gish, and shallow pools
abound, the water is apt to be more or less infected with decaying
vegetable substances. Many people living in such localities, and wishing
to obtain water with as little trouble as possible, dig a hole in the
ground, a few feet in depth, and allow the stagnant surface water to
accumulate. This water is used for drinking and cooking. The result is
that ague prevails in such localities.

Care should be taken that wells, from which the water is used for
household purposes, are located at a distance from barn-yards, privies,
sinks, vaults, and stagnant pools.

PURIFICATION OF WATER. There are various methods of purifying water. It
may be accomplished by distillation, which is the most perfect method;
by filtration through sand, crushed charcoal, and other porous
substances, which deprives it of suspended impurities and living
organisms; by boiling, which destroys the vitality of all animal and
vegetable matters, drives out the gases and precipitates carbonate of
lime, which composes the crust frequently seen upon the inside of
tea-kettles or boilers; by the use of chemical agents, which may be
employed to destroy or precipitate the deleterious substances. Alum is
often used to cleanse roily water, two or three grains in solution,
being sufficient for a quart. It causes the impurities to settle to the
bottom, so that the clear water can be poured or dipped out for use. One
or two grains of the permanganate of potassium will render wholesome a
gallon of water containing animal impurities.

HOW TO USE WATER. Very little if any water should be taken at meal time,
since the salivary glands furnish an abundance of watery fluid to assist
in mastication. When these glands are aided with water to "wash down"
the food, their functions become feeble and impaired. The gastric juice
is diluted and digestion is weakened. Large draughts of cold water ought
never to be indulged in, since they cause derangement of the stomach.
When the body is overheated, the use of much water is injurious. It
should only be taken in small quantities. Thirst may be partially
allayed, without injury, by holding cold water in the mouth for a short
time and then spitting it out, taking care to swallow but very little.
Travelers frequently experience inconvenience from change of water. If
the means are at hand, let them purify their drinking water, if not,
they should drink as little as possible. Persons who visit the banks of
the Oh