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THE ULTIMATE SOURCE 



denudation. If there have been hills upon its boundary, 

 those will send down streams upon it. If there are no hills, 

 it will be in the track of some distant watershed sending its 

 winding river to the sea ; or perhaps, it will be the scene 

 of volcanic action ; or of secular cooling and contraction, with 

 upheaving of the earth crust in irregular mountain thrusts. 

 The contorted strata of many of the rock salt deposits tell of 

 the pressure and crushing to which the salt has been subjected 

 by these very movements. Indeed, the present stratigraphi- 

 cal condition of many salt deposits, and the myriad cracks 

 and flaws in the salt crystal can hardly be attributed to any 

 other cause. In whatever way produced, streams will cross the 

 site of the salt formation, and the work of denudation will be 

 in time accomplished. Streams will grow into rivers, which 

 will cleave across the ancient sea basin, cutting it down from 

 its topmost stratum to the base of the rock salt deposit, or lower 

 still ; and as the work progresses, hills and cliffs of rock salt, 

 with their gypsum and other coverings, will grow up on either 

 handj as at the Trans-Indus salt range, and at Cardona in Spain. 

 Or it may happen that the site is not the scene of powerful 

 denudation, and that the rock salt will be buried out of 

 sight, and out of knowledge, for an indefinite time. Or that 

 the movement of elevation continues until the rock salt lies 

 secure at such altitudes as at Hallein, or Arbonne, where it is 

 actually found. Or that movements of depression carry the 

 region once again to the bottom of the ocean, where the rock 

 salt, secure beneath the gypsum, receives an enormous addition 

 to its other coverings. All these are not only possibilities, 

 they are certainties, and have happened. Geology will bear 

 me out in this. It would pass the limits of this paper to enter 

 further into detail. 



I have now disposed of the chief objections to the marine 

 view of the origin of rock salt. There remain some minor 

 objections of comparatively little account. Superior salt is 



