300 Von Hoff on the Origin of' Meteoric Stones* 



a little more than 400 feet. Hence a meteoric stone whose dia- 

 meter to that of the assumed body stood in similar relations as 

 that body to Vesta, would belong to the class of aerolites of the 

 smallest size. For chemically produced inorganic bodies, na- 

 ture has only a measure of the relations of their component 

 parts, but no measure for the masses regarded as a whole. 



It is extremely probable that the elementary ingredients from 

 which heavenly bodies are formed, are analogous or similar to 

 one another, since the laws of nature, which produce regularly 

 the greatest phenomena of the heavens, act with such uniformity. 

 It is, on this account, also probable that the substances resulting 

 from the union of the elementary ingredients, and of which the 

 planetary bodies consist, are extremely similar to one another ; 

 still, however, as is self-evident, without prejudice to that pre- 

 dominating variety in the detail that seems to be observed so 

 universally by nature, and which we also perceive in the other- 

 wise extremely uniformly arranged solid structures of our globe. 



We find that the lowest portions known to us of the crust of 

 our earth consist of crystalline, granular, compound mineral 

 masses. Although this known part of the crust is so small, yet 

 the information we thus possess is by no means without import- 

 ance for obtaining an idea of the internal constitution of the 

 earth. Since all the mineral substances brought to the surface 

 by the agency of volcanos, and some of them probably from a 

 very great depth, seem to belong to such rocks, we may assume, 

 at least, that the same compounds without going so far as to 

 believe that they actually extend to the centre still form an 

 essential and important constituent part of our planet. 



If such rocks are essential component parts of the earth, they, 

 or at least similar structures, may hold a prominent place in other 

 planets ; nay, from the above mentioned uniformity of the laws 

 and operations of nature, it is even probable that granular crys- 

 talline mineral structures, of various kinds, are essential compo- 

 nent parts of all planetary bodies ; that, therefore, in the forma- 

 tion of these bodies, such mineral compounds are produced from 

 elementary substances ; and that, even now, when original matter 

 is united in space to constitute solid bodies, this takes place by 

 the formation of granular crystalline mineral substances. An 

 especially important part seems to have been assigned to iron in 

 the economy of nature : that it forms a large and important part 



