Part 53 (1/2)
PART II.
AIR.
CHAPTER XVIII.
Q. _Of what is atmospheric AIR composed?_
A. Princ.i.p.ally 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_).
Q. _What becomes of the HYDROGEN of the FUEL?_
A. Hydrogen (being very inflammable) _burns with a blaze_, and is the cause of the _flame_ which is produced by combustion. (_see p. 34_).
Q. _What becomes of the NITROGEN of the air, amidst all these changes and combinations?_
A. The _nitrogen of the air escapes_, and is _absorbed by the leaves_ of gra.s.s, trees, and various other vegetables.
Q. _What is meant when it is said, that OXYGEN ”SUSTAINS LIFE?”_
A. It means this: if a person _could not inhale oxygen_, he would _die_.
Q. _What GOOD does this inspiration of OXYGEN do?_