The digestion of healthy children of seven to fourteen years old is good; the period is one of great growth, demanding a gain of from five to twelve grams per day. Half the nitrogenous food may be of animal origin. Fat is absolutely necessary at this age, and when the coarser forms are repulsive, great care must be taken to give it in a delicate or concealed form.

The incessant activity of the child in the open air if left to himself permits the ready assimilation of whatever comes to hand, but when confined in the too often stuffy school-room, the food should be selected with knowledge. The school luncheon should be supervised with as great care as the food of the infant.

A few simple rules, if followed out intelligently, will enable the mother or provider to furnish a suitable lunch. The food should be such as can be readily assimilated, that is, it should not be concentrated, as fried meat or doughnuts or rich cake or pastry, and it should not be highly spiced. It may contain some sugar, as in ice cream, because sugar is soluble, and if not eaten in too large quantities (an ounce at a time), is readily digested.

There should be some starchy food because starch is converted slowly and furnishes energy over a longer period of time than sugar. The food should be appetizing and attractively displayed, or, if taken from home, put up neatly.

The value of such generalizations lies in the number of observations upon which they are based, and in this case they are too few for a final decision. Further, the facts are from German sources almost exclusively, because no others gave the whole series; and it seemed better to adhere to a uniform standard of calculation in view of the great gaps in our knowledge. It is given in this imperfect state in order to induce a fuller study of the question.

From what we do know of the American standards, it seems probable that the curve of carbohydrates would be less marked, and that the curve of fats would be nearly coincident with that of the proteids, except in that part showing the amount from the tenth to the twentieth year, if drawn to represent American practice.

The steepness of the curve of carbohydrates shows the need of a full supply of the material which serves as the source of power for the very great activity of youth. The child naturally runs all day long; the activity, the amount of work done, is enormously in excess of that done in after life, aimless though it may seem. It is none the less work because it is work of heart and lungs, and muscular exercise in play.

It is useful work, in that it builds up a structure for the grown man to use; it is the building time, and the building cannot be well made, strongly put together, without it.