Does cows’ milk contain germs?  Yes, even if it is handled faultlessly; but when carelessly handled the number of germs is enormous.

Are all of the germs injurious?  Most are harmless or cause only the souring of the milk.

What other germs are occasionally present?  Typhoid fever, diphtheria, scarlet fever, cholera, tuberculosis and many forms of diarrhea germs.

Do I need to sterilize milk under all circumstances?  When you cannot obtain it fresh in warm weather.  Hence during warm weather in cities and towns; when you do not know that the cows are healthy or that the milk has been cleanly handled; when milk is kept over twenty-four hours, especially if there is no ice at hand.  When there are epidemics of typhoid fever, scarlet fever, diphtheria, or any form of bowel disease accompanied by diarrhea.

How many methods of heating milk are there?  First, sterilizing, in which the milk is heated to 212 degrees F., for one hour or one and one-half hours.  Second, pasteurizing, when you heat the milk to 155 degrees or 170 degrees F. for thirty minutes.

[594 Mothers’ remedies]

Will the temperature of 155 degrees F. for one-half hour be sufficient to kill the germs of the diseases mentioned above?  Generally.

How long will milk so treated keep on ice?  Heated to 212 degrees F. for an hour will keep for two or three weeks; that heated (pasteurized) to 155 degrees F. will keep for two or three days.

Is cows’ milk as digestible when sterilized?  No, and it should be modified for infant feeding the same as milk not heated.

When milk is heated for an hour to 212 degrees F. (sterilization), is it injured in any way?  It is rendered harder to digest, and is more constipating; scurvy may be caused if it is used as the sole food for a long time.  It is so objectionable that the method is not recommended for general use.

When should I heat it 212 degrees F.?  For use on long journeys of days traveling.  Then you should heat for one hour upon two successive days, leaving the cotton stoppers in the bottles.

Does heating milk to 155 degrees F. for one-half hour injure it in any way?  It does not affect the taste or make it more constipating.  The unfavorable effects, if any, are slight.  Get clean and fresh milk and the effects will be really of no account.

What pasteurizer would you recommend.  Freeman’s or Walker-Gordon.

What shall I do with the milk after it has been pasteurized?  Cool it quickly by placing the bottles in cold water—­never leave them in the room where pasteurized, and never place them, when warm, in an ice chest.

Why this caution?  Because it requires from two to four hours to cool them in the air, or in the ice box, and during that time a good many undeveloped germs may mature and injure the keeping properties of the milk.  You can cool the bottles of milk in cool water in from ten to twenty minutes if you change the water frequently, or if ice is put into the water.