29 



NUMBER OF BACTERIA PER GRAM OF SUBSOIL 



DRIED TO CONSTANT WEIGHT AT 



100 110C 



TABLE XI 



THE FATE OF UREA IN THE SOIL 



IMPURE CULTURES: To asertain the changes which take 

 place when urea is added to nitrogenous media, 100 cc of the 

 1% peptone solution were measured into 250 cc Erlenmeyer 

 flasks and sterilized. To each flask was added one gram of 

 urea. They were then inoculated with soils 1, 10, 13, 25, 27, 

 28, 34, 35, 45, 49, 61 and 68. After seven days incubation 

 at 33C, each flask gave off strong odor of ammonia. An 

 inquiry into the presence of carbonate was then instituted 

 with positive result. I therefore conclude that the organisms 

 which transform urea to ammonium carbonate in the presence 

 of abundant available nitrogen supply, are universally distri- 

 buted within our soil. To ascertain the trend of the reaction 



