In the history of chemistry, fire air was postulated to be one of two fluids of common air. This theory was positioned in 1775 by Swedish chemist Carl Wilhelm Scheele

Carl Wilhelm Scheele

Carl Wilhelm Scheele was a German-Swedish pharmaceutical chemist. Isaac Asimov called him "hard-luck Scheele" because he made a number of chemical discoveries before others who are generally given the credit...

. In Scheele’s Chemical Treatise on Air and Fire he states: “air is composed of two fluids, differing from each other, the one of which does not manifest in the least the property of attracting phlogiston, whilst the other, which composes between the third and forth part of the whole mass of the air, is peculiarly disposed to such attraction.” These two constituents of common air Scheele called Foul Air (“verdorbene Luft”) and Fire Air (“Feuerluft”); afterwards these components came to be known as nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

 and oxygen

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

, respectively.