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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 exa- 
mination. 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 carried into 
the depth of from three to four fathoms, and there so intimately com- 
bined 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, were they united with the 
ferruginous matter, and by these means produced the above remark- 
able phenomenon. On many fragments one can observe the tran- 
sition 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 
undecomposed in it. — This iron-stone, Mr. Cramer adds, is exceed- 
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