Jean François Aubuisson de Voisins (1769–1841) was a French geologist and engineer who studied under Abraham Gottlob Werner at Freiberg together with Humboldt, von Buch and Jameson. Werner had coined the term geognosy to define a science based on the recognition of the order, position and relation of the layers forming the earth. His theory of the marine origins of the Earth's crust (Neptunism) was widely accepted at the time. Aubuisson however challenged this view, and showed that igneous rocks such as basalt were similar to surface lava flows, and not chemical precipitates of the ocean. His highly successful two-volume Traité de Géognosie, published in 1819, was one of the earliest geology books in French. It describes the earth, its size, atmosphere and oceans, the processes affecting its surface, the different categories of rocks and minerals found in its crust, and how mineral deposits are formed.