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 lessening 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, large quantities of cold drinks are injurious. Fluids taken into the stomach are not subject to the slow process of digestion, but are immediately absorbed and carried into the blood. This is the reason why liquid nourishment, more speedily than solid food, restores from exhaustion. The minute vessels of the stomach absorb its fluids, which are carried into the blood, just as the minute extremities of the arteries open upon the inner surface of the stomach, and there exude the gastric juice from the blood. When food is chiefly liquid, (soup, for example,) the fluid part is rapidly absorbed. The solid parts remain, to be acted on by the gastric juice. In the case of St. Martin, [Footnote: The individual here referred to--Alexis St. Martin--was a young Canadian, eighteen years of age, of a good constitution and robust health, who, in 1822, was accidentally wounded by the discharge of a musket which: carried away a part of the ribs, lacerated one of two lobes of the lungs, and perforated the stomach, making a large aperture, which never closed; and which enabled Dr. Beaumont (a surgeon of the American army, stationed at Michilimackanac, under whose care the patient was placed) to witness all the processes of digestion and other functions of the body for several years.] in fifty minutes after taking soup, the fluids were absorbed, and the remainder was even thicker than is usual after eating solid food. This is the reason why soups are deemed bad for weak stomachs; as this residuum is more difficult of digestion than ordinary food.