GEOLOGICAL REMARKS. 201 



the slaty rocks of the primitive class, must have 

 taken place, not by the application of an external 

 force subsequent to the process of aggregation in 

 the component particles of the stone, but during 

 that process ; and must have been determined by 

 the laws of crystallization, chemical affinity, and 

 galvanic influence, as well as by the mechanical 

 power of gravity. This inference naturally pre- 

 sents itself to the geologist, on examining the as- 

 pect of the rocks which form Ben-Ledi, and the 

 environs of Loch-Katterin. In looking at the 

 slaty texture edgewise, the slightest inspection 

 satisfies the mind, that the incurvations could not 

 have been produced but by the same cause, what- 

 ever it was, which acted in the original 'forma- 

 tion of the stone. 



Besides, it is evident, that the structure is 

 the same, at the greatest distance from any 

 mass of a different substance which might be 

 imagined to have acted on the rock by heat or 

 pressure, as in its vicinity; and the known 

 laws, by which the propagation of pressure or 

 force among the particles of soft or non-elastic 

 bodies is regulated, render it impossible that, un- 

 dulation on so small a scale could have proceeded 

 from the operation of any agent not at hand. 

 The masses of quartz (which often appear as if 

 closely wrapped round by the substance of the 

 slate, like what might have taken place, had the 

 slaty matter formed around them as a sort of nu- 

 clei, by the accretion of successive layers) are, 



T 2 



