Children, in accordance with the law of the relation between mass and surface in a cube, have, relatively to their mass, about thrice the body surface possessed by an adult. The greatest loss of heat occurs by radiation from the skin and by the evaporation of sweat, therefore undue loss from this extensive area should be prevented by its suitable covering; otherwise the child is placed at a far more serious disadvantage than would be suffered by an adult similarly situated; for in his case growth as well as equilibrium must be maintained. Few parents realise the further fact that the power of heat regulation is very imperfect at birth; indeed its slow development accounts for the instability of a child's temperature for many years after. The fallacy therefore of seeking to strengthen a young life by inadequate clothing, by enforced and prolonged inactivity, or by abstinence from the source of all energy--food--must be persistently exposed. Quite recently, also, Dr. Eurich has advanced evidence to show that the quality of sleep is adversely affected where the sleeper is insufficiently protected from cold, thus emphasising the injury to health associated with going to bed with cold feet. All parents are ambitious that their offspring shall be distinguished by the energy, the stability, the endurance and the power which characterise the cream of humanity. The lives of young people are carefully planned with this object in view. The waking hours of most girls and boys are distributed in ordered sequence between what is intended to be concentrated work and vigorous more or less exciting play. But the fact has been very commonly ignored that these young people are built up of young cells, which cells are passing through almost every conceivable phase of instability in the course of development; consequently recurring periods of leisure and rest are as important to nutrition and nervous stability, more especially in the case of girls, as are the most elaborate arrangements for exercise. Thus it comes about that many youths and maidens suffer from chronic though unrecognised fatigue, while others are unable to employ pleasurably even a short space of "time to themselves," finding no interest in occupations from which excitement is absent. The habitual limitation of the hours of sleep among the rising generation is equally serious. The loss which would be unbearable,[123] says Dr. Acland, even among our most favoured children, were it not for the indulgence permitted them during their long holidays. Is it not a parental duty to insist upon the necessary provision for rest being made in every school, and ought not inviolable rules upon the subject be laid down in their home circles? Sleep, be it remembered, is the property of animals possessed of brains and endowed with consciousness; it affords mechanical rest, and is accompanied by a respite from the chemical changes which are particularly rapid during childhood and adolescence. The intense