306 MITCHILL ON THE EARTHQUAKES OF 1811, 1812, AND 1813. 



4. This, when it passed through water, produced bubbles and froth, 

 and after their extrication, formed visible vapour, obscuring the atmos 

 phere. 



5. Hot water was ejected with considerable force. 



6. Coal or carbonated wood was thrown up in a similar manner, and 

 about the same time. 



7. Light, in some instances, was extricated, and from the circum- 

 stances of its appearance, may be considered, not as an accidental coin- 

 cidence of the earthquake, but as a natural and necessary accompani- 

 ment. But, in most places, there was no luminous appearance. 



8. Sounds were sometimes heard, but by no means uniformly or 

 steadily. In very many cases there was no noise at all. 



9. The gas, ($ 3. and 4.) the hot water, ($ 5.) and the coal, ($ 6.) lead 

 conclusively to the existence of subterranean fire ; and the light ($ 7.) 

 and sound ($ 8.) induce the same belief. 



10. But, after all, it is not very evident what kindles the flame be- 

 neath ; by what means it is supported by air, and kept from extinction 

 by water; how deep it lies; how it convulses the superincumbent strata, 

 and communicates its tremors instantaneously, for several hundred 

 miles. Nor am I able to explain to my satisfaction, why a certain part 

 of the bed of the Mississippi was its focus ; nor why it happened during 

 the winter season. 



I console myself, however, that the history which I have written will 

 give valuable information to the curious on these subjects, and assist 

 some more happy inquirer into nature, to deduce a full and adequate 

 theory of earthquakes. 



Let me, nevertheless, before I lay down my pen, request the reader 

 to consider this paper as a sequel to the history of the earthquakes in 

 New-England, as has it been written by the learned and ingenious Samuel 

 Williams, LL. D. and published in the transactions of the American 

 Academy of Arts and Sciences at Boston. 



