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 girls.] End of Project Gutenberg's The Care and Feeding of Children, by L. Emmett Holt