is very inconvenient and hard and troublesome, it is really the only
safe way of stopping the spread of these diseases; and I am sure
anyone of you would be willing to take this extra trouble sooner than
let any of your friends catch a disease from you, and perhaps die of
it. Quarantine is also the best and safest thing for the patient,
because it keeps him quiet and at rest until he has completely
recovered, and until all danger that the poison of the disease will
attack his lungs or heart or kidneys is over.

In some of the best schools now there is an examination of all the
children every morning, by a visiting doctor sent by the Board of
Health. If the doctor finds any child that has red and watery eyes, or
is running at the nose, or sneezing, or coughing, or has a sore
throat, he usually sends him home at once, so that the other children
will not catch the infection. The school doctor is not thinking only
about what seems to be a cold, although, as you know, it is very
important that anyone with a cold should take good care of himself and
should not let others catch it from him. The doctor sends the child
home because this is just the way in which several other infectious
diseases may begin--_measles_, _scarlet fever_, _chicken pox_,
_whooping cough_, and _diphtheria_. For most infectious diseases, as
you will remember, are caught from germs floating in the air and
breathed into the nose and throat.

The Board of Health takes care of the public in many ways besides
these. It keeps a very careful watch upon the water supply of the
town, or city, so as to keep the houses and factories from running
their drainage, or _sewage_, into it; for this, as you already know,
might cause the spread of typhoid fever and of other diseases of the
bowels and stomach.