49 2 Typhoid Fever 



fluorescence, while the typhoid bacillus does not destroy the 

 port wine color. Savage* and Ironsf have made use of the 

 color reaction for the routine detection of the colon bacillus 

 in water. The best adaptation of the method is by Stokes, J 

 who adds it to the various sugar bouillons in the proportion 

 of o. i gram per liter, and uses the medium in the fermen- 

 tation tube. The colon bacillus always ferments the sugars 

 and produces a typical color reaction. 



Hiss recommends the use of two special media one 

 for plates, the other for tube cultures. The first consists 

 of 5 grams of agar-agar, 80 grams of gelatin, 5 grams of 

 Liebig's beef-extract, 5 grams of sodium chlorid, and 10 

 grams of glucose to the liter. The agar is dissolved in the 

 1000 c.c. of water, to which have been added the beef- 

 extract and sodium chlorid. When the agar is completely 

 melted, the gelatin is added and thoroughly dissolved by 

 a few minutes' boiling. The medium is then titrated to 

 determine its reaction, phenolphthalein being used as the 

 indicator, and enough HC1 or NaOH added to bring it to 

 the desired reaction i. e., a reaction indicating 1.5 per 

 cent, of normal acid. To the clear medium add one or two 

 eggs, well beaten in 25 c.c. of water; boil for forty-five 

 minutes, and filter through a thin layer of absorbent cotton. 

 Add the glucose after clearing. 



This medium is used in tubes, in which the culture is 

 planted by the ordinary puncture. The typhoid bacillus 

 alone has the power of uniformly clouding this medium without 

 showing streaks or gas-bubbles. 



The second medium is used for plating. It contains 10 

 grams of agar, 25 grams of gelatin, 5 grams of beef -extract, 

 5 grams of sodium chlorid, and 10 grams of glucose. The 

 method of preparation is the same as for the tube medium, 

 care always being taken to add the gelatin after the agar 

 is thoroughly melted, so as not to alter this ingredient by 

 prolonged exposure to high temperature. The preparation 

 should never contain less than 2 per cent, of normal acid. 

 Of all the organisms upon which Hiss experimented, with 

 this medium Bacillus typhosus alone displayed the power of 

 producing thread- forming colonies. 



The colonies of the typhoid bacillus when deep in Hiss's 



*"Jour. of Hyg.," 1901, i, p. 437. 



ilbid., 1902, n, p. .437. 



J"Jour. of Infectious Diseases," 1904, i, p. 341. 



"Journal of Experimental Medicine," Nov., 1897, vol. n, No. 6. 



