128 INFECTION AND IMMUNITY 



are used for the purpose for which they are in- 

 tended, and that streets and back yards no longer 

 serve as receptacles for filth, as was usual during the 

 presanitary period, even in great cities like London 

 and Paris. The axiom tout a /' tgout now governs 

 the practice not only in Paris but wherever the fun- 

 damental principles of sanitation are understood and 

 sewers have been constructed. 



Unfortunately, the cost of sewer construction, the 

 reluctance of taxpayers to part with their money, and 

 the ignorance or indifference of municipal authorities 

 have conspired to prevent the accomplishment of this 

 fundamental sanitary measure in very many towns in 

 the United States, and our endemic plague typhoid 

 fever continues to claim a large annual quota of 

 victims in such localities. Even in the national capital 

 our sewer system is incomplete, and in many out-of- 

 the-way places, especially in the densely populated 

 alleys of the city, shallow box privies are in use as 

 receptacles for human excreta. The typhoid-fever 

 rate, owing to this and other causes, is disgracefully 

 high. 



Mortality rates in towns and cities throughout the 

 civilised world depend to a large extent upon the 

 purity of the water supply and the efficiency of 

 the system of sewage disposal ; and the constant im- 

 provement which is shown by the mortality statistics 



