104 On Transition Rocks. [Aug. 



But Joes it follow, Sir, that because Werner has never per- 

 sonally visited every quarter of the globe, and seen with his own 

 eyes every rock in situ, and the nature of its composition, he 

 may not from what he has seen and actually did visit, as well as 

 from the accounts and specimens transmitted to him by others, 

 have discovered by his genius and penetration the true principle 

 of arrangement on which the crust of the earth is formed. 

 Certainly not. As well might Mr. Allan object to the botanical 

 arrangement of Linnteus, because thousands of plants have been 

 discovered in New Holland, and elsewhere, to which that great 

 naturalist was an entire stranger. The arrangement of Werner, 

 then, provided the phenomena of nature be found conformable 

 to his views, is not to be rejected merely because he never tra- 

 velled beyond the bounds of Germany. 



I am not sure, Sir, whether Dr. Hutton ever saw more of the 

 crust of the earth than Werner ; and certainly he never saw the 

 central parts of it, about which, notwithstanding, he has told 

 us so many wonderful things. If Werner generalized too libe- 

 rally from a " circumscribed field," certainly Dr. Hutton was 

 not behind him here. His conclusions are of a far more exten- 

 sive nature than those of Werner, and surely drawn from pre- 

 mises comparatively much less extensive. 



It is observed, too, that the appearances of the country about 

 Edinburgh (the residence of Dr. Hutton) are greatly more 

 favourable to the theory adopted by that philosopher than those 

 of almost any other part of the world that has been hitherto 

 explored. If Werner, then, formed his theory from the appear- 

 ances of the country around Freyberg, Dr. Hutton seems no less 

 to have taken his from those around Edinburgh. 



But it is not in this way that the merits or demerits of either 

 theory are to be estimated. Which of the two is most useful ? 

 Which of them teaches us best to distinguish minerals from one 

 another? Which of them is best confirmed by the observations 

 of succeeding naturalists ? These are the important inquiries. 



With the wish of Mr. A. " that arrangements of this nature 

 were less dictated by theory," we cordially agree ; but when he 

 talks about " the pupils of the Wernerian school being pecu- 

 liarly fettered by an ideal necessity of supporting the principles 

 of their master," and their " totally neglecting that minute 

 detail which is alone capable of placing the student in a situation 

 to draw conclusions of his own," we are tempted to exclaim 

 with the poet, Mulato nomine, de te f alula narrator ; for if 

 there be a department in which the Wernerian system seems to 

 excel all others, it is, I think, in the minuteness with which its 

 details are conducted, and the happy power which it possesses of 

 discriminating what others almost always, though really distinct, 

 confound. Mr. Allan himself acknowledges (p. 41!>) that Dr, 



