240 METALS TN THE ATMOSPHERE. 



station des Avniils In'hnv i\w Moiitiei-s: at 8.100 feet at tlic li()si)ic«' of 

 the (Ti-eat St. Bcnianl — and conipaivd the evaporation residue from 

 this snow with Ihe dust collected in the towers of several cathedrals 

 at Paris, Geneva. Lausaiuie. Varsovie. and at Samara on the Volga. 

 He concluded that iron is as surely present in recent snows as in the 

 dust of centuries accunudat(Ml in the clock towers of the old churches. 

 In all cases the appearance of this metal indicated that it had heeu 

 subjected to high tcm])ei-atui'es. 



These corpuscles, found always in greater (juantities in the snows of 

 lower altitudes than from higher regions, do not always have the same 

 characteristics, and students of them have classified them into several 

 groups : 



1. Irregular amorphous grayish fragments, measuring from 0.1 to 

 0.'2 mm. in diameter. 



2. Mammilated particles, black and oi)a(iue, much smaller, measur- 

 ing only 0.01 to 0.05 mm. 



3. Fibrous particles of about the same size. 



4. Spherical corpuscles, })lack and opaque, diameter 0.01 to 0.02 

 mm. 



5. Corpuscles apparently with a tiny vase-like neck. 



Moreover, these minute ferruginous corpuscles divide into two 

 classes, some which have been deposited on the surface of the earth, 

 others of an extra-terrestrial origin. The effects of showers of 

 meteors are shown in an incontestable manner. Ehrenberg, Arago, 

 Quetelet, Daubree. and Nordenskiold have brought forAvard a great 

 numl)er of facts in this connection. Examining a fine dust which on 

 the 25th of January. 1851), fell in the Indian Ocean, covering the 

 decks of the good ship Joskih Bates, Ehrenberg showed that this 

 powder, which to the naked eye appeared to be only little agglom- 

 erate grains, was in reality formed by drops composed of metallic 

 iron and iron oxide solidified and creased in a manner analogous to 

 that of the Batavian tears. He considered this proof that a mass of 

 meteoric iron is made incandescent by the friction of the air. Sedi- 

 ments of this sort may come from the superficial fusion of meteorites, 

 or, as Daubree has indicated in his memoir on the meteorite of 

 Orgueil," they may be simply the result of disintegration. 



The dust is so friable that some bits were reduced to a powder by 

 the pressure of the fingers. Its different parts are cemented togethei- 

 with some alkaline salts so soluble in water that this liquid will 

 woi-k a c()m[)lete disintegration into a fine powder that will pass 

 through the hardest filters. Numerous cases of rains of fire which 

 should apparently be attributed to the fall of incandescent debris of 

 meteorites are familiar. The Baron de Reichenbach insisted strongly 



o Journal des Savants. 1870. 



