Adeney — Aerobic Bacterml Fermentation . 11 



IN"©. 1 . Analysis of solution at commencement of experiment. 



T^o. 2. Analysis of solution five months later. 



No. 3. Analysis of a portion of solution from No. 2 after allowing 

 it to ferment eight days longer. 



No. 4. Analysis of a portion of the solution from No. 3 after 

 allowing it to ferment three clays longer. 



No, 5. Analysis of another portion of the original solution after 

 keeping for five months. 



On comparing the results of No. 3 with those of No. 1, it 

 appears that 0*00148 grm. of nitrogen as nitrous anhydride, 

 0-0031 grm. of nitrogen as ammonia, and 3*56 c.c. of carbon dioxide 

 were formed, while 3*94 cc. oxygen were consumed. 



The proportion of nitrogen as nitrous anhydride to that as ammonia 

 is so nearly as 1 : 2 that it seems fair to assume that this first step of 

 fermentation consisted almost entirely of a direct oxidation according 

 to the equation : — 



3CON2H4 + 3O2 = 3CO2 + N2O3 + 4NH3. (1) 



It will be seen from this equation that the volume of carbon dioxide 

 formed is equal to that of the oxygen consumed, one-half of the latter 

 being taken up to form nitrous anhydride, and one-half to form carbon 

 dioxide. The analysis of No. 3 shows that the volume of carbon 

 dioxide formed was very nearly equal to the volume of oxygen 

 consumed. 



Assuming this equation to correctly indicate the process of 

 oxidation, we may differentiate the products due to respiratory 

 changes from those due to enzymic action. Thus, the volume of 

 oxygen equivalent to the nitrogen as nitrous anhydride may be 

 obtained by calculation ; then twice that volume equals the carbon 

 dioxide formed at the same time. The remaining carbon dioxide may 

 then be taken as due to enzymic action ; and the nitrogen as ammonia 

 equivalent to it may be calculated according to the equation : — 



CON2H4 + H2O = CO2 + 2NH3. 



(2) 



