The discovery of extinct volcanoes in the 18th century and the anthology on volcanoes by Giovanni Targioni Tozzetti (1779)

This work aims to represent the panorama of the level reached by volcanological knowledge in the eighteenth century, having as reference the book on volcanoes written by Giovanni Targioni Tozzetti. The study starts from the precursors of the seventeenth century, Kircher and Borelli, followed in the successive century by Gimma and Moro. The findings of the extinct volcanoes of Guettard and Desmarest in France, Raspe in Germany, Fortis, Strange, Arduino, Ferber in Italy and observations on the Vesuvius area of Bartaloni are then examined. We then discuss the travels of Micheli, and his discovery of extinct volcanoes in Tuscany (Monte Amiata, Radicofani) published only later by Targioni, but occurred before the discoveries of other scholars. Then we go to the examination of the book on volcanoes, which begins with an essay by Targioni in which, based mainly on the examination of Tuscan geothermal phenomena, he proposes his theory of the fomite to explain the activity and extinction of volcanoes. He examines rock samples from his and other collections and hypothesizes that subterranean rocks subjected to very strong heat are transformed into volcanic rocks. Since the book on volcanoes has the character of an anthology, our synthesis of the writings of Galiani, Pliny the younger, Magalotti, Strange, De Bomare, Serao, Derham, Mead, De Gennaro and Minervini follow. Finally, we discuss the choice of contributions in the anthology made by Targioni, but also his geological intuitions and the justifications of his mistakes.