BACTERIA. IN AIR, SOIL, WATER, AND FOOD 175 



household in the care of food suppHes. For this 

 reason food is kept at a low temperature to prevent 

 bacterial growth, and to preserve food for any 

 length of time it is sterilized and sealed while boiling 

 hot. Besides sterilization and low temperature, 

 perfect cleanliness is the most important measure to 

 be employed against the invasion of bacteria and its 

 resulting decomposition. Unclean utensils, dish tow- 

 els, and ice boxes will infect the best food materials 

 very quickly, and are no doubt the indirect cause of 

 many causes of food poisoning which we call "pto- 

 main-poisoning. ' ' 



Unclean methods of handling meat, fish, and milk 

 are particularly favorable to the development of 

 bacteria which produce highly poisonous substances. 



Bacteria are found in all milk, the amount varying 

 with the cleanliness of the cow, of the stable, of the 

 utensils, of the milker, and all other persons who may 

 handle it. Pathogenic bacteria are often found in 

 milk, and may come from a diseased cow, from a 

 diseased milker, from polluted water used upon 

 utensils, or from insects which often carry infectious 

 materials upon their feet and bodies; in fact, the 

 ways of handhng milk from the cow to the consumer 

 take it through so many hands, utensils, and varia- 

 tions of temperature that infection through mUk 



