Adeney — Dissolved Gases and Fermentative Changes. 



601 



products formed, we see clearly that, although as above shown, the peaty matters 

 j^layed an essential part in the changes which occurred during fermentation, but 

 little carbon dioxide was formed, and that, so far as oxidized products are 

 concerned, the fermentation was practically a nitrogen fermentation. The total 

 figures are : — 



The total nitrogen oxidized was, as will be seen from these figures, 

 '01405 grammes, a quantity decidedly in excess of the ammoniacal nitrogen 

 absorbed. 



4"59 c.cs., of carbon dioxide is equivalent to 0"0025 grammes carbon, which is 

 but a small fraction of the total quantity of the organic carbon originally present 

 in solution PA/3, viz. 0"023 grammes. 



We have seen that the reverse action to this took place in the solution P/3, 

 which contained but little ammonia relatively to peaty matters. Thus the total 

 volume of carbon dioxide formed was equal to 14'73 c.cs. This volume is 

 equivalent to O'OOS grammes carbon. The oxidised nitrogen, it will be remem- 

 bered, only amounted to 0'0003 grammes. 



One fm'ther feature in connection with one of these experiments demands some 

 notice. It is the very sudden diminution of carbon dioxide (shown by the first 

 analysis in experiment 5) which occurred while the solution was kept in a 

 stoppered bottle, only partially filled, from the 17th to the 21st July. No suitable 

 explanation has occurred to my mind to account for this loss. No doubt a portion 

 was due to diffusion into the air-space in the bottle, but with the records of the 

 preceding experiments with the same solution, before one, it is difficult to conceive 

 that the loss was wholly due to this cause. Another source of loss lies doubtless 

 in the possibility of a portion of the gas being fixed by fermentation. 



On turning to the experiments with PA/10, we find the influence of dilution 

 shown as markedly as we have already seen it to be in the case of solution P/3 

 and of the more dilute solution P/9. 



Experiment \a shows that the nitrous nitrogen formed was practically equal to 

 the ammoniacal nitrogen absorbed, but that the fermentative products differ essen- 

 tially in one particular from those obtained simultaneously with nitrification with 

 the less dilute solution, in that a considerable volume of carbon dioxide was 

 formed. But notwithstanding this, tlie oxygen theoretically equivalent to the 

 nitrous nitrogen = 7'85 c.cs., is slightly in excess of that consumed. 



