La grotte du chien : un laboratoire européen des connaissances chimiques avant la création de laboratoires institutionnels à Naples

Near Naples there is a volcanic origin cave known as the Grotta del Cane, or Cave of the Dog, where a mysterious vapour, hanging low to the ground, could kill (notably, the namesake dogs). For many centuries, scholars from all over the world (mainly Europe, naturally) were drawn there to witness the famous phenomenon, which allowed people to see with their own eyes the passage from life to death just by means of an animal’s respiration. (Many dogs died demonstrating the mortal threat at play). The simple reason for this deadly hazard was invisible because it was a transparent gas, revealing its dangerous properties by entering the body in an unknown manner. The deadly effect on a dog was not always the test case; many different kinds of scientific experiments were performed by local scholars for foreign visitors, and the grotto quickly and widely became a notable site for chemical studies. The goal of this paper is to describe by means of travel journals, chemical writings, books about volcanic elements, reports about experiments en plein air the history of the Cave of the Dog as a site of scientific enquiry about gases from the late XVII century to the early XIX.