as meat and eggs.
Excess of protein probably leads to degeneration of tissues, and plays a
part in causing the degenerative diseases already mentioned. Habit is
important here as in other ways of living, but cereals and vegetables
should in large measure make up the diet of sedentary persons and indeed
of everyone in warm weather.

The amount of food required in 24 hours depends on many factors: age,
height, weight, occupation, season, and habit. Underweight and
overweight are both abnormal conditions; probably the latter is the more
easily remedied. Both require the advice of a physician. Rapid reduction
of weight involves certain dangers, especially for persons with weak
hearts.

Food may cause sickness either because it is in itself harmful, or
because it carries disease germs. Meat from diseased animals should be
destroyed before it reaches the market, but bacterial activities in food
originally wholesome may form in it poisonous substances.

The chief diseases known to be carried by food, water, or milk are
typhoid fever, paratyphoid, dysentery and other diarrhoeal diseases,
scarlet fever, diphtheria, septic sore throat, and tuberculosis. The
sole problem here is to keep human and animal excretions out of food,
water, and milk. Since thorough cooking kills disease germs, danger
arises chiefly from raw foods. All fruits and vegetables eaten raw
should first be thoroughly washed.

Water is essential to health. At least three pints should be taken
daily, the amount varying somewhat according to diet, exercise,
temperature, and so forth. Most persons drink too little water.

Cities and towns should of course have public supplies of pure water.
Contamination of water, when it occurs, is caused chiefly by sewage
from cesspools, privies, and drains. All well or spring water must be
constantly watched and Boards of Health are always ready to examine
samples of water and to report whether it is safe to drink. At the
present time a porcelain filter is the only satisfactory kind for a
household, but many domestic filters are so badly cared for that in
actual practice they are worse than none. Danger from a filter
containing an accumulation of impurities is greater than the danger from
most ordinary water supplies. Boiling water for ten minutes kills all
pathogenic germs, but this method is inconvenient on a large scale and
is not practical for continued family use.

Every effort should be made to insure a regular suppl