214 THEORY of the EARfH. 



actual exiftence is well known, but of which the proper ufe in 

 the conftitution of the world is ftill obfcure. 



WE have thus furveyed the machine in general, with thofe 

 moving powers, by which its operations, diverfified almoft ad 

 infinitum^ are performed. Let us now confine our view, more 

 particularly, to that part of the machine on which we dwell, 

 that fo we may confider the natural confequences of thofe ope- 

 rations which, being within our view, we are better qualified 

 to examine. 



THIS fubject is important to the human race, to the pofTeflbr 

 of this world, to the intelligent being Man, who forefees events 

 to come, and who, in contemplating his future intereft, is led 

 to enquire concerning caufes, in order that he may judge of 

 events which otherwife he could not know. 



IF, in purfuing this object, we employ our fkill in refearch, 

 not in forming vain conjectures ', and if data are to be found, 

 on which Science may form juft conclufions, we fhould not long 

 remain in ignorance with refpect to the natural hiflory of this 

 earth, a fubject on which hitherto opinion only, and not evi- 

 dence, has decided : For in no fubject is there naturally lefs de- 

 feel: of evidence, although philofbphers, led by prejudice, or 

 mifguided by falfe theory, have neglected to employ that light 

 by which they fhould have feen the fyftem of this world. 



BUT to proceed in purfuing a little farther our general or pre- 

 paratory ideas. A folid body of land could not have anfwered 

 the purpofe of a habitable world ; for a foil is necefTary to the 

 growth of plants j and a foil is nothing but the materials col- 

 lected from the definition of the folid land. Therefore, the 

 furface of this land, inhabited by man, and covered with 

 plants and animals, is made by nature to decay, in diffolving 

 from that hard and compact flate in which it is found below 

 the foil ; and this foil is necefTarily wafhed away, by the con- 

 tinual circulation of the water, running from the fummits of 

 the mountains towards the general receptacle of that fluid, 



THE 



