FAUJAS DE SAINT-FOND (Barthélémy). Recherches sur les volcans éteints du Vivarais et du Velay. Grenoble, Joseph Cuchet ; Paris, Nyon aîné, Née & Masquelier, 1778. In-folio, marbled calf, spine decorated, red edges (period binding). First edition of this important study on the formation of volcanoes, more complete than any previous work. The study on the extinct volcanoes of Vivarais and Velay is preceded by a Discourse on burning volcanoes and various analytical Memoirs on schorls, zeolite, basalt, pozzolan, lavas and the various substances found in them. "The author's descriptions and illustrations of the extinct volcanoes are excellent, and have scarcely been surpassed in later publications", says Zittel. The work is illustrated with 3 vignettes and 20 superb plates out of text, including one fold-out, engraved on copper by Fessard, mostly after drawings by Veyrène and Gautier d'Agoty. They depict volcanoes, geological sites and minerals. Faujas de Saint-Fond (1741-1819), professor and administrator at the Natural History Museum, was one of the founding fathers of geology and vulcanology. A close friend of Buffon, he collaborated on the geological section of his Histoire naturelle. A very fine copy bound in contemporary style, complete with the list of subscribers. Covers slightly restored. In French in the text, n°169 - Hoover, n°294 - Ward & Carozzi, n°779 - Zittel, p. 46.