remove hurtful substances which may be taken with it, such as alcohol,
mustard, pepper, 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,