I dintorni del Vesuvio come laboratorio francese delocalizzato: Il caso della grotta del cane a metà ’700

Near Naples there is a cave known as the Dog’s grotto where a mysterious vapour hovered low to the ground can kill. For many centuries scholars from all over the world (mainly Europe, of course) came there attracted by the famous phenomenon, which allowed people to see with their own eyes the slight passage from life to death just by means of breathing. This action so familiar and innocent became in such place clearly hazardous, but the physical reason of that was simply invisible: as it was a transparent fluid, which was able to reveal its dangerous properties by entering the bodies, in a unknown manner Anyway, the death of “the dog” was not the rule, the point is that many times different kind of scientific experiments were performed by local scholars for foreign visitors, so the grotto was quickly and widely considered a site for chemical studies. The paper goal is to describe by means of travel journals, chemical writings, books about volcanic stuff, reports about experiments en plein air and pictures the history of the Grotta del cane as a site of scientific enquiry about gases from the late XVII century to the early XIX. Then, going through the scholars and personalities interested in this site and the different historical periods involved, I will try to highlight the effects of all these different interests on the social, cultural and political value of this place of the Kingdom of Naples.