FOREIGN CORRESPONDENCE, 



85 



analysis it ajopears to consist principally of olivine, angite, a mineral 

 analogous to Felspar, pure iron, and su phuret of iron. 



The first discovery of minerals in meteoric stones, or aerolites, is 

 due, we believe, to Gustav Rose and Professor Rammelsberg. This 

 eminent German chemist has endeavoured to show in a memoir, pub- 

 lished in Poggendorff's Annalen (Ix. 130), that the residuum which 

 remains insoluble after aerolites have been boiled in acid consists of 

 a mixture of minerals such as are generally found in volcanic rocks on 

 the surface of the earth. Thus, for instance, the rocky parts of the 

 meteoric stone which fell at Chateau-Renard (Provence), and which 

 was analysed by Dufrenoy, consists of a mixture of albite and amphi- 

 bolite ; and in the aerolites which fell at Blausko and at Chantonnay, 

 a mixture of amphibolite and labradorite was discovered. 



According to Gustav Rose* (Poggend. Ann. for 1825, 173 and 192), 

 a meteoric stone found at J uvenas (Departement de I'Ardeche) is com- 

 posed of a finely granular tissue of olivine, augite, and labradorite, 

 blended together so as to resemble dolerite. Berzelius and Rammels- 

 berg afi&rm that in the well-known Siberian mass of meteoric iron, 

 investigated by Pallas, the olivine only differs from common olivine 

 by the absence of nickel, which is replaced by oxide of tin. As 

 meteoric olivine, like our basalt, contains from forty-seven to forty- 

 nine per cent, of magnesia, constituting, according to Berzelius, almost 

 the half of the earthy constituents of meteoric stones, we cannot be 

 surprised at the great quantity of silicate of magnesia found in these 

 cosmical bodies. f A meteoric stone may be grey, earthy, or metallic 

 inside ; but its outside is invariabty covered by a black shiny crust or 

 rind, a few tenths of a line in thickness. This peculiarity at once 

 characterizes an aerolite. The black crust is doubtlessly produced by 

 a fusion of the elements of the meteorite ; but, as Humboldt has 

 justly remarked, the greatest heat of our porcelain ovens would be 

 insufficient to produce anything similar to the crust of meteoric 

 stones, the interiors of which remain wholly unchanged. 



Whilst some aerolites contain as much as ninety-six per cent, of 

 iron, others will be found to contain barely two per cent. The inde- 

 fatigable researches of Berzelius have shown that fifteen elements may 

 be sought for with success in meteoric stones. They are : iron, nickel, 

 cobalt, manganese, chromium, copper, arsenic, zinc, potassium, sodium, 

 sulphur, phosphorus, carbon, silicium, and magnesium. To these we 

 may add tin and calcium, from what has been already stated above. 



Gibers has remarked that it is a curious, but hitherto unregarded 

 fact, that while shells, &c. are found in secondary and tertiary for- 

 mations, no fossil meteoric stones have as yet been discovered, " May 

 we conclude from this circumstance," says he, " that previous to the 

 present and last modification of the eai-th's surface no meteoric stones 



* See also Rammelsberg, Hanclwoi-terbuch der Miiieralogie (first supplement, 

 1843, p. 102). 



t Berzelius, Jaluesber. vol. XV. 217 and 231 ; also Humboldt, Cosmos, vol. I. 

 p. 119 et seq. 



