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CHAPTEE VII 



THE DETECTION OF PATHOGENIC BACTERIA IX WATER 



So far we have been considering the presence in water 

 and powers of growth and multiplication possessed by 

 ordinary water bacteria when maintained under varying 

 conditions of temperature, aeration, quality of water in 

 which they were either normally present or into which 

 they were artificially introduced, &c. We have so far, 

 however, purposely abstained from the consideration in 

 this respect of any bacteria known to possess pathogenic 

 properties (excepting in the case of ice), as to this im- 

 portant branch of the subject we now propose directing 

 our special attention. Before discussing the numerous 

 experiments which have been made on the vitality of 

 particular pathogenic bacteria when purposely intro- 

 duced into various waters, it will be convenient to learn 

 to what extent disease germs have been found normally 

 present in water. 



Already in 1878 Pasteur l found that animals into 

 which he had injected some impure water developed 

 symptoms of septicaemia, showing that this water must 

 have contained amongst others certainly some patho- 

 genic bacteria ; Schuschny and Fodor 2 obtained similar 

 results in the case of rabbits inoculated with impure 



1 Bulletin de V Academic de Medecine, 1878. 



2 Archiv f. Hygiene, 1885, vol. iii. p. 118. (See ' Die hygienische 

 Beurtheilung des Trinkwassers,' Hueppe, Schilling's Journal far Gasbe- 

 leuchtung und Wasscrversorgung, 1887.) 



S 



