Cape Biot in eastern Greenland were named in his honour. Biography Jean-Baptiste Biot was born in Paris on 21 April 1774 the son of Joseph Biot, a treasury official. He was educated at Lyceum Louis-le-Grand and École Polytechnique in 1794. Biot served in the artillery before he was appointed professor of mathematics at Beauvais in 1797. He later went on to become a professor of physics at the Collège de France around 1800, and three years later was elected as a member of the French Academy of Sciences. In July 1804, Biot joined Joseph Louis Gay-Lussac for the first scientific hot-air balloon ride to measure how the Earth's magnetic field varies with elevation (NNDB 2009, Reese 2004, O'Connor and Robertson 1997). They reached a height of 4000 metres (13,100 feet) (NNDB 2009, Reese 2004). Later, in Sept. 1804, a solo flight took Gay-Lussac up to 7010 metres (23,000 ft) (quite dangerous without supplementary oxygen (Reese 2004)). Biot was also a member of the Legion of Honour; he was elected chevalier in 1814 and commander in 1849. In 1815, he was elected a Foreign Member of the Royal Society of London, in 1816 a member of the Royal Swedish Academy of Sciences, and 1822 a Foreign Honorary Member of the American Academy of Arts and Sciences. In addition, Biot received the Rumford Medal in 1840, awarded by the Royal Society in the field of thermal or optical properties of matter. (O’Connor and Robertson 1997). In 1850 Jean-Baptiste Biot published in the Journal des savants a 7-page memoir from his recollections of the period of the late 1790s and early 1800s concerning his encounters with Laplace. Jean-Baptiste Biot had a single son, Édouard Constant Biot, an engineer and Sinologist, born in 1803. Edouard died in 1850 and his father made extraordinary efforts to ready for publication the second half of Edouard's last book, a reference translation of the Chinese classic Tcheou-li. It had been left in manuscript, unfinished. To publish it in correct form, Jean-Baptiste Biot wrote, he had to consult Stanislas Julien, the famous Sinologist,