~15.~ Tobacco has a smarting, sickening taste. Do you think it would be
good to eat? Why not?

~16.~ You know that tobacco makes people sick when they first begin to
use it. This is because it contains a very deadly poison, called
_nicotine_.

~17.~ If you give tobacco to a cat or a dog, it will become very sick. A
boy once gave a piece of tobacco to a monkey, which swallowed it not
knowing what a bad thing it was. The monkey soon became sick and died.

~18.~ Many learned doctors have noticed the effects which come from
using tobacco, and they all say it does great harm to boys, that it
makes them puny and weak, and prevents their growing up into strong and
useful men. If tobacco is not good for boys, do you think it can be good
for men? Certainly you will say, No.


SUMMARY.

1. Both animals and plants are sometimes diseased. Flesh obtained from
sick or diseased animals is unfit for food.

2. Unripe, stale, and mouldy foods are unfit to be eaten and likely to
cause severe illness.

3. Foods are sometimes spoiled by having things mixed with them which
are not food, or which are poisonous.