32 ROYAL SOCIETY OF CANADA 
Ottawa river water in many respects—a conclusion that is in accord 
with our prediction from a knowledge of the rivers and the country 
through which they travel. 
Ice from Ottawa and Rideau Rivers. 
The ice blocks analysed were cut in February, when the thickness 
of the ice on the Ottawa river was about 22 inches; that on the Rideau 
river, about 18 inches. Both blocks showed from 4 to 6 inches on the 
surface of so-called “snow” or “slush” ice: i.e., ice formed partly of 
snow. ‘This layer of ice, which, though not so transparent as the rest 
of the block, was nevertheless fairly solid and clean. From inspection 
one would say that both ices were satisfactory, being clear, non-porous 
and practically free from suspended matter. 
Thoroughly representative samples were procured by sawing a sec- 
tion, about 5 inches wide, from the centre of each block and throughout 
its whole thickness. The ice thus obtained was broken up and allowed 
to melt in a clean, covered vessel, the resulting waters constituting the 
first series, as follows: 
Analysis of Ice. 
(In parts per million.) 
From From 
Ottawa River Rideau River 
(Above Chaudiere (Above Billings 
Falls) Bridge) 
Mreevammoniiay coe -ce sees een .04 .06 
Albuminoidiammonia 2-7 4. .041 .135 
Nitrogen as Nitrates and Nitrites.... . .049 .049 
CRIOTNEMPRES ER TN Eee .05 15 
TOLALSONAS AR AI2O EE RAT neon e 4.4 5.4 
SolidslatierMeonibionnma. cece terse trace trace 
Comparing these data with those of the waters, previously given, it 
is at once apparent that in freezing, a very large quantity of dissolved 
organic matter has been eliminated. Taking, first, the albuminoid am- 
monia, as an index of this peaty matter, it will be noticed that the reduc- 
tion by freezing in the case of the Ottawa river is from .227 p.p.m. to 
041 p.p.m., and in that of the Rideau river from .400 p.p.m. to .135 
p.p.m. Similarly with the Total Solids,” practically half of which 
is organic matter, the reduction from freezing has been from 56 p.p.m., 
and 145.2 p.p.m. to 4.4 p.p.m. and 5.4 p.p.m. respectively. The 
chlorine is also much reduced, and the mineral matter (solids after 
ignition) entirely disappears. 

