^5 



Interpo'sing layers between currents of lava, being thus 

 established, we are to look, if any thing similar can be 

 observed between basalt strata: but no such thing is to 

 be found. Our basalt strata, whether of the same, or of 

 different varieties, pass into each other per saltum, Avithout 

 interrupting the solidity of the mass, dr without exhibit- 

 ing a particle of extraneous matter between them.* 



Thirdly. I observed, in a former Memoir, that, on our 

 basaltic coast, nature changes her materials, and the stile 

 of her arrangement, every ' two or three miles ;' ' & fact, 

 which opposes unsurmountable difficulties to the position, 

 that the basalt strata, forming this coast, are of volcanic 

 origin. I will select two or three; of these numerous little 

 systems, and state the order in which the strata are ar- 

 ranged in each of them, in a vertical direction; to' givt! 

 the advocates for their volcanic origin an opportunity of 

 exerting their ingenuity, by shewing hovf they manage 



their 



* I am aware, that tlie ochreous layers, or strata, lying between our greater 

 basalt strata, may be stated, as contradicting tins position. 



The nature of these ochres (common to all basaltic countries) has given rise to 

 much controversy; which were I to enter into now, I would be led too far from 

 the present question. But, as this fossil makes a most conspicuous figure in many 

 parts of Antrim, I think it well entitled to a place in the statistical survey of 

 that county ; the basahic part of which I have undertaken, to oblige my friend, 

 Mr. Dubourdieu. 



On the present occasion I shall only say, that I accede to the conclusion, 

 which Mr. St. Fond adopted, after long doubt, and much puzzling; to wit, 

 " That these ochres were pure basalt, altei-ed by some chemical operation of 

 " nature, with which we are unacquainted." 



