290 ^ep^y to ^^'' Alkm's Ohservat'ions [Apnit, 



In page 'ISS, De Luc complains of Mr. Allan for a partial 

 statement of his doctrine. His words are : " Those," says Mr. 

 Allan, " who were inclined to consider this rock as an original 

 deposite, have accounted for its formation in different ways." " I 

 think," adds De Luc, " that as Mr. Allan mentions me tor a part 

 of the subject, he ought to have expressed not only the way that I 

 have explained the production of granite, but the proof which he 

 might have found in my works." M. De Luc's paper consists of 

 ten pages, and the greater part of it is occupied in correcting tl>e 

 inaccuracies of Mr. Allan. 



Mr. Allan very politely thanks you, sir, for the confirmation you 

 have given to his opinions, in your very clear and distinct account 

 of your late observations in Cornwall. He seems anxious to make 

 it appear that30u are on his side. But it is quite clear to me that 

 what you say gives no sort of countenance to his doctrine. He 

 maintains that the granite of St. Michael's mount must be held to 

 be primitive, or part of tlie nucleus round which Werner conceives 

 all other rocks were deposited. You, on the contrary, have 

 shewn that there exists at that place irresistible proof of the granite 

 there not being part of the above nucleus ; and very truly observe 

 that had Mr. Allan " given his reasoning powers fair play, he 

 would, from his own observations, have come to the same conclu- 

 sion." The granite of St. Michael's [Mount is either primitive, or 

 it is not. If it be primitive, Mr. Allan's statements, as I have 

 already shewn, demonstrate it to be connected with gneiss, and not 

 with transition rocks. And if it be not primitive, its connection 

 with transition rocks forms no objection to the system of Werner. 

 It only shows that the principles of that system are purely inductive, 

 and readily accommodate themselves to tiie progrc--s of discovery. 

 Mr. Allan tells us that he argues against Werner and not against 

 his pupils. But as you well observe, " it is not doing justice to 

 Werner to compare the opinions which he held 13 years ago with 

 our present knowledge." \i Air. Allan does not argue against the 

 Wernerian doctrines as they at present appear in the best writers 

 on the subject, his arguments are frivolous. He might as well set 

 himself to overthrow the system of Burnet or of JBulfon. You 

 have also shewn that he was innaccurate in the account which he 

 gave of the application of the word killas. 



Mr. Allan tells us that " he is satisfied that the sentiments con- 

 tained in my paper are not all, originally at least, my own;" and 

 one of his proofs is that *' some of these sentiments l)ad long 

 before leached him from another quarter." Proof positive, no 

 doubt ! Had Mr, Allan the humility to imagine that his paper was 

 not calculated to excite some attention, among the other "men of 

 science" of this jdace, interested in the same sort of speculations 

 with himself? I do most readily give him credit for every good 

 quality ; but really this is more than I can bring myself to admit. 

 It would be a degree of humility, indeed, which most people, I 

 believe, would not be disposed to look upon as any recommenda- 

 5 



