Jean-Joseph Rallier des Ourmes

Jean-Joseph Rallier des Ourmes was an eighteenth-century French mathematician, born on 26 May 1701 and dead on 23 June 1771. The son of Julien Francois Rallier and Marie de Baudouard, he became a counsellor at the presidial court of Rennes and worked on mathematical questions as well as on agricultural problems. In 1757 he was one of the founders of the Societe d agriculture, de commerce et des arts de Bretagne. His many writings are scattered in various collections, notably the Encyclopedie, to which he contributed fourteen articles on arithmetic, and the Memoires des savants etrangers of the Academie des sciences, where he published on magic squares, on using the divisors of a number to solve arithmetical problems, on finding all the prime numbers in an unlimited run of odd numbers, and on methods of division and extraction. He died aged seventy at his chateau de la Riviere near Vitre.