Ch. XVI.] OF THE PREVAILING THEORY. 385 



bounds of probability that the chemical union of the elements 

 of the fused mass, whence resulted such a vast body of definite 

 minerals, should be accompanied by the evolution of numerous 

 currents of electricity, or of analogous fluids ? for we know 

 that the oscillations of the particles of matter, whether pro- 

 duced mechanically, or during chemical combinations, will 

 elicit streams both of common and galvanic electricity. If, 

 then, it be acceded that the primary rocks may have been 

 traversed by such currents during their formation, we have 

 an explanation of the regular disposition of the granitic rocks, 

 of veins, and of other crystalline substances ; and, indeed, not 

 only of the subordinate parts, but also of the entire mass. 



This idea will remind the reader of Mr. R. W. Fox's expe- 

 riments, from which he has concluded that the Cornish metal- 

 liferous veins were formed by electro-magnetism. By such 

 imaginary currents, crossing each other in different directions, 

 we also fancy that the phenomena of intersecting veins might 

 be accounted for, the more powerful ones having uninter- 

 ruptedly continued their course, whilst the weaker ones ex- 

 perienced various degrees of diversion, being either partially 

 or altogether involved in the impetus of their stronger oppo- 

 nents. But whether the bearings of the beds and veins of the 

 primary mass originated from this source, or from any innate 

 disposition of the constituent particles of its minerals to affect 

 certain lines of combination, will probably remain a mystery 

 for many ages ; but the time may possibly come, when, by 

 accumulated experience, circumstances which are now inex- 

 plicable may receive a more rational solution. At present, 

 however, we cannot obtain any certain knowledge concerning 

 the formation of the earth, earlier than that epoch when the 

 granitic and their associated schistose groups existed, and fur- 

 nished, through the operation of causes similar to those now 

 in action, the materials of which the oldest derivative rocks 

 are constituted. These groups are, therefore, fairly entitledj 

 if this view be correct, to the appellation of primary, since 

 they appear to have been formed before all rocks which are 



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