Dr. Walter Flight — History of Meteorites. 159 



Silicic acid 62-65 Potash 2-02 



Phosphoric acid 0*11 Soda 4-01 



Alumina 14-93 Chlorine 0-06 



Iron oxide 0*74 Water (hygroscopic) 0-34 



Iron protoxide 4-64 Organic matter and combined 



Manganese protoxide 0-07 water 1 2-86 



Lime 5-09 



Magnesia 300 100-12 



This composition corresponds with, the formula : 

 2RO,SiO, + Al,0 3 ,3Si0 2 + H 3 0. 



The origin of this cryoconite is highly engimatical. That it is not 

 a product of the weathering of the gneiss of the coast is shown by 

 its inferior hardness, indicating the absence of quartz, the large pro- 

 portion of soda, and the fact of mica not being present. That it is 

 not dust derived from the basalt area of Greenland is indicated by 

 the subordinate position iron oxide occupies among the constituents, 

 as well as by the large proportion of silicic acid. We have then to 

 fall back on the assumption that it is either of volcanic or cosmical 

 origin. 



That dust can be carried enormous distances has been well 

 established. Darwin 2 refers to instances of dust having fallen on 

 ships when more than a thousand miles from the coast of Africa, and 

 at points sixteen hundred miles distant in a north and south direction. 

 If the Greenland dust were volcanic, it would probably have been 

 wafted from Iceland or Jan Mayen, or some as yet unknown volcanic 

 region in the interior of Greenland. Nordenskjold found it to bear 

 the closest resemblance under the microscope to the ash of 

 Vesuvius (1822), and a specimen of that which fell at Barbadoes 

 and probably came from St. Vincent. Looked at in the mass, how- 

 ever, it is at once seen that the volcanic ash is of a brownish 

 red ; the cryoconite is grey. The magnet when placed in contact with 

 the Vesuvian ash extracted nothing ; out of that from Barbadoes 

 it drew magnetic particles, which, however, were not metallic, nor 

 did they contain nickel or cobalt. 



The cryoconite, nevertheless, whencesoever it comes, contains one 

 constituent of cosmical origin. Nordenskjold extracted, by means 

 of the magnet, from a large quantity of material, sufficient particles 

 to determine their metallic nature and composition. These grains 

 separate copper from a solution of the sulphate, and exhibit con- 

 clusive indications of the presence of cobalt (not only before the 

 blowpipe, but with' solution of potassium nitrite), of copper, and of 

 nickel, though in the latter case with a smaller degree of certainty, 

 through the reactions of this metal being of a less delicate character. 

 Moreover, ammonia removes from cryoconite a humus-like substance 

 that, among other characteristics, in its powers of resisting powerful 

 oxidizing reagents, closely resembles the organic compound found in 

 he residue of Ovifak iron after treatment with acid. 



1 This passed off when the mineral was heated to temperatures ranging from 100° 

 to a red heat. 



2 C. Darwin. Journal of Researches Vogage of M.M.S. Beagle, new ed. 



1870, p. 5. 



