306 APPLIED BACTEEIOLOGY 



hydrochloric acid are added to 100 c.c. of distilled water. 

 From 0"1 to 0"3 c.c. of this solution is added to a series of 

 test-tubes containing 10 c.c. of sterile nutrient broth ( = 0-05 

 to 0*15 per cent, of phenol). The tubes are then incubated 

 at blood-heat for twenty-four hours, to destroy any stray 

 organisms that may have gained access to the tubes. From 

 0"1 to 0"5 of a c.c. of the water under examination is then 

 added to the tubes, the contents well mixed, and the tubes 

 again returned to the incubator. If, after twenty-four 

 hours' incubating at blood-heat, any of the tubes appear to 

 be turbid, they are submitted to ordinary plate-cultivation, 

 and the resulting colonies carefully examined in sub- 

 cultures. Frankland states that when only a few typhoid 

 bacilli are present, the incubation must be prolonged for 

 forty-eight or even seventy-two hours. 



We have found the above method to be a very reliable 

 one, although somewhat tedious. In practice, however, we 

 prefer to use simple carbol-gelatine containing 0"05 per 

 cent, of phenol. This quantity is quite sufficient to restrain 

 the growth of liquefying organisms, and, moreover, with this 

 quantity there is no danger of losing the typhoid bacillus if 

 it is present. 



2. Eisner's Method. — Dr. Eisner, of Berlin, has recently 

 published* the results of an investigation made to ascertain 

 the possibility of an early recognition of enteric fever by the 

 bacteriological examination of the stools. He has been able 

 to recognise the Eberth-Gaffky bacillus in some cases in as 

 short a time as forty-eight hours. Dr. Eisner went over 

 the existing methods for the separation of the B. typhosus 

 and coli, with no better results than have previously been 

 obtained. In all cases but one he found that either 

 persistent organisms other than those sought to be isolated 

 would grow to a sufficient extent to spoil the plate (e.g., 

 * Zeitschr.f. Hyg., xxi., 1. 



