CHAPTER X 

 BACTERIA IN WELLS, SPRINGS, TANKS AND ICE 



WITH the introduction of public water-supplies in 

 towns and cities, the use of water from domestic wells 

 has become more restricted. The result of the change 

 is apparent in the gradually dimishing mortality from 

 typhoid fever, as is illustrated, for instance, by the 

 reduction of the typhoid death rate from 34 per 10,000 

 to 1.1 in the city of Vienna within three years after the 

 installation of a municipal water-supply of good quality. 

 The change in the typhoid fever death rate in Massa- 

 chusetts is fully as striking. 



BACTERIA AND WELL-WATER 



Extended observation in many places justifies the 

 belief in the connection existing between the use of water 

 from shallow wells and an increased death rate from 

 typhoid fever. It is a matter of common knowledge 

 that domestic wells are frequently located in places 

 where pollution from various sources is not excluded. 

 It is not, however, generally realized how large a pro- 

 portion of such wells may receive polluted materials 

 without manifesting it in the taste or appearance of 

 the water. The brightness and sparkle of well-water 



(90) 



