Excessive physical or mental exertion, whether immediately before or after meals, interferes with digestion. If before, the energies of the blood will be directed to the part of the body in most active exercise, and cannot suddenly be withdrawn. If after, they will be diverted before having performed their legitimate part in the process of digestion. A short period of relaxation before, and of absolute repose after meals, is most favorable to the proper action of the stomach. The repose should not be carried to the extent of sleeping, for in sleep the stomach, as well as the rest of the body, seeks release from duty. =Drink.=--Thirst warns us that the blood is too thick, or that it contains some acrid matter which should be eliminated. Free perspiration makes large demands upon the fluids of the body, and copious draughts of water are required to supply the lack. In this way the system is flushed, the clogged pipes and pores are opened, the waste matter removed, and the system made healthy. In cities the water is usually introduced into houses through lead pipes. Herein lies a danger, and the purer the water and the newer the pipe, the greater the danger. The water gradually corrodes the metal and holds a small quantity of it in solution. After a few months of service, an insoluble coating forms upon the inner surface of the pipe, and protects it from further corrosion. It is a wise precaution to run off the water that has lain in the pipes over night, or during the temporary absence of the family, before using. =Coffee and Tea.=--The Americans drink more coffee and the English more tea, _per capita_, than any other nation. As to the wholesomeness of these beverages opinions are greatly at variance. Used in moderate quantities, and especially by persons who lead an active out-door life, no harm is likely to ensue. Many persons drink them for the taste, which is often heightened by the use of cream and sugar, and never stop to question whether they are injurious or otherwise. Such persons usually drink too much. If either produces wakefulness, it should not be used before retiring at night, and if the nerves are unduly stimulated, at any time, its use should be discontinued. Tea should be steeped, not boiled. It contains a certain proportion of tannic acid which is dissolved by boiling, and when drunk, produces a deleterious effect upon the mucous membrane of the stomach, causing dyspepsia with its attendant evils. Children should not be permitted to drink either tea or coffee.