Great moderation must be observed in the amount of food we take daily. Too rich food would induce not only diseases of the digestive organs, but also disorders of metabolism, like obesity, gout, or diabetes, and thus shorten life. Arteriosclerosis is also promoted by such a diet. The more food also the more exercise should be taken, and the more we work the more food should we take. Aged persons should take less proteid food and more carbohydrates. Proteid food is better suited to young persons who are growing. Besides carbohydrates, milk is also especially indicated for old persons, as are also certain amounts of fat, butter, etc. The amount of food should also depend upon the climate; thus, in winter more fat should be taken, for fat produces heat. Inhabitants of northern climes eat much fat, and in Scandinavia more butter is taken than in southern countries. In hot summer weather little proteid food is required, and carbohydrates, vegetables, and fruit are more suitable. Much depends on the preparation of food. In the process of cooking the food should be brought into the most advantageous form for absorption and assimilation. Therefore much depends upon the way in which the food is cooked, and the great importance of this fact is shown by the establishing of courses in cooking in Berlin under the direction of Prof. H. Strauss. In the choice of food attention must be paid to its digestibility. A robust man, who works hard and takes much exercise, can digest easily the most indigestible vegetable food, whereas a man occupied with scientific work and sitting down all day will have a greater difficulty in digesting it. Aged persons, whose digestive glands are atrophied, are unable to digest food which presents great difficulties to the action of their juices. Therefore raw milk, whipped eggs, tripe, lamb, rice, sago, tapioca, barley, and soft boiled eggs, are the most digestible foods for them. Of the vegetables, rice is among the easiest to digest, and it will also soonest disappear from the stomach. There are special preparations made from various kinds of cereals, finely ground, and containing the most nourishing elements, and these may be advisable for aged persons. There are also albuminous foodstuffs in which the albumin is changed into the form of peptones. However, it has been shown by Professor Ewald that they contain very little peptone, but mainly albumose, its precursor. Others of these foodstuffs have the starch transformed into dextrin or maltose. There can be no doubt that aged persons will thrive and prosper on the best of these preparations, which also have the advantage that they can be taken in conjunction with milk. Another point in their favor is that they require little mastication. We add here a table after Professor Ewald, of Berlin, on the digestibility of the various kinds of food:— TABLE INDICATING THE DIGESTIBILITY OF DIFFERENT KINDS OF FOOD.