SCARBA. GEOLOGY. 177 



form of a rock. The supposition is indeed sufficiently 

 confirmed by numerous facts in the history of rocks, 

 proving their softness and flexibility even at this day, 

 when first taken from their beds; examples of which 

 have been noticed in this work on different occasions. 



These considerations will account for the peculiarities 

 visible in the contortions of Scarba ; and the spectator 

 who examines them will readily acquiesce in the expla- 

 nation, although no adequate idea can be conveyed of 

 the value of these proofs ; since even drawings are inca- 

 pable of representing them in a satisfactory manner. 



The facts are themselves interesting in a general view, 

 as bearing materially on a subject which has been the 

 occasion of some controversy, and is of no small im- 

 portance in geological theory. Many geologists have 

 been unwilling to admit of the mechanical derangement 

 of rocks, and have consequently had recourse to other 

 modes of accounting for such appearances. Saussure 

 seems to have been the first to suppose that contortions 

 might have resulted from crystallization, and the respect 

 due to his name renders it proper to notice an opinion 

 which seems unsupported by any chemical analogies with 

 which we are acquainted. 



Those which occur here, present circumstances irrecon- 

 cileable to the notion of a chemical arrangement, while 

 they display ample proofs of mechanical disturbance. 

 Where the mass of beds, consisting of quartz rock and 

 schist, is erected from its once horizontal position, or is dis- 

 posed in the extensive undulations visible in the diagram, 

 the regular alternation of tbe two substances continues; 

 the whole having equally undergone the degree of flexure 

 exhibited in its present disposition. The actual cur- 

 vature at any one point is in this case so small, that 

 even the presumed rigidity of the quartz rock has been 

 capable of yielding to it. But the present argument 

 would not be affected should we even admit that this 

 general mass had been deposited in its present position ; 



VOL. II. N 



