Deleterious results may also occur from the too free use of water. Physicians see cases of indigestion almost every summer that have gradually been provoked by too copious drinking. Such cases occur almost exclusively among those who are performing laborious work in very hot places. After a day or two of excessive water-drinking, appetite for solid food lessens and some gastric distress, usually a sense of fullness and distention, is noticed. Later flatulence, sour stomach, vomiting, and sometimes purging occur; this is due to the fact that gastric juice is so diluted that it can digest but little food, and that but slowly. Although appetite is lessened, more food is eaten than can be digested before putrefaction or abnormal fermentation takes place. The products of these latter changes excite vomiting, or purging and sometimes both. Most frequently these changes are assisted by indiscretion in eating.

The quantity of water needed by a man varies greatly under diverse conditions. It may be said, however, that an average of from fifty to sixty ounces of water is required each day; twenty-five ounces more are obtained from the so-called solid food of which water constitutes an average of 50 per cent. If we say that from two to four pints or from four to eight glasses of water are required daily, the quantity may be more readily comprehended. The variations in the needs of individuals are due to: (1) Their varying size; (2) the character of the food they eat; (3) the quantity and kind of labor they perform; (4) the temperature of the air; (5) the dryness of the air. A small woman or a child needs less water than a large man. Some fruits and vegetables contain as much as from 90 to 95 per cent, of water; meats, from 60 to 80 per cent.; and some articles of food, 10 per cent, and less. The amount of water required as fluid will, therefore, necessarily, vary with the character of the food ingested. If the surrounding air is hot, evaporation from the skin and lungs will take place rapidly and must be compensated for by drinking. The rapidity of such elimination is increased greatly if the air is both dry and hot. Physical labor also provokes perspiration, deep and more vigorous breathing, and therefore elimination from the skin and lungs. Oertel has demonstrated that the elimination of fluid by these channels was much greater during mountain climbing than when the same distance was traveled upon a level. Therefore the character of work done influences the craving of the system for water.

Water is eliminated by the skin, the lungs, the kidneys, and the feces. The variability of action of the skin and lungs has just been illustrated. The kidneys are particularly sensitive to the existence in the stomach and intestines of water in quantities greater than are actually required, and respond by eliminating rapidly a part of that which is in the blood, to permit the absorption of the former. The kidneys act most freely in cold weather, when the skin is least active. If stools of a liquid character are passed frequently, elimination of water by the kidneys is lessened. Because of the varying activity of these organs a statement can be made of only the average elimination by each of them. Approximately, 28 per cent, of the water eliminated escapes from the body through the skin; 20 per cent, through the lungs; 50 per cent, through the kidneys; and 2 per cent, through the feces.

Water is absorbed almost exclusively from the intestines. A comparatively small quantity may be absorbed from the stomach, and possibly a trifle from the mouth. It is taken up by the portal veins and the lymphatics. Not only does the quantity of water swallowed and eliminated vary, but also does the ability of the intestines to absorb it. In health this function of the alimentary canal changes little, if at all; but in pathologic conditions - as, for instance, in cholera, severe diarrhea, and dysentery - there is often evacuation from the mucous membrane of the intestines rather than absorption by it.

Most persons drink too little water rather than too much. Especially is this true of those who lead a sedentary life, and of many others during the winter season. It is necessary, therefore, whenever elimination seems imperfect, to inquire as to the quantity of water and other fluids that is being consumed daily. From four to eight glasses are required by the average person. Under exceptional circumstances this allowance must be increased.

The temperature of drinking-water should be governed by the needs of the stomach. Iced water will stimulate a more rapid and more copious secretion of gastric juice. Hot water will soothe an irritated stomach if taken into it before food is swallowed, and will help to cleanse it of mucus, bacteria, and remnants of food. When the stomach is secreting an insufficient amount of gastric juice, it is well to give a glass of iced water before or with an albuminous meal. If starches form the chief constituent of the meal, iced water should not be given, because the cold lessens salivary secretion and salivary digestion in the stomach. When an excess of gastric juice is formed a copious draft of hot water taken twenty minutes before a meal is beneficial. Ordinarily, drinking-water may be cooled, but should not be excessively cold. Iced water should not be taken when one is overheated. Many cases of gastro-intestinal derangement in summer are due in part, if not altogether, to the excessive use of cold drinks.

If water is drunk during meals, it should be taken only when the mouth is empty, and in moderate quantity. Food which is only half masticated must not be washed into the stomach by drinking fluids. It is often best to drink water freely when digestion is at its height or has passed that point - say three or four hours after meals, especially if the stomach's contents is strongly acid. It will then help to wash the digested and disintegrated food from the stomach, and dilute the acids of the stomach so that they can be more quickly neutralized by the secretions in the duodenum. Mattil and Hawk1 recently have studied experimentally the effect of drinking water at mealtimes, and conclude that, if it is drunk when the mouth does not contain food, it does good. From one to two liters of water taken at meals caused fat, protein, starch and sugar to be absorbed more perfectly than when little water was drunk, doubtless because the gastric and pancreatic juices are increased and peristalsis is made more active.

An important cause of constipation is a lack of sufficient fluid to keep the fecal matter soft. A mild grade of constipation can frequently be corrected by the drinking of one or two glasses of water, preferably hot, when the patient first leaves his bed in the morning, for it then stimulates peristalsis.

Water is essential to the maintenance of good elimination. It is a most important diuretic and diaphoretic. In many

1Jnl. American Chemical Soc, Vol. XXXIII, No. 12, Dec, 1911.