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



floe ice lias been frequently recorded ; sometimes it is clearly traceable 

 to neighbouring land, at others, as in the case of the kryokonite of 

 Professor Nbrdenskiold,* and the dust of the East Greenland, f and 

 Spitzbergen ice-fields, J its source is more or less conjectural. 



At Floeberg Beach every breeze strewed the ice with dust from 

 shore, consisting of fine sand from the neighbouring hills (effervescing 

 with acid), and organic debris of all sorts, bits of saxifrage and moss 

 and lemming pellets predominating. Such dust was generally confined 

 to the surface of the ice, but a fragment from a bud of Saxifraga 

 oppositifolia, recognised by its claw, was found in a dust-line 45 feet 

 deep in the ice of a large berg off the " south ravine," and a dust-line 

 4 feet deep in the ice of our watering berg, marking the bottom of one 

 of three successive " super- glacial lakes, "§ yielded a lemming hair and 

 a shred of bird's down. 



Another kind of dust of less obvious origin commonly occurred in, as 

 well as on, the floes. It was first noticed in the " Cleft Moeberg," already 

 described in connexion with the chlorine estimations. The walls of the 

 cleft exhibited duplicate sections of an old surface pool, and the bottom 

 of the pool was marked with a dust-line. A similar, but fainter, line 

 passing through the whole berg, lay 8 feet deeper down without any 

 appearance of a pool over it. In these and other dust- lines observed 

 in the floes the line consisted of scattered black points in the ice, some- 

 times two or three in a cubic inch, oftener only the same number 

 in a cubic foot. Each spot consisted of a single air-cell, rarely 

 more than inch in diameter, with its lower half lined with impal- 

 pable dust, but otherwise like the air-cells around it. The spot was 



Fig. 2. 



sometimes quite solid. Specimens were obtained for examination by 

 chipping out lumps of ice holding granules or freighted cells, washing 

 them in their own surface-melting, and putting them into clean bottles 

 till the cells released a little bubble and the dust fell to the bottom, 

 often retaining its shape till shaken. As the surface of a wasting floe 

 progressively lowers, these granular masses are collected into groups, 

 and keep below the general surface in little pits. 



Enough dust was obtained from the " Cleft Floeberg" and from the 



* Prof. Nordenskiold's " Expedition to Greenland," Arctic Manual, p. 325. 

 f " Gl-erman Arctic Expedition." Koldewey, p. 290. 

 X " Parry's" 4th Voyage, pp. 73-75. 

 § " Parry," 4th Voyage, p. 75. 



