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?_

In scarlet fever in from three to five days, rarely later than a week;
in measles in from nine to fourteen days, occasionally as late as
twenty days; in whooping-cough in from one to two weeks; in
chicken-pox in from fourteen to sixteen days; in German measles in
from ten to sixteen days. In diphtheria the time varies much; it may
be only one day, and it may be one or two weeks. In mumps it is
usually a little less than three weeks, the average being twenty days.

_Which of these diseases are most contagious?_

Measles and chicken-pox are very contagious, and very few children who
have not had them can come near a person suffering from either disease
without taking it. Whooping-cough is almost as contagious as measles,