QUALITATIVE BACTERIOLOGICAL ANALYSIS. 197 



Coliform Organisms Isolated by C. Sternberg from Water. 



No. I. Gelatine Plates. Typical growth. 



Broth. Diffused growth without any surface pellicle. 



Witters Peptone and Salt Solution. No indol produced. 



Milk. Unchanged after seventeen days. 



Litmus-whey. 5*5 per cent. acid. 



Sugar-media. Gas formation. 



Potato. Thick greyish- white growth. 



Microscopical Characters. Short and long motile 



rods, not stained by Gram. 

 Anti-typhoid serum. Completely agglutinated by 



the serum diluted 1-1400. 



No. II. Resembled No. I. in most of the tests, but the 

 acidity was 9 per cent., and the limit of the dilution which 

 caused agglutination was 1-600. 



METHODS WHICH HAVE BEEN PROPOSED FOR THE ISOLATION 

 OF THE B. TYPHOSUS FROM WATER. 



In order to study gelatine plates and make sub-cultures of 

 suspicious organisms, numerous efforts have been made to repress 

 the growth of the saprophytic microbes without hindering the 

 development of the B. typhosus. Chantemesse and Widal pro- 

 posed to add 0'25 per cent, of carbolic acid to the nutrient 

 gelatine. Holz, however, showed that 0*20 per cent, of carbolic 

 acid prevented the development of the B. typhosus in Esmarch 

 roll tubes and on Koch's plates; the same effect was not ob- 

 tained when O'llT per cent, of carbolic acid was employed, 

 the B. typhosus always grew well, and the liquefying bacteria 

 were destroyed. Tiemann and Gartner found 0'25 per cent, of 

 carbolic acid very useful, and showed that the growth of the 

 typhoid bacillus was only slightly hindered when this amount 

 of carbolic acid was added to the water for three hours. Plates 

 made at the end of this time were found to be almost completely 

 free from foreign organisms. Holz's experiments showed that 

 it was not safe to use more than 0'15 per cent, carbolic acid 

 even for the three hours exposure. Parietti suggested a 

 solution containing 5 grammes of phenol and 4 grammes of 

 pure hydrochloric acid in 100 c.c. of distilled water : varying 



