222 BACTERIOLOGICAL EXAMINATION OF WATER. 



tion in sugar-media; (6) milk unchanged; (7) indol not pro- 

 duced in peptone water ; (8) acid produced in litmus-whey not 



exceeding 3 per cent, of ^ alkaline solution ; (9) typical growth 



on potato ; (10) pathogenic action ; (11) agglutination with 

 anti-typhoid serum. Two of the specimens came from towns 

 (Meaux, Saint-Omer) where typhoid fever existed at the time. 

 The B. typhosus was only transitory in these two cases, for new 

 specimens of the water taken a month later did not contain the 

 bacillus. Six other specimens were obtained from towns where 

 enteric fever had existed, but at the time was not in epidemic 

 form. The examinations of the water from Chateaudun and 

 Dijon were of special interest. An epidemic of typhoid fever 

 appeared in Chateaudun during the winter of 1895-6 amongst 

 the civil and military population. The water-supply was first 

 examined on January 21 by means of phenolated media ; the 

 B. typhosus was not found. A second examination was made 

 on March 15 by Eisner's method ; on this occasion the 

 typhoid bacillus was isolated. On May 10 and again on 

 June 15 the B. typhosus was detected, though from the 

 beginning of March the outbreak lost its epidemic form and 

 only appeared as rare and isolated cases. Typhoid fever also 

 appeared in an epidemic form in Dijon during the winter of 

 1895-6, but examinations of the water-supply, both in 1895 

 and early in 1896, by phenolated media failed to demonstrate 

 the presence of the B. typhosus. In April 1896, however, 

 when enteric fever no longer existed in the town, Eisner's 

 method showed that a bacillus, identical with the B. typhosus, 

 was present in the water-supply. In May and June the same 

 bacillus was isolated, though no enteric fever existed in either 

 the civil or military population. In this outbreak water 

 apparently containing the B. typhosus was consumed for three 

 months without any epidemic of enteric fever appearing. 



In 1899 Kubler and Neufeld examined specimens of water 

 from a farm where enteric fever existed. By means of Eisner's 

 method B. typhosus was isolated from the water in a well sup- 

 plying drinking-water to the farm. The tests on which the 

 authors relied for the differentiation of the typhoid bacillus 

 were as follows : Characteristic growth on potato, gelatine, and in 

 litmus-whey, absence of indol in broth, absence of gas formation 



