122 THE STORY OF THE BACTERIA. 



on these streams above the points at which the 

 water is taken, polluting it with their sewage. 

 Now so prevalent is typhoid fever all over the 

 civilized world that the sewage of every large 

 town is liable to contain greater or less numbers 

 of living typhoid bacilli. 



The city of Albany, N. Y., which takes its 

 drinking-water from the Hudson River a 

 short distance above the town, just after it 

 has received the sewage of Troy and that of 

 several smaller towns on the banks of both the 

 Hudson and the Mohawk above, is an example 

 of a city which relies upon a water supply 

 always both filthy and dangerous. 



Philadelphia is another great city whose 

 water supply from the Schuylkill River is of 

 the most dangerous and disgusting character, 

 from its large admixture of sewage and human 

 waste. The typhoid-fever statistics of Phila- 

 delphia are abundant witnesses to the almost 

 incredible apathy or carelessness of its authori- 

 ties. 



In older countries where the sanitary dan- 

 gers which always grow with the increase and 

 massing together of the people have been 



