Adeney — Dissolved Gases and Fermentative Changes. 



599 



therefore confirm the evidence which was afforded by the experiment with tap- 

 water recorded in Tables IX. and XIII., to the effect that the minute quantities of 

 peaty matter in the tap-water underwent a fermentation, though an extremely 

 slow one, into carbon dioxide and nitric acid. 



The influence of dilution on the fermentation illustrated by these experiments 

 becomes more decidedly apparent when the oxygen consumed, and the products 

 formed, dm-ing the different stages of fermentation represented by experiments 2, 

 3, and 4, with less dilute solutions, and by experiments 5 (bottle III.), and 6 

 (bottle V.) are respectively added together and compared. Thus : — 



In the less dilute solution P/3, it becomes evident from the above figures that 

 during fermentation a considerable quantity of ammonia was absorbed, and that 

 the quantity of nitric acid formed was, for the period during which the solution 

 was under examination, only about one-foiu'th that of the ammonia originally 

 present. 



On the other hand, in the more dilute solution the reverse action appears to 

 have taken place, since the quantity of nitric acid formed was nearly double that 

 of the ammonia originally present. 



Again, the volume of carbon dioxide formed in proportion to that of the 

 oxygen consumed was larger, relatively, in the less than in the more dilute 

 solution. 



The fact that peaty matters, when mixed with ammonium chloride, readily 

 undergo fermentation is more clearly demonstrated by the experiments recorded 

 in the next Table XV. 



These experiments, it will be noticed, were made with another portion of the 

 same solution of peat, but with this difference, it was mixed with a relatively 

 larger quantity of ammonium chloride. The results then obtained show that a 

 variety of interchanges may occur between peaty matters and ammonia during 

 fermentation. 



Thus from experiment 2 we find 7*26 c.cs. oxygen, and 0*004 grammes of 

 ammoniacal nitrogen were taken up, and only 0*00225 grammes of nitrous nitrogen 

 were formed ; the volume of oxygen theoretically equivalent to this quantity of 

 nitrous nitrogen being 5*38 c.cs., a volume much less than that actually consumed. 

 From experiment 3 we find the quantities of oxygen and ammoniacal nitrogen 

 taken up are respectively 6'8 c.cs. and 0*004 grammes, and that of nitric nitrogen 



