OF THE EARTH. 499 



crease the most valuable soils, by forming tbe cal- 

 careous tracts so noted for their fertility. The manure 

 of ages past, they become that of ages to come, since 

 they are inexhaustible : and as they are also perpetually 

 increasing, we may imagine that a future world, when 

 one shall arise from the ruins of the present, will as 

 far excel it as this on which we live is superior to that 

 which preceded. This can never concern us : yet in 

 contemplating the revolutions by which Life has so 

 often been widely destroyed, it is pleasing to reflect 

 that every change is improvement, and that, out of 

 evil, good is for ever produced. And thus seeing that 

 the perpetual progress of the earth is to wards improve- 

 ment, while that progression leads us to imperfection 

 as we trace it in the reverse order, we also perceive 

 the evidences of that continued Design and Superin- 

 tendence which philosophy has so often been accused of 

 disbelieving, as geology now furnishes me with those 

 demonstrations of them which have never yet been de- 

 rived from any other department of nature, and which 

 have been hitherto overlooked by that science itself. 



On the Causes of the Revolutions of the Globe. 



The general causes of these revolutions have been 

 suggested in the former remarks on the elevations of 

 the strata and on volcanoes. We perceive, in the 

 first place, that volcanoes eject fluid matter which be- 

 comes rock, and that the force which ejects this fluid, 

 be its nature as obscure as it may, is one of great power, 

 since it is capable of elevating the superincumbent 

 strata, even where these consist of such enormous 

 masses as those which form the coral islands. And 

 though we have not ourselves witnessed the elevation 

 of such an island, we can entertain no doubt of the 

 fact, because existing men, and men under the records 



K K 2 



