A. Principally of two gases, oxygen and nitrogen; mixed together in the following proportion: viz. 1 part of oxygen, to 4 parts of nitrogen.
Q. What are the uses of the oxygen of the air?
A. It is the oxygen of the air which supports combustion, and sustains life.
Q. What is meant when it is said, that the oxygen of the air “supports combustion?”
A. It means this; that it is the oxygen of the air which makes fuel burn.
Q. How does the oxygen of the air make fuel burn?
A. The fuel being decomposed (by heat) into hydrogen and carbon; the carbon combines with the oxygen of the air, and produces combustion.
Q. What does the combination of carbon and oxygen produce?
A. The carbon of the fuel combining with the oxygen of the air makes carbonic acid gas. (see pp. [36], [37]).