[ 539 ] 



XI. 



THE COUESE AND NATUEE OF FEEMENTATIVE CHANGES IN NATURAL 

 AND POLLUTED WATEES, AND IN AETIFICIAL SOLUTIONS, AS 

 INDICATED BY THE COMPOSITION OF THE DISSOLVED GASES. 

 (Pakts L, II., AND III.) By W. E. ADENEY, Assoc. E. C. Sc. I., F. I. C, Curator 

 and Ex-ExamiDer in Chemistry in the Eoyal University, Ireland. 



[Bead Apeil 24, 1895.] 



CONTENTS. 



Introduction, ........ 539 



Method of experimenting, 544 



Apparatus employed, ....... 546 



Extraction of Gases in Solution 556 



Methods employed for the determination of Inorganic 



Nitrogen, 557 



Errors, 557 



The Preparation and Analysis of Solutions and Dilutions, 559 



Pakt I.— 



Fermentation of easily-fermentable matters, . . 563 

 Experiments with Sewage-water. — Table I., . 664 

 „ „ ,, „ ,, III., . 669 

 j» ,, J, ,» ,, v., . 571 

 Comparison of Eesults with those afforded by ordi- 

 nary Methods of Analysis, .... 574 

 Experiments with Asparagine and Potassium 



Sodium Tartrate.— Tables VII. and VIII., . 576 



Experiments with Sewage-waters. — Table IX., . 586 



" Fixation " of Atmospheric Nitrogen, . . 587 



' ' Fixation ' ' of Carbon Dioxide audj Ammoniacal 



Nitrogen, 578, 588, 603 



Experiments with Sewage-water. — Table X., . 589 

 Experiments with Potassium Sodium Tartrate. — 



Table XI., . . . • . , . .590 

 Experiments wilh Potassium Sodium Tartrate and 



Ammonium Chloride. — Table XII., . . 591 



Experiments with White of Egg.— Table XIII., . 692 



Part II.— 



Experiments with difficultly Fermentable Matters, 593 



Expei-iments with Extract of Fresh Peat. — Table 



XIV., 696 



Experiments with Extract of Fresh Peat and Am- 

 monium Chloride. — Table XV., 



597 



General Conclusions from Experiments with Solu- 

 tion of Peaty Matters and Ammonium Chloride, 603 



Eelation between the Oxygen consumed and 

 Nitrous Acid formed during Fermentation of 

 Ammonia.— Table XVI 605, 606 



Nitrification of Pure Urea : an exception. — Table 



XVII., 611 



Similar volumes of CO2 formed during fermenta- 

 tion in solutions containing similar atomic 

 proportions of Carbon, as Urea, and as Potas- 

 sium Sodium Tartrate, . . . .613 



Theory of Nitrification, 613 



Part III.— 



Bearing of the foregoing Experiments on the Ana- 

 lysis of Potable and Polluted Waters, . .616 



General Conclusions, 618 



Introduction. 



It is, I believe, now generally accepted that the organic matters which, by one 

 means of another, find their way into surface waters, are oxidised, and eventually 

 reduced to simple substances by the operations of micro-organisms, and not 

 by mere chemical changes independent of them. To these operations the term 

 "fermentation" is usually applied. 



TEANS. EOY. DUB. SOC, N.S. VOL. V., PAET XI. 



4H 



