72 A MANUAL OF BACTERIOLOGY 



Glycerin beef-broth is prepared in the same manner, 

 4 to 6 per cent, of the best glycerin being added to the 

 fluid after filtration. 



Glucose broth. For the cultivation of anaerobic or- 

 ganisms the addition of 0-5 to 2 per cent, of grape sugar 

 is an advantage. It should be added after nitration. 



Egg broth. Besredka and Jupille l describe the com- 

 position of this as follows : 



White of egg (10 per cent, solution) . . 4 parts 

 Yolk of egg (10 per cent, solution) . . 1 part 

 Nutrient broth . . . . .5 parts 



The egg-white is beaten up with ten times its volume 

 of distilled water, filtered through cotton- wool, heated 

 to 100 C., and filtered through " papier Chardin." The 

 liquid is tubed and sterilised at 115 C. for twenty minutes. 

 The yolk is beaten up with ten times its volume of distilled 

 water and a sufficiency of normal caustic soda solution 

 is added to clarify it (about 1 c.c. per 100 c.c.). It is then 

 treated as the egg-white. The authors recommend the 

 use of L. Martin's broth for this medium. 



Peptone water. Add to distilled or tap water 1 to 2 

 per cent, of peptone and \ per cent, of common salt, 

 dissolve by heat, make faintly alkaline, steam for one 

 hour and filter. 



For the cholera vibrio it is an advantage to add 1 per 

 cent, instead of \ per cent, of common salt (Dunham's 

 solution). 



Beer-wort. Procure beer-wort (preferably unhopped) 

 from the brewery. Allow it to stand in a cool place 

 for twelve hours, filter, and then steam for an 'hour and 

 filter again. Fill into sterile test-tubes and sterilise. 

 This medium is not neutralised. 



Nutrient gelatin. This is prepared in precisely the same 

 manner as nutrient beef- or Lemco-broth with the addition 



1 Ann. de VInst. Pasteur, xxvii, 1913, p. 1009. 



