Ch. XVI.] TO THE PREVAILING THEORY. 373 



of chemical solution ; and moreover, that they are also oc- 

 casionally present in granite, trap, lava, and analogous rocks : 

 facts which demonstrate that the so-called strata have not de- 

 rived their inclined positions from elevation : and when to these 

 instances are added those beds admitted to have been formed 

 on inclined planes, there is a great preponderance of evidence 

 against the generally received opinion that strata were ori- 

 ginally horizontal and have been subsequently tilted up by 

 some internal moving power. 3. We cannot subscribe to 

 this doctrine of elevation, because the protrusion of granite, 

 the supposed cause of such movements of the strata, is not 

 justified by any known analogy. The internal fire, the pri- 

 mum mobile of all the commotions and derangements of the 

 solid crust of the earth, appears to be adequate to the up- 

 raising of vast tracts of country, but this is effected without 

 altering the previous position of the various rocks and uncon- 

 solidated deposits. It causes fissures and chasms in the su- 

 perimposed rocks, through which it forces aerial fluids, lava in 

 a state of fusion, fragments of rocks, mineral substances, and 

 other kinds of volcanic ejecta, which arrange themselves around 

 the apertures so as to form conical hills or mountains composed 

 of highly inclined and irregularly concentric layers. But in 

 none of these cases have any appearances been observed which 

 indisputably establish such elevations of the strata as are now 

 the subject of consideration. And even granting that granite 

 has been so protruded, such an elevation could not have been 

 effected without causing fissures through the incumbent strata; 

 for even the comparatively small effects of actual volcanic 

 operations, which are unattended by local tiltings up of the 

 beds, produce such openings : and if this were the case, how 

 could the adjacent strata have escaped total destruction ? for 

 immediately the expansion overcame the resistance, a dread- 

 ful explosion must have inevitably followed. It may perhaps 

 be argued, that the strata, when thus upheaved, were in a 

 ductile state, in consequence either of their being intensely 

 ignited, or of their not having been as yet consolidated : but 



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