Produced by Bryan Ness, Viv and the Online Distributed Proofreading Team at http://www.pgdp.net DISCOVERY OF OXYGEN PART 2 EXPERIMENTS BY CARL WILHELM SCHEELE (1777) Re issue Edition: Published for THE ALEMBIC CLUB BY E. & S. LIVINGSTONE LTD. 16 & 17 TEVIOT PLACE EDINBURGH 1964 [Illustration] PREFACE The portions of Scheele's "Chemical Treatise on Air and Fire" here reproduced in English are intended to form a companion volume to No. 7 of the Club Reprints, which contains Priestley's account of his discovery of oxygen. Not only have the claims of Scheele to the independent discovery of this gas never been disputed, but the valuable volume of "Letters and Memoranda" of Scheele, edited by Nordenskjöld, which was published in 1892, places it beyond doubt that Scheele had obtained oxygen by more than one method at least as early as Priestley's first isolation of the gas, although his printed account of the discovery only appeared about two years after Priestley's. The evidence of this has been found in Scheele's laboratory notes, which are still preserved in the Royal Academy of Science in Stockholm. In his "Chemical Treatise" Scheele endeavours, at considerable length, to prove by experiments his views as to the compound character of heat and of light. These portions of the work have been entirely omitted from what is reproduced here. All the places where omissions have been made are indicated. Every care has been taken in the endeavour to make the translation a faithful reproduction of the meaning of the original, whilst literal accuracy has been aimed at rather than literary elegance. L. D. CHEMICAL TREATISE ON AIR AND FIRE.[A] +1.+ It is the object and chief business of chemistry to skilfully separate substances into their constituents, to discover their properties, and to compound them in different ways. How difficult it is, however, to carry out such operations with the greatest accuracy, can only be unknown to one who either has never undertaken this occupation, or at least has not done so with sufficient attention. +2.+ Hitherto chemical investigators are not agreed as to how many elements or fundamental materials compose all substances. In fact this is one of the most difficult problems; some indeed hold that there remains no further hope of searching out the elements of substances. Poor comfort for those who feel their greatest pleasure in the investigation of natural things! Far is he mistaken, who endeavours to confine chemistry, this noble science, within such narrow bounds! Others believe that earth and phlogiston are the things from which all material nature has derived its origin. The majority seem completely attached to the peripatetic elements.