side, with an external aperture. Nature had formed a kind of valve, which closed the aperture from the interior, and thus prevented the contents of the stomach from escaping; but on pushing it aside, the process of digestion could be seen. Through this opening, the appearance of the coats of the stomach and food, at different stages of digestion, were examined.

296. In view of this table, the question may be suggested, Is that article of food most appropriate to the system which is most casily and speedily digested? To this it may be replied, that the stomach is subject to the same law as the muscles and other organs; exercise, within certain limits, strengthens it. If, therefore, we always eat those articles most easily digested, the digestive powers will be weakened; if overworked, they will be exhausted. Hence the kind and amount of food should be adapted to the maintenance of the digestive powers, and to their gradual invigoration when, debilitated.

Observation. Food that is most easily digested is not always most appropriate to a person convalescing from disease. If the substance passes rapidly through the digestive process, it may induce a recurrence of the disease. Thus the simple preparations which are not stimulating, as water-gruel, are better for a sick person than the more digestible beef and fish. 297. The question is not well settled, whether animal or vegetable food is best adapted to nourish man. There are nations, particularly in the torrid zone, that subsist, exclusively, on vegetables; while those of the frigid zone feed on fish or animal food. In the temperate zone, among civilized nations, a mixed diet is almost universal. When we consider the organization of the human system, the form and arrangement of the teeth, the structure of the stomach and intestines, we are led to conclude, that both animal and vegetable food is requisite, and that a mixed diet is most conducive to strength, health, and long life.

296. How is the question answered, whether that article is most appro priate to the system which is most easily digested? Give observation 297. What is said of the adaptation of animal and vegetable food to man?

298. The food should be adapted to the distensible charac ter of the stomach and alimentary canal. The former will be full, if it contain only a gill; it may be so distended as to contain a quart. The same is true of the intestines. If the food is concentrated, or contains the quantity of nutriment which the system requires, in small bulk, the stomach and intestines will need the stimulation of distention and friction, which is consequent upon the introduction and transit of the innutritious material into and through the alimentary canal. If the food is deficient in innutritious matter, the tendency is, to produce an inactive and diseased condition of the digestive organs. For this reason, nutrient food should have blended with it innutritious material. Unbolted wheat bread is more healthy than hot flour cakes; ripe fruits and vegetables than rich pies, or jellies.

Observation. 1st. The observance of this rule is of more importance to students, sedentary mechanics, and those individuals whose digestive apparatus has been enfeebled, than to those of active habits and firm health.

2d. The circumstance that different articles of food contain different proportions of waste, or innutritious matter, may be made practically subservient in the following way: If, at any particular season of the year, there is a tendency to a diarrhœa, an article that contains a small proportion of waste should be selected for food; but, if there is a tendency to an inactive or costive condition of the intestinal canal, such kinds of food should be used as contain the greatest proportion of waste, as such articles are most stimulating to the digestive organs, and, consequently, most laxative.

299. In the selection of food, the influence of season and climate should be considered. Food of a highly stimulating character may be used almost with impunity during the cold

298. What is said of the distensible character of the stomach and alimenta tary canal? What is the effect of eating highly concentrated food? Why is the unbolted wheat bread more healthy than flour cakes? Give observation 1st, Observation 2d. 299. What kind of food is adapted to cold weather? Te warn weather?

weather of a cold climate; but in the warm season, and in a warm climate, it would be very deleterious. Animal food, being more stimulating than vegetable, can be eaten in the winter but vegetable food should be used more freely in the spring and summer.

300. The influence of food on the system is modified by the age of the individual. The organs of a child are more sensitive and excitable than those of a person advanced in years. Therefore a vegetable diet would be most appropriate for a child, while stimulating animal food might be conducive to the health of a person advanced in life.

Observation. When the digestive organs are highly impressible or discased, it is very important to adopt a nutritious, unstimulating, vegetable diet, as soon as the warm

season commences.

If a

301. Habit is another strong modifying influence. person has been accustomed to an animal or vegetable diet, and there is a sudden change from one to the other, a diseased condition of the system, particularly of the digestive apparatus, usually follows. When it is necessary to change our manner of living, it should be done gradually.*

302. Some temperaments require more stimulating food than others. As a general rule, those persons whose sensa tions are comparatively obtuse, and movements slow, will be benefited by animal food; while those individuals whose constitutions are highly impressible, and whose movements are quick and hurried, require a nutritious and unstimulat ing vegetable diet.

The system is gradually developed, and all changes of food, apparel, labor, exercise, or position, should be gradual. Even a change from a bad to a good habit, on this principle, should be gradual.

300. What kinds of food are appropriate to old age? Why? What kinds to childhood? Why? 301. What is the effect when there is a sudden change from a vegetable to an animal diet? How should all ehanges of the system be made? 302. Do different temperaments require different kinds of food? What general rule is given?

CHAPTER XVI.

HYGIENE OF THE DIGESTIVE ORGANS, CONTINUED.

303. The MANNER in which food should be taken is of much practical importance; upon it the health of the digestive organs measurably depends. But few circumstances modify the proper manner of taking food, or should exercise any controlling influence.

304. Food should be taken at regular periods. The interval between meals should be regulated by the character of the food, the age, health, exercise, and habits of the individual. The digestive process is more energetic and rapid in the young, active, and vigorous, than in the aged, indolent, and feeble; consequently, food should be taken more frequently by the former than by the latter class.

305. In some young and vigorous persons, food may be digested in one hour; in other persons, it may require four hours or more. The average time, however, to digest an ordinary meal, will be from two to four hours. In all instances, the stomach will require from one to three hours to recruit its exhausted powers after the labor of digesting a meal. before it will again enter upon the vigorous performance of its duties.

306. Food should not be taken too frequently. If food is taken before the stomach has regained its tone and energy by repose, the secretion of the gastric juice, and the contraction

303. Why is it important that we regard the manner of taking our food? 804. How should the intervals between meals be regulated? 305. What is the average time required to digest an ordinary meal? 306. Why should not food be taken too frequently?