you by putting on the freshly scraped skin of your arm some
weak smallpox germs from a clean healthy calf which has been
vaccinated. Your arm will in a few days get sore and you will not feel
well for about one week, but you will be made safe from smallpox for
several years.

Fifty nurses were vaccinated in Philadelphia and cared for many sick
with the smallpox, staying with them day after day, but not one of the
nurses took the disease. _Every one should be vaccinated when a year
old and again at the age of ten or twelve years._

=Colds.=--Some colds are catching, but we generally take cold because
we have weak bodies or have been careless. If you want to be free from
colds, remember these six rules:--

Don't sit still in wet clothes or with wet feet.

Don't sit in a cold draft or in a cold room.

Don't sit on the damp ground or on the ice when you are resting from
skating.

Don't cool off quickly after exercising.

Sleep in a room with the windows _wide_ open.

Take a cold bath every morning and draw fresh air to the bottom of the
lungs many times every day.

=Tuberculosis or Consumption.=--This disease is so common and deadly
that twenty persons die from it in our country every hour. It is
caused by tiny germs (Fig. 63) which lodge in the lungs, glands,
bones, or other parts of the body, where they give off poison and hurt
the tissues. We take these germs into the body with dust or food, and
also by putting to the lips a drinking cup or other things used by a
consumptive. Generally the germs will not grow in a strong body, even
when they have lodged there.

=Preventing Consumption.=--Living in poorly lighted houses without
much fresh air, working in dusty rooms, using much strong drink and
tobacco, eating poor food, losing sleep, neglecting a cough, and
taking little or no outdoor exercise weaken the body so that the
consumption germs can grow in it. Deep breathing, sitting and walking
erect, living in rooms with sunshine, sleeping with the windows open
eight or nine hours every night, and eating good food will prevent one
from taking consumption and will often cure the disease. Persons with
this sickness give out the germs in their spit, which should be caught
in a cup and burned.

=The Hookworm Disease.=--This is a sickness affecting thousands of
persons in the South. It is caused by tiny worms half as large as a pin
hanging fast to the lining of the bowels. The worm is sometimes called
the lazy ger