E S S A .Y S 



AND 



O B S E R V A T I O N S, 

 PHYSICAL AND LITERARY, 



A R T I C L E f . 



An EJfay on Mark, by the late DoSIdr AiNSLifi 

 Thyfidan. 



INTRODUCf ION. 



IN many parts of this country the value 

 of land has of late been greatly raifed 

 by the application of marie. It is di- 

 vided into fhell-marlc and earth-marle. 

 Shell marie is compofed of animal fliells 

 dillolved. Earth-marle is a foffil. Its 

 colour is various ; white, blue, black, 

 red. Its hardnefs is as various as its co- 

 VoL. HI. A Idur; 



