Appendix. 215 



for three hours. Repeating this process on three suc- 

 cessive days solidifies the serum so that it may be subse- 

 quently sterilized in flowing stream for twenty minutes 

 on three successive days. 



PHENOL BROTH. 



To 1000 c.c. water add separately, and in the following 

 order, 100 grams dextrose, 50 grams pepton, i.o grams 

 phenol. Heat until all constituents are dissolved, boil 

 for fifteen minutes, and sterilize for fifteen minutes at 



IIO-I20C. 



NEUTRAL RED BROTH. 



To neutral broth is added 0.5 per cent dextrose and 

 i per cent of a 0.5 per cent aqueous solution of Griibler's 

 neutral red. Sterilize at 100. 



MACCONKEY'S MEDIA. 



A. Agar. 



Agar 1.5 grams 



Sodium taurocholate (pure) 0.5 gram 



Pepton 2.0 grams 



Water 100.0 c.c. 



This is boiled, clarified, and filtered as usual, then 

 i.o gram lactose is added, and the medium tubed and 

 sterilized for three successive days at 100. 



B. Broth. 



Sodium taurocholate (pure) 0.5 gram 



Pepton 2.0 grams 



Glucose 0.5 gram 



Water 100.0 grams 



Boil, filter, and add sufficient neutral litmus, fill fer- 

 mentation tubes, and sterilize at 100 degrees. 



