and only some
solid waste is left.

=23. Work of the liver.=--The food is now in the blood, but has not
become a part of it. It is carried to the liver. There the liver changes
the food to good blood, and then the blood hurries on and feeds the
cells of the body. Spoiled food may be swallowed and taken into the
blood with the good food. The liver takes out the poisons and sends them
back again with the bile. The liver keeps us from getting poisoned.

=24. Bad food.=--Sometimes the stomach and intestine cannot digest the
food. They cannot digest green apples, but they try hard to do so.
They stir the apples faster and faster until there is a great pain.
Sometimes the stomach throws up the food and then the pain and
sickness stop. Spoiled food makes us sick in the same way.

=25. Too fast eating.=--When the food stays too long in the stomach or
intestine it sours, or decays, just as it does outside of the body.
This makes us very sick. When we eat too much, or when we do not chew
the food to small pieces, the stomach may be a long time in digesting
the food. Then it may become sour and make us sick.

=26. Biliousness.=--When the food is poor or becomes sour, it is
poorly digested. Then the liver has more work to do, and does not
change the food to blood as it should. It also lets some of the sour
poisons pass by it. These poison the whole body and make the head
ache. We call this _biliousness_. The tongue is then covered with a
white or yellow coat and the mouth tastes bad. These are signs of
sickness. The stomach and liver are out of order.

=27. Rules for eating.=--If we eat as we should, our stomach will
digest its food. We must follow three rules.

_First_, we must chew the food in the mouth until all the lumps are
fine. Then the food will be ready for the stomach.

_Second_, we must eat slowly. If we eat fast we cannot chew the food
well. The stomach cannot take care of food if it comes too fast. We
must swallow all of one mouthful before we put another into the mouth.

_Third_, we must eat only at meal times. The stomach needs a rest.
Even a little candy, or apples, or nuts will keep the stomach at work,
and tire it out. A child needs to eat more often than his father. So,
besides his meals, he should have something to eat in the middle of
the morning and some more in the afternoon. But he should not be
eating at all hours. He ought not to eat little bits just before
dinner, for that spoils his meal.

W