Isolation of Specific Pathogenes. 



77 



bacteria. It is also pointed out that the iron oxychloride 

 is bactericidal in 48 hours. 



Drigalski (Drigalski, igo6) has suggested the separa- 

 tion of B. typhi from other bacteria in water through 

 its greater motility. He succeeded in isolating typhoid 

 bacilli from two springs by the following method: five 

 to ten liters of water were allowed to stand for 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 amoimt of water 

 to be used varying with the contamination. 



The most promising methods for examination of water 

 for B. typhi may be. conveniently summarized in the 

 following tabular view adapted from Willson's paper. 



TABULAR SUMMARY. 



(i) Filtration. 



(2) Chemical preclp. 



f Schiider's process. 

 J Picker's process. 

 I Alum process. 

 I. Muller's process. 



(3) Serum agglutination. 



(4) Enrichment — Hoffman and Ficker's process. 

 Isolation (5) Gambler's process. 



Gelatin (Eisner's, etc.) 

 Bile-salt agar. 

 Examination Glucose and lactose agars. 



of water [(6) Solid media . Drigalski-Conradi medium. 



forTy- En(io'S medium 



phoid Loeffler's malachite-green 



bacilli. agar. 



Morphological and cultural characters, etc. 

 [Identification ^^^^^^^ _tions {A|f u«naW 



Of the comparative advantages of these methods it is 

 still too early to speak with finality. Up to the present 



