272 ON THE MINERALOGY OP DI8K0 ISLAND. 



19. Ferruginous Clay, of a reddish-brown colour, the Eisen- 



thon of Werner. 



20. Bolus, in small veins. 



21. Bituminous Wood, very rarely in minute beds, in wacke 



and basalt. 



22. Brown-coal. 



23. Pitch-coal, above described. 



The Primitive Rocks, which constitute some small islands on 

 the south side of Disko, are very rarely accompanied with any 

 of the simple minerals. The Felspar of the granite sometimes 

 becomes opalescent; the granite contains occasionally com- 

 pact and prismatic Epidote, also Diallage and Tourmaline ; at 

 Kangek it sometimes, but very rarely, contains some cubes of 

 Pyrites ; and in one place, I observed Magnetic Iron, in no- 

 dules, mixed with it. In the islets of Fortune Bay, I noticed 

 some specks of the green oxide of Copper in the micaceous 

 schistus. 



XX. 



