vaccination that small-pox is kept down. In countries or in
communities where vaccination is neglected, frightful outbreaks of
small-pox occur every now and then just as in olden times.

_What is the best time for vaccination?_

The time usually selected is from the third to the sixth month. It may
be deferred in a very delicate child who is not likely to be exposed
to small-pox, or in a child suffering from any form of skin disease.

_Which is preferable for vaccination, the arm or the leg?_

The part which can be most easily protected and kept at rest is to be
chosen. In infants who do not yet walk or creep, the leg is to be
preferred? in older children, in most circumstances, the arm. If older
children are vaccinated on the leg, they should not be allowed to walk
much while the vaccination is active.

_When should vaccination be repeated?_

An unsuccessful vaccination proves nothing and should be repeated in
two or three weeks. If success fully vaccinated in infancy, a child
should invariably be revaccinated before puberty. If exposed or likely
to be exposed to small-pox at any time vaccination should be repeated.

[Illustration: Weight chart for the first year; the curved line
indicates the average rate of gain.]

[Illustration: Weight chart, one to fourteen years. The upper line
indicates the average for boys; the lower (dotted) line that for