Franciscus dele Bo Sylvius Biography

Franciscus dele Bo Sylvius, the first physician in the Netherlands to defend that the blood circulated in the vessels, was a descendent from an aristocratic protestant family (Calvinist) originally from Flanders with a successful business tradition. His grandfather immigrated to Germany because of religious persecution. Franciscus was born in Hanau, Germany, but spent most of his life in the Netherlands, where he received his education. He attended Medical School at the University of Leiden from 1633 to 1635, but finished in Basel, Switzerland, in 1637. After obtaining his M.D., he practiced medicine for a year and a half in Hanau, but decided to return to Leiden to work as an unpaid lecturer of anatomy at the University of Leiden, while hoping for a paid academic position.

Sylvius had a special interest in brain anatomy, and his studies led to the discovery of the lateral cerebral fissure (cleft), also known as the Sylvian fissure, and the Sylvian angle, that is formed by the lateral cerebral fissure with a line perpendicular to the superior border of the brain hemisphere. The Sylvian fissure, also known as the Aqueduct of Sylvius, is a groove at the external face of the brain, which separates the frontal lobe from the parietal temporal-occipital lobe. This structure is a narrow, elongated cavity of the midbrain that connects the third and fourth ventricles.

Besides anatomy, Sylvius had a special interest in iatrochemistry (from the Greek iatros for physician, i.e., physician's chemistry), a new theory of the seventeenth century that claimed that the cure of diseases through the administration of medicinal preparations, as well as all physiologic and pathologic processes, could be explained on a chemical basis. The theory also defended the use of chemistry as a tool to both the understanding of the ways drug compounds acted and the development of new treatments. Sylvius made a synthesis of the chemical notions of Paracelce (Theophrastus Bombastus von Hohenheim) and Van Helmont, and is considered the founder of the Iatrochemical School. From the iatrochemical perspective, Sylvius studied the process of digestion. One experiment attributed to Sylvius was the use of an inexpensive diuretic (fluid eliminating) compound made from the oil of Juniper berries mixed with grain alcohol.

Without peospects of being appointed to a paid position at the University of Leiden, Sylvius moved to Amsterdam in 1641, where his medical practice became very successful. He was already famous in Amsterdam as an anatomist, especially because of his studies on brain anatomy, what granted him a membership in the prestigious Amsterdam College of Physicians. However, it was only in 1658 that he was finally invited to become professor of medicine at the University of Leiden. From 1669 until 1670, Sylvius occupied the position of vice-chancellor of the university. In Amsterdam, he began writing a treatise entitled New Idea In Medical Practice (Praxeos Medica Idea Nova), but died at the age of 58, after completing only the first volume. Franciscus Sylvius also wrote a descriptive treatise on the natural history of pulmonary tuberculosis that became a classic in late Renaissance Europe.