Chemical Changes in Mixtures of Sewage and Sea- Water. 343 
In the second series, the quantities involved are much smaller, 
and the changes apparently much slower and more difficult to trace 
in any definite direction. 
Experiments in Open Vessels. 
The time at our disposal has only been sufficient to perform 
one series of experiments under fully aerobic conditions, the results 
of which are given below. 
For reasons already mentioned a Table is appended of the 
number of c.c. of weak ammonia solution actually employed in 
Nesslerizing during the determinations of nitrogen as ammonia, 
albuminoid ammonia, and nitrates. 
The sewage used was (as its examination showed) very dilute, 
and this possibly accounts for the slow rate of change which its 
nitrogenous constituents experienced when mixed with sea-water. 
As in the case of the experiments in closed vessels, some free 
ammonia would seem to have disappeared during the first stages of 
the fermentation, but afterwards the amount increased. Nitrifica- 
tion seems to have set in after about a fortnight. 
SeA- WATER AND | PER Cent. SrwaGe 1n OPEN VessELs av 21° C. 
(Quantities in parts per 100,000.) 
29 428 9 (18 39 
2? 644 39 (27 39 
PO mIMonthsyee -| 0224 — — |Some.| *064 _- — 
Unoxidized Nitrogen as— ee Oxygen } 
itrogen as— Ey ab- 
Total | sorbed. 
Time. Nitro- |(K MnO, 
gen. a 
au nee Rae Total. |Nitrites| Nitrates at OT) 
So Be 
Original Mixture, . .| -0112 °0146 | -0258 | None.| — — | -0780 
After 24 hours (1 day), 0072 -0132 | 0204 Ho 7005 | 0254] -0825 
9) 92 oo, (4 Gens), °0144 °0132 | -0276 99 005 | -0826] -0812 
ASR G Atay reap (ly 5i5.05)5 -0199 "0082 | -0281 39 "006 | -0541 — 
57 BOO ng CUM on Mp °0164 °0132 | -0296 50 006 | 0356 | -0799 
) 
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