57 



large scale, the accumulations produced by impermeable veins 

 will be found according to the following order : — 



When the splits or veins run from south-west to north-east the 

 " bunches " will be found principally on the eastern side ; if the 

 splits run from south-east to north-west the deposits will be found 

 on the western side, being the natural consequences of the oblique 

 mechanical interruptions of the solvents transmitted through the 

 grain of the rocks by means of the magnetic currents. Nume- 

 rous minor variations must necessarily occur from the effects of 

 local causes ; but we need not describe them, as we hope that 

 the principle here laid down will be found sufficient for the 

 guidance of the practical miner. 



Recapitulation. 



In the preceding observations we have endeavoured to reduce 

 to order and system those vague indications applied by miners 

 to guide them in their subterranean operations, and concentrate 

 those scattered rays of information which have been obtained 

 by long experience, but have been hitherto so much diffused as 

 to lose their value. 



First. We have shown that the cleavage planes are not mere 

 local phenomena, but an universal structure — a polar grain, 

 formed uniformly more or less vertically from pole to pole, 

 caused by a subterranean molecular action, or the circulation of 

 the magnetic currents from south to north. 



Secondly. That the crystallization and meridional structure of 

 the primary base, from aqueous solutions of the elementary sub- 

 stances, have been, and continue to be, formed by the constant 

 action of the currents of terrestrial magnetism from south to 

 north. 



Thirdly. The order of the splits, and transverse fractures in 

 the crystalline crust of the earth, is caused by the magnetic ten- 

 sion ; with the progressive opening and filling of the ruptures by 

 the moving solvents in the intersecting rocks, according to the 

 nature of their respective contents. 



Fourthly. We have also exhibited the order of the disloca- 

 tions, or " heaves," and the influence of the impermeable splits 

 on the contents of the fractures. The more closely and minute 

 the investigation is made, the more convincing is the result; 



