Dr. Mac Culloch on the Hill of Kinnoul. 221 



of that author are well known, and I believe that in this country 

 it is not necessary to enter into any refutation of his conclusions. 

 As far indeed as the appearance of the trap rocks and their peculiar 

 mineralogical character are concerned, the Huttonian theory offers an 

 explanation better able to fulfil the requisite conditions than his 

 hypothesis. I shall therefore decline entering into a comparative 

 statement of systems so well known, or investigating the solidity 

 of the examples which the French geologist has adduced from 

 Great Britain. Although never formally discussed, the arguments 

 and objections are familiar to most of those who have engaged in 

 geological researches, and a full examination of his individual cases 

 would lead into a dissertation foreign to the purpose of this notice. 

 I may therefore briefly remark that the chief part of the hill in 

 question consists of trap, which, like the other rocks of this fa- 

 mily that alternate with secondary strata, is known in the Wer- 

 nerian nomenclature, by the term of foetz trap. I do not pretend 

 to name its rank in the several formations enumerated under this 

 general title, as I much doubt if the assigned characteristics are con- 

 stant. If they are universal it will not be difficult to give it its 

 place in the system when I have described its features and con- 

 nections. 



The phenomena which are most interesting in this hill render 

 it necessary to take a range somewhat wide before describing the 

 rock itself, without which we should be unable to trace its con- 

 nection with the neighbouring rocks and the surrounding country. 



Those who are acquainted with the mineral geography of Scot- 

 land know that a great portion of its northern district is separated, 

 in many places very accurately, by a tract of breccia from the 

 secondary rocks which occupy its middle portion. An irregular 

 line drawn through Troup head, Dunnotter, Blair gowrie, Delvin, 



Vol. iv. 2 f 



