mental actions, wear of the viscera in carrying on the functions of life; and the tissue thus wasted has to be renewed.  Each day, too, by radiation, his body loses a large amount of heat; and as, for the continuance of the vital actions, the temperature of the body must be maintained, this loss has to be compensated by a constant production of heat:  to which end certain constituents of the body are ever undergoing oxidation.  To make up for the day’s waste, and to supply fuel for the day’s expenditure of heat, are, then, the sole purposes for which the adult requires food.  Consider now the case of the boy.  He, too, wastes the substance of his body by action; and it needs but to note his restless activity to see that, in proportion to his bulk, he probably wastes as much as a man.  He, too, loses heat by radiation; and, as his body exposes a greater surface in proportion to its mass than does that of a man, and therefore loses heat more rapidly, the quantity of heat-food he requires is, bulk for bulk, greater than that required by a man.  So that even had the boy no other vital processes to carry on than the man has, he would need, relatively to his size, a somewhat larger supply of nutriment.  But, besides repairing his body and maintaining its heat, the boy has to make new tissue—­to grow.  After waste and thermal loss have been provided for, such surplus of nutriment as remains goes to the further building up of the frame; and only in virtue of this surplus is normal growth possible; the growth that sometimes takes place in the absence of it, causing a manifest prostration consequent upon defective repair.  It is true that because of a certain mechanical law which cannot be here explained, a small organism has an advantage over a large one in the ratio between the sustaining and destroying forces—­an advantage, indeed, to which the very possibility of growth is owing.  But this admission only makes it the more obvious that though much adverse treatment may be borne without this excess of vitality being quite out-balanced; yet any adverse treatment, by diminishing it, must diminish the size or structural perfection reached.  How peremptory is the demand of the unfolding organism for materials, is seen alike in that “schoolboy hunger,” which after-life rarely parallels in intensity, and in the comparatively quick return of appetite.  And if there needs further evidence of this extra necessity for nutriment, we have it in the fact that, during the famines following shipwrecks and other disasters, the children are the first to die.

This relatively greater need for nutriment being admitted, as it must be, the question that remains is—­shall we meet it by giving an excessive quantity of what may be called dilute food, or a more moderate quantity of concentrated food?  The nutriment obtainable from a given weight of meat is obtainable only from a larger weight of bread, or from a still larger weight of potatoes, and so on.  To fulfil the requirement, the quantity must be increased as the nutritiveness is diminished.  Shall, we, then, respond to the extra wants of the growing child by giving an adequate quantity of food as good as that of adults?  Or, regardless of the fact that its stomach has to dispose of a relatively larger quantity even of this good food, shall we further tax it by giving an inferior food in still greater quantity?