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which had been immersed in water, and had suffered decay. 

 But he soon, however, changed his opinion, when he considered, 

 how prodigiousthe quantity was of which it consisted ; which, he 

 thought, must have been vastly beyond what could have been fur- 

 nished by any forest. Again, had it been of diluvian origin, he ex- 

 pected, that he should have found the vegetable ruins scattered, in 

 detached and irregular masses ; but here the vein of bituminous 

 matter had, every where, an uniform appearance, and constantly 

 preserved the same rectilinear course, undisturbed by the inequa- 

 lity of the mountain. Besides, in this wood, he could discover no 

 transverse fibres ; nor could he find with it either bark, branches, or 

 leaves. From these circumstances, he was induced to relinquish 

 the opinion, that it had ever belonged to the vegetable kingdom ; 

 and concluded it to be entirely of mineral origin. Bitumen possess- 

 ing, in his opinion, a peculiar innate, and to us a hidden power of 

 coagulating and assuming the form of wood ; this being a work not 

 of the subterranean archceus, but the result of a specific power in- 

 herent in the bitumen. 



Above and beneath this stratum of bituminous matter, is a bed of 

 very fine potter's clay, about six feet thick, which keeps the same 

 horizontal level, and passes along with the fossil wood, directly in a 

 straight line, through every recess of the mountain, neither rising or 

 declining with its slope *. 



Francisco Stelluti, in 1637, described some strata of fossil wood, 

 found near Todi and Aqua Sparta, in Umbria ; the description of 

 which exactly accords with the kind which we are at present ex- 

 amining, in its consisting of large oval and compressed pieces, lying 

 horizontally, resembling the trunks of trees, but larger, some being 

 above three feet broad ; in having neither roots, branches, nor fibres, 

 but something like bark ; and something resembling the heart of 



* Bitumen et lignum fossile bituminosum descriptum a D. Matthia Zaccharia Pil- 

 lingen, medico Altenburgensi. Altenbergi, anno 1674. 



