Jean-Francois Daubuisson (1769 1841), geologist and engineer, was an Officer of the Legion d'Honneur, Knight of St Louis and Chief Engineer at the Royal Mining Corps. He published numerous papers on geology, mining and hydraulics, and is best known for his textbooks, Traite de Geognosie and Traite d'Hydraulique. He studied geology and mineralogy in Freiburg with Abraham Werner, the key proponent of Neptunism, the theory that all rocks had an aqueous origin. Later in his career Daubuisson was to side with the Plutonists, who argued that basalts formed from molten rock. However, in this paper,...