y of strength and reserve
force, if the patient is in good health, the blood cells will win the
battle; if the condition of the patient is poor, the blood cells will
lose the battle and tuberculosis, or consumption, has its beginning in
that patient from the time the blood cells lose their fight. We know the
battle has been lost because the well-known symptoms of the disease soon
appear. The blood cells do not retreat when defeated; they go on
fighting to the best of their ability. Whether they ever succeed in
overcoming the bacteria, depends upon the treatment the patient gets,
and his personal conduct. We give him a maximum of fresh air and
sunlight because these are the great enemies of all kinds of bacteria.
We force his feeding and try to stimulate his appetite, hoping thereby
to give him strength so that his blood cells will fight actively in his
interest. We take steps to reduce his fever so that his strength may not
be wasted and burned up. If we succeed, with the necessary active
cooeperation of the patient, the blood cells finally overcome the
bacteria and the patient recovers from the disease.

This is the story of the invasion of almost every disease. It is the
story of the white blood cell.

The white blood cell is active in another way and it is a very
interesting way. When you cut yourself the blood cells immediately
surround the entire cut. They line up like an army defending a city.
They form a perfect wall, millions of them, ready to pounce upon all
enemies in the form of bacteria or microbes, that have the temerity to
try to creep into the wound unseen.

This is the reason that so very few of the hundreds of little surface
wounds and scratches which every one gets, ever become infected or go
wrong in any way.

When a microbe does get inside, under the skin, and becomes active, as
they sometimes will, the white blood cell, appreciating that it cannot
defeat the enemy, begins to build a wall around him and locks him in.
This compels the enemy to limit his activity within the wall, which he
does, and so an abscess is formed, which bursts when the bacteria fill
it so full that the wall gives way and empties the poison out on the
surface of the skin, thus saving the body from the poison of the microbe
which would spread all through the body, were it not for the wall formed
by the active, busy little white blood cell.

The foregoing simple explanation of "how we catch disease" will no doubt
be suggest