368 



HUMAN BIOLOGY 



The difliculty of supervising a water supply and of supplying 

 water which is safeguarded and not merely passively "safe" 

 increases with diminishing size of community, and reaches 

 its hmit at the farm well. 



A modern water plant for the farm, including adequate 

 protection of the well and a pumping outfit with storage 

 tank, will cost more per capita than the New York City 

 supply, both as to installation and for operation and main- 

 tenance. In general the rural supply is inadequately pro- 

 tected. On the other hand it has the advantage of isolation. 

 Many dangerously pollutable wells are harmless because of 

 the absence of disease among the immediate members of 

 the family. 



Both the typhoid fever and dysentery rates confirm the 

 opinion as to relative safety of urban and rural water supplies 

 in the United States, based upon sanitary and engineering 

 information. 



Table vii 

 typhoid fever and dysentery: death rates, u. s. registration area, 



I9IO-I92O 



The typhoid fever death rate has fallen 75 per cent in 

 cities during the ten year period and that of rural popula- 

 tions, 59 per cent. The city populations have an advantage 

 in security against communicable diseases transmitted 

 through discharges from the bowel, because they have 

 used their combined resources to buy engineering skill to 

 dispose of human wastes in a sanitary manner and for the 

 protection of their communal water supplies. It has been 

 stated that nine-tenths of the problem of rural sanitation 

 consists in protecting the water supply of the household 

 from pollution by its own human wastes. 



