164 HISTORY OF GEOLOGY AND PALAEONTOLOGY. 



Collections in Vienna, said in 1751 that such stones had 

 been erroneously regarded as rarities, and should be thown 

 away! Fortunately this advice was not followed. 



A Commission of French observers was entrusted with the 

 investigation of a meteorite that fell at Luce, in the province 

 of Maine, in September 1768. The Commission drew up a 

 detailed description of the mineral constitution of the stone, 

 but stated it to be a physical impossibility that the stone 

 could have fallen from the heavens. 



The great Wittenberg physicist, Chladni, at last demonstrated 

 the correctness of the popular idea regarding meteorites. 

 He published in 1794 a classical work, On the Origin of the 

 mass of iron found by Pallas in Siberia, and the explanation of 

 the physical appearances associated with the falling of this and 

 other similar masses. Chladni regards meteorites as fragments 

 of cosmic bodies, which, while travelling through space with 

 enormous rapidity, come into the neighbourhood of the earth 

 and are attracted by it ; they become heated by the friction of 

 the atmosphere, melt superficially, and finally break up owing 

 to the development of gases and elastic fluid materials. This 

 is, in its essential features, the view that is at present held by 

 most authorities. 



Since the appearance of Chladni's work a great number of 

 meteors have been reported, and a careful register of meteor- 

 ites has been drawn up in the writings of several astronomers, 

 while the best specimens have been placed in museums. 



Although it might have been supposed that the full details 

 and the precise scientific basis of Chladni's work would con- 

 vince all investigators, this was far from being the case. Some 

 still held the opinion that meteorites were of telluric origin, 

 while Laplace and Berzelius regarded them as volcanic refuse 

 from the moon. Tschermak thought them fragments from 

 the volcanic eruptions taking place on the earth and on other 

 cosmic bodies. 



The Englishman Howard was the first to investigate the 

 chemical composition of meteorites. He showed that all 

 meteorites have a similar composition, and chiefly consist of 

 silicic acid, magnesia, iron, nickel, and sulphuret of iron. The 

 investigations of other chemists have confirmed Howard's 

 results, and demonstrated the presence in smaller quantity of 

 a number of additional elements. In comparison with 

 terrestrial rock-material the number of ingredients is very 



