MODE IV. LIGNITE. 589 



which seems to be entirely formed of it; and 

 near Vitry, on the banks of the Seine, there is 

 a thick bed of trunks of trees well preserved 

 (Gillet Laumont). In the department of Arriege, 

 the clefts, of this lignite are penetrated with 

 sparry carbonate of lime. In Liguria, near Cas- 

 tel-Nuovo, at the mouth of the Magra, it is in 

 thick and very extensive beds. In Hessia, near 

 the mountain of Ahlberg, the layer is two yards 

 thick. In Steinberg, near Munden in Hanover, 

 it forms two layers, one 10 yards, and the other 

 six, which are separated by a bed of rock from 

 12 to 14 inches thick. In England, at Bovey 

 near Exeter, there are 17 thick beds, which are 

 at a depth of about 66 feet, under sand, and in 

 potters clay. In Iceland it is very abundant, 

 and is called surtitrbrand ; the trunks which 

 form these heaps are very distinct, and seem 

 merely to have been compressed. 



" But this lignite is still more common in little 

 detached masses ; sometimes it accompanies the 

 preceding varieties ; sometimes it is found alone, 

 in small layers, in the midst of beds of argil or 

 of sand. It is met with almost every where, and 

 is used as fuel in those places where it is abun- 

 dant. 



" This vegetable, rather than mineral com- 

 bustible, being scarcely decomposed, would not 



