Johannes David Hahn - Professor of Philosophy and Natural Sciences

Johannes David Hahn, drawn by Pieter de Goeje from an original by an unknown painter

Johannes David Hahn

Born Jul 09, 1729 in Heidelberg
Died Mar 09, 1784 in Leyden

Biography: 

Professor of Philosophy and Natural Sciences at the University of Utrecht (1753-1775), and Director of the Botanical Garden at the same place (1759-1775). Professor of medicine and chemistry at the University of Leyden (1775-?). According to Boswell in Holland 1763-64 he was the sometime physician to Belle de Zuylen.

Life with Boswell: 

Boswell heard Hahn lecture about Nitre (a chemical used for the making of gunpowder) at Utrecht on January 19, 1764. On April 8 Boswell supped at the professor's with whom he also met on May 21. On this last occasion, Hahn "told stories of Rücker's forgetting law, and officer hearing voices blaspheming".