444 SPECIAL RESULTS IN THE URANO LOGICAL 



of their consisting of an assemblage of distinct combinations 

 was for a long time not adverted to ; their component parts 

 were examined only generally, and it was thought sufficient to 

 remove by means of a magnet any metallic iron which might 

 be contained in them. After Mohs had drawn attention to 

 the analogy of some aerolites with certain telluric kinds of 

 rock, Nordenskjold attempted to shew that olivine, leucite, 

 and magnetic iron, were the constituent parts of the aerolite 

 of Lontalax, in Finland ; but the fine observations of Gustav 

 Rose have shewn beyond a doubt that the meteoric stone of 

 Juvenas consists of magnetic pyrites, augite, and a feldspar 

 which has much resemblance to labradorite. Berzelius was 

 thus led to examine by chemical methods the mineral nature 

 of the several combinations in the aerolites of Blansko, Chan- 

 tonnay, and Alais (Kongl. Yetenskaps Academiens Handlin- 

 gar for 3834). The path thus happily indicated by Ber- 

 zelius has been since extensively pursued. 



" a. The first and more numerous class of meteoric stones, 

 viz. those with metallic iron, contain this substance, some- 

 times in minute interspersed particles, and sometimes in 

 larger masses, which occasionally even form, as it were, a 

 connected iron skeleton, thus constituting a transitional 

 link with those masses of meteoric iron in which, as in the 

 Siberian mass of Pallas, other substances are not found. 

 The olivine which they always contain causes them to be rich 

 in magnesia, and is itself the ingredient which is decomposed 

 when these meteoric stones are treated with acids. Like the 

 telluric olivine it is a silicate of magnesia and protoxide 

 of iron. The part of the stones which is not attacked by 

 acids is a mixture of feldspatic and augitic substances, the 

 nature of which can only be determined by calculation from 



