164 Kew Fuhllcailoiis. 



The IiitroduSion ftates, that, in compofing the following 

 fyftcm, the author has been careful " to attribute no effeft 

 to anv caufe of which the known powers arc inadequate to 

 its produdion," as well as " to alledge no caufe vvhofe ex- 

 iftence has not been proved to him by experience or credible 

 teftinionv." 



In the firft ElTav he obferves that the earth could not 

 have alfumed the form of a fpheroid comprelfed at the poles, 

 if its fupcrficial parts had not originally been, to a certain 

 depth, in a foft or liquid fiate ; and that the lower ftrata of 

 primitive calcareous rocks being, in proportion to their depth, 

 coniinually thinner than thofe which red upon them, equally 

 evince the whole to have been formerly in a foft ftate, and 

 to have yielded to compreflion while they were dried and 

 hardaned. He therefore fuppofes the fuperlicics of the globe 

 to have been univerfally fluid, its interior compofition folid 

 and cavernous, at the time when the prefcnt laws began tq 

 operate upon it. The fuperficial fluid he conceives to have 

 been heated at lead to 33° Fahr. Diflolved or fufpcndcd in it 

 were portions of the eight generic earths, of all the known 

 metallic fubftances, of all the fimple falls, and of all inflam- 

 mable matters folid and liquid. Siliceous earth and iron were 

 of all the folid materials in the mixture the mod copious. 

 Calcareous earth mud even then have cxiRed, for it' is a 

 component part in many primitive rocVs. As the fluid mafs 

 was moved ; as its heat pafled into new combinations ; as 

 the eleiSlive attra£lions of its various materials began recipro- 

 cally to operate; the folidifiable materials were precipitated 

 in ihe order of their affinities, fomewhat didurbed by the me- 

 chanical agency, which at the fame time ueceiTarily affefted 

 them. In their precipitation they were univerfally cryftal- 

 lifed. Where filiceous and argillaceous earths chiefly abound- 

 ed, quartz, fckl-fpar, and mica, were confufedlv depofited in 

 ftrata of granite and gneifs. One'depolition fucceeded an- 

 other till vgd uniform blocks were formed. Carbon, iron, 

 and others of the folidifiable materials of the chaotic flood, 

 were unavoidably involved with the fubfiding flony particles. 

 Where the matjrials were intermingled in dirferent propcn-- 

 tions, other forts of primitive rv'x'k, luch as filiceous Icliidus, 



filiceous 



