It has been found that a solid lump of food requires much more time and labor of the stomach for digestion than divided substances. It has also been found, that as each bolus, or mouthful, enters the stomach, the latter closes, until the portion received has had some time to move around and combine with the gastric juice, and that the orifice of the stomach resists the entrance of any more till this is accomplished. But, if the eater persists in swallowing fast, the stomach yields; the food is then poured in more rapidly than the organ can perform its duty of preparative digestion; and evil results are sooner or later developed. This exhibits the folly of those hasty meals, so common to travelers and to men of business, and shows why children should be taught to eat slowly. After taking a full meal, it is very important to health that no great bodily or mental exertion be made till the labor of the stomach is over. Intense mental effort draws the blood to the head, and muscular exertions draw it to the muscles; and in consequence of this, the stomach loses the supply which it requires when performing its office. When the blood with its stimulating effects is thus withdrawn from the stomach, the adequate supply of gastric juice is not afforded, and indigestion is the result. The heaviness which follows a full meal is the indication which Nature gives of the need of quiet. When the meal is moderate, a sufficient quantity of gastric juice is exuded in an hour, or an hour and a half; after which, labor of body and mind may safely be resumed. When undigested food remains in the stomach, and is at last thrown out into the bowels, it proves an irritating substance, producing an inflamed state in the lining of the stomach and other organs. It is found that the stomach has the power of gradually accommodating indigestive 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.