COAL. 309 



yet wanting in many other parts of the world, but 

 knowledge, industry, wealth, and the stimulus of 

 want, to prove that it is a far more common substance 

 than it has hitherto appeared to be. 



Now, though I have given but a few of the locali- 

 ties of coal quoted by authors, I have suppressed many 

 more, and ought assuredly to suppress some of these. 

 Many of them are instances of the lignite formation, 

 not of the coal series under review ; but the present 

 confusion on this subject being inextricable, I shall 

 suffer the few statements which are proved to require 

 correction, to stand over to the next chapter. 



It remains to say a few words respecting the deposits 

 improperly distinguished by the term Basaltic coal, 

 equally applied to the lignites in similar positions. 

 If the peculiarities of these coal fields are highly in- 

 teresting to the miner, their geological differences are 

 simple and easily apprehended. They are analogous 

 to all the phenomena occurring where trap intrudes 

 among the stratified rocks: the only fact deserving 

 note here, being the peculiar influence which these 

 have exerted on the coal beds. They are found among 

 these, either in the shape of intersecting veins, or of 

 parallel ones, forming pseudo-strata ; being accompa- 

 nied by the usual disturbances, sufficiently described. 

 It is in these cases that coal becomes charred, or co- 

 lumnar, or is converted into plumbago ; while the 

 siliceous schists and indurated sandstones which often 

 accompany it, are analogous consequences from the 

 same cause. 



An arrangement of the varieties of coal having been 

 given in the Classification of Rocks, it needs not be 

 repeated here. The connexion of its mineral charac- 

 ters with lignite and with peat, are important, both in 

 a chemical view, and as illustrating the natural history 



