of Granite and Sandstone in Sutherland, 285 



But geologists, even where they admit the production of 

 granite from fusion, have very thoughtlessly assumed, that it 

 must always have been elevated in the fluid state, and in this 

 state brought into contact with the several rocks which it may 

 touch. Not only there is no necessity for this supposition, 

 but the fact must often have been otherwise. Every thing in 

 the history of granite proves successive productions of this 

 substance, as I have demonstrated on sundry occasions ; and 

 that solid stratified rocks have been elevated by granite, is one 

 of the very bases of geology. There is, consequently, no rea- 

 son why a previous and consolidated mass of granite also 

 should not have been elevated by a posterior eruption of the 

 same rock ; so far, indeed, is the case otherwise, that a large 

 portion of the history of the changes of the globe is implied in 

 this very fact. In such a case, the strata lying on the granite 

 might be disturbed in any manner ; elevated to the highest 

 possible angles, and also broken or bent. But they would not 

 contain veins of the granite in immediate contact with them ; 

 because they were deposited on its solid surface, and elevated 

 afterwards only in consequence of its elevation. And in 

 reality, while Scotland presents numerous instances of this very 

 fact, the case before us is but one of them. The sandstone, 

 and the lignite formation after it, have been deposited on the 

 consolidated granite of this district ; while a subsequent eleva- 

 tion, of which I have not yet discovered the cause, or The 

 Granite, has brought the whole secondary strata into the posi- 

 tion which they now display. 



I may now proceed to describe the lignite formation, or what 

 is called the coalfield of Sutherland. That I formerly noticed 

 its general nature in the paper on Lignites, does not preclude a 

 proper description of that which the scattered peculiarity of its 

 positions in Scotland renders additionally interesting. 



Sutherland^ August^ 1819. 



OCT.— DEC. 1828. 



