Vol. 50.] ACID ROCKS OF THE INNER HEBRIDES. '215 



them, he ignored that overwhelming evidence, not making even an 

 allusion to its existence, and proceeded to refer to a single locality, 

 one which I had specially cited as affording ample proof of my 

 statements, but where he affirmed that he had found blocks of 

 Tertiary granite in the gabbro. The occurrence of these blocks, he 

 actually affirmed, now settled the question beyond further dispute 

 in his favour. In the debate that followed the reading of the paper, 

 adverting to this extraordinary method of reasoning, I affirmed that 

 the structures described by him as occurring in his ' inclusions ' 

 seemed rather to point to intrusive veins, but that even if the 

 • inclusions ' were actually detached and enclosed blocks, they could 

 not justify the sweeping deduction that he drew from them, and 

 could not for a moment be held to invalidate the copious evidence 

 brought forward by me from the whole volcanic region, and even 

 from the very locality now in question, that the acid rock actually 

 cuts through the basic masses. Even if the so-called ' inclusions ' 

 were enclosed blocks of granite, how could Prof. Judd suppose 

 that a few such blocks from one little ridge were to disprove the 

 definite testimony of scores of sections cited from all parts of the 

 region ? I contended that until that testimony was examined and 

 disproved it was idle to bring forward such statements and reasoning 

 as appeared in his paper. 



Possibly I might once more have remained content with a verbal 

 reply printed in the report of the debate in our Journal. But, while 

 his paper was passing through the press, Prof. Judd added a 

 postscript wherein he expressed himself in such a way as to leave 

 me no choice but to defend my fair fame. He says that he omitted 

 all reference to " the alleged existence of veins proceeding from the 

 granite into the gabbro" from " a desire not to complicate the very 

 definite issue raised in the title of this paper." One would suppose 

 that less complication would have been likely to arise had he refrained 

 from introducing a fresh kind of evidence and a novel mode of argu- 

 ment until he had disposed of the definite statements already opposed 

 to him. He then asserts : " I can only add that, since this assertion 

 [that veins of granite cut the gabbro] was made, I have revisited 

 all the localities referred to, but have never succeeded in finding 

 true granite-veins penetrating the gabbro. It was, in fact, while 

 vainly engaged in searching for such veins that I discovered the 

 very conclusive evidence of the inclusions described in this paper. 

 It appears to me that the existence of these inclusions of granite in 

 the gabbro is absolutely irreconcilable with the occurrence of veins 

 of the same granite cutting through the gabbro." 1 



In consequence of these remarks, though I felt that they could be 

 conclusively answered at once, I deemed it best to re-examine the 

 locality in Skye before making any reply. I have since traversed 

 the ground very carefully, and I now lay the results of this re- 

 examination before the Society. 



I propose to show that my published account of the relations of 



1 Op. cit. p. 194. 



