97 



larger than a pistol bullet, which, on many occasions, it 

 afterwards forsook: 



Or, we must admit the water to haAe been coeval 

 with the basalt; to which, of course, we cannot ascribe 

 an igneous origin. 



Sixthly. As we know the high statfe of ignition, in 

 which lava issues from a volcano, it is reasonable to ex- 

 pect, that, when, in its course, it meets with extraneous 

 substances, it should produce upon them such altera- 

 tions, as are the usual effect of intense heat, applied to 

 these same substances. Basalt, likewise, is often found in 

 contact with similar matters. Hence, by a minute exa- 

 mination of these contacts, we have an obvious mode of 

 ascertaining, whether the basalt also had encountered 

 them, in tlie same state of ignition, we know the lava 

 did. 



As my country, to a great extent around me, is com- 

 posed of nothing but basalt and limestone, I have no 

 other substance but limestone, upon which I can make 

 observations. This, however, I apprehend, will be found 

 abundantly sufficient, to decide the question. 



About one hundred yards from the beautiful cavern, 

 called Long Gilbert, near the eastern extremity of the 

 calcareous fapade, a mile from Portrush, we find, half 

 way up the precipice, a vast basaltic I'ock, inserted in 

 the middle of the limestone mass; and, at the contact, so 

 united to the limestone, as to form, with it, but one 

 solid mass. 



The 



