This section is from the book "The Home Cyclopedia Of General Information", by Charles Morris. Also available from Amazon: Home Cyclopedia of Necessary Knowledge.
[Fr., from Gk. air, air; aein, to blow.] The gaseous fluid which we breathe and which surrounds the earth. It is a mixture of oxygen and nitrogen, with a small amount of carbon dioxide, the average proportions being, by volume: oxygen, 20.96 per cent.; nitrogen, 79.00 per cent.; carbon dioxide, 0.04 percent. (See Atmosphere; Compressed Air ; Liquid Air.)
 
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