In summer time, or in hot climates the year round, an abundant supply of water is of great importance in keeping the body from becoming overheated, by pouring itself out on the skin in the form of perspiration, and cooling us by evaporation, as we shall see in the chapter on the skin.
The Meaning of Thirst.

None of us who has ever been a mile or more away from a well, or brook, on a hot summer's day needs to be told how necessary water is, for comfort as well as for health.

The appetite which we have developed for it--_thirst_, as we call it--is the most tremendous and powerful craving that we can feel, and the results of water starvation are as serious and as quick in coming as is the keenness of our thirst.

Men in fairly good condition, if they are at rest, and not exposed to hardship, and have plenty of water to drink, can survive without food for from two to four weeks; but if deprived of water, they will perish in agony in from two to three days.
[Illustration: THE CHAINED CUP An "Exchange" for disease germs.] We should Drink Three Pints of Water a Day.

Although all our foods, either as we find them in the state of nature, or as they come on the table cooked and prepared for eating, contain large quantities of water, this is not enough for the needs of the body; to keep in good health we must also drink in some form about three pints, or six glassfuls, of water in the course of the day.