AND OBSERVATIONS. 



113 



a fragment of syenite, with large and beautiful 

 crystals of hornblende, and also very distinct ones of 

 sphene. Near Lochnell, there is a rock of granular 

 quartz with a slaty structure, resembling a fine 

 grained sandstone. A similar rock occurs at Airds 

 and Portnacroich, where it is frequently quarried 

 for building. 



Lismore.- — The island of Lismore is composed 

 of foliated granular limestone, with small crystals 

 of iron-pyrites, evidently subordinate to, and exhi- 

 biting the characters of, the great clay-slate forma- 

 tion, which extends as far as Easdale on the south- 

 west, and through the district of Appin to Balahu- 

 lish on the north-east, and even farther in that di- 

 rection. The rock, in many instances, appears to be 

 only clay-slate, with a greater than usual proportion 

 of lime. Lismore seems to have been a favourite 

 spot in former times, and was long the seat of the 

 Bishop of the Isles, the remains of whose residence 

 are still to be seen. 



Balahulish. — But by far the most interesting 

 field of observation which occurs in this direction, 

 is the district around Balahulish. Here granite 

 and syenite appear together, followed by gneiss, mi- 

 ca-slate and clay- slate, which occur in succession. 

 The granite and syenite are found to the east and 

 south-east of the proprietor's house, and of the inn, 

 both situated on the south side of Loch Levin. I dk 

 covered the junction of the granite and adjoining 

 gneiss or mica-slate on the height, about a mile east- 



VOL. III. h 



