Page:Geology and Mineralogy considered with reference to Natural Theology, 1837, volume 1.djvu/397

 Rh almost exclusively from strata of the Transition series. Examples of Coal in any of the Secondary strata are few and insignificant; whilst the Lignites of the Tertiary formations, although they occasionally present small deposites of compact and useful fuel, exert no important influence an the economical condition of mankind.

It remains to consider some of the physical operations on the surface of the Globe, to which we owe the disposition of these precious Relics of a former world, in a state that affords us access to inestimable treasures of mineral Coal.

We have examined the nature of the ancient vegetables from which Coal derives its origin, and some of the processes through which they passed in their progress towards their mineral state. Let us now review some further important geological phenomena of the carboniferous strata, and see how far the utility arising from the actual condition of this portion of the crust of the globe, may afford probable evidence that it is the result of Foresight and Design.

It was not enough that these vegetable remains should have been transported from their native forests, and buried at the bottom of ancient lakes and estuaries and seas, and there converted into coal; it was further necessary that great and extensive changes of level should elevate, and convert into dry and habitable land, strata loaded with riches, that would for ever have remained useless, had they continued entirely submerged beneath the inaccessible