s an essential feature,
but this should not increase either the work or the expense of supplying
the meals. Each single meal can, and should, be simple in itself and, at
the same time, differ sufficiently from the meal preceding and the one
following to give the necessary variety in the course of the day. The bill
of fare should, of course, include fruits (for their tonic effects) and
very small amounts perhaps of substances which stimulate the appetite,
such as pepper, mustard, etc., known as condiments.

*Purity of Food.*--The fact that many of the food substances are perishable
makes it possible for them to be eaten in a slightly decayed condition.
Such substances are decidedly unwholesome (some containing poisons) and
should be promptly rejected. Not only do fresh meats, fruits, and
vegetables need careful inspection, but canned and preserved goods as
well. If canned foods are imperfectly sealed or if not thoroughly cooked
in the canning process, they decay and the acids which they generate act
on the metals lining the cans, forming poisonous compounds. The contents
of "tin" cans should for this reason be transferred to other vessels as
soon as opened.

Foods are also rendered impure or weakened through adulteration, the
watering of milk being a familiar example. The manufacture of jellies,
preserves, sirups, and various kinds of pickles and condiments has perhaps
afforded the largest field for adulterations, although it is possible to
adulterate nearly all of the leading articles of food. A long step in the
prevention of food and drug adulteration was taken in this country by the
passage of the _Pure Food Law_. By forcing manufacturers of foods and
medicines to state on printed labels the composition of their products,
this law has made it possible for the consumer to know what he is
purchasing and putting into his body.

*Alcohol not a Food.*--Many people in this and other countries drink in
different beverages, such as whisky, beer, wine, etc., a varying amount of
alcohol. This substance has a temporary stimulating or exciting effect,
and the claim has been made that it serves as a food. Recently it has been
shown that alcohol when introduced into the body in small quantities and
in a greatly diluted form, is nearly all oxidized, yielding energy as does
fat or sugar. If no harmful effects attended the use of alcohol, it might
on this account be classed as a food. But alcohol is known to be harmful
to the body.