22 



REDUCTION OF NITRATES CONTINUED 



IMPURE CULTURES: The medium used in this experiment 

 was the 1% peptone solution to which was added one gram of 

 potassium nitrate per liter. This solution was distributed in 

 150 cc. Erlenmeyer flasks in amounts of 50 cc each, and after 

 inoculation with one gram of soil was incubated at 33C for 

 the length of time and with the results recorded below in table 

 No. VIII. 



TABLE VIII 



