Dr. Mac Culloch on the Hill of Kinnoul 227 



accordingly I have laid before the Society some small specimens 

 found there by Lord Gray's workmen in removing earth at the 

 foot of one of the precipices. It forms veins of different dimen- 

 sions" in the fragments of rock, with which it is intimately united : 

 it is of a finer green colour than that which is found in Rum, but 

 none of the specimens which I procured contain the red spots for 

 which this mineral is principally valued. It sometimes is associated 

 with a green quartz, coloured apparently by the same material, the 

 more transparent parts having the aspect of plasma, which not im- 

 probably owes its colour to chlorite. I did not succeed in finding 

 this mineral in the face of the rock from which these specimens ap- 

 pear to have been detached, but among the agate pebbles there to 

 be seen I obtained some which present appearances illustrative of 

 its composition. These pebbles are frequently incrusted with a 

 coating of chlorite, and in those to which I allude the chlorite 

 penetrates the external part of the agate to the eighth of an inch, 

 so as to convert the outer crust into heliotrope. I may here also 

 add that I have observed this mineral among the agates found in 

 Ayrshire, and that it occurs in the island of Mull, where it forms 

 spheroidal nodules in basalt, so that it is not rare in Scotland. 

 When I say that zeolites are not found in Kinnoul, I ought to add, 

 that I picked up one loose and bad specimen of red stilbite. 



On the top of the great mass of trap which I have now described, 

 there is to be seen a portion of a bed of conglomerate, consisting 

 of trap pebbles imbedded in a cement of the same nature, a rock 

 improperly designated by the name of trap tuff. The origin of 

 this rock is not easily explained, but I must defer the remarks that 

 might be offered on this subject to some future opportunity. 



The last and most remarkable circumstance occurring in Kinnoul 

 is that of an extensive range of those junctions with other rocks 



