Every ill child presents certain well-defined alterations in the manner of performance of the various functions of the body. Thus, the pulse and respiration may be altered in character and frequency; the surface temperature may be elevated; the color and condition of the skin may be changed; the appetite may be diminished; weight may be lost, and so on. These alterations from the normal state are termed symptoms.

Healthy children, on the other hand, as uniformly show evidences of their well-being, which, for want of a better name, may be called the features of health. Of these every mother should have a full knowledge, so that by appreciating variations she may anticipate the complete development of disease, and early summon skilled aid, at the time when it is of most service.

Early life must be divided into two periods, namely, infancy and childhood. Infancy is the time elapsing between birth and the complete eruption of the milk teeth, an event that transpires about the end of the second year of life. Childhood extends from this age to the development of puberty, or to the age of thirteen or fifteen years. It is important to remember these two divisions, as frequent reference will be made to them in the subsequent pages.

With this brief preparation, the study of the features of health may be entered upon.