HYGIENE OF DIGESTION.—­With the stomach and other digestive organs in a state of perfect health, one is entirely unconscious of their existence, save when of feeling of hunger calls attention to the fact that food is required, or satiety warns us that a sufficient amount or too much has been eaten.  Perfect digestion can only be maintained by careful observance of the rules of health in regard to habits of eating.

On the subject of Hygiene of Digestion, we again quote a few paragraphs from Dr. Kellogg’s work on Physiology, in which is given a concise summary of the more important points relating to this:—­

“The hygiene of digestion has to do with the quality and quantity of food eaten, in the manner of eating it.

“Hasty Eating.—­If the food is eaten too rapidly, it will not be properly divided, and when swallowed in coarse lumps, the digestive fluids cannot readily act upon it.  On account of the insufficient mastication, the saliva will be deficient in quantity, and, as a consequence, the starch will not be well digested, and the stomach will not secrete a sufficient amount of gastric juice.  It is not well to eat only soft or liquid food, as we are likely to swallow it without proper chewing.  A considerable proportion of hard food, which requires thorough mastication, should be eaten at every meal.

“Drinking Freely at Meals is harmful, as it not only encourages hasty eating, but dilutes the gastric juice, and thus lessens its activity.  The food should be chewed until sufficiently moistened by saliva to allow it to be swallowed.  When large quantities of fluid are taken into the stomach, digestion does not begin until a considerable portion of the fluid has been absorbed.  If cold foods or drinks are taken with the meal, such as ice-cream, ice-water, iced milk or tea, the stomach is chilled, and a long delay in the digestive process is occasioned.

“The Indians of Brazil carefully abstain from drinking when eating, and the same custom prevails among many other savage tribes.

“Eating between Meals.—­The habit of eating apples, nuts, fruits, confectionery, etc., between meals is exceedingly harmful, and certain to produce loss of appetite and indigestion.  The stomach as well as the muscles and other organs of the body requires rest.  The frequency with which meals should be taken depends somewhat upon the age and occupation of an individual.  Infants take their food at short intervals, and owing to its simple character, are able to digest it very quickly.  Adults should not take food oftener than three times a day; and persons whose employment is sedentary say, in many cases at least, adopt with advantage the plan of the ancient Greeks, who ate but twice a day.  The latter custom is quite general among the higher classes in France and Spain, and in several South American countries.