2i8 THEORY of the EARTH. 



and for the afcertaining this portion of time, we muft again 

 have recourfe to the regular operations of this world. We 

 fhall thus arrive at facts which indicate a period to which no 

 other fpecies of chronology is able to remount. 



IN what follows, therefore, we are to examine the conftruc- 

 tion of the prefent earth, in order to underftand the natural 

 operations of time pad ; to acquire principles, by which we 

 may conclude with regard to the future courfe of things, or 

 judge of thofe operations, by which a world, fo wifely ordered, 

 goes into decay ; and to learn, by what means fuch a decayed 

 world may be renovated, or the wafte of habitable land upon 

 the globe repaired. 



THIS, therefore, is the object which we are to have in view 

 during this phyfical inveftigation ; this is the end to which are 

 to be directed all the fteps in our cofmological purfuit. 



THE folid parts of the globe are, in general, compofed of 

 fand, of gravel, of- argillaceous and calcareous ftrata, or of the 

 various compofitions of thefe with fome other fubflances, which 

 it is not neceflary now to mention. Sand is feparated and 

 fized by firearm and currents ; gravel is formed by the mutual 

 attrition of ftones agitated in water ; and marly, or argillaceous 

 ftrata, have been collected, by fubfiding in water with which 

 thofe earthy fubftances had been floated. Thus, fo far as the 

 earth is formed of thefe materials, that folid body would appear 

 to have been the production of water, winds, and tides. 



BUT that which renders the original of our land clear and 

 evident, is the immenfe quantities of calcareous bodies which 

 had belonged to animals, and the intimate connection of thefe 

 mafles of animal production with the other ftrata of the land. 

 For it is to be proved, that all thefe calcareous bodies, from the 

 collection of which the ftrata were formed, have belonged to 

 the fea, and were produced in it. 



WE find the marks of marine animals in the moft folid parts 

 of the earth, confequently, thofe folid parts have been formed 



after 



