112 MINERALOGICAL NOTICES 



the stratified structure may still be discerned ; but 

 the specimens are porous, resembling pumice-stone ; 

 and so light, that some of them are found to swim 

 in water. 



That they have undergone the action of fire, can 

 hardly be doubted, when it is known, that no such 

 mineral is found in Scotland except on the site of 

 Beregonium, which has many appearances of having 

 been a vitrified fort. And to this may be ascribed 

 the tradition respecting its destruction by fire; 

 not to any volcanic appearance that can be observed 

 on the neighbouring hill. The mistake on this 

 subject, seems to have been occasioned by the wild 

 and rugged aspect of the conglomerate rock, decom- 

 posing and tumbling down in huge fragments. 



It is said, that the remains of wooden pipes have 

 been discovered under ground, which had conveyed 

 water to the fort from the hill now mentioned. If 

 this be fact, we may date the existence of Beregoni- 

 um as long subsequent to the Horn an period of our 

 history. It had, probably, been distinguished as a 

 residence or stronghold of some of our kings, while 

 hostilities subsisted between Ireland and Scotland, 

 or at the commencement of the Norwegian and Da- 

 nish invasions of the western isles ; and hence, the 

 origin of the traditionary title it has so long enjoy- 

 ed. 



Beneath the clay-slate of Beregonium, a species 

 of extremely compact mica- slate is discoverable, con- 

 taining hornblende intimately mixed. I found here 



