Jean-François Daubuisson (1769-1841), geologist and engineer, was an Officer of the Légion 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, Traité de Géognosie and Traité 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, published in French in 1803, he describes his observations of the basalts of Saxony and argues that they, and all basalts, are sedimentary. This English translation by the Secretary of the Wernerian Natural History Society was published in 1814, and provides a fascinating insight into this discredited but once influential theory of the Earth.