Von Hoff on the Origin of Meteoric Stones. 299 



The same view is countenanced by the nature of the slaggy crust 

 which would seem to be the product of an instantaneous pro- 

 cess, * perhaps of the last step of the great principal operation, 

 and is intimately connected with the breaking up of the mass 

 into pieces, for all the fracture surfaces are coated by this crust. 



Even the planetary rapidity of motion which has been noticed 

 in the progress of fire-balls and meteoric stones, corresponds 

 better with the idea now under consideration, than with that of 

 a mere descent of a solid body, in which latter case so great a 

 rapidity could not be produced.-f- 



If this hypothesis should be considered too daring, and too 

 little supported by other better known phenomena, or by ascer- 

 tained physico-chemical laws, I must freely confess that I can- 

 not bring forward any farther proof of a positive description, 

 and that I must chiefly appeal to the fact, that, of all the 

 theories, it affords the greatest facility for the explanation of 

 nearly the whole of the phenomena presented by meteoric stones. 

 I have also to request the attention of my readers to the following 

 facts : Planets exist of extreme variety in regard to their volume. 

 They must at one period have been formed by a process con- 

 formable to the laws of nature. We have no grounds for consi- 

 dering that the formation of planetary and other similar bodies 

 has ceased. Ascertained phenomena in the region of the fixed 

 stars, permit, nay favour the conjecture, that extremely large 

 heavenly bodies are still being formed, while, probably, also 

 others are dissolved. Great and small are expressions which 

 ought not to have any influence in deciding such a question. 

 The Sun, Jupiter, Uranus, and Vesta are heavenly bodies ha- 

 ving a similar nature. The diameter of Vesta is upwards of 

 3000 times less than that of the Sun ; and a body whose diame- 

 ter should bear the same relation to that of Vesta, as the diame- 

 ter of Vesta does to that of the Sun, would have a diameter of 



base, an imperfect kind of square, has two of its adjoining sides about sir- 

 tenths of an inch long each, and the other two each about five-tenths; whilst 

 two of the triangular sides of the pyramid are about six-tenths on every ride 

 of each triangle, all of which are a little curved ; and the other two triangu- 

 lar sides are only five-tenths on the sides where these two last join," p. 32. 

 EDIT. 



* Chladni's " Feuermeieore," p. 49. 



t Mayer in < Voigt's Magazin," vol. v. p. 15 ; also Bessel and Benzenberg. 



