272 1HE ORT of the EAR T H. 



THE only queftion, therefore, which it concerns us to decide 

 at prefent, is, Whether thofe operations of extreme heat, and 

 violent mechanic force, be only in the fyftem as a matter of acci- 

 dent ; or if, on the contrary, they are operations natural to the 

 globe, and necefTary in the production of fuch land as this 

 which we inhabit. The anfwer to this is plain : Thefe opera- 

 tions of the globe, remain at prefent with undiminiihed activi- 

 ty, or in the fulnefs of their power. 



A ftream of melted lava flows from the fides of Mount ./Etna. 

 Here is a column of weighty matter raifed an immenfe height 

 above the level of the fea, and rocks of an enormous iize are pro- 

 jected from its orifice fome miles into the air. Every one ac- 

 knowledges that here is the liquefying power and expanfive 

 force of fubterranean fire, or violent heat. But that Sicily 

 itfelf had been raifed from the bottom of the ocean, and that 

 the marble called Sicilian Jafper, had its folidity upon the fame 

 principle with the lava, would ftumble many a naturalift to ac- 

 knowledge. Neverthelefs, I have in my poffeffion a table of 

 this marble, from which it is demonftrable, that this calca- 

 reous ftone had flowed, and been in fuch a flate of fufion and 

 fluidity as lava. 



HERE is a comparifon formed of two mineral fubftances, to 

 which it is of the higheft importance to attend. The folidity 

 and prefent ftate of the one of thefe is commonly thought to 

 be the operation of fire ; of the other, again, it is thought to 

 be that of water. This, however, is not the cafe. The im- 

 mediate ftate and condition of both thefe bodies is now to be 

 confidered as equally the effect of fire or heat. The reafon of 

 our forming fuch a different judgment with regard to thefe two 

 fubjects is this ; we fee, in the one cafe, the more immediate 

 connection of the caufe and the effect, while, in the other, we 

 have only the effects from whence we are in fcience to invefti- 



gate the caufe. 



BUT 



