Abstract

Compelling evidence is presented that Glauber worked as a laborator (laboratory assistant) for Landgrave Georg of Hesse-Darmstadt from 1632/33 till he was appointed apothecary in Giessen in 1635. During this time, he was also used as laborator by the landgrave’s personal physician, Helwig Dieterich. Glauber became a famous chemist, whose alchemical secrets were keenly solicited by King Frederik III of Denmark, Queen Christina of Sweden, and, according to the 1662 diary of Ole Borch, King Charles II of England. A 1689 letter to Queen Christina contains detailed descriptions of Glauber’s alkahest, his decomposition and redintegration of saltpeter, and his ‘most secret sal armoniacum’, which is interpreted here for the first time.