462 DR. W. FLIGHT, GREEKLAND METEORITES, 



skjold an opportunity of determining whether the snow brought 

 cosmical matter to the earth's surface. A cubic metre of appa- 

 rently pure snow, collected towards the end of the fall, left on 

 melting a small black residue. From some of this substance, 

 when heated, a liquid product distilled over; a portion when 

 burnt left a red ash ; while a magnet extracted particles which, 

 when rubbed in an agate mortar, exhibited metallic characters, 

 and on being treated with acid proved to be iron. Although the 

 possibility must be admitted that this material may have been 

 derived from the chimneys and iron roofs of the city, already 

 covered with a thick layer of snow, the result was sufficiently in- 

 teresting to make it desirable that a similar experiment should be 

 tried with snow falling remote from towns. For this purpose 

 snow was collected on the 13th March 1872, by Dr. Karl Nor- 

 denskjold at Evoia, in Finnland, to the north of Helsingfors, and 

 in the centre of a large forest. It was taken from oft' the 

 ice of the Rautajerwi, at a spot which is separated by a dense 

 wood from tlie houses of that northern station. When melted, 

 this snow yielded a soot-like residue, which under the miscro- 

 scope was found to consist not only of a black carbonaceous sub- 

 stance, but white or yellowish- white granules, and from it the 

 magnet removed black grains, which when rubbed in a mortar were 

 seen to be iron. Here again the material was too small in amount 

 to allow of a determination of the presence of nickel and cobalt ; 

 in other words, to establish the meteoric origin of the metal. The 

 Arctic Expedition of 1872 presented an opportunity for the col- 

 lection of snow in a region as far removed as possible from human 

 habitation. On the 8tli August, the snow covering the drift-ice 

 at Lat. 80° N. and Long. 13° E. was observed to be thickly 

 covered with small black particles, while in places these pene- 

 trated, to a depth of some inches, the granular mass of ice into 

 which the underlying snow had been converted. Magnetic par- 

 ticles were abundant, and their power to reduce copper-sulphate 

 was established. Again, on the 2nd September, at Lat. 80° iSf. 

 and Long. 15° E., the ice-field was found covered with a bed of 

 freshly fallen snow, 50 mm. thick, then a more compact bed 

 8 mm. in thickness, and below this a layer 30 mm. thick of snow 

 converted into a crystalline granular mass. The latter was full of 

 black granules, which became grey when dried, and exhibited 

 the magnetic and chemical characters already mentioned ; they 

 amounted to • 1 to 1-0 millegramme in a cubic metre of snow. 

 Analysis of some millegrammes enabled Nordenskjold to establish 

 the presence of iron, phosphorus, cobalt, and probably nickel. 

 The filtrate from the iron-oxide gave a small brown precipitate, 

 which gave a blue bead with borax. The portion insoluble in 

 acid consisted of fine angular colourless matter, containing frag, 

 ments of Diatoms. This dust from the polar ice North of Spitz- 

 bergen bears a great resemblance to the remarkable substance, 

 cryoconite,* which was found in Greenland in 1870, very evenly 



* A. E. Nordenskjold. An Account of an Expedition to Greenland ; 

 Geol. Mag. vol. ix. p. 353. ^ See also above, p. 395. 



