28 Outlines of Geology, 



flint, it appears likely, from an examination of the neighbouring 

 soils, that it has, at one time or other, everywhere existed ; 

 indeed the enormous quantity of alluvial flints, and the deposits 

 of rounded masses and nodules of chalk, which fill up the hollows 

 in many parts of the chalk strata, are abundant indications of the 

 destruction to which the chalk has been exposed. A degradation 

 to which its exterior situation and its softness render it peculi- 

 arly liable. 



The cliffs at, and about Brighton, are particularly remarkable 

 for the changes and devastations which they record. The town 

 stands upon a bed of fragmented calcareous matter and flints, 

 which, on the east, is seen resting upon shingles, consisting chiefly 

 of flints, but mixed with rounded masses of granite, slate, and 

 porphyry, cemented together by crystallized carbonate of lime, 

 apparently derived from the solvent action of water upon the 

 superincumbent chalk, thus forming a hard and durable breccia. 

 Nodules of pyrites, and of crystalline carbonate of lime, are not 

 uncommon in chalk. They are of a radiated texture, and the 

 latter often unusually hard. 



Having stated thus much respecting the composition and con- 

 tents of the chalk strata, I have little or nothing to add, relative 

 to their origin and that of their included fossils. The nature and 

 characters of chalk seem to announce it as an aqueous deposit; 

 but we must not be so bold as some geologists, who conclude that 

 it is the detritus of coral reefs, and the dust of shells originally 

 derived from the antediluvian ocean. The existence of various 

 organic remains announce the existence of those animals at the 

 time of its deposit, but we never find in it the bones of quadru- 

 peds, or of animals of existing species ; and this circumstance 

 appears to declare it of a date anterior to that of those superincum- 

 bent beds, which we examined at our last meeting. The origin of 

 flints, their arrangement, the peculiarities which they occasionally 

 exhibit, and the fossils they occasionally include, are subjects 

 that entirely baffle all theory, and it would be mere waste of time 

 to recite the hypotheses they have given rise to. Like the chalk, 

 however, they bear marks of aqueous, rather than of igneous 



