21
The Discovery of Oxygen
It was well established that air was essential for fire and that a candle would burn
only a finite time in a closed vessel. The works of Robert Boyle, Robert Hooke
(1635–1703) and John Mayow (1641–1679) were of fundamental importance in
this regard. Also, elemental oxygen had been isolated on a number of occasions
throughout history, but its nature and relation with combustion had not been realised. Just to mention two examples, Stephen Hales (1677–1761) collected the gas
(oxygen) obtained by heating potassium nitrate (saltpetre), but simply described it
as “air”. Pierre Bayen (1725–1798) obtained oxygen in 1774 by heating mercury
oxide, but believed the gas to be carbon dioxide (fixed air). Scheele is reported to
have been fascinated by fire since his childhood [1], and from his early letters to
Retzius, it can be concluded that he conducted systematic experiments on
redox-reactions already in Malmö.
21.1 Scheele’s Discovery of Oxygen
The problem when trying to investigate Scheele’s study of air and combustion is
that he never discussed these experiments in his letters. From preserved letters, it is
clear that Bergman knew nothing of Scheele’s discoveries until early 1776, when
the manuscript of his Chemische Abhandlung von der Luft und dem Feuer
(Chemical Treatise on the Air and the Fire) was finished. In Bergman’s edition of
The Chemical Lectures of H.T. Scheffer published in 1775, the only reference to
oxygen is a note on the last page, apparently added after the book was sent to the
printer saying that “smoke of phlogisticated nitric acid” (nitrogen monoxide) gives
a convenient way of determining the goodness of air, since it turns red and its
volume is diminished (oxidation to nitrogen dioxide). Interestingly enough, Bergman’s first insights into the chemical properties of air thus seem to originate from
the works of Priestley, results that Bergman discussed in a letter to Gahn on
August 21, 1775 [2]. It is not known why Scheele did not tell Bergman of his
© Springer Nature Switzerland AG 2020
A. Lennartson, Carl Wilhelm Scheele and Torbern Bergman, Perspectives on the
History of Chemistry, https://doi.org/10.1007/978-3-030-49194-9_21
277
The Discovery of Oxygen
It was well established that air was essential for fire and that a candle would burn
only a finite time in a closed vessel. The works of Robert Boyle, Robert Hooke
(1635–1703) and John Mayow (1641–1679) were of fundamental importance in
this regard. Also, elemental oxygen had been isolated on a number of occasions
throughout history, but its nature and relation with combustion had not been realised. Just to mention two examples, Stephen Hales (1677–1761) collected the gas
(oxygen) obtained by heating potassium nitrate (saltpetre), but simply described it
as “air”. Pierre Bayen (1725–1798) obtained oxygen in 1774 by heating mercury
oxide, but believed the gas to be carbon dioxide (fixed air). Scheele is reported to
have been fascinated by fire since his childhood [1], and from his early letters to
Retzius, it can be concluded that he conducted systematic experiments on
redox-reactions already in Malmö.
21.1 Scheele’s Discovery of Oxygen
The problem when trying to investigate Scheele’s study of air and combustion is
that he never discussed these experiments in his letters. From preserved letters, it is
clear that Bergman knew nothing of Scheele’s discoveries until early 1776, when
the manuscript of his Chemische Abhandlung von der Luft und dem Feuer
(Chemical Treatise on the Air and the Fire) was finished. In Bergman’s edition of
The Chemical Lectures of H.T. Scheffer published in 1775, the only reference to
oxygen is a note on the last page, apparently added after the book was sent to the
printer saying that “smoke of phlogisticated nitric acid” (nitrogen monoxide) gives
a convenient way of determining the goodness of air, since it turns red and its
volume is diminished (oxidation to nitrogen dioxide). Interestingly enough, Bergman’s first insights into the chemical properties of air thus seem to originate from
the works of Priestley, results that Bergman discussed in a letter to Gahn on
August 21, 1775 [2]. It is not known why Scheele did not tell Bergman of his
© Springer Nature Switzerland AG 2020
A. Lennartson, Carl Wilhelm Scheele and Torbern Bergman, Perspectives on the
History of Chemistry, https://doi.org/10.1007/978-3-030-49194-9_21
277