74 CHARACTERS OF STRATA 



who thus exceed the limits of that which can be use- 

 ful only when kept under due restraint. 



Whatever analogies therefore may be found all 

 over the world, not only among the natures of the 

 strata, but in their relative order of stratification, 

 there is no where that resemblance which can autho- 

 rize us in supposing that they have either been si- 

 multaneous or under the influence of an universal 

 law. The instances hereafter quoted in the Chapter 

 on the actual successions of rocks, will illustrate and 

 confirm this view. But the resemblances are more 

 general, or rather the analogy is more extensive, 

 among the most ancient strata than among the more 

 recent ; and as we ascend in the order of the series, 

 or descend in the order of time, the discrepancies in- 

 crease. This is what might be expected, even from 

 contemplating the view elsewhere given of the com- 

 position of rocks; the more ancient appearing to 

 have been at one time under the influence of a com- 

 mon power from which the others have been exempt. 

 Thus we may perhaps account for the prevalence of 

 gneiss, hornblende schist, and micaceous schist, 

 among the lowest strata ; although the nature of the 

 rocks whence the original materials were procured, 

 may also have been a modifying cause. But even 

 here, it will hereafter be shown, that the order of 

 succession is only general, and very far indeed from 

 being so particular as it has been imagined. 



The further we examine upwards, the more we 

 shall be convinced that all successions are analogous, 

 and not identical ; though the accuracy of the ana- 

 logy in the order of succession, or the extent covered 

 by some one definite series, is extremely various. By 

 commencing at the very surface of the earth, we 



