Air

Air is the name given to that compound of gases constituting the substance of our atmosphere. Formerly, all æriform fluids were called 'airs' (oxygen being called dephlogisticated air); but in this sense the word 'gas' is now used. The chemical composition of air, its chief properties, and the phenomena they give rise to, will be found treated under Atmosphere; also at Air-pump, Barometer, Balloon, Gases, Storms, Wind, and other articles.