Franciscus Sylvius

Franciscus Sylvius
Franciscus Sylvius
Born	15 March 1614 Hanau, Holy Roman Empire
Died	19 November 1672 (1672-11-20) (aged 58) Leiden, Republic of the United Netherlands
Doctoral advisor	Adolph Vorstius Emmanuel Stupanus
Other academic advisors	Otto Heurnius
Doctoral students	Burchard de Volder
Other notable students	Ehrenfried von Tschirnhaus
Influences	Paracelsus Jan Baptist van Helmont

Franciscus Sylvius (15 March 1614 – 19 November 1672), born Franz de le Boë, was a Dutch physician and scientist (chemist, physiologist and anatomist) who was an early champion of Descartes', Van Helmont's and William Harvey's work and theories. He was one of the earliest defenders of the theory of circulation of the blood in the Netherlands, and commonly falsely cited as the inventor of gin.

Sylvius, a latinization of "de le Boë" translated as "of the woods", was born in Hanau, Germany to an affluent family originally from Cambrai, but worked and died in Netherlands. He studied medicine at the Protestant Academy of Sedan, and from 1632–1634 in Leiden under Adolph Vorstius and Otto Heurnius. In 1634 he held a disputation Positiones variae medicae under the presidency of Vorstius, in which he defended the proposition that there should be a pulmonary circulation. After that Sylvius made a study tour to Jena and Wittenberg, and on 16 March 1637 he defended a thesis entitled De animali motu ejusque laesionibus at the University of Basel under the presidency of Emmanuel Stupanus. After practicing medicine in his hometown Hanau he returned to Leiden in 1639 to lecture. In this period he became famous for his demonstrations on circulation. From 1641 on he had a lucrative medical practice in Amsterdam. While in Amsterdam he met Glauber, who introduced him to chemistry. In 1658 he was appointed the professor of medicine at the University of Leiden and was paid 1800 guilders which was twice the usual salary. He was the University's Vice-Chancellor in 1669-70.