342 Scientific Proceedings, Royal Dublin Society. 
Sra-WATER AND | peR CENT. SEWAGE IN STOPPERED BorriEs 
AT 21° C. 
The number of cubic centimetres of Standard Ammonia solution (1 ¢.¢. = 
‘O01 mg. NH,) actually required in the different determinations for :-— 
500 . (4 Ot .c. of mixture 
oR = 125 c.c. of mixture. ae 125 (ealeulaneay 
Exper: Time. Unoxidized Nitrogen as— Oxidized | Oxidized 
ment. Nitrogen | Nitrogen] Total 
as c ? 
Free Albd. | Totaq,.: Niveateol Nieves: pec 
TEl yp NH. 2 
1 When mixed, 2°6 2°5 5-1 1-0 0-62 571 
99 After 6 hours, 2°6 2°5 51 15 0:94 6°04 
a6 aie A oats 0-7 4-0 4:7 1:5 0°94 5°64 
95 ae AONE as 1-2 2°5 337 2°3 1:44 5°14 
2 When mixed, 1:4 1-1 2°5 0:8 0°50 3°00 
9 After 12 hours, 1-0 0°7 1°? 2°9 1°81 3°dl 
9p 99 US 9g 1:2 Heit 2°3 1-4 0°88 3°18 
on Hy Bes" Log 1-0 0-9 Lots) IL) 12716) 3°09 
99 ap OO. op 1°5 1-0 2°5 1-0 0°62 3°12 
9 59 D235 Dell Traces. 2-1 1:5 0-94 3°04 
The Table brings out some curious features, which we scarcely 
like to discuss, as the body of evidence is not sufficient, we think, 
to warrant us in expressing any very definite conclusions. Asa 
provisional criticism, we may offer the following remarks. The 
figures corresponding with the total nitrogen are sufficiently 
uniform to give us some confidence in the others. 
As regards these, it would appear that, in the earlier stages of 
the fermentative process, interchanges occurred between the free 
and albuminoid ammonia. Thus, in both series of experiments, 
free ammonia disappeared at the commencement, and afterwards 
increased. Very possibly the mixture here functioned at first as a 
Pasteur’s solution, the micro-organisms absorbing free ammonia 
for tissue formation. 
In the first series of experiments, there is a fairly steady decrease 
in unoxidized nitrogen, and a decided, though not so steady, increase 
in nitrates. 
