128 MILK BACTERIA AND HEALTH. 



tion. It is also useful as a means of education, because the 

 more widely can .we extend the knowledge of the possibility 

 of the distribution of these diseases by milk the greater 

 will be the care which the milk producer will take 

 to keep his milk from possible sources of infection. 

 The distribution of knowledge is thus the most efficient 

 means of protecting the community from a repetition of 

 such epidemics. But the discovery of the source of such 

 a milk epidemic is rarely of any immediate value to the com- 

 munity. The infection of the milk is, in most cases, a very 

 temporary one, commonly ceasing before the milk has been 

 placed under suspicion, and certainly before it has been defi- 

 nitely proved that milk from a given source is the cause of 

 the epidemic. The exclusion of the milk in question from 

 the public milk supply is like locking the door after the 

 horse is stolen, for milk at this later date is probably just 

 as free from infection as any other milk that is brought into 

 the city. To discover its source is, therefore, rarely of prac- 

 tical value in allaying any individual milk epidemic. The 

 value of such investigations comes in the more general way 

 of producing, little by little, a greater and greater protec- 

 tion of the milk supply from such possible contamination. 



DIARRHEAL DISEASES. 



A somewhat extended consideration is necessary of the 

 miscellaneous diseases characterized by intestinal disturb- 

 ances, of which a diarrhea is one of the most common symp- 

 toms. These occur particularly in warm weather, and are 

 especially common in children. This class of diseases, in- 

 cluding summer complaint, cholera infantum and various 

 other less sharply marked intestinal disturbances, is the one 

 that causes the largest amount of sickness and death among 

 young children in warm weather. They are, therefore, of 

 primary importance in considering the problem of milk 

 bacteria. 



