the brain and nerves. Whatever does harm to the brain and nerves must
injure the special senses also. We have learned how alcohol and tobacco,
and all other narcotics and stimulants, injure and sometimes destroy the
brain cells and their nerve branches, and so we can understand that a
person who uses these poisonous substances will, by so doing, injure the
delicate organs with which he hears, sees, smells, etc.

~32.~ Persons who use tobacco and strong drink sometimes become blind,
because these poisons injure the nerves of sight. The ears are
frequently injured by the use of tobacco. Smoking cigarettes and
snuff-taking destroy the sense of smell. The poison of the tobacco
paralyzes the nerves of taste so that they cannot detect flavors.
Tea-tasters and other persons who need to have a delicate sense of taste
do not use either alcohol or tobacco.


SUMMARY.

1. We have five special senses--hearing, seeing, smelling, tasting, and
feeling.

2. The ear is the organ of hearing, and has three parts, called the
external ear, the middle ear, and the inner ear. The inner ear contains
the nerve of hearing.

3. The middle ear is separated from the external ear by the drum-head.
The drum-head is connected with the inner ear by a chain of bones.

4. Sounds cause the drum-head to vibrate. The ear-bones convey the
vibration from the drum-head to the nerve of hearing.