fixed air

English

Etymology

Coined by Scottish chemist Joseph Black in 1756 because it can be absorbed, or fixed, by strong bases.

Noun

fixed air (uncountable)

1. (chemistry, now historical) Carbon dioxide; carbonic acid.
   • 1790, Edmund Burke, Reflections on the Revolution in France, Oxford 2009, p. 8:

     The wild gas, the fixed air is plainly broke loose: but we ought to suspend our judgement until […] we see something deeper than the agitation of a troubled and disturbed surface.

   • 1997, Roy Porter, The Greatest Benefit to Mankind, Folio Society 2016, p. 246:

     Lavoisier then elucidated the exchange of gases in the lungs: the air inhaled was converted into Black's fixed air, whereas the nitrogen (‘azote’) remained unchanged.

References

• Glossary of Archaic Chemical Terms