
SECTION III., 1907. [81] TRANS. R. $. C. 
VIIL.—On the Purification of Peaty Waters by Freezing. 
By Prawn i) Saurr, M'A. FC; 
Chemist, Dominion Experimental Farms. 
Read May 15, 1907. 
In the course of an investigation to ascertain the relative purity of 
the ice from the Ottawa and Rideau Rivers, certain data were obtained 
of an interesting character, illustrative of the purification of “ upland, 
surface ” waters by freezing. 
Both waters are “ peaty ” and highly coloured and they are, further, 
characterized by a very small mineral content. The Ottawa river, by 
reason of its much larger body of water, its succession of rapids and 
water falls, and its passage through a country less likely to contaminate 
it, naturally offers a more favourable source for supply than the Rideau 
river, which in addition to its smaller volume and much shorter length 
is at intervals through a considerable portion of its course rendered more 
or less stagnant by the locks which serve to convert the river into a canal 
system. 
Analyses of these river waters made in the month of November are 
presented ; they serve to show that the differences in the nature or quality 
of the waters is one of degree rather than of kind. Presumably, both 
rivers, at the point of collection, are unpolluted. 
Analysis of Waters of Ottawa and Rideau Rivers. 
(In parts per million.) 
Ottawa River Rideau River 
(Above Chaudiere (Above Billings 
Falls) Bridge) 
TAO, AMMONIA aise pease ero eee .012 .024 
Albuminoid ammonia:-.- "ue .227 .40 
Nitrogen as Nitrates and Nitrites...... .113 .034 
CRIONIMENA LME Waiver cea RU Be Er EAN .6 2.5 
HOLAISONAS AL AIS EN PP RTL 56.0 145.2 
SONAS AI eTMIANITION ES: Me Lee CL 24.8 82.8 
That both waters contain large quantities of dissolved vegetable 
organic matter is evident from the high figures for the albuminoid am- 
monia; the Ottawa river water, however, it will be remarked, is in this 
respect much the purer. There would be no object for the purposes of 
this paper in critically considering and comparing these data, but it may 
be pointed out in passing, that they show the superior quality of the 
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