their digestibility.

The great abundance and variety of food in this country, permit this
principle to be put into practice. A variety of mixed foods, as milk,
eggs, bread, and meat, are almost invariably associated to a greater or
less extent at every meal.

Oftentimes where there is of necessity a sameness of diet, there arises a
craving for special articles of food. Thus on long voyages, and during
long campaigns in war, there is an almost universal craving for onions,
raw potatoes, and other vegetables.

166. Hints about Meals. On an average, three meals each day, from
five to six hours apart, is the proper number for adults. Five hours is by
no means too long a time to intervene between consecutive meals, for it is
not desirable to introduce new food into the stomach, until the gastric
digestion of the preceding meal has been completed, and until the stomach
has had time to rest, and is in condition to receive fresh material. The
stomach, like other organs, does its work best at regular periods.[25]

Eating out of mealtimes should be strictly avoided, for it robs the
stomach of its needed rest. Food eaten when the body and mind are wearied
is not well digested. Rest, even for a few minutes, should be taken before
eating a full meal. It is well to lie down, or sit quietly and read,
fifteen minutes before eating, and directly afterwards, if possible.

Severe exercise and hard study just after a full meal, are very apt to
delay or actually arrest digestion, for after eating heartily, the vital
forces of the body are called upon to help the stomach digest its food. If
our bodily energies are compelled, in addition to this, to help the
muscles or brain, digestion is retarded, and a feeling of dullness and
heaviness follows. Fermentative changes, instead of the normal digestive
changes, are apt to take place in the food.

167. Practical Points about Eating. We should not eat for at least
two or three hours before going to bed. When we are asleep, the vital
forces are at a low ebb, the process of digestion is for the time nearly
suspended, and the retention of incompletely digested food in the stomach
may cause bad dreams and troubled sleep. But in many cases of
sleeplessness, a trifle of some simple food, especially if the stomach
seems to feel exhausted, often appears to promote sleep and rest.

[NOTE. The table on the next page shows the results of many
experiments to illustrate the time taken for the