In gastric catarrh, where there is an accumulation of mucus or fermenting matter, with or without nausea and vomiting, hot water alone is useful. In addition to its action in diluting the contents of the stomach and the intestines, and its cleansing and antiseptic effect on their mucous membranes, the reflex effect of very hot water, slowly sipped, is a stimulation of their muscular coats, which furthers the passage of the digested food from the stomach into the intestines. The quantity taken must be from ½ to 1 pint, in order to obtain a thorough cleansing and yet not to cause an overdistention of the stomach. In acute nephritis, inflammation of the kidneys, small quantities of very cold water, repeated at half-hourly intervals, act as a diuretic. Care must be had, however, not to overtax the stomach and heart by overfilling the system with fluids. In obesity, water-drinking is essential as a means of dissolving and carrying out of the body the large amount of broken-down material which results from the increased tissue destruction caused by exercise, hot and cold baths, and other means employed to decrease the weight. For constipation and biliousness two glasses of cold water should be taken before breakfast, with an interval of twenty minutes between, the last glass being taken one hour before breakfast. _Contraindications._—Cold water taken into the stomach produces more marked effects than water applied to an equal area of the skin. The quantity of water taken is a factor as well as the temperature. Cold-water drinking lowers the temperature and slows the pulse, so that drinking cold water must be strictly prohibited when one is in a state of fatigue, whether perspiring or not. Feeble persons should not drink cold water, except in very hot weather, or just before starting out for a brisk walk in the open air, or when about to engage in other exercise. With the air of the room at 70° F., a woman in fair condition, moving about making her toilet, may safely drink cold water slowly, except when there is a feeling of chilliness. In the latter case, the powers of reaction being diminished, chill and internal congestion, often resulting in great injury, may be produced. Cold-water drinking is always prohibited when in a state of fatigue. Ice-water should never be taken. When taken with meals, it greatly retards digestion and may do much harm. =Enemas.=—=Coloclysters.=—Another valuable internal use of water is for emptying the lower bowel, and washing out the large bowel in cases of catarrhal inflammation.