( HS ) 

 its fragments angular, acute at the extremi- 

 ties, and femi-pellucid. It is more than 

 moderately heavy, the file will not touch it, 

 and it gives fparks flrongly with fteel. 

 Notwithftanding their great hardnefs, how- 

 ever, the generality of thefe flints eaiily 

 break into fmall pieces under the hammer. 

 Some of them, in the quarry of Battaglia, 

 are placed between the llrata of the carbo- 

 nates of lime; but they frequently alfo 

 form a continuation with them ; fometimes, 

 indeed, divided by a fudden and abrupt fe- 

 paration, but frequently, likewife, by infen- 

 fible gradations ; in which latter cafe there 

 is a fpecious appearance of an infenfible 

 tranfition of the lime into filex ; and the 

 opinion that this is really the fad has been 

 adopted by many. 



A piece which exhibits this appearance 

 lias one part of it white ; w^hich colour in- 

 fenfibly difappears, and is fucceeded by a 

 reddiHi tinge, that gradually increafes till 

 the remainder of the piece at length ailumes 

 the red, bro\\n, or black colour v;hich is 

 R 3 proper 



