PAL.E0NT0L0GICAL REPORT OF GEOLOGICAL SURVEY. 513 



grey or reddish * The classification of the colors could not be more 

 completely reversed. 



This color of the ashes is probably, also, in immediate connection 

 with the nature of the vegetation which has formed the coal. In the 

 peat formations the matter formed by the heaping and decomposition 

 of trees gives white ash ; a compound of small herbaceous plants, 

 ferns, rushes, canes, mosses, gives red ash; and a mixture of both 

 forms the grey color of the ashes of some beds. 



The external appearance of the coal is as much varied as its chemi- 

 cal elements. The trees, sometimes, when they are very resinous, 

 have formed, by their decomposition, such a compact and homogeneous 

 mass, that the coal receives a peculiar appearance ; it is then known 

 by the name of cannel coal. Another species of wood preserves, 

 even in the coal, some trace of its primitive texture, and shows, in its 

 fracture, a peculiar reflection of light, called, by the miners, the birds 

 eye. 



The coal is mostly stratified in thin laminae or coats, alternately 

 shining and dull — an appearance which clearly indicates an annual de- 

 posit of decayed vegetable matter, and the action of the water on it, 

 during the winter time, or before the beginning of a new vegetation. 

 The stratification of peat is exactly the same as that of coal ; but the 

 layers are variable in thickness, from the sixth of an inch to one inch 

 and more, becoming natuarally thinner under a great compression, and 

 nearer to the bottom of the beds. 



The laminated appearance of coal is already a proof against the of- 

 ten repeated opinion, that it has been formed by the overthrow of vast 

 forests; but there is a more conclusive argument against it. One 

 acre of ground, covered with dense forest, and when its yield is care- 

 fully estimated, would afford, in 120 years, 10,450 cubic feet of wood; 

 supposing the growth of peat to be only one foot in the same number 

 of years, one acre of bog would produce 19,660 cubic feet of peat, 

 (measured dry, and ready for burning.) A thick forest, overthrown 

 by a cataclysm, and buried in the sand, would scarcely make three 

 inches of coal. But some peat-bogs of Ireland, Germany and Switzer- 

 land, which have continuous beds of peat twelve to fifteen feet thick, 



•Table of analyses of coal from saline and other localities, in the Geological report of sa- 

 line eoal mines and Manufacturing Co. p. 60, by D. D. Owen, Cincinnati, 1855. 



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