Chemische abhandlung von der luft und dem feuer, nebst einem vorbericht von torbern bergman
Karl Wilhelm Scheele(1742-1786)
 Scheele, a German-born pharmacist, was undoubtedly one of the greatest experimentalists in eighteenth century chemistry. He studied in Stockholm and Upsala, discovered chemical matter such as oxalic acid, citric acid, benzoic acid, lactic acid, uric acid, arsenious acid and molybdic acid etc., and also contributed to the discovery of elements such as chlorine, manganese, barium, molybdenum, tungsten, nitrogen and oxygen. Unfortunately he failed to attain fame as the discoverer of these new elements because he did not complete his investigations nor did he publish his discoveries until others had announced the same results.
 Scheele’s greatest achievement was his discovery of oxygen made in 1771-2 two years before Priestley’s discovery. He immediately made a detailed description of this discovery and the experimentation in this work in 1775, but it was not published until 1777 because of the publisher’s negligence. By that time, however, Priestley had already announced his discovery of oxygen. In this book, Scheele described air as consisting of two gases, a gas necessary for combustion and a gas that prevented combustion (nitrogen). He further illustrated that this ‘fire-air’ was absorbed in several materials, and demonstrated that oxygen could be artificially separated from oxide of mercury, black oxide of manganese and saltpeter etc. He also investigated the darkening action of sunlight on silver chloride thus applying chemical analysis to the science of photography for the first time. Although an English or French edition of this work occasionally appears, an original edition such as this volume is now a work of extreme rarity.