DOMAIN VI. CARBONACEOUS. 



pitch. Its specific gravity is 1,259. It is said 

 to be sometimes lighter than water*. 



" This variety is found in layers of little thick- 

 ness, in marly, schistose, calcareous, or sandy 

 beds. The organic tissue of wood is sometimes 

 observed in it. 



" This lignite is found in France; in Pro- 

 vence; at Belestat, in the Pyrenees; in the de- 

 partment of the Audef, near the village of Bains, 

 six leagues to the south of Carcassone ; this 

 sometimes contains amber; and near Quilian, 

 in the same department, in the communes of 

 Ste. Colombe, Peyrat and Bastide ; it is at the 

 depth of 10 or 12 yards, in oblique layers, be- 

 tween beds of sandstone; but these layers are 

 neither pure nor continuous. Jet, proper to be 

 worked, is found in masses, the weight of which 

 seldom exceeds 50 pounds. These mines have 

 been wrought for a long time, and have pro- 

 duced a considerable quantity of jet, which is 

 cut and polished in the same country. 



cc In Germany, near Wittemberg in Saxony ; 

 it is also there wrought and polished. Very 

 fine jet has been found in Spain, in Galicia, and 



" * I doubt if real jet be ever lighter than water. This property 

 seems rather to belong to the next variety." 



f An account of the manufacture of jet, in the department of the 

 Aude, may be found in the Jour, des Mines, No. 4, p. 35. P- 



