60 Bacteria in Relation to Country Life 



in temperate climates. It is estimated that the mor- 

 tality from dysentery in England towards the end of 

 the last century was but a fraction of a per cent of that 

 at the middle of the century. In the United States, the 

 death rate from dysentery was 6.32 per cent of the total 

 mortality in 1850; 2.65 per cent in 1860; 1.60 per cent 

 in 1870; and less than 1.5 per cent in 1880. 



To sum up, therefore, drinking-water is a factor of 

 great moment in the spread of certain diseases and may 

 become the carrier of the germs of cholera, typhoid, and 

 certain forms of dysentery. Its purification and pro- 

 tection from pollution have necessarily become important 

 features of modern sanitation. 



