Nutritious foods are those which contain substances that can be digested, absorbed into the blood, and assimilated or made a part of our bodies, and so promote growth and supply the waste.

Nutritious foods are nourishing or stimulating.

Nourishing foods are those that supply all the nutrition that the body needs, and develop perfectly every animal function, but do not increase the strength and rapidity of organic actions beyond the point of full nutrition.

Bread, vegetables, fruits, grains, sugar, salt, and water are nourishing foods.

Stimulating foods. All food that nourishes the body is in one sense stimulating, as it gives renewed energy to the bodily functions. But there are foods which impart more speed and energy to the organs than are necessary to perfect nutrition. Animal food is of this class. People who work, either with their brains or their muscles, wear out faster than people who only live and grow; and they need stimulating food to give the excess of energy that work demands,- not stimulants, but stimulating food. Stimulants are quite different.

Stimulants. Condiments and alcoholic drinks are classed as stimulants, because they impart no nourishment, do not make new tissue, nor help to remove the waste. They simply excite the bodily organs to greater activity for the time being, as a whip spurs an animal to greater speed ; and the result is either greater weakness after the stimulating effect has passed, or a craving for these excitants that nothing else will satisfy. The bodily functions are spurred to unnatural activity; and there is truth, in more senses than one, in the expression, " He is living too fast."

Innutritions foods are those which are not assimilated, which are by nature indigestible, or have been made so by improper combinations and modes of cooking.

The bran of wheat and other grains, the skins of peas, beans, and corn, the skins, cores, and seeds of fruit, heavy bread, soggy pastry, rich heavy cake, and all greasy fried food are either entirely unassimilated, and therefore do not nourish, or they are so difficult of digestion that some of the organs are excited to excessive action to rid the system of them, and so the digestive organs and, in time, the whole system suffer from being overtaxed. We often speak of food as digestible and indigestible, and many suppose that indigestible food should never be eaten. But there are some foods, portions of which are entirely indigestible and pass from the system unchanged and without causing any disturbance in the digestive canal. And it is evidently the provision of Nature that such foods should be eaten, for a certain bulk seems necessary in our food to stimulate a thorough action of the digestive fluids. If we do not eat enough to distend the stomach, so that the churning motion of the muscular coats can affect every part of the food, the digestion is imperfect. Or if the food be sufficient in quantity, but be wholly nutritious or highly condensed food, that is capable of entire absorption, the effect is too stimulating, and serious disorders of the alimentary canal are the result. To remedy this, it is generally necessary for persons in health, and who have strong digestion, to eat a certain amount of innutritious food, which furnishes the bulk required and gives all parts of the digestive apparatus their proper amount of work to perform. While there is a marked difference in the length of time required for digestion by the various nutritious foods, there is often as great a difference in the digestive power of individuals, so it is impossible to prescribe the same diet for everybody. Milk is considered a wholesome food, and cheese is a cheap and nourishing food for laboring people; yet there are some persons who cannot take milk, and others to whom cheese is an active poison.

Many argue in favor of an exclusive vegetable diet because we can obtain from vegetables or grains all the necessary elements of food. No doubt many people eat too much animal food, but it is unwise to go to the extreme of excluding it altogether. The structure and conformation of the teeth and alimentary canal are equally well adapted to the digestion of animal or vegetable food or an admixture of both, and the highest degree of bodily and mental vigor is found usually among those who use a mixed diet. It was evidently intended by Nature that we should eat both animal and vegetable food, and until Nature's laws have been violated and our appetites perverted, it is safe to follow them in our choice of food. " A natural, healthful appetite for plain, wholesome food is the voice of the physical system making known its needs, and may always be trusted as an unerring guide to the proper choice of diet." But when we have to resort to condiments or stimulants to excite an appetite, we may be sure that something is wrong.

A fair proportion by weight is one third animal and two thirds vegetable food.

It has been estimated that an average daily diet should contain the different substances proportioned as follows :1 Proteids, .40 pounds.

Starch, etc., 1.00 " Fats, .40

Salts, .10 pounds.

Water, 6.00 "

Suggestion to the Teacher.

For further information and receipts on cookery for invalids, see "Boston Cook Book," pages 407- 413, and "Diet for the Sick," by Mrs. Henderson. Do not allow the pupils to make any dish in the lesson involving any principle not explained in this or previous lessons.

1 See " The Chemistry of Foods and Nutrition," by Professor At-water, beginning in the "Century," May, 1887.