214 



under which the specimens are collected. To 

 describe their general mineral characters would 

 be little else than to repeat the remarks on the 

 overlying rocks, which have preceded. 



CLAY, SAND, MARLE, 



Marie is recognized by its effervescence ; 

 sometimes by containing fragments of shells. It 

 would be trifling to describe the characters of 

 substances so familiar as clay and sand. 



The same remarks may be made on coal, 

 alluvia, and peat ; substances, of which the cha- 

 racters are as familiar as the names. 



