Chalk and Flint Formation. 1 5 



and Dover, and also occasionally in seams running 

 down the cleavage of the chalk in the cliffs, varying 

 in thickness, as stated, from an inch and a half to 

 the thinness of Bristol board. It is plain from the 

 latter case, that the chalk was not lying as soft mud 

 at the bottom of the sea when the flint ran down its 

 cleavage, but that the chalk, even if originally 

 formed or deposited there, had been upheaved, and 

 had dried and cracked, and then, after the formation 

 of these fissures, the fluid matter of the flint had 

 run into them. But this goes quite against the 

 theory of the flint having been deposited from 

 thermal waters while the chalk was lying in process 

 of formation at the bottom of the sea. 



A different account must be found of the origin 

 of the chalk and flint formation, such as will be 

 consistent with all these phenomena, and will afford 

 a sufficient explanation, both of those which are of 

 the land and of those which are marine, or of the 

 shore, — an origin common to both, yet belonging to 

 neither. That origin we shall prove to be meteoric. 

 However startling this may seem to some, who have 

 been accustomed to limit the admission of meteoric 

 falls of stones to a few marked by certain character- 

 istics, it is yet agreeable to a favourite theory 

 generally accepted by both geologists and astrono- 

 mers. It is allowable to refer to it briefly and 

 summarily here, as calculated to meet any objection 

 of this sort ; at least to those by whom that theory 

 is entertained. 



It was a deduction of the great French astrono- 

 mer, Laplace, from the relative times of revolution 

 and rotation of the planets and their satellites, that 

 probably at a very remote period the sun and all the 

 bodies of the solar system had been one nebulous 



