21, YORKSHIRE. 331 



Where the furface has been free from mofs 

 or other vegetable produftion, the accumu- 

 lated matter is WHOLLY calcareous; of a 

 light colour, refembling the marl of Nor- 

 folk, except in its being difcoloured more 

 or lefs with a chalybeat tinge. Where mofs, 

 liverwort, and other veo-etables have been 

 incruflcd, a stone-like substance is form- 

 ed : the former is called " marl," — the latter 

 ** flone.'* 



At prefent, the face of the flope is hol- 

 lowed out into great irregularity, by digging 

 for and carrying away the mcrl, leaving 

 maffes ^of 7?^;?f, fome of them containing 

 many cubical feet, {landing above the pre- 

 fent furface. 



Thcfe ftones, though light, being full of 

 hollowneffes within — mere bundles of mofs 

 and algcE — -have, by being long expofed on 

 the furface, acquired a very great degree of 

 hardnefs, their fmallcr afperities being with 

 difficulty brol:en off. 



By immcrging the fragments in the acid 

 of fea-falt weakly diluted, the calcareous in- 

 cruftation is Icifurciy diffDlvcd, leaving the 

 vegetable matter entire, and to appearance 



as 



