🇸🇪12/19 - The first chemist to discover oxygen, Carl Wilhelm Scheele

• Born: 9 December 1742
• Died: 21 May 1786 (aged 43)
• Known for: Discovered oxygen

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By the time he was a teenager, Scheele had learned the dominant theory of gases which in the 1770s was the phlogiston theory.

When Scheele discovered oxygen he called it "fire air" as it supported combustion. Scheele explained oxygen using phlogistical terms because he did not believe that his discovery disproved the phlogiston theory.

The first English edition, Chemical Observation and Experiments on Air and Fire was published in 1780, with an introduction "Chemical Treatise on Air and Fire".