ild should be voluntarily exposed to this
disease, and particularly one who is delicate or prone to disease of
the lungs should be protected against it.

_When and how is measles contagious?_

Measles may readily be conveyed from the very beginning of the
catarrh, two or three days before any eruption is present. It is not
often carried by healthy persons. Its poison does not cling long to a
sick room.

_What is German measles?_

German measles, or rubella, is a distinct disease and has nothing to
do with ordinary measles. It is extremely rare for a child to be much
sick with it. There is usually a very extensive eruption which may
cover the body, but few other symptoms.

_What are the first symptoms of scarlet fever?_

Generally it comes suddenly, with vomiting, high fever, and sore
throat. The eruption usually appears within twenty-four hours as a red
blush, first upon the neck and chest, and spreads rapidly.

_When and how is scarlet fever contagious?_

Scarlet fever is only slightly contagious for the first one or two
days of the attack. It is most contagious at the height of the disease
and during desquamation. It may be carried by healthy persons and by
the clothing or bedding from the sick room.

_How does whooping-cough begin?_

For a week or ten days it cannot be distinguished from an ordinary
cold on the chest. Then the attacks of coughing gradually become more
severe and vomiting may follow. After a severe coughing fit the breath
is caught with a peculiar noise known as the "whoop."

_How does chicken-pox begin?_

It usually comes out gradually, as widely scattered pimples over the
scalp, face, and body, many of which soon become small vesicles,
resembling tiny blisters. There is itching and local discomfort but
little fever, and the child rarely seems to be very ill.

_How does diphtheria begin?_

Sometimes suddenly, but usually gradually, with sore throat and
swelling of the glands of the neck, with white patches upon the
tonsils, or a free discharge which may be bloody, from the nostrils.

_How does mumps begin?_

As a swelling upon the jaw, beneath the ear. As it increases it
extends forward upon the cheek and backward behind the ear. It affects
one or both sides.

Mumps is not very common in young children, and in them it is usually
mild. After twelve or thirteen years it is likely to be more severe.

_How long after exposure do the first symptoms appear in the different
diseases?