Instinct guides somewhat in the selection of food where conditions of living are simple. Under more complex conditions there must be a scientific study of the whole situation in order that the individual may cope with it. Then, too, with such a variety of foods from which to select, it is easy to be tempted beyond our means, and to disregard the simple and the wholesome. We know that it is easy to develop a taste for some one food in excess, as for instance, sweets or dishes rich in fat and too highly flavored, and the physician adds his word here to the plea for a study of food and its functions. The conclusion is this, that the housekeeper who has the welfare of her family at heart will not confine her interest in food to cooking processes and new recipes. Good cooks we must have, and our standard of cooking could easily be raised. But other facts about food are important to-day, and as we learn to prepare and serve food daintily, we must study such topics as the following: What food is, its composition and how it nourishes us; how it is manufactured and transported; “pure food”; sanitary and convenient markets; the cost of food and how to buy; principles of food preparation; suitable combinations and amounts of food. These topics are all treated in this volume, and should be considered as important as the actual preparation of food. FOOD MATERIALS =What is food?=——This would seem to be a difficult question to answer as we look about a modern grocery or market with its bewildering assortment of foods. It seems hardly possible to describe such a variety of articles in a brief sentence, or to find a definition that will apply to all. Yet we seem to know instinctively what food is, although we may not find it easy to give a definition. Even the lower animals are guided in selecting food by some natural instinct and seldom make a mistake. A widely used government bulletin gives this definition: “Food is that which taken into the body builds tissue or yields energy or does both.” Probably we have learned this in our physiology, and admit it to be true, but for practical purposes, we need a more complete statement than this. Let us carefully determine what our foods really are, and what elements they contain, in order that we may select wisely for purposes of nutrition, and also that we may learn how to prepare food materials in a way that will utilize everything in them and waste nothing.