SIGAUD DE LA FOND, [Joseph Aignan]. Essai sur différentes espèces d'Air-Fixe ou de Gas, Pour servir de suite & de supplément aux Elémens de Physique du même Auteur. Paris: P. Fr. Gueffier, 1785. New edition, revised and enlarged [by Urbain François Rouland, nephew of Sigaud], in-8; xxviii (Approval, Privilege, Notice of the editor, Preface), 499p., [1p. errors], 8 folding plates. Bound in contemporary spotted basane, spine ribbed and decorated, marbled endpapers. Prize copy decorated with the iron of the Ecole centrale de Lyon on the first board; upper cover damaged, corners dull, extremities rubbed, good condition inside despite badly folded plates. The original edition of 1779 contained only 400 pages and 5 plates.