r coat of the small
intestine.]

Fine threads of blood vessels (capillaries) take it up from the stomach
and intestines. Also along the intestines there are little projections
(villi), through which the food passes into a blood stream leading to
the liver, where the blood is then purified. These projections also
contain lacteals or little vessels containing blood without its red
corpuscles. A duct carries this colourless blood mixed with absorbed
food to the left side of the neck, where it empties into the blood
stream. These lacteals have a special affinity for the fat of the food.
Most of the rest of the food, including the proteid and the
carbohydrate or starchy portion now in the form of sugar, passes into
the capillaries, and then is led to the liver.

The liver will not let through more sugar than is required, storing it
up for future use. It also acts as a careful guardian, by arresting
many poisons which would otherwise pass into the general circulation.
The liver requires for the proper performance of its functions plenty
of pure blood, hence the necessity for fresh air and exercise, that the
lungs may work well. The liver is easily influenced by alcoholic
beverages, and by getting too hard work to do through eating rich
foods. A consideration of this delicate and intricate process, whereby
the digested food is absorbed, will show that badly-digested food can
not hope to be well assimilated, consequently attention should be paid
to the quantity and quality of the food we eat (_see_ Digestion; Diet).

[Illustration: Fig. 2.--Two villi containing lacteals. The white canals
are lacteals, the darker lines indicate blood vessels (capillaries).
Magnified 100 diameters. (_From "Quain's Anatomy_.")]

Whatever thus makes living substance is nourishment; whatever fails to
do so is not. If food be taken, and even digested, without being thus
assimilated, it becomes an injury to a patient instead of a help. In
cases of fever, inflammatory disease, or wasting sores, much rich food
feeds the fire. It is like laying rafters on the roof of a burning
house for purposes of repair. In such a case small quantities of milk,
or milk and hot water (_see_ Digestion), represent the total food which
can be effectively used in the body. We write on this subject that in
treatment our friends may watch not to injure by making the blood too
rich in elements which the system cannot usefully assimilate. Such
foods as oatmeal jelly and whe