QUALITATIVE BACTERIOLOGICAL ANALYSIS. 215 



Chichester soil. The organisms were obtained in pure culture, 

 but no attempt at naming them was made ; they were simply 

 indicated as Chich. 1, Chich. 2, &c. " The culture media of 

 experiment were a flask containing 200 c.c. of sterile distilled 

 water and about 10 c.c. of ordinary peptone broth ; and 

 sterilised soil, the soil used in each instance being that from 

 which the particular soil bacillus of experiment had been 

 isolated. The temperature at which the experiments were 

 performed was either that of the 37 C. incubator, the tempera- 

 ture of an outside shed (3 14 C.) or, in a few cases, the 

 temperature of the laboratory (13-19 C.). The general method 

 of investigation consisted in inoculating the different media 

 with a definite quantity of a pure broth culture of one of the 

 soil organisms, and at the same time with an equal quantity of 

 pure broth culture of the typhoid bacillus, both cultures being 

 of the same age." The relative proportion of the two sorts of 

 bacteria present was determined at stated intervals by brushing 

 two or more agar plates with a sterile brush dipped in the 

 nutrient fluid. Surface colonies, generally discrete, were 

 obtained, and from these plates the relative proportion of each 

 organism present could be ascertained. Chichester 1 was a 

 fluorescent organism which did not liquefy gelatine. When 

 grown in a liquid medium at 37 C. with B. typhosus, the colonies 

 of both organisms could be easily detected twenty-four hours 

 after the inoculation; but, after six days, no colonies of 

 B. typhosus could be detected. The same result was obtained 

 when the medium was kept at 4 to 12 C. In sterile soil at 

 37 C. Chichester I. caused the disappearance of the typhoid 

 bacillus in six days, but at 8 to 12 C. the typhoid bacillus 

 could be detected after six days, though it was not found at the 

 end of fourteen days. Experiments on the same lines were 

 made with Chichester 2, which was a large, stout bacillus?, ami 

 formed spores freely. It was easily distinguished from thr 

 typhoid bacillus. In all the experiments conducted ai; 

 37 C. the typhoid bacillus at first grew more rapidly than 

 Chichester 2. As growth proceeded, however, Chichester 

 2 gradually increased more rapidly than the typhoid 

 bacillus, and eventually gained the upper hand. At shed 

 temperature, Chichester 2 maintained the ascendency at the 



