6io T3rphoid Fever 



form, so that it can stand alone, and by adapting its size to the Novy 

 jar, so that satisfactory anaerobic conditions can easily be attained. 

 Hesse* has recommended the following medium: 



Agar-agar S grams (4.5 grams absolutely dry). 



Witte's peptone 10 " 



Liebig's beef-extract S " 



Sodium chlorid 8.5 " 



Distilled water 1000 " 



Dissolve the agar-agar in 500 cc. of the water over a free flame, making up the 

 loss by evaporation. Dissolve the other ingredient, in the remaining 500 cc. 

 of water, heat until dissolved, replacing the loss by evaporation. Pour the two 

 solutions together, heat for thirty minutes and add distilled water to replace 

 loss by evaporation. Filter through cotton until clear. Adjust reaction to i 

 per cent, acidity. Tube — 10 cc. to a tube. Sterilize in the autoclave. 



The medium is used for plating. The material containing the 

 micro-organisms must be so dilute that only a few colonies will 

 develop upon the plates. The typhoid colonies greatly outgrow the 

 colon colonies and may attain to a diameter of several centimeters. 

 They show a small opaque center and an opalescent body and appear 

 circular. 



Capaldif recommends the following medium for plating t3T)hoid 

 and colon colonies: 



Witte's peptone 20 grams 



Gelatin 10 



Agar-agar 20 



Dextrose or mannite 10 



Sodium chlorid 5 



Potassium chlorid 5 



Distilled water 1000 



Dissolve the agar in 500 cc. of water, the other ingredients in the other 500 cc. 

 of water. Pour together, add 10 cc. of NaOH, filter, and tube. 



Upon this medium the typhoid colonies are small, glistening, 

 bluish, and translucent. Colon colonies are larger, opaque, and 

 brownish. 



EndoJ recommends the employment of the following medium upon 

 which colonies of the typhoid bacillus grow large and remain colorless 

 while those of the colon bacillus remain small and red: 



1000 cc. of meat infusion. 

 30 grams of agar-agar. 

 10 grams of peptone (Witte's). 

 S grams of sodium chlorid. 



Neutralize and clear by filtration, then add 10 cc. of a 10 per cent, solution of 

 NaOH to alkalinize, 10 grams of chemically pure lactose and 5 cc. of a filtered, 

 saturated, alcoholic solution of fuchsin. Next add 25 cc. of a 10 per cent, sodium 

 sulphitesolution, by which the intense red given by the fuchsin is entirely bleached 

 by the time the agar-agar is cold. After adding the necessary reagents and while 

 still warm and perhaps red, tube the medium. The tubes should be kept in the 

 dark. 



* "Zeitschrift fur Hygiene," 1908, Lvin, 441. 

 t "Zeitschrift fiir Hygiene," 1896, xxiii, 475. 

 t"Centralbl. f. Bakt.," etc., 1904, xxxv. 



