158 Dr. Walter Flight— History of Meteorites. 



with a bed of freshly fallen snow, 50 mm. thick, then a more com- 

 pact 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 0*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 head with borax. The portion insoluble in acid consisted of 

 fine angular colourless matter, containing fragments of diatoms. 

 This dust from the polar ice north of Spitzbergen bears a great re- 

 semblance to the remarkable substance, cryoconite, 1 which was 

 found in Greenland in 1870, very evenly distributed in not incon- 

 siderable quantity on shore-ice, as well as on ice thirty miles from 

 the coast and at a height of 700 metres above the sea. The dust of 

 both localities has probably a common origin. 



The cryoconite is chiefly met with in the holes of the ice, forming 

 a layer of grey powder at the bottom of the water filling the holes. 

 Considerable quantities of this substance are often carried down by 

 the streams which traverse the glacier in all directions. The icehills 

 which feed these streams lie towards the east, on a slowly rising 

 undulating plateau, on the surface of which not the slightest trace of 

 stone or larger rock masses was observed. The actual position of 

 this material, to which Nordenskjold has given the name of cryo- 

 conite (fcpvo? ice, and kovli dust), in open hollows on the surface of 

 the glacier, precluded the possibility of its having been derived from 

 the ground beneath. 



The grey powder contained a not inconsiderable amount of organic 

 matter, which, even at the low temperature of the ice, undergoes 

 putrefactive decomposition. A quantity, amounting to from two to 

 three cubic metres, which was lying in the dried-up bed of a glacier 

 stream, emitted a very offensive odour, bearing some resemblance to 

 that of butyric acid. 



"When examined with the microscope, the chief constituent of this 

 powder appears to consist of colourless, crystalline, angular, trans- 

 parent grains, among which are a few yellow and less transjiarent. 

 Some had distinct cleavage-surfaces, and were possibly a felspar ; 

 other crystal fragments, having a green colour, were probably augite ; 

 while other black, opaque particles could be removed with a magnet. 

 These foreign constituents, however, are present in so small a 

 quantity that if all the white grains consist of one and the same 

 mineral, it may be regarded as homogeneous. The specific gravity of 

 this mineral is 2-63 ; the hardness apparently inconsiderable, and 

 the form probably monoclinic. It resists the action of acids : by 

 long digestion with sulphuric acid 7-73 per cent., with hydro- 

 chloric acid 16*46 per cent, were dissolved. Lime carbonate was 

 not present. According to Lindstrom's analysis, it consists of: 



1 A. E. Nordenskjold. An Account of an Expedition to Greenland. Geol. Mag. 

 Vol. IX. p. 355. 



