368 ON VOLCANOES AMD EARTHaUAKES. 



Of the Seat and of the Theory of Volcanoes. 



As the disputed question respecting the seat of the 

 volcanic fire, is intimately connected with the theory 

 of Volcanoes, it is necessary to consider these two 

 subjects together. It has heen imagined that the 

 seat of the volcanic fire was superficial, and that it 

 lay among the coal strata ; the eruptions having heen 

 attributed to the combustion of this substance. It is 

 to trifle with a reader of any sense or knowledge, to 

 bestow a serious thought on such puerilities. But 

 the propounder was the greatest of Geologists ; the 

 condition of Geological science is not to be wondered 

 at. Were such strata proved to exist beneath vol- 

 canic mountains, their depth would not be sufficient 

 to produce effects which bespeak the profundity of the 

 abvsses whence such enormous masses of matter and 



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such extensive disturbances proceed. Besides, in the an- 

 tient volcanoes, such stores of coal, even had they 

 existed, must long ago have been consumed ; while 

 the black smoke of volcanoes does not consist of in- 

 flammable matter, and they eject no bitumen. But 

 it is useless to enumerate other objections of equal 

 weight. Be the cause of the fire what it may, it is 

 not seated within the volcanic mountain. Had that 

 been the case, many of these would have been de- 

 stroyed, instead of having constantly received, for such 

 long periods, such vast accessions of matter. This 

 alone proves that the cause is deep seated, and that 

 the cavities which have supplied the volcanic portions 

 of JEtna, Teneriffe, or Vesuvius, are so remote as 

 to be protected from the great weight of these moun- 

 tains by the crust of solid earth which lies above 

 them. The phenomena of submarine volcanoes also 

 prove the great depth of their causes; as, from no 



