René-François de Sluse

René-François Walter de Sluse, who lived from 1622 to 1685, was a Walloon mathematician and clergyman, a canon of Saint Lambert's Cathedral in Liège and abbé of Amay. Born in Visé in the Prince-Bishopric of Liège, in present-day Belgium, he studied at the University of Leuven and became doctor of laws of the Sapienza University of Rome in 1643, then spent ten years in Italy studying languages, mathematics and astronomy. His most important publication, Mesolabum, was printed in 1659. He contributed to the development of calculus, working on spirals, tangents, turning points and points of inflection, and with Johannes Hudde he found algebraic algorithms for finding tangents, minima and maxima that Isaac Newton later used. He corresponded with Blaise Pascal, Christiaan Huygens, Henry Oldenburg, John Wallis and Michelangelo Ricci, and he was elected a Fellow of the Royal Society in 1674. The conchoid of de Sluze is named after him.