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chalk, and the apparent conversion 

 of animal remains into flint, has 

 given rise to much speculation 

 respecting its origin; and it was 

 at one time maintained, that flint 

 and chalk were convertible, or 

 capable of undergoing a mutual 

 transmutation. One thing appears 

 very certain, that the veins of flint 

 so freely distributed throughout 

 the chalk, are invariably confined 

 to that formation. I propose to 

 submit a few observations from the 

 pens of our first writers on this 

 interesting and intricate subject, 

 for after having considered the 

 matter in every point of view ; 

 after having carefully read the 

 opinions of others, and again and 

 again examined strata of flint 

 nodules and tabular flints, flints 

 horizontally and diagonally distri- 

 buted throughout the numerous 

 chalks pits in my neighbourhood ; 

 after having observed their crushed 

 but not disordered condition, and 

 having commonly found flints im- 

 bedded in flints, I am totally 

 unable to arrive at anything ap- 

 proaching to a legitimate deduction 

 from the various phenomena. 



"That the beds of chalk and 

 flint were deposited periodically," 

 says Dr. Mantell, "cannot admit 

 of the slightest doubt. Specimens 

 are not unusual, in which angular 

 fragments of black flint, that could 

 not possibly have been originally 

 formed in "their present state, are 

 imbedded in chalk. Sir Henry 

 Englefield was the first who di- 

 rected the attention of geologists 

 to the subject of the shattered 

 condition of the flints found in 

 certain strata. In a paper read 

 before the Linnsean Society, he 

 notices several beds of shattered 

 flints, which occur in a chalk-pit 

 at Carisbrook, in the Isle of "Wight ; 

 and, after describing their situation 

 and appearance, proceeds to offer 

 some conjectures upon the probable 



cause of their destruction. This he 

 supposed might have been occa- 

 sioned by some sudden shock or 

 convulsion, which in an instant 

 shivered the flints, though their 

 resistance stopped the incipient 

 motion ; for the flints, though 

 crushed, are not displaced, which 

 must have been the case, had the 

 beds slid sensibly. Chalcedony 

 is often found occupying the hol- 

 lows of flints, and on this sub- 

 ject it has been remarked that 

 although in the present com- 

 pact state of the matter of flint, 

 it is not easy, though possible, 

 to force a fluid slowly through its 

 pores, yet it is probable that 

 before its consolidation was com- 

 plete, it was permeable to a fluid 

 whose particles were finer than its 

 own; and that the particles of 

 chalcedony, whilst yet in a fluid 

 state, being finer than those of 

 common flint, did thus pass through 

 the outer crust to the inner 

 station they now occupy; where 

 they also allowed a passage through 

 their own interstices to the still 

 purer siliceous matter, which is 

 often crystallized, in the form of 

 quartz, in the centre of the chalce- 

 dony, and is so entirely surrounded 

 by it, that it could have no access 

 to its present place, except through 

 the substance of the chalcedony, 

 and the flint enclosing it." In 

 Professor Buckland's Bridgewater 

 Treatise we find the following : 

 " We may in like manner refer 

 the origin of those large quantities 

 of silex, which constitute the chert 

 and flint beds of stratified forma- 

 tions, to the waters of hot springs, 

 holding siliceous earth in solution, 

 and depositing it on exposure to 

 reduced degrees of temperature and 

 pressure, as silex is deposited by 

 the hot waters that issue from the 

 geysers of Iceland." Again Dr. 

 Mantell, "the nodular masses of 

 flint are very irregular in form, 



