250 A. LIVERSIDGE. 



and Long. 30° E., yielded particles of metallic iron ; also 

 on September 2nd, in Lat. 80° N. and Long. 15° B., freshly 

 fallen snow collected from the icefield yielded from O'l to 

 l'O milligram of black magnetic particles to the cubic 

 metre of snow; iron, cobalt and phosphorus were detected 

 and probably nickel was present also ; the portion insoluble 

 in acid contained fragments of diatoms and minute trans- 

 parent angular particles. 



Dr. Moss speaks of similar dust 1 : — "Occasionally deposits 

 of atmospheric dust were to be met with throughout the 

 stratified ice sometimes scattered in very minute points 

 which when examined proved to be air cells coated with 

 the impalpable dust, sometimes occurring in comparatively 

 conspicuous quantities in lines cutting the stratification 

 and marking what had once been the bottom of a super- 

 glacial lake. Similar dust was to be found on the present 

 surface of the floes occasionally greatly magnified in appear- 

 ance by the growth amongst it of an alga (Nostoc aureum). 

 The dust often occurred in little granules so that in mass 

 it formed an oolite. . . . All the specimens of ice dust 

 obtained by me from the floe bergs are undoubtedly the air 

 carried debris of crystalline rock not traceable to the 

 neighbouring shore." 



On February 26, 1883, a fine dust was discovered in the 

 snow in Trondhjem Amt in North Norway. Dr. Reusch of 

 the Mineralogical Faculty of the Christiana University 

 found that it was not of volcanic origin as had been imagined, 

 but that it consisted of fine particles of quartz sand, horn- 

 blende and talc, mixed with very fine particles of vegetable 

 matter. The dust must have^been carried a very long 

 distance, the whole of the country having been for months 

 covered with deep snow. The wind blew strongly from 

 N.N.W. 



1 Voyage to the Polar Sea, in H.M.S. "Alert and Discovery," Capt. Sir 

 G. Nares, Vol. n., p. 61. 



