PHYSIOGRAPHY. 61 



Bituminous Coal. 



Creek in Munroe co. (Ohio,) and in Liverpool in the same state, where 

 a salt well, while boring, yielded about fifteen gallons per day. In New 

 York, it is found floating upon the surface of Seneca Lake, and is hence 

 known in commerce under the name of Genesee or Seneca-Oil. In Wood- 

 bury, and some other places in Connecticut, the Elastic Bitumen is found 

 in connexion with a bituminous limestone. The black limestone in the 

 vicinity of Quebec affords exudations of Petroleum. 



6. The different varieties of Bitumen allow of considerable application 

 for illuminating, for fuel in fire-works, in the manufacture of varnish and 

 of black sealing-wax. Mingled with grease or common pitch, it is used 

 for paying the bottoms of ships. The ancients employed Bitumen in the 

 construction of their buildings; the bricks of which the walls of Baby- 

 lon are built are cemented with hot bitumen. The Egyptians are also 

 said to have employed it for the embalming of bodies. 



BITUMINOUS COAL. Bituminous Mineral 

 Coal. MOHS. 



No regular form or structure. Fracture conchoidal, un- 

 even. 



Lustre resinous, more or less distinct. Color black or 

 brown, passing in earthy varieties into greyish lints. Some- 

 times exhibits tarnished colors. Streak unchanged, except 

 that it sometimes becomes shining. Opake. 



Sectile, in different degrees. Hardness =!(). .. 2-5. 

 Sp. gr. = 1-223, moor-cod from Teplitz ; = 1-270 com- 

 mon brown coal from Eibiswald in Stiria ; =-1-271, black 

 coal from Newcastle ; =1-288, bituminous wood; 1-423, 

 cannel coal from Wigan in Lancashire. 



Compound Varieties. Massive : composition lamellar, 

 faces of composition smooth and even, different gradations; 

 granular texture often impalpable, in which case fracture is 

 uneven, even or flat conchoidal. Ligniform shapes, the 

 structure of which resembles that of wood, sometimes very 

 distinct, but often obliterated, with the exception of some 



6 



