$70 CALORIFICATION. 



Ought it then, I would ask, to be considered 

 a matter of surprise, that the immediate union 

 of the pure solar rays with opaque matter, 

 should be capable of producing all the pheno- 

 mena of combustion, and that the uncombined 

 state of the solar rays, which fall on the most 

 lofty summit of the most lofty mountains, should 

 be accompanied by volcanic eruptions; whe- 

 ther they be situated at the polar or meridional 

 regions of the world. At those elevated points, 

 the rarity and purity of the medium affords 

 neither abatement to the power, nor resistance 

 to the motion of the solar rays ; the union, 

 therefore, which takes place with the opaque 

 matter on which they fall, may be supposed to 

 be of the most active kind. 



SECTION III. 



The Cause and Nature of Earthquakes. 



These principles will more especially explain 

 the cause of earthquakes, of those violent 

 shocks of nature which take place, that develate 

 and tear- asunder the bowels of the earth, ex- 

 tending far and near, and involving whole 



proofs which I have offered in support of my opinion, as well 

 as to the demonstrative proposition, that a body which acts 

 equally in evtry direction, cannot act particularly in any one 

 direction. 



