146 i III. DIST. CHAR. Substance. 



with a brown calcareous spar. 

 Common pit coal. Kirw. p. 52-57. F. Veg. 

 Common pit or slate coal frequently consti- 

 tutes the substance of vegetal petrifac- 

 tions f. 



Mineral charcoal, James, p. 90. F. Veg. This 

 substance sometimes forms the matter of extra- 

 neous fossils,, after its original woody texture 

 has been obliterated, v. Note, p. 52 f f. 

 c. 104. THE METALLIC MINERAL SUBST. (Suh- 

 stantia miner, melallica) of an extraneous fossil 

 is usually an ore of iron ; more rarely of cop- 

 per, silver f gold, quicksilver, lead, or zink. 



Obs. Metals when found in the earth in a pure 

 or simple state are called native when their respec- 

 tive metallic properties are lost by a combination 

 with other matter,, they are said to be mineralized, 

 and the compound is called an ore Earths and 

 stones,, when they contain metallic substances ( either 

 native or mineralized} in a certain proportion are 



f* A contrary assertion has been advanced by one of our most 

 distinguished mineralogists. But every praclical coal-miner in 

 this kingdom must repeatedly have observed pit-coal under an 

 organic form that is, not merely with impressions of vegetal 

 forms, confined to the surface of the stratum, but with the mass 

 or body of the coal actually constituting the substance of petri- 

 factions. 



tt Bovcy coal is not enumerated under this section, as it re- 

 tains the texture of the original wood. We consider it as an or- 

 ganic substance constituting reliquia, not as mineral, v. p. 135. 

 A. 96. 



