PROF. NORDENSKIOlD, EXPEDITION TO GREENLAND. 395 



Part II. (" Geol. Mag.," vol. ix., p, 355, &c.) 



These holes in the ice, filled with water, are in no way connected 

 with each other, and at the bottom of them we found everywhere, 

 not only near the border, but in the most distant parts of the 

 inland ice visited by us, a layer, some few millimetres thick, of grey 

 powder, often conglomerated into small round balls of loose con- 

 sistency. Under the microscope^ the principal substance of this 

 remarkable powder appeared to consist of white angular transparent 

 grains. We could also observe remains of vegetable fragments ; 

 yellow, imperfectly translucent particles, with, as it appeared, evi- 

 dent surfaces of cleavage (felspar ?) ; green crystals (augite) ; and 

 black opaque grains, which were attracted by the magnet. The 

 quantity of these foreign components is, however, so inconsiderable, 

 that the whole mass may be looked upon as one homogenous sub- 

 etance. An analysis by Mr. G. Lindstrom of this line glacial sand 

 gave — 



Silicic acid 



- 



. 



62-25 



Alumina 



- 



- 



14-93 



Sesquioxyd of Iron 

 Protoxyd of Iron 

 Protoxyd of Manganese 

 Lime 



- 



- 



0-74 

 4-64 

 0-07 

 5-09 



Magnesia 



- 



- 



3-00 



Potassa 



- 



- 



2-02 



Soda - 



- 



- 



4-01 



Phosphoric acid 

 Chlorine 



- 



- 



Oil 

 0-06 



Water, organic substance (100° to 



red 





heat) - 

 Hygroscopic water (15° 



to 100°) 



- 



2-86 

 0-34 



100-12 



After long digestion with sulphuric acid only 7 * 73, and wit h 

 muriatic acid 16*46 per cent, was dissolved. The remainder was 

 entirely white after heating to redness. The analysis gives the 

 atomic relation — 



or the formula — 



2R^Al-{.1 Si-\. H 



2 R Si2 + Al Si3 + H 

 Specific gravity = 2*63 (21°). Hardness inconsiderable, crys- 

 tallization probably monoclinic. 



The substance is not a clay, but a sandy trachytic mineral, of 

 a composition (especif^.lly as regards soda) which indicrctes that it 

 does not originate in the granite-region of Greenland. Its ori^-in 

 appears therefore to me very enigmatical. Does it come from the 

 basalt-region ? or from the supposed volcanic tracts in the interior 

 of Greenland ? or is it of meteoric origin ? The octahedrally crys- 

 tallised magnetic particles do not contain any traces of nickel. As 

 the principal ingredient corresponds to a determinate chemical 

 formula, it would perhaps be desirable to enter it under a separate 



