[ 3o8 ] 



k lliall be better accounted for, admits of an eafy explanation, 

 by fuppoling that the fame eruption which broke up the original- 

 calcareous bed, -wherever it lay, and raifed thefe fragments of it 

 to their prefent fituations, mufl, in fo doing, not only have 

 disfigured and wholly changed the appearance and (hape of the 

 former furface, but may naturally be conceived to have thrown 

 out, at the fame time, fuch a quantity of argillaceous matter 

 as was fufficient completely to bury every other part and veflige 

 of it, except thefe maffes which feem to have efcaped, as it. 

 were, by accident.. 



That eruptions, and of the kind here fiippofed, did exift in 

 the diftrid in queftion at fome very early period, naturalifls 

 of great eminence have, long fince, attempted to deduce from 

 other confiderations than thofe contained in this paper; but as 

 their reafonings in proof of this are immediately conneded with-. 

 a very important mineralogical queftion, which, though much 

 difcuffed, remains flill in controverfy *, I fliall not avail myfelf 

 of their authority, refpedable as fome names are' which I 

 might otherwife adduce in fupport of this opinion. It is not 

 my intention, nor is it, 1 believe, at all neccffary to my prefent 

 fubied, to introduce here any confidcration of the extenfive and 

 difficult queftion to which I allude; for whether the bafaltic 

 columns, and other analogous covering of this and fimilar coun- 

 tries, fliall be attributed to the immediate agency of fire or of 

 water, the confequences which I have endeavoured to irace, 



from 



* It will eafily be perceived tliat the queftion alluded to is that on the origin of 

 hafaltes. 



