THE SCHISTOSE ISLANDS. 107 



still remain in their history. These detached parts are 

 even more useful in connecting the islands that consist 

 of stratified rocks, with each other and with the coast, 

 than in approximating the masses of trap; a rock, it is 

 probable, which is often originally of an insulated and 

 partial nature. By tracing in succession the several 

 islands here ranked, as nearly as possible according to 

 their geographical and physical relations, by attending 

 to the connexions indicated by the various scattered por- 

 tions, and by examining the neighbouring coasts of the 

 mainland, a continued series may be established; which 

 will be found interesting whether simply considered as 

 proving an existing regular order, or as indicating past 

 changes, from which their continuity has been broken, 

 and the coasts have received their present forms. 



It is proper here to remark, that the order adopted in 

 describing them, is not conformable to the one elsewhere 

 followed; namely, that of commencing with the rocks 

 lowest in position, and thence proceeding upwards 

 according to the succession of the strata. But there 

 is no particular convenience in this case in adhering to 

 the general rule ; besides which, the history of the western- 

 most isles of this group will be far more intelligible by 

 treating the whole in the order here followed. 



The advantages of any particular order arise chiefly 

 from its giving a fixed point of departure. This may 

 sometimes be found as conveniently in the uppermost as 

 in the lowermost rocks ; while, independently of the reason 

 above assigned, the connexion of Inish Capel and of Ker- 

 rera with Mull, renders it convenient to commence with 

 those islands. Thus the chain of connexion with the con- 

 tinental land will be more easily preserved ; a connexion 

 which the claims of physical geography render it at all 

 times desirable to maintain when possible. 





