Formation of Flints in Chalk. 421 



mixture of silex ; and both thes concretions and the flint) strata 

 appear to have originated during t ie fluid state of the matrix in 

 which we find them imbedded, and to have proceeded with it through 

 a nearly contemporaneous process of consolidation ; the separation 

 of the siliceous from the calcareous ingredients having been modi- 

 fied by attractions which drew to certain centres the panicles of the 

 siliceous nodules as they were in the act of separation from the 

 original compound mass, and the distances of the siliceous strata 

 having probably been regulated by the intervals of precipitation of 

 the matter from which they were derived, each new mass as 

 it was discharged forming a bed of pulpy fluid at the bottom of the 

 then existing ocean, which being more recent than the bed pro- 

 duced by the last preceding precipitate, would rest on it as a foun- 

 dation similar in substance to itself, but of which the consolida- 

 tion was sufficiently advanced to prevent the ingredients of the last 

 deposit from penetrating or disturbing the productions of that which 

 preceded it. 



The result of a succession of such deposits as are here supposed 

 would be the accumulation of a formation of homogeneous strata, 

 each containing in a fossil state such organic remains as happened 

 to be entangled in the successive precipitates. The identity of these 

 remains in that immense succession of beds which constitutes the 

 mass of the chalk formation, is consistent with the identity of the 

 matrix containing them ; there being no reason to believe in any 

 change of circumstances in the then existing condition of our globe, 

 from the commencement to the completion of the deposition of the 

 beds of chalk, since we find no admixture of sand or pebbles 

 (the wreck of older strata), nor any symptom of interruption or 

 irregularity in the processes from which has resulted that enormous 



Vol. iv. 3 h 



