AEROLITES. 593 



aggregates of hornblende and albite (Chateau- Renard), or of 

 hornblende and labrador (Blansko and Chantonnay). 



According to the general summary of results given by a 

 sagacious chemist, Professor Rammelsberg, who has recently 

 occupied himself uninterruptedly, and as actively as success- 

 fully, with the analysis of aerolites and their composition 

 from simple minerals, " the separation of the masses fallen 

 from the air into meteoric iron and meteoric stones is not to 

 be admitted in its strictest sense. Meteoric iron is some- 

 times found, though seldom, with silicates intermixed (the 

 Siberian mass weighed again by Heis of 1270 Russian pounds, 

 with grains of olivin), and on the other hand many meteoric 

 stones contain metallic iron. 



" A. The meteoric iron, whose fall it has been possible to 

 observe only a few times (Hradschrina, near Agram, on the 

 26th of May, 1751, Braunau, 14th of July, 1847), while most 

 analogous masses have already laid long upon the surface of 

 the earth, possesses in general very similar physical and che- 

 mical properties. It almost always contains sulphuret of 

 iron mixed with it in finer or coarser particles, \yhich, how- 

 ever, do not appear to be either iron pyrites or magnetic 

 pyrites, but a sulphuret of iron. 18 The principal mass of such 

 a meteoric iron is also not pure metal, but consists of an alloy of 

 iron and nickel, so that this constant presence of nickel (on the 

 average 1 per cent, sometimes rather more, sometimes rather 

 less) serves justly as an especial criterion for the meteoric 

 nature of the whole mass. It is only an alloy of two isomor- 

 pJious metals, not a combination in definite proportions. There 

 are also present in minute quantity : cobalt, manganese, magne- 

 sium, copper, and carbon. The last-mentioned substance is 

 partly mixed mechanically, as difficultly combustible graphite ; 



* Rammelsberg, in Poggeudorfi, Annalen, vol. Ixxiv. 1849, 

 p. 442. 



