164 HOUSEHOLD BACTERIOLOGY 



fresh from the fire. The purest milk obtainable for 

 the table contains thousands of bacteria to the cubic 

 centimeter, while commercial milk may have many 

 millions. Buttermilk and other forms of acid milk 

 also contain correspondingly large numbers. Many 

 hundreds of these harmless bacteria are known and 

 named, while the harmful or pathogenic bacteria 

 number only a few score. It is these few malevolent 

 microbes that must be avoided, and hence all tha 

 precautions we have adopted as to cleanliness in 

 hospital, market, dairy and kitchen. But if life is to 

 be worth living we must learn where these objection- 

 able varieties come from in order to concentrate at 

 the proper place our use of that eternal vigilance 

 which is the price of health. 



Here are a few suggestions. Human contact with 

 food is probably the greatest source of danger. If a 

 piece of dry bread fall on the floor of a clean private 

 house the bacteriologist teils us it might be picked up 

 and eaten with impunity. Not so if this bread were to 

 be dropped on the floor of a trolley car, especially in the 

 old days when expectoration was common. The 

 driver's hand which grasps the top of the milk bottle 

 which he delivers may leave bacteria there and the 

 bottle should be washed before the milk is poured 

 out. The diminishing of the number of bacteria in 

 our food by the practice of cleanly habits (and no one 

 of these habits is more important than the thorough 

 washing of the hands before handling and preparing 

 food and before meals) is recommended by all hygien- 

 ists; but there should be no morbid fear of the con- 

 sumption of foods that have been the dependence of 

 the race since the dawn of civilization and before, 

 simply because we do not ordinarily eliminate from 

 them every trace of bacterial life. 



