56 A MANUAL OF BACTERIOLOGY 



Instead of infusion made from meat, meat extracts are now 

 commonly used. The following is the composition of " Lemco " 

 broth : 



Lemco ....... 10-20 grm. 



Peptone (Witte) 10-20 grm. 



Sodium chloride ..... 5-10 grm. 



Water (preferably distilled) ... 1 litre 



The constituents are dissolved with the aid of heat, neutralised, 

 clarified and filtered. Lemco may also be used to make all the 

 other media for which acid beef-broth is employed. 



Veal-broth. For some purposes veal presents advan- 

 tages over beef, e.g. for growing the tubercle bacillus. 

 When obtained from the butcher's the veal is frequently 

 powdered with flour ; this should be brushed and washed 

 off as completely as possible, as it renders the broth 

 turbid and difficult to clarify. The veal-broth is made 

 in precisely the same way as peptone beef-broth. It is, 

 however, often slightly alkaline, so that less alkali is 

 required for neutralisation. For the cultivation of the 

 tubercle bacillus about 4 to 6 per cent, of glycerin should 

 be added. 



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 organisms 

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

 advantage. It should be added after filtration. 



Egg broth. Besredka and Jupille 1 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 

 Ordinary nutrient broth . . . . .5 parts 



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

 of distilled water, filtered through cotton- wool, heated 



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



