482 



AUGUSTO BONAZZI 



Indications are, therefore, that the organism of nitrosofermen- 

 tation acting in the soils with which the present work was under- 

 taken, behaves towards free carbon dioxide in a manner similar 

 to the organisms with which Winogradsky and Godlewsky were 

 working. Additional proof on this point is furnished by experi- 

 ments in solutions in which the above disturbing factors were 

 eliminated. 



Experiment 244 



In each of two large flat bottomed Fernbach flasks were placed 

 50 cc. of the ordinary Omeliansky solution, and both were inocu- 

 lated with an active culture of Nitrosococcus from Wooster soil, 

 in equal amounts. One was incubated with no additional treat- 

 ment while a small container of concentrated potassium hy- 

 droxide was placed in the neck of the other and the flask sealed with 

 a manometer tube so as to avoid negative pressures in the system. 

 After incubation at 25° C. for fifteen days the following results 

 were obtained. 



TABLE 2 



There is evidently no doubt that the organisms acting in 

 Wooster soil are physiologically similar to those acting in 

 European soils. 



A system containing the ordinary Omeliansky solution for 

 nitrite formation from ammonium 'sulphate, and magnesium 

 carbonate as a base, derives its free carbon dioxide from various 

 sources. 



The interaction of the nitrogen and carbon sources, as they are 

 added, leads according to equation I, to the formation of CO2. 

 By the process of nitrification itself, according to equation II, 

 more free CO2 is formed, while the atmospheric carbon dioxide 



