422 THE CANADIAN NATURALIST. [Vol. viii. 



To this work must be added that of the brines expressed 

 during the process of freezing, which increase the specific gravity 

 of Arctic waters during the winter months, when land drainage 

 is at a minimum. 



The amount of heavy brines formed by the process of freezing 

 must not be measured merely by the whole quantity of ice esti- 

 mated to be formed annually. Salt water ice continues to 

 express brines as the temperature diminishes, and to form heavy 

 brines by osmotic action during variations in temperature below 

 the freezing point of salt water. From this property, salt water 

 ice may be regarded as an intermittent but a productive source 

 of heavy brines throughout the winter. These will not only carry 

 part of their salt, but also part of their cold downwards, either 

 to the bottom or to a zone where their specific gravity is the 

 same as that of the medium to which they sink. They will also 

 gather way, as sheets, horizontally, or vertically, towards the 

 lighter and warmer southerly lying seas, which they will ulti- 

 mately displace by virtue of their density, either from increased 

 salinity or low temperature, or both combined, and thus insti- 

 tute south flowing and accelerate north flowing currents. 



Among the leading consequences which appear to flow from 

 the mechanical effect of ice within the Arctic and Antarctic 

 circles, the following may be outlined : 



1. A series of cold winters, by increasing the thickness of ice 

 in the Polar Seas, will retard the progress of the Tidal Wave 

 towards Smith's Sound, through Robeson Channel, and move 

 the place of meeting of the tides, which now occurs near Cape 

 Frazer, further up Kennedy Channel, and ultimately, ceteris 

 paribus, into the Paloeocrystic Sea itself. By parity of reason- 

 ing, a similar argument applies to Behring Straits and the chan- 

 nels towards Polar areas in the Spitzbergen Seas. 



2. The quantity of ice coming down Kennedy Channel will 

 diminish with the northerly movement of the place of junction 

 of the Tidal Waves. 



3. The warm currents from the south will advance further to 

 the north up Smith Sound and elsewhere, ameliorating the cli- 

 mate of North-west Greenland, etc. ; but an increased quantity 

 of ice will be poured into Baffin Bay and Davis Strait, through 

 the different sounds and straits to the west, and also from East 

 Greenland round Cape Farewell, thus increasing the strength of 

 the Labrador current and the severity of the climates of the 

 shores it washes. 



