596* DOMAIN VI. CARBONACEOUS. 



and they may be said almost to consist of fos- 

 sile wood. Another near Altendorf, on the bor- 

 ders of Hessia, about 1800 feet in height, pre- 

 v sents vast quantities of fossile wood, under a stra- 

 tum of stone, not less than from 80 to 140 yards 

 in thickness *. 



Bovey coal. One of the most remarkable lignites is the Bo- 

 vey coal of England, already mentioned. Dr. 

 Kidd observes, that it is attended with a kind of 

 porcelain clay, derived from the waste of the 

 adjoining granite hills, subsiding into this heath, 

 which is a natural basin f . The sandy quartz, 

 and fragments of felspar, correspond with those 

 of the adjacent granite. This lignite often rises 

 in the form of trees, but is often compressed in 

 straight flat pieces, three or four feet in length, 

 which are called board-coal, from a natural re- 

 ' semblance; an observation which may also be 



* Parkinson, Org. Rem. vol. i. He supposes that petrified wood 

 passes through a bituminous fermentation, after which it is saturated 

 with water full of siliceous particles. See also ii. 285, where he 

 adds, that animal matter, by long residence in water, was first con- 

 verted into the adipocere of Fourcroy, resembling spermaceti. This 

 ingenious writer has also observed, i. 364, the presence and in- 

 fluence of bituminous matter in the semi-opal, and other stones of a 

 waxy lustre ; so it may enter into the opal. But as Klaproth only 

 found inflammable matter, may not the carbon, which forms a large 

 proportion of bitumen, here exert its power? 



* Outlines, i. 166. 



-. 



