2 • Elevation and Subsidence, 



n,!so be found in some of tlie other articles many things not heretofore puT>- 

 lished. The latter cannot be well interpreted, without the assistiincc of tho 

 former. It generally requires all the old knowledge to explain new dis- 

 coveries, and therefore for the convenience of the larger class of readers, we 

 must trespass> somewhat upon the patience of the lesser number. 



To understand clearly, the nature of those causes that have produced at 

 various times, the great beds of rock, which constitute the exterior layers of 

 the earth's crust, is not difficult, provided the attempt be made in the right 

 direction ; and yet this knowledge remained undiscovered by man, until near 

 the commencement of the present century. Strange as it may appear, thc- 

 eluc to the history of vast mountains and even whole continents of stone, 

 was not found where It would be naturally sought for, in the mineral por- 

 tion > of our planet, but where it could be least suspected of lying concealed, 

 in the study of the animal kingdom. Geologists have succeeded in discov- 

 ering and explaining the structure of the globe, for a distance of several railes- 

 beneath the surface ; but these triumphs of science were only accomplished, 

 through the assistance afforded by the organic remains, imbedded in the dif- 

 ferent formations. The study of these relics of ancient life, is therefore not 

 only of great interest, but also of an importance nearly equal to all the ad- 

 vantages that countries rich in mineral treasures may derive fi*om such re- 

 sources. 



In the earlier ages of the existence of the human race, it had become 

 known that in certain regions^ sea-shells, lx)nes of fishes and other reraaias- 

 of marine animals, were to be found, upon the dry land, in places far from 

 the shore, upon the summits of lofty hills, or deeply buried in the solid rock, 

 and facts of so extraordinary a character, could not but have given birth to 

 a vast deal of discussion. The history of geology, should properly com- 

 mence at that moment when the first inquiring persou began to wonder by 

 what process these exuvia3 of the sea came to occupy positions apparently 

 so anomalous. What those speculations may have been, we can never know ; 

 — the thought permitted to pass away unrecorded, must be lost forever. 

 Doubtless many theories w^ere conceived, but they liave not, and perhaps it 

 is not important timt they shou'd liave been preserved. 



Among the anc-icat Urcciansj the idea of the elevation and subsidence of 

 land, or that it s.ynietiin^\s sinks down and after lying for a time, beneath the 

 waves rises a.'^iiin, bringjtig.upvWth it, the deposit of marine remains accu- 

 mulated up)n it while, submorgeii appears to have been much favored by' 

 their ab est. piiilosophers. Tiin&'Av^stotlc in one of his works, says " the 

 <listributi:.-iji of land and sea Inparftcuiai- regions, does not endure throughout 

 all liaie, but it becomes sea \u ihose parts where it was land, and again it 

 becomes }:inJ w'.u.Te it was sea ; and I here is reason for thinking that these 

 changes take p'ace according to a certain system, and within a certain pe- 

 riod ;" •' neither the Tana's nor the Nile, can have flowed forever. The 

 places where they rjie were cnco dry, and there is a limit to their opera- 

 ti :)ns ; there is Jione to time. So also of all other rivei'S ; they spring dp. 

 and they ]).'rish, an.l the sea a' so continually deserts and invades others.— 



