Chap. 45.] Theory of tht Earth. 305 



manner ihe known laws of nature were likely to a<5t 

 upon a mafs of materials fuch as enter into the com- 

 pofition of this globe. 



The firft principle of the law of gravitation is, that 

 the conftituent particles of all bodies attract each other 

 mutually, whence arife their common centers of gra- 

 vity. Hence all fluids aflume a fpherical form, from 

 the particles mutually attracting each other j and no 

 bodies but fluids being capable of obeying the laws 

 of gravitation, fo as to become fpherical, it is prefumed 

 that the earth was . originally in a fluid ftate. The 

 earth revolves round its center, and the centrifugal 

 force increafes in proportion to the diftance from the 

 axis of motion ; all bodies, therefore, revolving round 

 their axis in a ftate of fluidity, will necefifarily depart 

 from the fpherical form, and afiume that of an oblate 

 fpheroid. Such, by actual menfuration, is found to 

 be the form of the earth ; and this is alib demon- 

 ft rated, by aftronomical obfervations, to be the cafe 

 with all the other planets. It is therefore highly 

 probable, that all thefe bodies were originally fluid, 

 and only departed in fome meafure from the fpheri- 

 cal form, in confequence of a revolution on their 

 axis. 



It is not natural or eafy to fuppofe, that the earth 

 and planets have, fmce their exiftence, been reduced, 

 by any folvent principle, from a folid to a fluid fcate. 

 It is much more obvious to believe, that fuch was 

 their ftate at their firft creation. It follows of confe.- 

 quence, that they had a beginning, and have not exifted 

 from eternity, as fome fantaftical writers have been 

 inclined to imagine. 



If fuch was the original ftate of the earth, it fol- 

 lows, that it was at firft abfolutely unfit for animal and 

 vegetable lifej and, therefore, thefe muft have been 



VOL. II. X after- 



