Giulio Carlo de' Toschi di Fagnano

Giulio Carlo de' Toschi di Fagnano (1682 to 1766), Count Fagnano and Marquis de Toschi, was an Italian mathematician born in Senigallia. Trained in philosophy and theology at the Collegio Clementino in Rome, he taught himself mathematics afterwards and worked mainly on geometry and algebraic equations. He is best known for his study of the lengths and division of arcs of the lemniscate, and he was probably the first to turn attention to elliptic integrals, which makes his work a forerunner of the theory of elliptic functions. His results were collected in the two volumes of Produzioni matematiche (1750). Euler, asked to assess them for the Berlin Academy, was so impressed that he began his own research on the subject and went on to the addition formula for elliptic integrals. Lagrange dedicated his first publication to him.