328 



PALEOZOIC TIME — CARBONIFEROUS AGE. 



The coal .itself varies much in character. In some regions, as in 

 the Schuylkill (at Pottsville, Mauch Chunk, etc.) and Wilkesbarre 

 coal fields, at Peak Mountain, in Virginia, and in Ehode Island, 

 it is of the kind called Anthracite (see page 68), which is non-bitu- 

 minous, and burns with very little bluish flame. At Pittsburg, and 

 through nearly all of the Appalachian coal field, and in the other 

 coal areas of North America, it is Bituminous coal, which burns 

 readily with a bright-yellow flame. 



The bituminous coal is either the ordinary brittle kind, break- 

 ing into lustrous angular pieces, or the compact Cannel coal, dis- 

 tinguished by its firmness, slight lustre, conchoidal fracture, and 

 the absence of any laminated structure. Cannel coal often gra- 

 duates into ordinary bituminous coal. 



In many places there are vegetable remains in the coal itself, 

 such as impressions of the stems of trees, or leaves, or charcoal- 

 like fragments which in texture resemble charcoal from modern 

 wood. Fig. 561 a represents a specimen of this kind from Tusca- 

 loosa, Ala., as figured by Bunbury : it has a fibrous appearance to 

 the naked eye, but under a pocket-lens shows rectangular meshes 

 over the whole (fig. 561 b), like the structure of the leaves of some 

 water-plants. 



Even the solid anthracite has been made to divulge its vegetable 

 tissues. On examining a piece partly burnt, Professor Bailey 



Fig. 561. 



Fig. 562. 



found that it was made up of carbonized vegetable fibres. The 

 annexed figures 562 a, b, c, are from his paper on this subject. He 



