Franciscus Sylvius

also called Franz, or François, De le Boë, or Du Bois

born March 15, 1614, Hanau, Ger.died Nov. 15, 1672, Leiden, Neth.

physician, physiologist, anatomist, and chemist who is considered the founder of the 17th-century iatrochemical school of medicine, which held that all phenomena of life and disease are based on chemical action. His studies helped shift medical emphasis from mystical speculation to a rational application of universal laws of physics and chemistry.

http://www.britannica.com/EBchecked/topic/577670/Franciscus-Sylvius