Poisson

Poisson, Simeon Denis (1781-1840), French mathematician, was successively assistant professor, professor, and examiner at the Polytechnique, his connection with it lasting forty years. He produced some profound mathematical works, and was the discoverer of some important truths, gaining thereby an European reputation. In 1837 he was made a peer of France. His Treatise on Mechanics is of the highest value to advanced students, and his Mathematical Theory of Heat is a masterly examination of the causes of the conduction of heat.