Unpublished translation, 'Physical researches on fixed air' by Felice Fontana English translation of a paper originally written in Italian by Fontana. Fontana's discussion was inspired by Dr [Joseph] Priestly's work on fixed air [carbon dioxide or carbonic acid]. He attempts to fill gaps in understanding of its nature and inherent properties. Numerous corrections, deletions, and marginalia appear in ink throughout. Subject: Chemistry Fontana's paper was published as a pamphlet in Italian in 1775: Fontana, Felice. 'Ricerche fisiche sopra l'aria fissa'. Gartano Cambiagi: Florence, 1775. 1775