VOLTA, Alessandro (1745-1827) - Lettere…sull'Aria Infiammabile Nativa delle Paludi. Milan: Marelli, 1777. First edition of this essay addressed to Francesco Castelli in which Volta describes the discovery of "Aria infiammabile" a new type of gas, the methane of current days. The Italian scientist correctly postulated that the gas was originated by the decomposition of animal and plants and started to experiment pratical applications. 8vo (200 x 125mm). Vignette on title, numerous engraved head-and-tailpieces (light waterstain to the right margin of the first leaves). Modern half-vellum binding.