He is noted as one of the founders of the integral, and author of Epistola de Transmutatione Curvarum Linearum in Rectus [On the Transformation of Curves into Straight Lines] (1659).[1] From 1653 he studied at Leiden University where he interacted with Frans van Schooten, Johannes Hudde, and Christiaan Huygens. In 1658 he and Hudde left for Saumur in France. He returned to Leiden the next year as a physician.