BACTERIOLOGICAL EXAMINATION OF WATER. 



Conclusions arrived at from this research may be summarised 

 as follows : 



(1) As regards the appearances of the cultures on the various 

 media: the varieties of B. coli in typhoid stools cannot be 

 distinguished bv cultural characteristics from the varieties of 

 B. coli found in healthy stools. 



(2) As regards reaction to anti-typhoid serum : the varieties 

 of B. coli isolated from typhoid dejecta show much greater 

 sensibility to agglutination than the varieties of B. coli found in 

 normal stools. Consequently if cultures of B. coli isolated from 

 suspected water supplies are found to come within the typhoid 

 range of agglutination, there appear to be fair grounds for 

 assuming that the water supply in question has been polluted 

 with typhoid dejecta 



Having ascertained that the B. coli present in the intestines 

 of patients suffering from enteric fever may acquire an increased 

 sensibility to the agglutinins existing in anti-typhoid serum, it 

 appeared desirable to test experimentally the possibility of 

 producing the same sensibility in vitro. With this object in 

 view a pure culture of the colon bacillus, isolated from a 

 typhoid stool, was grown in Berne anti-typhoid serum for six 

 months at blood temperature. It was then planted out on agar, 

 and the resulting growth tested as to its sensibility to the 

 agglutinins contained in Berne serum. No change in the 

 sensibility was observed ; the bacillus reacted to the serum 

 in exactly the same manner as before the experiment was 

 commenced. The specific serum having failed to influence the 

 B. coli, an experiment was then devised by which the culture 

 was kept under the influence of the toxins produced by the 

 typhoid bacillus. A sterile Berkefeld candle, placed in a glass 

 mantle, was connected by means of a short piece of india-rubber 

 tubing, previously fitted with a pinch-cock, to a sterile glass 

 tube passing through an india-rubber bung fitted into a 

 Kitasato flask. The arm of the flask arid the mouth of the 

 glass mantle were plugged with sterile wool. Sterile broth 

 was then introduced into the mantle and the flask, the former 

 being inoculated with a culture of B. typhosus and the latter 

 with a culture of B. coli, which, when isolated from a typhoid 

 stool, showed no sensibility to agglutination. By releasing the 



