AprnEy—JDissolved Gases and Fermentative Changes. ave 
The results of the experiments recorded in the previous Table will be more 
readily seen when expressed in a tabular form as follows :— 
Taste XILX.—-Showing quantitatively the fermentative changes which occurred in the 
composition of the dissolved gases, and of the inorganic nitrogen com- 
pounds during the experiments recorded in the previous Table. 
No. of Duration 
Experi- of CO2 Oo N as NH; N as N203 N as N20; 
ment. Experiment. 
1 22 days, . nee LO” — 2°23 — — + 0002 
la 5 months. . Sle secbiles — 5°43 — 0002 — + 0004 
2 7 days, c - | + 0°50 - 1:00 — —_ + 0? 
2a | 35 days, - - | +1:46 — 2°71 a _ + 0002 ? 
3 1 year, : - | +1°89 — 4°15 — 0005 _ + °0002 
3a 1 year, ° 7 |) tls4te — 4:00 — 0005 = + °0002 
4 4 months, . . | + 2:40 -7:77 — 0023 + 00112 | + 0007 
4a 4 months, . -| +2:18 -777 — 00235 | +°00144 | + -00087 
5 4 months (nearly), | — 0-06 — 6°43 — 0016 — + 0016 
5a 9 months, . | — 0:18 — 6°61 — 0016 — + 00175 
On examining the results recorded in the above Table it at once becomes 
apparent that the fermentative properties of the humus employed for the experi- 
ments are alike in character to those which I showed in my first communication 
were so characteristic of fermented organic matters and of peaty colouring matters, 
and to which I have already referred. 
For example, in experiments 1 and 1a, in which the humus was present in 
comparatively large, and the ammonia in extremely small, quantity, we have a very 
slow fermentation, the products of which are carbon dioxide and nitric acid, which 
was partly derived from the nitrogen of the humus. 
In experiments 2 and 2a, it is evident that the time allowed for fermentation 
was insufficient, and only a slight fermentative change is exhibited, resulting simply 
in the production of small volumes of carbon dioxide, the consumption of small 
volumes of oxygen, and the doubtful formation of a small quantity of nitric acid. 
In the succeeding experiments 3 and 3a, a part of the same solution as that 
employed for experiments 2 and 2a, and which was kept in a vessel freely exposed 
to the air between the dates February 24th and March 16th, was diluted, on date 
TRANS. ROY. DUBL. SOC., N.S. ‘VOL. VI., PART XI. 2T 
