464 DR. W. FLIGHT, GREENLAND METEORITES. 



by its inferior hardness, indicatino; the absence of quartz, the 

 hirge proportion of soda, and the fact of mica not being present. 

 That it is not dust derived from tlie basalt area of Greenland is 

 indicated by the subordinate position iron-oxide occupies among 

 the constituents, as well as by the large proportion of sihcic acid. 

 We have then to fall back on the assumption that it is either of 

 volcanic or cosmical origin. 



That dust may be carried immense distances has been well 

 established. Darwin* refers to instances of its 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 wafced 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 to a specimen of 

 that which fell at Barbadoes and probably came from St. Vincent. 

 Looked at in the mass, however, 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 failed to 

 extract anything ; 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 which, among other characteristics, in its 

 powers of resisting powerful oxidising reagents, closely resembles 

 the organic compound found in the residue of Ovifak iron after 

 treatment with acid. 



Hail, which fell at Stockholm in the autumn of 1873, was found 

 by Nordenskjold to contain grey metallic particles that reduced 

 copper from its sulphate. Although the roofs of the buildings 

 suri-ounding the Academy, in the courtyard of which these hail- 

 stones fell, are of iron, the grains were rounded, and of light 

 colour, instead of a reddish-brown. The observation is of sufficient 

 interest to allow of its being placed on record. 



It has been shown that small quantities of a cosmical dust, 

 containing iron, cobalt, nickel, phosphorus, and carbonaceous 

 substances, fall with other atmospheric precipitates on the earth's 

 surface. Nordenskjold, in his paper, alludes to the theory, already 

 advanced, we believe, by Hai dinger, that this deposit may play an 



* C. Darsvin. Journal of Researches of a Naturalist ; Voyage of H. M.S. 

 " Beac/le" new ed., 1870, p. 5. 



