A Handbook of Health | Page 9

have been turned into sugar
and absorbed by the blood vessels in its wall; and the meats, milk, eggs,
and similar foods have been digested in the same way.
There still remains the bulk of the fats to be disposed of. These fats are
attacked by the pancreatic juice and the bile, and made ready for
digestion. Like other foods, they are then eaten by the cells of the
intestinal wall; but instead of going directly into the blood vessels, as
the sugars and other food substances do, they are passed on into another
set of little tubes or vessels, called the lymphatics. In these they are
carried through the lymph glands of the abdomen into the great lymph
duct, which finally pours them into one of the great veins not far from

the heart. Tiny, branching lymphatic tubes are found all over the body,
picking up what the cells leave of the fluid which has seeped out of the
arteries for their use and returning it to the veins through the great
lymph duct.
All these different food substances, in the process of digestion, do not
simply soak through the lining cells of the food tube, as through a
blotting paper or straining cloth, but are actually eaten by the cells and
very much changed in the process, and are then passed through the
other side of the cells, either into the blood vessels of the wall of the
intestine or into the lymph vessels, practically ready for use by the
living tissues of the body. It is in the cells then that our food is turned
into blood, and it is there that what we have eaten becomes really a part
of us. It may even be said that we are living upon the leavings of the
little cell citizens that line our food tube; but they are wonderfully
decent, devoted little comrades of the rest of our body cells, and
generous in the amount of food they pass on to the blood vessels.
As the food-pulp is squeezed on from one coil to another through the
intestine, it naturally has more and more of its nourishing matter sucked
out of it; until, by the time it reaches the last loop of the twenty feet of
the small intestine, it has lost over two-thirds of its food value.
The Final Stage--the Journey through the Large Intestine. From the
small intestine what remains of the food-pulp is poured into the last
section of the food tube, which enlarges to from two to three inches in
diameter. It is known as the large intestine, or large bowel. This section
is only about five feet long. The first three-fourths of it is called the
colon; the last or lowest quarter, the rectum, the discharge-pipe of the
food tube. The principal use of the colon is to suck out the remaining
traces of nourishing matter from the food and the water in which it is
dissolved, thus gradually drying the food-pulp down to a solid or pasty
form, in which condition it collects in a large "S" shaped loop of the
bowel just above the rectum, until discharged.
The Waste Materials. By the time that the remains of the food-pulp
have reached the middle of the large intestine, they have lost all their
nutritive value and most of their water. All the way down from the

upper part of the small intestine they have been receiving solid waste
substances poured out by the glands of the intestines; indeed, the bulk
of the feces is made up of these intestinal secretions, not, as is generally
supposed, of the undigested remains of the food. Ninety-five per cent of
our food is absorbed; the body-engine burns up its fuel very clean. The
next largest part of the feces is bacteria, or germs; and the third and
smallest, the indigestible fragments and remainders of food, such as
vegetable fibres, bran, fruit skins, pits, seeds, etc. Hence the feces are
not only worthless from a food point of view, but full of all sorts of
possibilities for harm; and the principal interest of the body lies in
getting rid of them as promptly and regularly as possible.
It can easily be seen how important it is that a habit should be formed,
which nothing should be allowed to break, of promptly and regularly
getting rid of these waste materials. For most persons, once in
twenty-four hours is normal; for some, twice or even three times in the
day. Whatever interval is natural, it should be attended to, beginning at
a fixed hour every morning.
Constipation, and how to Prevent It. Constipation should not be treated
by the all too common method of swallowing salts, which will cause a
flood of watery matters to be poured through the food tube