Meteoric Stones. . 95 



the most probable. To get an idea of the elements of another 

 planetary body, were it only the one lying nearest us, the moon, 

 gives to such an examination an interest which in itself it would 

 be destitute of. 



The general results of my investigations have been, that me- 

 teoric stones of two sorts have fallen on the earth. Those which 

 belong to the same kind, have a lilce composition and appear to 

 come from the same mountain. The one sort is rare. Hitherto 

 there have not been observed more than three meteoric stones 

 belonging to it, which fell in Siannern in Moravia, in Jonzac 

 and Juvenas, in France. They are thus characterized ; they 

 do not contain metallic iron, the minerals of which they are 

 composed are more distinctly crystalline, and magnesia is not 

 a prevailing element of them. Of these I have not had any spe- 

 cimen to examine. The other sort is made up of the great num- 

 ber of meteoric stones, which have been hitherto examined. They 

 are frequently so like one another in color and external appear- 

 ance, that we might believe them to have been struck out of one 

 piece. They contain malleable metallic iron in vaiiable quan- 

 tity. We have an example of an enormous block, which was 

 constituted of a mere continuous web of iron, the cavities of 

 whicli the mineral fill up, and which came down whole in the 

 fall, solely because the iron-web held them together. Some are 

 composed more of the mineral and less of iron, in which case 

 they do not cohere, but burst apart from the heat, which the ex- 

 treme compression of the atmosj^here by means of their irresisti- 

 ble velocity, moving with the rapidity of a heavenly body to- 

 wards the earth, has produced in the few moments they are {}ass- 

 ing through the air, and from which their outermost covering is 



continually niched to a black slag thinner than the thinnest post- 

 paper. We may say then, that the meteoric stones si 



pposed 



proceed from the moon, come entirely from two unlike volcanos, 

 the eruptions of one of which either take place oftener than the 

 other, or are projected in such a direction as that they oftener reach 

 the earth. Such a circumstance agrees well with the fact, that a 

 certain part of the moon has the earth continually in the zenith 

 and directs all its projectiles straight towards the earth, though 

 they do not proceed straight thither, because they must also suf- 

 fer the motion, which they had before as parts of the moon. If 

 that is the part of the moon which sends to us the meteoric iron 



