C S56O 



XXX. On a saline Substance from Mount Vesuvius. By James 

 Smithson, Esq. F. R, S, 



Read July 8, 1813. 



It has very long appeared to me, that when the earth is 

 considered with attention, innumerable circumstances are per- 

 ceived, which cannot but lead to the belief, that it has once been 

 in a state of general conflagration. The existence in the 

 skies of planetary bodies, which seem to be actually burning, 

 and the appearances of original fire discernible on our globe, 

 I have conceived to be mutually corroborative of each other ; 

 and at the time when no answers could be given to the most 

 essential objections to the hypothesis, the mass of facts in 

 favour of it fully justified, I thought, the inference that our 

 habitation is an extinct comet or sun. 



The mighty difficulties which formerly assailed this opinion, 

 great modern discoveries have dissipated. Acquainted now, 

 that the bases of alkalies and earths are metals, eminently 

 Gxydable, we are no longer embarrassed either for the pabu- 

 lum of the inflammation, or to account for the products of it. 



In the primitive strata, we behold the result of the combus- 

 tion. In them we see the oxyd collected on the surface of 

 the calcining mass, first melted by the heat, then by its in- 

 crease arresting farther combination, and extinguishing the 

 fires which had generated it, and in fine become solid and 

 crystallized over the metallic ball. 



