René-François de Sluse

René-François de Sluse, also called Renatus Franciscus Slusius, was a Walloon mathematician and clergyman, born at Visé in the Prince-Bishopric of Liège on 2 July 1622 and dead in Liège on 19 March 1685. He studied at Leuven, took a doctorate in laws at Rome in 1643 and spent ten years in Italy studying languages, mathematics and astronomy, then became a canon of Saint Lambert's Cathedral in Liège in 1650 and abbot of Amay in 1666. His main mathematical work, Mesolabum, appeared in 1659. He contributed to the early calculus, working on spirals, tangents, turning points and points of inflection, and with Johannes Hudde found algebraic rules for tangents, maxima and minima that Newton later used. The conchoid of Sluze bears his name. He corresponded with Pascal, Huygens, Oldenburg, Wallis and Michelangelo Ricci and was elected a Fellow of the Royal Society in 1674.