JeanMarie Constant Duhamel (February 5, 1797 – April 29, 1872) was a noted French mathematician and physicist. His studies were affected by the somewhat troubled Napoleonic era. He went on to form his own school École SainteBarbe. Duhamel's principle is named for him. He was primarily a mathematician but did studies on the mathematics of heat, mechanics, and acoustics. ^{[1]} He also did work in calculus using infinitesimals. Duhamel's theorem for infinitesimals says that the sum of a series of infinitesimals is unchanged by replacing the infinitesimal with its principal part.
