ccommodating
its digestive powers to the food it habitually receives. Thus, animals,
which live on vegetables, can gradually become accustomed to animal
food; and the reverse is equally true. Thus, too, the human stomach can
eventually accomplish the digestion of some kinds of food, which, at
first, were indigestible.

But any changes of this sort should be gradual; as those which are
_sudden_, are trying to the powers of the stomach, by furnishing matter
for which its gastric juice is not prepared.

In regard to the nature of the meals prepared, the breakfast should
furnish a supply of liquids, because the body has been exhausted by the
exhalations of the night, and demands them more than at any other
period. It should not be the heartiest meal, because the organs of
digestion are weakened by long fasting, and the exhalations. Dinner
should be the heartiest meal, because then the powers of digestion are
strengthened, by the supplies of the morning meal. Light and amusing
employments should occupy mind and body for an hour or more after a full
meal.

But little drink should be taken, while eating, as it dilutes the
gastric juice which is apportioned to each quantity of food as it enters
the stomach. It is better to take drink after the meal is past.

Extremes of heat or cold are injurious to the process of digestion.
Taking hot food or drink, habitually, tends to debilitate all the organs
thus needlessly excited. In using cold substances, it is found that a
certain degree of warmth in the stomach is indispensable to their
digestion; so that, when the gastric juice is cooled below this
temperature, it ceases to act. Indulging in large quantities of cold
drinks, or eating ice-creams, after a meal, tends to reduce the
temperature of the stomach, and thus to stop digestion. This shows the
folly of those refreshments, in convivial meetings, where the guests are
tempted to load the stomach with a variety, such as would require the
stomach of a stout farmer to digest, and then to wind up with
ice-creams, thus destroying whatever ability might otherwise have
existed, to digest the heavy load. The fittest temperature for drinks,
if taken when the food is in the digesting process, is blood heat. Cool
drinks, and even ice, can be safely taken at other times, if not in
excessive quantity. When the thirst is excessive, or the body weakened
by fatigue, or when in a state of perspiration, cold drinks are
injurious. When the body