J.OXGA. GEOLOGY. 42.5 



supposed to alternate with the same rock. As this pheno- 

 menon is important and in need of explanation, while the 

 appearances are in themselves insufficient for its eluci- 

 dation, I shall defer the inquiry till I have examined 

 Scalpa, where the same facts are found in a more approxi- 

 mate and consolidated order. 



I may conclude this article by mentioning, with the 

 same general views, that the rock Scuir Dearg, lying to 

 the north-west of this island, is also formed of the red 

 sandstone ; thus adding another point to the very few 

 from which the general connexion between these islands 

 and the adjoining mainland must be established. 



