188 Dr. Mac Culloch's Supplement to the 



It is occasionally mixed with the stilbite, but is also found in very- 

 large masses, either alone or intermixed with crystals of calcareous 

 spar. These masses have fallen from the cliffs above, and lie de- 

 tached on the shore. They consist principally of a confused crys- 

 tallization, but cavities are also found in them in which the mineral 

 has crystallized at liberty and in its regular form. These crystals 

 exceed a quarter of an inch in length, and the substance is here 

 invariably of a white colour. There is nothing more remarkable in 

 this mineral than the contrast between its present and its original 

 state with respect to hardness. The lumps which I have described 

 sometimes exceed twenty pounds in weight, yet they remain entire 

 on the beach notwithstanding they must have fallen, together with 

 the other rocks which are here found, from an elevation of many 

 hundred feet. At the present time the slightest contact causes them 

 to crumble into atoms. 



To the varieties of analcime which were formerly enumerated I 

 may add another which is also to be found at this spot. It is of a 

 brick-red colour, but not crystallized, and is largely mixed with the 

 amygdaloidal rock that predominates at this place. 



I formerly mentioned that epidote was found crystallized in cavi- 

 ties of the different trap rocks both in Garsven and in Glamich. In 

 addition to that, I may here say that fragments of the same rocks are 

 to be found at the foot of the former hill, in which this mineral 

 appears to form a constituent part of the trap, being uniformly 

 mixed with the other ingredients throughout the whole mass. 



It has been said in some of the popular accounts of Scotland, that 

 agate pebbles were found near Dunvegan, but having never seen 

 specimens from Sky, and doubting the authority on which the report 

 was founded, I took no notice of this circumstance in the former 

 paper. I have now however found them, although in no great 



