296. In view of this table, the question may be suggested, Is that article of food most appropriate to the system which is most easily 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 over-worked, 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 appropriate 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 character 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.