A salary of 1800 guilders marked the appointment of Franciscus Sylvius to the faculty of medicine at Leiden University in 1658, a sum double the standard rate for his peers. Born Franz de le Boë in Hanau in 1614, this physician and chemist redirected the course of medical science through the lens of iatrochemistry.
Academic Foundation
The scholar pursued medical studies at the Academy of Sedan before enrolling at Leiden University between 1632 and 1634. Under the guidance of Adolph Vorstius, he submitted his dissertation, Positiones variae medicae, defending the hypothesis of pulmonary circulation. By 1637, he completed his doctoral thesis, De animali motu ejusque laesionibus, at the University of Basel. Following a tour of Jena and Wittenberg, he returned to Leiden in 1639 to begin lecturing and demonstrating human circulatory processes.
Twenty questions, eight minutes on the clock, and a percentile measured against everyone who has taken it. No sign-up.
Take the IQ test →Iatrochemical School of Medicine
Sylvius championed the belief that all life and illness are products of chemical reactions. This framework, known as the Iatrochemical School of Medicine, applied universal physical and chemical principles to biological processes. In his 1671 publication, Praxeos medicae idea nova, he argued that human digestion relies on interactions between acids and bases originating in stomach, pancreatic, and saliva secretions. His work in Amsterdam, encouraged by encounters with Glauber, deepened his integration of chemistry into medical practice.
Anatomical Research and Legacy
His investigative focus extended to the cerebral structure. In 1663, he provided a detailed description of the lateral fissure in the brain, now identified as the Sylvian fissure. His legacy is further marked by the Sylvian aqueduct and the mineral sylvite, both named in his honor. Posthumously, his 1679 book, Opera Medica, clarified that scrofula and phthisis are specific manifestations of tuberculosis. His academic career concluded at Leiden, where he served as rector magnificus and founded the first university chemical laboratory.
Professional Interests
Beyond his laboratory pursuits, Sylvius maintained a significant collection of 17th-century art. His holdings included 190 paintings, among them eleven works by Gerard Dou and nine by Frans van Mieris. These assets highlighted his status within the Dutch Republic, where he practiced medicine and educated students such as Jan Swammerdam, Niels Stensen, Reinier de Graaf, and Burchard de Volder.
Fast facts
- Born: 1614, Hanau
- Died: 1672, Leiden
- Education: University of Basel, Leiden University, Academy of Sedan
- Primary Role: Professor of Medicine, Leiden University
- Major Contribution: Founded the Iatrochemical School of Medicine
- Anatomical Discovery: Sylvian fissure
- Major Publication: Praxeos medicae idea nova (1671)
- Languages: Latin
Questions readers ask
Did Franciscus Sylvius invent gin?
No, this is a common misconception. Historical evidence indicates the origins of gin are attributed elsewhere, likely Italy.
What was the core principle of the Iatrochemical School?
It proposed that all physiological functions and disease processes occur through chemical actions governed by laws of physics and chemistry.
Achievements
- Held posts at Leiden University
- Educated at Academy of Sedan, Leiden University and University of Basel
- Fields of research: anatomy, chemistry, medicine and physiology
.jpg)
