566 



AoENEY — Dissolved Gases and Fermentative Changes. 



Table II. 



The volume of oxygen given in column 4 as equivalent to the weights of N2O5 

 in the preceding column have been added for convenience of comparison ; they 

 have been calculated from the equation : — 



2NH3 + 4O2 = N2O5 + 3H,0. 



This equation gives 3-19 c.cs., oxygen at N.T.P. as the volume required to oxidize 

 O'OOl grammes nitrogen as NH3 to N2O3. 



Column 5 gives the sum of the volumes of carbon dioxide actually formed, 

 and of oxygen theoretically equivalent to the nitric acid formed, and have also 

 been added for comparison with the volumes of oxygen actually consumed. 



The figures in the above Table, when allowance is made for errors, show that 

 in the case of each of the solutions 1/100, 1/90, 1/80, in which the fermentation 

 extended to the complete oxidation of ammonia, the quantities of carbon dioxide 

 and nitric acid formed, and the volume of oxygen absorbed, were practically 

 directly proportional to the quantities of fermentable matter originally present in 

 them. 



We also see that in all the other solutions down to 1/40, in which the sewage 

 matters were gradually increased in relation to the dissolved oxygen, the volume 

 of carbon dioxide formed was still directly proportional to the quantities of sewage 

 matters originally present therein, and that the first effect of gradually increasing 

 the proportion of sewage matters was the oxidation of relatively smaller quantities 

 of ammonia ; and as the proportions of sewage matters were still further increased, 

 the ammonia began to be formed, instead of oxidized. 



