Sources of Bacterial Infection 181 



proved sanitation of the dairies, and to-day 

 in many places, by paying a little more, the 

 consumer may get milk which comes from 

 carefully supervised dairies and intelligently 

 controlled dealers. This is called certified milk. 



It is possible by the boiling of milk, or by 

 properly exposing it to a lower temperature for 

 a considerable time, called pasteurizing, to 

 destroy the dangerous germs. If the house- 

 holder is not averse to taking a little extra 

 trouble, a domestic pasteurizer may be used 

 on the kitchen range for each day's supply of 

 milk and cream. Then, he may go about his 

 business and worry no more about milk. 

 The Freeman pasteurizer is well adapted to 

 household use and requires no special skill 

 in management. 



Meat and Vegetables. The meat of tubercu- 

 lous cattle is not likely in civilized communi- 

 ties to be a serious source of evil, because 

 official inspection is widely practised and few 

 people eat uncooked meat. 



As the germs of various diseases may be 

 floating in the air in densely populated dis- 

 tricts, and are often present in farm and 



