EGG. GEOLOGY. 517 



division of the island it offers also less variety of structure 

 and composition ; exhibiting no where the columnar forms 

 which abound at the northern extremity. Feeble attempts 

 at regularity of form are indeed occasionally visible, but 

 in general the solid varieties are amorphous, although 

 chiefly formed of the same compact dark basalts which 

 are found in the columnar shape in other places. They 

 alternate with amygdaloidal beds, in which calcareous 

 spar, and chalcedony, with its common attendant ame- 

 thystine quartz, are the most common minerals. Me- 

 sotype and analcime also occur, but more rarely. The 

 varieties of calcareous spar are not numerous, and present 

 chiefly modifications of the primitive rhomb similar to 

 those which occur in the trap rocks of Faroe.* 



Near the cave mentioned in the subjoined note, veins 

 of very dark fine basalt occur in abundance throughout 

 the massive trap, which has here the several characters of 

 greenstone, porphyry, and amygdaloid. In the same 



* Some caves of considerable magnitude are found in the trap at the 

 south-eastern side of the island. One of these is well known as the scene 

 of a massacre committed by the MacLeods on the Macdonalds of this island 

 during the times of petty dominion and ceaseless warfare, admirers of 

 which are even now not wanting. The darkness which hangs over past 

 ages, conceals the tyranny and the misery of those times, as the mists 

 which hover on the mountain obscure its precipices and asperities ; while 

 the grandeur and the heroism of the one, are, like the altitude of the 

 other, enlarged to the eye of fancy. He who shudders at the incursions 

 of a Chickasaw or Mohawk tribe, the minute details of which are before 

 him, still admires the no less cruel warfare of a Highland clan, because 

 the circumstances which should place its atrocity full in his view are lost 

 in the obscurity of years. In the cave of the Macdonalds, and in the 

 unburied bones which strew its damp and obscure recesses, he may wit- 

 ness a proof of the horrors with which this state of society was attended. 

 Here he may contemplate the skeleton of the last survivor of this devoted 

 population, occupying the furthest crevice of the rock as the last refuge 

 from the deadly smoke, and picture to himself the agony of exertion with 

 which this ineffectual retreat was procured, until he is transported to 

 past times, and shudders as if these scenes were again to be acted and 

 as if he were himself to be the victim of an inveterate Macleod. 



