JURA. GENERAL DESCRIPTION. 183 



give a smooth outline to the declivities. An extensive 

 view of the northern islands, and of the coast of the 

 mainland, is to be obtained from these summits, of 

 which Ben an Oir is by much the most easy of access. 

 To the geologist, this landscape, various and splendid 

 as it is, will be less interesting than the perfect display 

 hence visible, of the structure and disposition of the 

 rocks which form the island itself. The continuity of 

 the strata, and the irregularities in the outline of the 

 general ridge, can be distinctly seen from one or other 

 of these summits, and best from the most northern ; 

 whence it is easy to trace that continuity for a con- 

 siderable space northward, even across the Coryvrechan 

 to Scarba. 



The soil of Jura partakes of the barrenness of the 

 rock on which it lies ; being sandy, and, from the 

 wetness of the climate and want of ready drainage, 

 much encumbered with peat. It contains but little land 

 really arable, and is chiefly employed in the rearing 

 of black cattle. 



Some insignificant lakes are found in the vicinity of 

 the high mountains ; and one or two streams, scarcely 

 to be dignified with the name of rivers, flow into the 

 sound which separates it from Isla; descending from 

 the Paps and, being, from the general moisture of the 

 climate, permanent. There appear to be no alluvia or 

 extraneous rocks worthy of regard : the geological interest 

 of the island is comprised in the very admirable exposition 

 which it affords of that important member of the primary 

 strata, quartz rock; which forms the basis, and indeed 

 the principal part of its structure. 



INDEPENDENTLY of its geology there are some cir- 

 cumstances connected with the natural history of Jura 

 which are deserving of notice. 



It has been said to abound in vipers, like Lamlash 

 and other islands ; in corroboration of which Mr. 



