There have been many speculations about the nature of the digestive
process, and in relation to them the celebrated Hunter remarked,
playfully, "To account for digestion, some have made the stomach a mill;
some would have it to be a stewing-pot, and some a brewing-trough; yet all
the while one would have thought that it must have been very evident that
the stomach was neither a mill, nor a stewing-pot, nor a brewing-trough,
nor anything but a _stomach_." All that can be said is, that digestion is
a chemical process, the mechanical agency spoken of being of service only
in thoroughly mixing the gastric juice with the food.
"FIVE MINUTES FOR REFRESHMENTS."
"Murder! murder!" the conductor might as well cry to passengers, as "Five
minutes for refreshments."
Now it makes less difference what we eat than how we eat. Cold hash, eaten
slowly, therefore, well masticated, and mixed with the saliva, is more
likely to "set well" than a light cake or a cracker, though it be "Bond's
best," if hurried down the throat.
What the English call the "blarsted Yankee style" of gulping down the food
half masticated, washing it down with drinks, will ruin anything but a
sheet-iron stomach in a cast-iron constitution. Talk about "mills." Why,
that most excellently contrived mill in the mouth is not suffered to
perform its duty. The hopper is too crammed; it clogs the whole machinery.
Eating between meals destroys the regular periods naturally established by
the stomach for digestion. Three meals should be sufficient for
twenty-four hours.
"Much has been said about exercising after eating, and the truth has been
often over-stated. The famous experiment with the two dogs is cited to
show that exercise after eating interferes with the process of digestion.
Observe just how much was proved by the experiment. Two dogs were fed to
the full, and while one was left to lie still, the other was made to run
about very briskly. In an hour or two both dogs were killed, and it was
found that the food was well digested in the dog that remained quiet, but
not in the other. (I have seen it stated the reverse.) This proves simply
that _violent_ exercise, taken _immediately_ after eating, interferes with
digestion. Other facts show that light exercise rather promotes than
impedes the process, and that even very strong exercise does not interfere
with it if a short interval of rest be allowed, so that the process may be
fairly commenced.
"The same is to some extent true of exercise of mind. It seems to be
necessary that there should be some measure of concentration of energy in
the stomach for the due performance of digestion, and any very decided
exercise, bodily or mental, tends to prevent this. In the dyspeptic, even
a slight amount of effort, either of body or mind, often suffices to do
it.
"It is very commonly said that it is wrong to eat just before going to
bed. Is this true? Cattle are apt to go to sleep after eating fully. Do
sleep and digestion agree well in their case, and not so in the case of
man? In some seasons of the year the farmer takes his heartiest meal at
the close of the labors of the day, and soon retires. Is this a bad
custom? Our opinion is that food may be taken properly at a late hour,
provided, first, that the individual has not already eaten enough for the
twenty-four hours,--that he has done so being true, probably, in most
cases; and provided, secondly, that he is in such a state of health that
digestion will not so act upon his nerves as to disturb his sleep. If it
will thus act, it is clear that he had better be disturbed when awake,
for he can bear the disturbance then with less of injury to his system."