ness
caused by a milk diet can be largely overcome by the use of salt with
the milk, or of some solid food, as toast or crackers, to prevent
coagulation and the formation of masses resistant to the digestive
fluids. Barley water and lime water in small amounts are also useful for
assisting mechanically in the digestion of milk. Milk at ordinary prices
is one of the cheapest foods that can be used.

[Illustration: FIG. 23.--DIRT IN A SAMPLE OF UNSANITARY MILK.]

102. Sanitary Condition of Milk.--Equally as important as composition
is the sanitary condition or wholesomeness of milk. Milk is a food
material which readily undergoes fermentation and is a medium for the
distribution of germ diseases. The conditions under which it is produced
and the way in which it is handled determine largely its sanitary
value, and are of so much importance in relation to public health that
during recent years city and state boards of health have introduced
sanitary inspection and examination of milk along with the chemical
tests for detecting its adulteration. Some of the more frequent causes
of contaminated and unsound milk are: unhealthy animals, poor food and
water, unsanitary surroundings of the animals, and lack of cleanliness
and care in the handling and transporting of the milk. Outbreaks of
typhoid and scarlet fevers and other germ diseases have frequently been
traced to a contaminated milk supply.[37]

103. Certified Milk.--When milk is produced under the most sanitary
conditions, the number of bacterial bodies per cubic centimeter is
materially reduced. In order to supply high grade milk containing but
few bacteria, special precautions are taken in the care of the animals,
and in the feeding and milking, and all sources of contamination of the
milk are eliminated as far as possible. Such milk, when sold in
sterilized bottles, is commonly called "certified milk," indicating that
its purity is guaranteed by the producer and that the number of bacteria
per unit does not exceed a certain standard, as 8000 per cubic
centimeter. Ordinary market milk contains upwards of 50,000.

104. Pasteurized Milk.--In order to destroy the activity of the
bacterial organisms, milk is subjected to a temperature of 157 deg. F. for
ten minutes or longer, which process is known as pasteurization. When
milk is heated to a temperature above 180 deg., it is sterilized. Below
157 deg., the albumin is not coagulated. By pasteurizing, milk is much
improved