GEOLOGY.—LECTURE II.

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struments of investigation can be applied to them—pro-vided they are capable of being elucidated by analogicalinferences from known facts. But in cases where thereare no histories to guide us, no distinct reasonings toassist us, and no experiments to enlighten us, there thehuman powers must be uselessly applied, and all theefforts of ingenuity wholly wasted. The discovery ofthe limits between what is capable of being known, andwhat must be for ever concealed from us, with regard tothe theory of the earth, is perhaps not very distant. Inevery view of the subject, some point must be takenfrom which to begin; some primary state of things, orsome part of an order of revolution; and where nochange is to be perceived, there it seems reasonable tosuspend our inquiries, and to consider the facts as ulti-mate. In this case, there is some foundation for gra-dually creating a theory; in the other, there is no basisto begin with. In the operations of nature, there is acontinued succession, a destruction and renovation offorms. But our view, and our period of existence, limitus to the few objects surrounding us. Suns and worldsmay be created, and may decay, by uniform laws, or-dained by infinite wisdom; and our earth, as a part ofthe planetary system, may participate in a new order.But these objects are far beyond mortal ken; the ima-gination soars towards them in vain; its efforts are idleand unavailing; its strength is wasted in dreams.

In the common course of natural events, there is so-lution, and decomposition, and consolidation, and theagency of water and of fire; but nothing results anala-gous to the primary bodies. Calcareous concretions areformed, rocks are destroyed by the agency of air, andnew masses regenerated: but they bear the stamp oftheir origin.