Chalk and Flint Formation. 25 



phry Davy. It is known, in the case of acknow- 

 ledged meteorolites, that they have fallen very hot, 

 and that they bear a film on the surface from the 

 sudden action of intense heat. Therefore a molten 

 condition of the flint is sufficiently consistent with 

 a meteoric source. The smaller flints very fre- 

 quently, if not generally, present a spherical or 

 ellipsoidal form somewhat flattened. The spherical 

 form would naturally be assumed by a small fluid 

 falling body in free space, as in the case of rain- 

 drops and hailstones ; or, in the case of more rapid 

 motion, the form would become elongated to the 

 ellipsoidal. And the flattened condition of many 

 flints often indented with the mark of another 

 spherical or ellipsoidal body, indicates their having 

 fallen, in a not fully hardened state, upon other 

 similar stones. That these small flints might 

 rapidly lose their heat in their descent, and pass 

 from the fluid to the solid state from meteoric 

 causes, may be seen in the fall of ordinary hail- 

 stones, which are simply frozen water, formed often 

 in the hottest weather. That each of these small 

 flints was formed separately, and not by fracture 

 followed by rolling and trituration, appears dis- 

 tinctly from its crust. On the other hand, large 

 splashes of fluid flint, like bucketsful, could not 

 be expected to assume or retain in falling a similar 

 spherical form, but only some approximate tendency 

 in the rounding of their parts, and would in falling 

 into water or upon irregular surfaces be greatly 

 modified. 



Not improbably the chalk and flint may be 

 separated constituents of one composite substance 

 analogous to felspar, which by the action of intense 

 heat was disintegrated, its silica molten, and part 



