Royal Physical Society. 431 



ness specimens, I said, " Here is the explanation of the Dun- 

 net riddle. The pebble was torn from the Lower Silurian, and 

 travelled upwards to the Old Red Sandstone of Dunnethead. 

 Secondly, there is a farther interest attaching to it, associated 

 as it is with the Maclurea and other organisms peculiar to 

 the Lower Silurian rocks of America, as mentioned by Sir 

 Roderick Murchison at page 422 of his Siluria, and who also 

 says these rocks (American) are " partly oolitic, in other 

 parts quartzose and cherty ;" and it is thus very pleasing to 

 find the West Highland rocks not only agreeing in organic 

 remains with those of America, but also in the mineral con- 

 stituents, both being " partly oolitic, and in other parts 

 quartzose and cherty." 



Thus, then, the more we examine even often-examined 

 districts, something new may be turned up ; the new, although 

 trifling in itself, may lead to facts of importance which will 

 explain difficult problems and solve puzzling mysteries ; and 

 thus I hope that these trifles possess sufficient interest to excuse 

 me for troubling you with this notice. There is a farther in- 

 terest attaching to them : both are new to Scotland ; and one, 

 the oolitic quartz, probably new to British rocks altogether ; 

 I have not found it mentioned in any geological work, except 

 " Siluria," as quoted in this paper. 



Whatever pleasure I may feel in my good fortune in these 

 West Highland discoveries, there is one sad drawback, and 

 a painful regret connected with the presentation of this paper, 

 — that my late valued friend Mr Hugh Miller should be lost 

 to us ; for I am sure, had he been spared to be present at the 

 reading of this, he would have hailed with pleasure the onward 

 march of a science which he so much loved and benefited. I 

 hope that you will kindly pardon this allusion to our great loss. 

 It is a tribute ^1 have long felt a wish to pay to the memory 

 of one whom I have long loved, and whose memory I shall 

 ever cherish. 



vol. i. 2 R 



