558 MULL. GEOLOGY. 



Kenneth and those which I have just described as found 

 at the Ross ; leaving no doubt that they form a portion 

 of the series already discussed. It is equally probable 

 that the whole of these are parts of the gneiss which 

 constitutes the adjoining mainland of Morven and the 

 islands to the westward ; disjoined, as in Sky, by the trap 

 which forms the bulk of the island. 



At a point which I can only mark by saying that it 

 occurs where StafFa and the rock of Ardnishker are seen 

 in one line, these strata suddenly disappear in the upper 

 parts of the clifF, being apparently overwhelmed by the 

 slope resulting from the fall of decomposed trap from 

 above. But they are still seen for a space along the 

 shore, and finally terminate where the point of the Ross 

 of Mull cuts the cathedral of lona. The trap rocks then 

 occupy the whole shore; but I must delay any remarks 

 on them until I have described the remainder of the strati- 

 fied rocks with which they are connected. 



The next in order are the secondary strata. These 

 occur but in small quantity, and occupy positions so 

 disjointed and obscured by the trap rocks, that it is 110 

 less difficult to describe than it is to discover them. When 

 it is recollected how often chance must conduce to the 

 discovery of rocks so insulated, it will not be surprising 

 if some have escaped my notice. Such omissions are, in 

 a geographical view, blemishes which it would be desire- 

 able to correct ; and where such materials as sandstone 

 and limestone are in question, they may be serious defects 

 in an economical view. But a survey that shall accom- 

 plish every thing, must be a work of time; nor will 

 any thing be contributed towards it by him who fearful 

 of being wrong where it is as yet impossible to be always 

 right, and unsatisfied with the best he is able to attain, 

 delays the record of his observations to the period of 

 perfection. 



The relations which the disjointed substances that form 

 these strata, bear to each other and to the primary rocks, 



