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which extends to the distance of several miles in the neighbourhood. 

 Under this lies a grey argillaceous stone, which feels somewhat 

 greasy, soft, and friable, and is scarcely three inches in thickness. 

 Below this there is a stratum of excellent iron-stone, of equal thick- 

 ness, the bottom of which consists of solid sand-stone, of a kind of 

 mill-stone, which often occurs in these districts. This iron-stone is 

 different from every other kind in the neighbourhood ; it is a com- 

 pact argillaceous iron-stone, of a reddish brown colour, and of a 

 rough fracture, sometimes mixed with shells ; among which there is 

 found, though very seldom, a variety which has a fibrous fracture, 

 with an almost metallic splendour, and seems worthy of further 

 examination. When I visited this work, he says, some masses of 

 this compact iron-stone were dug up, which contained charcoal. 

 This charcoal was found loose in the iron-stone, and partly grown into 

 its substance, and adhering to it. By what natural, or artificial fire, 

 this charcoal was burnt, or by what singular revolution it was car- 

 ried into the depth of from three to four fathoms, and there so inti- 

 mately combined with the iron-stone that it seems to form one body 

 with it, he observes, no mineralogist can with certainty explain. 



The hypothesis which Mr. Cramer formed respecting this singular, 

 and certainly uncommon subterranean mixture, is, that the charcoal 

 was burnt, in the neighbourhood, either in the usual manner, or by 

 natural fire, and that some fragments of it, by some convulsion of 

 nature, were thrown to the above depth, where they united with 

 the ferruginous matter, and by these means produced the above 

 remarkable phenomenon. On many fragments one can observe the 

 transition of the not completely burnt wood into iron-stone; even 

 the bark of the wood, actually converted into iron-stone, may be 

 clearly distinguished ; and the perfectly black natural, or artificial 

 charcoal, possessing all the properties of the charcoal of burnt 

 wood, lay undecom posed in it. This iron-stone, Mr. Cramer adds, 



VOL. i. oo 



