METEORIC DUSTS, N.S.W. 



247 



dust, and it may or may not have been present in the 

 metallic iron also ; the quantity of metal extracted by the 

 magnet and separately examined was too minute to deter- 

 mine this. Copper has been detected in many meteorites 

 and in several specimens of meteoric dust, and it was 

 found together with metallic iron, cobalt and nickel by 

 Mr. J. Y. Buchanan, m.a., f.r.s., chemist and physicist to 

 the "Challenger" expedition, in the clays, manganese 

 nodules and cosmic dust which were dredged up. 1 



A specimen of dust which fell on board a ship in the 



Atlantic was found by Gibbs to contain copper ; after 



driving off 18*53°/° of water the composition was found 



to be as follows : — 



Silica ... • 45*58 



Alumina 



Ferric oxide 



Manganic oxide 

 Calcic carbonate 

 Magnesia 



Potash 



Soda 



Cupric oxide ... 



lOO'OO 2 

 Mr. G. Tissandier 1 states that he found the dust 

 which he collected from one of the towers of Notre Dame 

 in Paris, into which no one had entered for years, to 

 closely resemble that which he detached by friction from 

 meteorites. He found metallic iron, probably of extra- 

 terrestrial origin, in all the samples examined. An analysis 

 of one gave him the following results : — 



Dust from the toiver of Notre Dame, Paris, 



Organic matter rich in carbon ... ... ... 32*265 



Soluble in water, chlorides and sulphates of the 



alkalies and alkaline earths, ammonium nitrate 9*220 





20*55 



. .. • . 



9*39 



• • • • . 



4*22 



... . 



11*77 



... .. 



2*21 



. .. . . 



3*64 



• • • . • 



2*33 







*31 



1 Proc. Eoyal Soc, 1876, p. 531. 



2 Watts' Dictionary of Chemistry, Vol. in., p. 982. 



