Adenoids not only obstruct breathing and weaken the whole system
through lack of adequate air, but they also press upon the blood
vessels and nerves of the head and interfere with normal brain
development. Moreover, they interfere in many cases with the hearing,
and in general hinder activity and growth. The removal of adenoids is
simple, and carries with it only temporary pain and no danger. Some
physicians claim that the growths disappear in later years, but even
if that is true, the physical and mental development of earlier years
is lost, and the person is backward in the struggle for life and
achievement.

[Illustration: FIG. 23.--Intelligent expression is often lacking in
children with adenoid growths.]

42. How to Build a Fire. Substances differ greatly as to the ease
with which they may be made to burn or, in technical terms, with which
they may be made to unite with oxygen. For this reason, we put light
materials, like shavings, chips, and paper, on the grate, twisting the
latter and arranging it so that air (oxygen in the air) can reach a
large surface; upon this we place small sticks of wood, piling them
across each other so as to allow entrance for the oxygen; and finally
upon this we place our hard wood or coal.

The coal and the large sticks cannot be kindled with a match, but the
paper and shavings can, and these in burning will heat the large
sticks until they take fire and in turn kindle the coal.

43. Spontaneous Combustion. We often hear of fires "starting
themselves," and sometimes the statement is true. If a pile of oily