NATURE OF FLINT. 



211 



burns to an opaque white, and lias what is termed a 

 conchoidal or shell-like fracture. The dark colour, it may 

 be added, is due to the presence o£ a small quantity of 

 organic matter, or carljon. 



If we fracture a nodule of flint freshly taken from a 

 chalk-pit, we shall find that the thin edges of the sharp 

 flakes which are seen to be produced have a pale-brown 

 horn colour when viewed by transmitted light, and that 

 as the flake becomes thicker the colour graduallv darkens 



Fra. 62. — A Chipped Fliut lniple)in.-ul-., from Icklingham, half 

 natural size. (From Sir J. Evans' " Stone Implements.") 



p2 



