DECOMPOSITION OF FLINT. 221 



porcelaneous external coating, quite different from the 

 interior ; and it is believed by Sir John Evans that this 

 white coating has been produced by the removal of a 

 portion of the flint which was still soluble " by the 

 passage of infiltrating water through the body of the 

 flint." That such a process must have been of incon- 

 ceivable slowness, and must have required countless years 

 for its accomplishment, goes without saying. We have, 

 indeed, some inkling of how extremely slow this process 

 must be, from the circumstance that the fractured surfaces 

 of the flints built into the walls of our very oldest churches 

 show not the slightest change from their pristine condition. 

 When, however, we examine the chipped flint implements 

 of our river gravels and caves, like the one shown in our 

 first illustration, we find their surfaces altered precisely in 

 the same manner as the flint fragments by which they are 

 accompanied. Hence we gain, from a totally independent 

 source, some idea of the immense antiquity of the period 

 when the old palaeolithic hunters inhabited the south of 

 England. 



Having thus reached the subject of flint implements, 

 we feel tempted to enter into the consideration of some of 

 their different types and the beds in which they occur, 

 but limits of space forbid our wandering into such 

 entrancing paths. Even, however, without entering into 

 this part of the subject, we trust that what we have 

 written will serve to show that a " Flake of Flint," when 

 considered from all points of view, is to the full as 

 interesting as a " Lump of Chalk." 



THE END. 



