Von Hoff on the Origin of Meteoric Stones. 291 



scssing no atmosphere and no water from which the iron could 

 absorb oxygen. Now it is not fully proved that the moon is des- 

 titute of an atmosphere resembling that of the earth, or that water 

 does not exist in the moon in a similar way as on the earth. We 

 have no evidence that the moon does not contain water under its 

 solid covering, or on the side which is constantly turned away from 

 us. We find further, that in the component parts of those me- 

 teoric masses which do not consist entirely of meteoric iron, the 

 process of oxidation has tak^n place. If, then, these bodies have 

 been derived from the moon, the process of oxidation must have 

 gone on there, consequently an absorption of oxygen must have 

 occurred there, and consequently oxygen must exist there. There 

 remains, besides, much that is unexplained in the occurrence of 

 native iron in the moon ; and if to this part of the hypothesis 

 w@ should oppose the theory, that perhaps in the earth itself, but 

 at a depth not yet reached by man, native iron may be found, 

 such a Conjecture could not be regarded as a very rash one. 



Further, the possibility of bodies being projected from the 

 moon with the force necessary to bring them within the range 

 of attraction of the earth, is not only not to be disputed, but 

 even mathematically demonstrated. But that such a power is 

 actually exerted on the moon, is not an ascertained fact, but 

 only an hypothesis. The circumstance that volcanic formations 

 of considerable magnitude are to be observed on the moon's 

 surface certainly supports the idea ; but the proof on this head 

 is not quite conclusive. 



Granting, however, that the chemical and physical constitu- 

 tion of meteoric stones and masses'of iron which have fallen from 

 the air, and granting that all the other circumstances we have hi- 

 therto adduced favour the notion of the lunar origin of these 

 masses, granting also, that the doubts started against the hypo- 

 thesis are to be regarded as insignificant ; there still remains the 

 question to be investigated if the phenomena accompanying the 

 fall of meteoric stones support in a similar manner this opinion. 

 According to the conjecture in question, meteoric stones are 

 the mountain rocks of the moon, which have been separated 

 from their original beds, and hurled away as solid masses. 

 Hence they may either fall in their original condition on the 

 earth, as a cannon-ball reaches its destination in ihe same state 



