494 



ATJGUSTO BONAZZI 



carbonate used in experiment 244 was pipetted in each flask and, 

 after inoculation, a container with concentrated KOH was 

 placed in the necks of nos. 1 and 2. After incubation at 25°C. 

 the solutions submitted to analysis gave the following results 

 (table 10). 



TABLE 10 



TREATMENT 



All CO2 removed throughout experiment 

 All CO2 removed throughout experiment 



Natural stagnant air 



Natural stagnant air 



NITRITE 



NITROGEN 



FOUND AT THE 



END OF 



INCUBATION 



PERIOD 



mgtn. 



0.13 

 0.38 

 7.52 

 6.24 



Repetition of this experiment (experiment 249) yielded the 

 results given in table 11. 



DISCUSSION AND CONCLUSIONS 



From the foregoing experiments the following considerations 

 seem justified. 



In the solution containing ammonium sulphate and magnesium 

 carbonate removal of all traces of carbon dioxide causes nitroso- 

 fermentation to come to a standstill, whereas if only the carbon 

 dioxide present at the start be removed but that developing 

 through reactions I and II (given on page 483) be allowed to accu- 

 mulate in the systems nitrosof ermentation could continue in a ratio 

 roughly proportional to the size of the inoculum. In fact, even 

 with a very small inoculum some nitrification could be detected. 



