per, and other irritating things.

~13. The Thoracic Duct.~--A portion of the food, especially the digested
fats, is absorbed by a portion of the lymphatic vessels called
_lacteals_, which empty into a small vessel called the _thoracic duct_.
This duct passes upward in front of the spine and empties into a vein
near the heart.

SUMMARY.

How a mouthful of food is digested:

1. It is first masticated--that is, it is chewed and moistened with
saliva.

2. Then it is swallowed, passing through the oesophagus to the
stomach.

3. There it is acted upon, and a part of it digested by the gastric
juice.

4. It is then passed into the small intestine, where it is acted upon by
the bile, the pancreatic fluid, and the intestinal juice.

5. The digested food is then absorbed by the walls of the stomach and
intestines.

6. The greater portion of the food is next passed through the liver,
where hurtful substances are removed.

7. A smaller portion is carried through the thoracic duct and emptied
into a vein near the heart.

CHAPTER IX.

BAD HABITS IN EATING.

~1. Eating too Fast.~--A most common fault is eating too fast. When the
food is chewed too rapidly, and swallowed too quickly, it is not
properly divided and softened. Such food cannot be easily acted upon by
the various digestive juices.

~2. Eating too Much.~--A person who eats food too rapidly is also very
likely to injure himself by eating too much. The digestive organs are
able to do well only a certain amount of work. When too much food is
eaten, none of it is digested as well as it should be. Food which is not
well digested will not nourish the body.

~3. Eating too Often~--Many children make themselves sick by eating too
often. It is very harmful to take lunches or to eat at other than the
proper meal-times. The stomach needs time to rest, just as our legs and
arms and the other parts of the body do. For the same reason, it is well
for us to avoid eating late at night. The stomach needs to sleep with
the rest of the body. If one goes to bed with the stomach full of food,
the stomach cannot rest, and the work of digestion will go on so slowly
that the sleep will likely be disturbed. Such sleep is not refreshing.

~4.~ If we wish to keep our digestive organs in good order, we must take
care to eat at regular hours. We ought not to eat when we are very
tired. The stomach cannot digest well when we are very much fatigued.

~5. Sweet Foods.~--