Such milk as we have described under the head of sanitary dairies, when it has been tested by the board of health and has received the approval of the medical profession, is known as "certified milk;" and, although the price is usually fifteen to twenty cents a quart, when compared with the cost of baby's illness it will prove to be cheaper than the dirty milk which sickens and kills the little folks.
There is no doubt that the increased use of "certified milk" has been a great factor in the reduction of deaths from infant diarrhea in recent years.
BOILING THE MILK
When certified milk cannot be had, it is absolutely dangerous to give raw, unboiled, or unpasteurized milk to the baby, particularly in warm weather; for the countless millions of manure germs found in each teaspoon of ordinary milk not only disturbs the baby's digestion, but actually makes him sick, causing colic, diarrhea, and cholera infantum. The only way this milk can be rendered safe is by cooking it—actually killing the bacteria. This process of boiling, however, does not make good milk out of bad milk nor clean milk out of that which is dirty, it simply renders the milk less dangerous.
There are two methods of killing bacteria—sterilization and pasteurization. By sterilization is meant the process of rendering the milk germ free by heating, by boiling. Many of the germs found in milk are comparatively harmless, merely causing the souring of milk; but other microbes are occasionally present which cause serious diseases, such as measles, typhoid and scarlet fever, diphtheria, tuberculosis, and diarrhea. It is always necessary to heat the milk before using in warm weather, and during the winter it is also important when infectious or contagious diseases are prevalent.
Milk should be sterilized when intended for use on a long journey, and may be eaten as late as two or three days afterward.
To sterilize milk, place it in a well-protected kettle and allow to boil for one hour and then rapidly cool. This process renders it more constipating, and for some children many of its nutritive properties seem to be destroyed, as scurvy is often the result of its prolonged use. When a child must subsist upon boiled milk for a long period, he should be given the juice of an orange each day. Children are not usually strong and normal when fed upon milk of this character for indefinite periods. All living bacteria (except the spores or eggs) may be destroyed by boiling milk for one or two minutes.
PASTEURIZATION
When baby is to use the milk within twenty-four hours, "pasteurization" is better than boiling as a method of destroying microbes.
There are many pasteurizers on the market which may be depended upon, among which are the Walker-Gordon Pasteurizer, and Freeman's Pasteurizer; but in the absence of either of these pasteurization may be successfully accomplished by the following method: