BACTERIA IN WATER. 169 



many a well of exactly this sort has been the cause of typhoid. 

 Though used for years without suspicion it has, nevertheless, 

 been a means of death. The trouble gives no warning when 

 it comes, and the well which has been pure for years, may 

 suddenly begin to distribute typhoid fever bacilli, without the 

 least suspicion on the part of those using it. In ignorance the 

 farmer not only drinks the water himself, but distributes the 

 germs to the city, insisting all the while that his well has " the 

 finest water in the country." The only safeguard is, either to 

 abandon the well entirely, or to have such an absolute isola- 

 tion between his vault and his well as to make. communication 

 between them by soil drainage an absolute impossibility. 

 There is no subject connected with bacteria which the agri- 

 culturist should more thoroughly understand and more fully 

 appreciate than that the water in his well is likely to become 

 contaminated with pathogenic bacteria from human feces, if 

 they are thrown upon the ground or are placed in a vault in 

 the vicinity of the well which is used either for drinking or 

 dairy purposes. 



BACTERIA IN STREAMS. 



The pollution of the water of streams is occasionally a matter 

 of significance to the agriculturist since this water is likely to 

 be used for various purposes. As mentioned on a previous 

 page this contamination of streams has become so serious as 

 to have required special methods and special legislature 

 directed toward allaying the evil. But even yet, and for long 

 years to come, the streams will be used as the natural means 

 of disposing of sewage. 



Fortunately for the purity of our rivers, these waters, though 

 largely contaminated at one point, soon purify themselves. 

 Although large numbers of bacteria and great quantities of 

 organic matter may be poured into a river by a large city, it is 

 found that after flowing for a few miles the organic matter and 

 the surplus bacteria have largely disappeared, and the water is 



