222 Primitive State and Subfcqutnt Changes hi 



forced acrofs die many deep vulleys that liucrfe£l the mountains in all dIrc£l:ions, without 

 firft filling up the valleys themfclves ? And, if this was the cafe, by what means were the 

 valleys fo entirely cleared of tlicm afterwards, as they appear now for the moft part to be? 

 The difficulty, however, I think, is mor^ apparent than real ; for it feems highly probable, 

 that at the time when thefe Hate mountains were formed under the water, there were no 

 valleys, but the whole mafs was one uniform bank, the valleys being afterwards formed by 

 the rivers as the water fubfided ; by this not impK)bable fuppofition, as it appears to me, 

 the obieftion is wholly removed. On defccnding from the (late rocks to the limcftone and 

 the derivative hills, the marks of fubmerfion are more numerous and unequivocal j fand, 

 pebbles, (hells, and other marine exuvix, being found in confiderable abundance. Follow- 

 ing the example of moft mincralogifts, I might indeed have mentioned the exiftence of 

 lime as of itfelf a fufiicient proof of fubmerfion : it appears to me, however, that there is 

 bv no means evidence fulTicicnt to fupport the large adcrtion, that all the lime which forms 

 fo confiderable a part of the furface of the earth, has been a(nually produced by the proccfs 

 of animalization. The only fad that I recolleft, which has any reference to this queftion, 

 would lead one to draw a direiflly contrary inference ; it being well known that the 

 e"gs of hens are without (hells, when care has been taken in the feeding of the bird to hin- 

 der its having accefs to mortar or any other fubflance that contains a large quantity of 

 calcareous matter. Thefe tokens of the prefence of water on the tops of mountains that 

 are now 2oco feet above the level of the fea, naturally lead me to enquire into the caufe 

 of this phetiomenon, in explanation of which two hypothcfcs have been ftarted ; one, that 

 the continents were forcibly elevated to their prefcnt height above the fea by fuccelTive ex- 

 plofions, as fome of the Lipari illands are blown to have been formed ; the other, that the 

 fea has gradually, or fuddenly, fubfided to its prefent level, but that no alteration has taken 

 place in the pofition of the mountains. The extreme fcarcity of acknowledged volcanic 

 produftions feems to render the firft fuppofition highly improbable ; and it may alfo be 

 objected to it, that an immenfe power, to which we fee at prefent fcarcely any thing ana- 

 logous, is called into exiftence, to accomplifli that which the operation of common allowed 

 caufes would effect juft as well. The grand dlfijculty is to account for the difappearing 

 of fo great a quantity of water, nor indeed have I ever feen this explained in a tolerably 

 fatisfacTlory manner : it is eafy to imagine vaft chafms in the earth into which the waters 

 have retired ; but of this there is no proof whatever : it is alfo contrary to the gradual dc- 

 creafc of the fea, which, from the prefent appearance of the earth, and from hiftorical re- 

 cords, appears probable. 



IV. I he Wcldi primitive mountains in mafs contain no metals; copper, however, is- 

 found in feveral of the hornftone ftratified mountains, of which the Parys mine, and thofe 

 at Llanberris and Pont-abergladyn are examples. In thefe mines the ore is for the moft 

 part yellow fulphurct of copper : the green and blue malachites, or carbonates of copper, 

 are found in limeftone, as at Orme's-head and Llanymynech-liill ; nor have 1 heard any in. 

 ftance of thefe two laft mines furnKhing copper in any ftate but that of carbonate. Car- 

 bonated copper is alfo found in the calcareous cement of fand rocks, as has been already 

 mentioned to be the cafe at Pym-hlll and Ilawkftone in the plain of Shrewfbury. Lead 

 and calamine, I believe, are not to be found In North Wales, in any of the primitive ftratified 

 rucks. Thefe metals are moft, frequently found in (late, with a matrix however of calcareous 



fpar. 



