MULL. GEOLOGY. 559 



can scarcely be discovered from the appearances visible 

 in this island. But they may be deduced from analogy, 

 and from an extensive comparison with each other and 

 with the adjoining shore of Morven. From these it follows 

 that the limestone is most probably the lowest of the series, 

 and I shall accordingly commence the description from the 

 most extensive portion of that rock which occurs.* 



This substance is so difficult to recognise among the 

 trap in which it lies, although extending for many miles, 

 that it has hitherto been confounded with that rock by 

 those who have examined this island,^ and is equally 

 unknown to the people of the country. The length of 

 its range may be seen in the map, but it must be remarked 

 that the belt of colour by which it is indicated is not 

 meant as the measure of its breadth, since it occupies 

 no space horizontally, being only seen in the vertical 

 faces of the cliffs. This expedient, as in the map of 

 Sky, is however unavoidable. In tracing the southern 

 shore of the island from Loch Don, trap only is found 

 for a considerable space. But at a point to the east 

 of Loch Speliv, the limestone commences and continues 

 to Loch Buy, being interrupted in its course only by 

 the opening of the former inlet. Along the whole of 

 this range it occupies the lowest position on the shore; 

 projecting near the "level of the sea so far from the cliffs 

 as in general to admit of a passage along their base, 

 when the state of the weather does not prevent a boat 

 from occasionally landing so as to assist the observer 

 in passing some of the most difficult points. It is not 



Plate XX. fig. 11,12. 



f No censure is implied by this remark. He who has experienced 

 the difficulties which the geologist must encounter in this almost inac- 

 cessible country, has felt the toils and privations that must be endured, 

 and knows the obscurity in which the subject is here peculiarly involved, 

 is more likely to ofter the apology of those who have left any thing 

 undone, or have misconceived the nature of the appearances before them. 

 He knows not how soon he may himsnlf want the same indulgence. 



