ORIGIN AND NATURE OF SPRINGS. 3 



little importance, in the geology of springs and riv- 

 ers. The various strata of sedimentary rocks are 

 by no means alike in physical or chemical constitu- 

 tion : some of them are hard, refractory, insoluble 

 in water ; others are soft, easily disintegrated, or 

 worn by the action of water moving over their 

 surfaces. Upon this difference in the structure or 

 solubility of rocks as now arranged, depends, in a 

 great measure, the formation of crevices and gorges, 

 the sources of springs and rivers. The debris 

 formed from aqueous action constitute for the most 

 part the material which makes up soils upon the 

 earth's surface, and hence it is plain to see, that 

 with undisturbed strata, the present arrangement 

 of arable soils could not have existed. It is the 

 solution of the constituents of different rocks in 

 percolating water, which renders a mineral spring 

 possible. Of course none of these could have been 

 found if everything was at a dead level, and the 

 strata were quietly reposing as originally deposited. 

 The breaking up, tilting, contorting, overturn- 

 ing of these rock layers has been complete ; and 

 consequently mountains, hills, valleys, precipices, 

 gorges, and rock fissures have been formed, 'and 

 from them and through them the springs flow, and 

 among them, often at high altitudes, beautiful lakes 

 repose. The number and the distribution of springs 

 in any section depend not only upon the inclination 



