76 METHODS USED IN THE STUDY OF BACTERIA 



Bipotassium phosphate 2 to 2.5 



Ammonium lactate 6 to 7 



Sodium asparaginate 3.4 



This medium has been used for special purposes, but for 

 many forms it has not been found as valuable as Uschinsky 

 thought. Brieger and others have found it useful in study- 

 ing the production of ptomains and toxins. On the whole, 

 the use of synthetic media in the past has been disappointing. 

 It is to be hoped that in some of Emil Fischer's polypeptieds, 

 substances will be found which will meet the demands of the 

 bacteria. 



A solid, synthesized medium has been used to a limited 

 extent. It consists of a nutrient solution to which water 

 glass or a sodium silicate jelly is added ; in this way a solid, 

 transparent medium is formed, and upon this the nitrifying 

 bacteria, which develop only on nonalbuminous media, have 

 been grown. 



