132 Correspondence — Prof. E. Hull. 



"probability" of Laurentian rocks existing 'in Donegal and else- 

 where in Ireland. But if so, Mr. Kinalian must excnse me if I 

 decline to accept colloquial speculations as scientific demonstrations. 

 Liter a scripta manent. Conversations are evanescent. As a matter of 

 fact, although Professor Jukes visited Donegal in company with the 

 Eev. Dr. Haughton, and Mr. E. H. Scott, he never hazarded an 

 opinion in print (as far as I am able to discover), and by such evidence 

 alone am I to be guided, that any portion of the Donegal rocks are 

 of Laurentian age. When recently I read my paper in extenso 

 before the Natural History Section of the Eoyal Dublin Society, at 

 which both Dr. Haughton and Mr. Kinahan were present, the former 

 disclaimed, on his own part at least, any priority in the determina- 

 tion of the Laurentian age of the gneissose series of Donegal. 



As I stated in my original commi;nication, which appeared in 

 Nature (26th May, 1881), Dr. Sterry Hunt was the first who, from 

 an examination of specimens from Donegal, recorded an opinion of 

 the Laurentian age of the older series of metamorphosed beds. 



Now, Sir, as regards the credit of this discovery, I beg to say that 

 I claim no particular credit either for myself or for any one else. 

 As the Director of the Irish Branch of the Geological Survey, I feel 

 a certain gratification that the determination of the age of the old 

 gneiss of Donegal, and its associated schistose rocks, has been made 

 by officers of the Survey ; for in my preliminary survey of that 

 district I was assisted by two senior ofiicers of the Survey, Mr. E. 

 G. Symes, F.G.S., and Mr. F. G. Wilkinson. They can testify as to 

 the care with which we examined an extensive district — and as to 

 the satisfactory nature of the determination of the unconformity 

 between the older and newer groups of metamorphosed beds. The 

 details themselves will appear in my paper now in course of pub- 

 lication. The determination w.as made not by voluntary effort, but 

 in accordance with ofiicial duty, and as the outcome of a previous 

 visit to the Northern Highlands of Scotland, under the guidance of 

 Professor Geikie, in the spring of 1880. I have not the least doubt 

 that if Professor Jukes had had the same opportunities of observa- 

 tion as myself, he would have arrived at the same conclusions with 

 regard to the age of the older series, as Harkness did with regard to 

 the age of the newer ; but, as a matter of fact, the determination of 

 the question had not been made till the spring of last year. 



I have now only to add that nothing can be more distasteful to 

 myself than to have my name brought as it were into competition 

 with that of my late friend and predecessor. Public duty has 

 obliged me to deal with questions which he ably handled, and some- 

 times I have arrived at different conclusions regarding them. But 

 I defy any one to point out any occasion in which I have failed fo 

 quote his published opinions when required, or to have knowingly 

 misrepresented them. It is, therefore, quite unnecessary for Mr. 

 Kinahan to assume the role of apologist or expositor of his former 

 chief; and I venture to think that he is not the person whom Pro- 

 fessor Jukes would have selected to undertake this office; had it been 

 required. 



