Dr. Walter Flight — On Meteorites. 361 



the air they weathered to a white non-crystalline powder. They 

 lay, without being sensibly dissolved, for a whole night in the water 

 formed by the melting of the snow. On being heated too, they fell 

 asunder into a tasteless white powder. The white powder that was 

 formed by the weathering of the crystals was analyzed after our 

 return, — 21 months after the discovery of the crystals — and was 

 found to contain only cai'bonate of lime. 



The original composition and origin of this substance appears to 

 me exceedingly enigmatical. It was not common carbonate of lime, 

 for the crystals were rhombohedral, and did not show the cleavage 

 of calcite. Nor can there be a question of its being arragonite, 

 because this mineral might indeed fall asunder " of itself," but in 

 that case the newlj' -formed powder ought to be crystalline. 



Have the crystals originally been a new hydrated carbonate of 

 lime, formed by crystallizing out of the sea-water in intense cold, 

 and then losing its water at a temperature of 10° or 20° above the 

 freezing-point ? In such a case they ought not to have been found 

 on the surface of the snoio, but lower down on the surface of the ice. 

 Or have they fallen down from the inter-planetary spaces to the 

 surface of the earth, and before crumbling down have had a com- 

 position differing from terrestrial substances in the same way as 

 various chemical compounds found in recent times in meteoric 

 stones ? The occurrence of the crystals in the uppermost layer of 

 snow and their falling asunder in the air, tell in favour of this view. 

 Unfortunately there is now no possibility of settling these questions, 

 but at all events this discovery is a further incitement to those who 

 travel in the High North to collect with extreme care, from snow- 

 fields lying far from the ordinary routes of communication, all 

 foreign substances, though apparently of trifling importance. 



Baron Nordenskjold then refers to the metallic particles found by 

 him on the snow during previous years (see Geol. Mag. Dec. 11. 

 1875, Yol. II. pp. 157-162), and says in conclusion : — 



It may appear to many that it is below the dignity of science to 

 concern one's self with so trifling an affair as the fall of a small 

 quantity of dust. But this is by no means the case. For it is esti- 

 mated that the quantity of the dust that was found on the ice north 

 of Spitzbergen amounted to from 01 to 1 milligram per square 

 metre, and probably the whole fall of dust for the year far exceeded 

 the latter figure. But a milligram on every square metre of the 

 surface of the earth amounts for the whole globe to five hundred 

 million kilograms (say half a million tons) ! Such a mass collected 

 year by year during the geological ages, of a duration probably in- 

 comprehensible by us, forms too important a factor to be neglected 

 when the fundamental facts of the geological history of our planet 

 are enumerated. A continuation of these investigations will perhaps 

 show, that our globe has increased gradually from a small beginning 

 to the dimensions it now possesses ; that a considerable quantity of 

 the constituents of our sedimentary strata, especially of those that 

 have been deposited in the open sea far from land, are of cosmic 

 origin ; and will throw an unexpected light on the origin of the fire- 



