ApEnEY— Organic Matters in River Waters. 309 
The ordinary method of analysis gave the following results :— 
Constituents expressed as parts per 100,000. 
No. tr. No. 2 
Nitrogen as freeammonia,. . 3 0°440 | 0°130 
Ni itrogen as albuminoid ammonia, c 0:006 0-010 
Nitrogen as nitrates, . ... .- 0:992 1:084 
Nitrogen GIS UNFORS 6 5 og eo 0-024 0-018 
GT ORIN N ee elisi Woon) ht Garret Ve 6°5 6°8 
Sample No. 1 was slightly turbid but practically colourless ; it 
contained a small quantity of matter in suspension. ‘Temperature 
at the time of collection was 54°5 Fahr. 
Sample No. 2 was very slightly turbid, but colourless, and 
practically free from suspended matter. The temperature when 
collected was 52°°5 Fahr. 
Both samples were neutral to test-papers. 
The above results led to the conclusion that the stream water, 
at both points represented by the samples, contained very little 
organic matter in solution, and that nitrification of ammonia was 
possibly rapidly proceeding in it. 
When, however, the history of the stream was taken into 
consideration, it seemed extremely likely that these organic matters 
were largely, if not entirely, unfermented, and that it was quite 
possible that denitrification, rather than nitrification, was going on 
in the water, more especially as nitrous acid was found in distinct 
quantities in both samples.’ 
These doubts could, as I have shown in my former communi- 
cation, be definitely settled by allowing the waters to ferment out 
of contact with air, and determining the changes in composition 
of the dissolved gases and inorganic nitrogenous bodies which 
would result. As I anticipated these doubts, I first analysed 
the dissolved gases in a portion of each sample immediately on 
uncorking the bottlesin which they were collected, and, at the same 
1§ee R. Warrington, F.R.S., on “ The Chemical Action of some Micro-organisms,”’ 
—C.58. J. 53, 742. Also J. H. M. Munro, D.8c., on ‘‘The Formation and Destruc- 
tion of Nitrates and Nitrites in Artificial Solutions, and in River and Well Waters.’’ 
—C.S8. J. 49, 667. 
