it Manures, 5. 



This is a flrong evidence of the utility of 

 chemical knowledge in the inveftigation of 

 fofTil manures. 



Before I left the county, I coUeded a va- 

 riety of fpecimens of marls, clays, and foils 

 of different parts of it. Thefe, with a ftill 

 greater variety which I have colleftcd in 

 other parts of the kingdom, I hope to find 

 leifure, at fome future time, to analyze-, and, 

 from the refults, endeavour to draw fome ge- 

 neral inferences. 



At prefent I Hiall confine myfclf to 



1. The chalk-marl of Thorp-market, in 

 the Hundred of North-Erpingham ; 



2. The clay-marl of Hemfby, in the Hun- 

 dred of Eaft-Fleg; 



3. The foft chalk of Thorp-next-Nor- 

 wich J commonly called Norwich marl ; and 

 to 



4. The hard chalk of Swaffham. 



I. Chalk-marl of Thorp-Market. 



The natural fituation of the white marls of 

 this Diftrld is Angular : they do not lie in 

 ftrata, as foflils in general do ; — nor in a con- 

 tinuation of rock^ like chalk and limeftone ; 



but 



