186 Outlines of Geology, 



As, then, I trust to find a sufficiency of facts, and those inte- 

 resting and important, to form the basis of these lectures, I shall 

 at once proceed to lay before you a brief account of the structure 

 of the earth's surface, without stopping to inquire whether the 

 globe we inhabit be an extinguished sun, or a mere pimple 

 brushed from the face of that luminary by the tail of a comet : 

 whether as Kepler thought, we are parasitic animals, sporting 

 upon the exterior of a huge leviathan whose nostrils are volcanoes, 

 and whose perspiration constitutes the ocean : or whether we may 

 assume the mineralogical conjecture, that the earth is a monstrous 

 crystal, the sides and cleavages of which represent the strata of 

 its surface. 



Tlie strata of the globe (for notwithstanding the anathema 

 with which Mr. Greenough opens his Essays on Geology^ I shall be 

 bold enough to use that term, under the presumption of its gene- 

 ral intelligibility) appear from the concurrent testimony of tra^ 

 Tellers, to present everywhere upon its surface, certain analogies 

 in respect to arrangement, and to succeed each other in a certain 

 definite order. In the valleys, and we will assume the valley of 

 the Thames, and the greater part of Essex, as an instance, we 

 find gravel, pebbles, sand, and other matters resulting from de- 

 tritus, mixed with more or less of vegetable remains, and consti- 

 tuting soils of various degrees of fertility and extent. The soil 

 being removed, we find clay and sand resting, probably every- 

 where, but evidently in many place upon chalk, and containing 

 «uch a remarkable assemblage of organic remains, some of veget- 

 able, and others of animal origin, as almost to baffle all conjectures 

 as to whence they came, or under what circumstances they were 

 brought together. The remains of sea animals are blended with 

 those of the land, quadrupeds with fish, and fresh- water fish with 

 those peculiar to the ocean. Animals of the land, the air, and the 

 water, are assembled together in most unaccountable incon- 

 gruity ; fruit and leaves, hazle nuts and pine cones, are mixed 

 with shark's teeth, crab's claws, and oyster-shells. No less than 

 five hundred varieties of fossil-fruit, mixed with sea-shells of 

 various descriptions, have been found in the clay of Sheppey 

 Island ; and Mr. Trimmer's brick-fields at Brentford have yielded 



