546 Dr. E. L. Moss. Observations on Arctic Sea-water and Ice. 



for verifications yielded 1121 of sulphuric acid* (S0 3 ) to 100 of 

 chlorine in the deep warm water of Smith's Sound, and 11'59 in the 

 polar water, showing an excess of "38 in the latter. 



Forchhammer attributes this disturbed proportion either to a scarcity 

 of fucoidal plants or to the vicinity of volcanoes. 



If it be assumed that the dilution of outflowing polar currents is due 

 rather to shore precipitation than to transference of polar precipita- 

 tion through the perennial floes, the littoral character of the currents 

 will alone account for the increase of sulphates. 



On quitting Robeson Channel, Her Majesty's ship "Alert" found 

 herself on the shores of a sea covered exclusively with the heavy ice 

 before met with only in outlying fragments. The pack edge ground- 

 ing along the shore in fourteen fathoms, and forced upwards towards 

 the beach, formed a barrier reef,. inside which the ship found shelter. 

 As soon as new floe consolidated it, it was found that the grounded 

 masses, resembling icebergs in their size and stratification, differed 

 from them in being salt, and the first chlorine estimations were made 

 in search of ice fit for the ship's use during winter. 



On the return of daylight, further observations both on the compo- 

 sition and structure of the ice were begun, in the hope that they would 

 throw some light on the place and mode of growth of the stupendous 

 floes. 



All but the surface of the floating ice was out of reach, but plenty of 

 sections were afforded by the great fragments forced upwards on the 

 beach. 



A floe grounded a quarter of a mile ahead of the ship had split into 

 several rectangular segments. Its largest masses were separated by a 

 narrow cleft passing vertically through the ice and exposing a fresh 

 section, measuring 47 feet at right angles to the plane of stratifica- 

 tion. The floe was belted with a shelf of ice, marking the sea-level 

 previous to its last upheaval. The cleft intersected this tide-mark 

 11 feet from its top surface. The floe sides under the mark were 

 grooved with the vertical channellings of last season's subaqueous 

 thaw, but neither the tide mark nor the groovings passed into the cleft, 

 and the sharp edges of the latter had evidently not been exposed to the 

 warmth of last summer. 



Dr. Rae has pointed outf how readily salt ice may lose its en- 

 tangled brine by drainage ; it thus also loses its cryohydrates when 

 the temperature rises above their freezing points; but since the 

 upheaval of this floeberg was recent, and since the temperature of the 

 air was yet below what the ice possessed when submerged, it was fair 



* Precipit ated with barium chloride instead of nitrate, as the latter, used by Forch- 

 hammer, requires much manipulative skill in its subsequent separation from the 

 sulphate. 



f Dr. Eae, " Proc. Phys. Soc," Part I, p. 14. . 



