of the Earth. 



found enclofed in it in prodigious num- 

 bers ; whereas of Oyfter-ftiells, (which 

 are in Gravity but as about 2 ^- to i) of 

 Echini (which are but as 2 or 2^ to i) 

 or the other lighter kinds of Shells ^ 

 icarce one ever appears therein ; but^ 

 on the contrary, in Chalk ( which is 

 lighter than Stone, being but as about 

 2 To to i) there are only found Echini^ 

 and the other lighter forts of Shells ; 

 it being extreamly unufual to meet 

 with fb much as one fingle Shell 

 of any of all the heavier kinds amongft 

 Chalk; but for the laid Echim^ and 

 other the lighter forts of Shells^ they 

 are very numerous and frequent, in ail 

 the Chalk-pits of Kfnt^ Surrey^ ^J[^^^ 

 Hartford/hire , Bark/hire , Oxford/hire , 

 and all others that I have fearch'd ; be- 

 ing found indifferently in the beds of 

 Chalk from the top quite down to the 

 bottom of the Pit; I having my feif 

 commonly obferved them to the very 

 bottom of all, in Pits that were an 

 hundred foot deep, and in Wells much 

 deeper. To conclude ^ thofe Shells, 

 and other Bodies, that were ftill light- 

 er than thefe, and confequently lighter 

 than Stone, Chalk, and the other 

 common Matter of the Earth, fuch as 



