278 BACTERIOLOGICAL EXAMINATION OF WATER. 



This water was placed in the mantle, inoculated with B. 

 typhosus, and filtration carried out as in the previous experi- 

 ments. The broth in the flask remained perfectly sterile until 

 the ninth day, when faint turbidity was noticed. A loopful 

 withdrawn through the lateral arm was planted out on agar, 

 and tested in the usual manner. The growth was completely 

 agglutinated by Berne serum diluted 11000, and when planted 

 out on the various media, the results obtained were identical 

 with those given by a true culture of B. typhosus. 



Experiment VII. The same water was used for this experi- 

 ment, which was conducted in exactly the same manner as 

 Experiment VI., a fresh No. 12 candle, however, being employed. 

 The B. typhosus again appeared in the filtrate on the ninth 

 day. 



Experiment VIII. The reservoir water was again employed, 

 but a large candle, No. 10, was used and fitted into a mantle 

 holding about 500 c.c. of water. The water in the mantle was 

 inoculated on three occasions with a twenty-four hours agar culture 

 of B. typhosus. The broth in the flask remained perfectly sterile 

 for ten days, but on the eleventh day turbidity was noticed, which 

 was found to be due to a pure culture of the typhoid bacillus. 



Experiment IX. A large candle, size No. 10, was employed, 

 and the mantle filled with sterile barrack sewage. A twenty- 

 four hours agar culture of the typhoid bacillus was planted out 

 in the sterile sewage, and filtration carried out in the same 

 manner as before. On the fifth day of filtration the typhoid 

 bacillus was found in the broth placed in the flask. 



Experiment X. The bougie used in Experiment VI. was 

 removed fiom the mantle and thoroughly cleaned with a stiff' 

 brush, the metal delivery pipe was also thoroughly washed and 

 flamed. The bougie was then replaced in a sterile mantle and 

 the apparatus fitted up in the usual manner. Sterile reservoir 

 water was then filtered through the candle, and next day the 

 broth in the flask was found to be turbid. The typhoid bacillus 

 was easily isolated from the turbid broth. This result appeared 

 to show that carefully cleaning a bougie would not remove the 

 B. typhosus which had evidently penetrated into the interior of 

 the material and was washed through into the filtrate by the 

 passage of the sterile water. 



