LETTER I. 21 



little narrowly on the Sand, I found feveral white 

 thin Shells of the fame breadth, fliape, and fize' 

 filled with Sand, or Gravel, and alfo with ftiffifh 

 Clay of different Colours j the Clay of feveral 

 having, I fuppofe, been lodged there for a little 

 while only, was fomewhat brittle ; in others, the 

 Clay having lain longer was of courfe the firmer 

 and tougher ; and in fome others, where the thin 

 Shell wasalmoft decayed, I found the Clay to 

 be fo ftrongly cemented together, that it was 

 fomewhat difficult to break it with the hand. 

 Pray then why might not that Stone I fent you to 

 Cambridge be one of thofe pieces of Clay thus 

 preferved fo long as till petrified? I know your 

 opinion is. That they were formed in fuch Shells 

 at the time of the Deluge. 



/ am^ Sir^ Tour &c. 



w. s. 



B 3 L E T- 



