QUALITATIVE BACTERIOLOGICAL ANALYSIS. 225 



was a motile bacillus, about the same size as the typhoid bacillus, 

 and did not stain with Gram. On potato it produced a moist 

 transparent growth. Milk was not coagulated after eight days 

 incubation at 37 C. Indol was not produced. In Petruschky's 

 litmus-whey the amount of acid formed was very small. The 

 agglutination test was then tried with serum from a goat im- 

 munised by repeated injections of the B. typhosus. This serum, 

 diluted 1-200, caused agglutination of the bacillus which had 

 been used to prepare it, the clumps being visible, macro- 

 scopically, in a quarter of an hour. It also caused agglutination 

 of the bacillus isolated from water when employed in dilutions 

 of 1-50, 1-100, and 1-200, but the clumps were not visible, 

 macroscopically nor microscopically, for from one to two hours. 

 The same delayed agglutination was also seen when two true 

 typhoid cultures from different sources, i.e., a typhoid spleen 

 and a typhoid abscess, were tested with the serum. The bacillus 

 isolated from water was also tested with a serum which, in a 

 dilution of 1500, caused agglutination of its own bacillus in 

 one to two hours. The " water bacillus" was agglutinated by this 

 serum diluted 1500, but the reaction was not apparent micro- 

 scopically for four hours. PfeinWs test was also applied, but 

 with some difficulty, as the typhoid serum had not a powerful 

 bacteriolytic action, and the minimal fatal dose of the water 

 bacillus varied from 0'046 mgm. to 0'092 mgm. per 100 

 grammes of body-weight of the experimental animal. Experi- 

 ments showed, however, that 0'05 c.c. of the typhoid serum pro- 

 tected against ten times the lethal dose of the bacillus, whereas 

 the same amount of normal serum from men and goats had no 

 protecting action against the same dose of the bacillus. The chain 

 of evidence seems fairly complete, and the bacillus isolated by 

 Fischer and Flatau must be regarded as the true B. typhosus. 

 Four weeks later the authors again examined the water from 

 Rellingen, but failed to find any traces of the B. typhosus. 



APART FROM THE ISOLATION OF THE B. TYPHOSUS, ARE THERE ANY 



MEANS OF DIAGNOSING POLLUTION OF A WATER SUPPLY WITH 



THE SPECIFIC DEJECTA OF CASES OF ENTERIC FEVER ? 



The cases just recorded show that, with one or two exceptions, 

 it has been impossible to isolate the B. typhosus from suspected 



