86 



ELEMENTS OF WATER BACTERIOLOGY 



from other bacteria in water through its greater motility. 

 He succeeded in isolating typhoid bacilli from two 

 springs by the following method: 5 to 10 liters of water 

 were allowed to stand one to two days in tall milk cans 

 at room temperature. Samples were taken from the 

 surface and plated on litmus-lactose agar (Drigalski- 

 Conradi medium), the amount of water to be used 

 varying with the contamination. 



Starkey (1906) has suggested the use of an apparatus 

 consisting of a piece of glass tubing bent so as to give 

 four successive connected loops. This is filled with phenol 

 broth, inoculated atone end, and incubated anaerobically. 

 The more actively motile bacilli find their way to the 

 fourth loop from which they may be isolated by plating. 



Review of Suggested Procedures. The methods of 

 examining water for B. typhi may be conveniently 

 summarized as follows: 



a. By filtration 



b. By agglutination 



f Schiider's process 



c. By chemical I Fischer's process 

 precipitation 1 Willson's process 



( M tiller's process 

 a. Hoffmann and Ficker's caffein 



i. Physical 

 concentration 



2. Enrichment 



process 



b. Jackson's lactose bile 



c. Parietti's carbol broth 



a. Eisner's gelatin medium 



b. Endo's medium 



c. Loeffler's malachite green 



medium 



d. Drigalski-Conradi agar 



e. Hiss's medium 

 /. Hesse's medium 



a. Morphological and cultural 



characters 



b. Agglutination 



