198 MINERALOGICAL DESCRIPTION 



angular, and none of them have the appearance of being water- 

 wprn. 



It. only now remains forme to mention what are generally 

 called the foffil bones, found in the rock of Gibraltar. Thefe 

 have been much talked of, and by fome looked upon as a phae- 

 nomenon beyond the power of explanation. The general idea, 

 which exifls concerning them, is, tliat they are found in a pe- 

 trified ftate.j and inclofed in the folid calcareous rock ; but thefe 

 are miftakes, which could only arife from inaccurate obfervation 

 and falfe defcription. 



In the perpendicular fifTures of the rock, and in fome of the 

 caverns of the mountain, (all of which afford evident proofs 

 of their former communication with the furface), a calcareous 

 concretion is found, of a reddiih brown ferruginous colour, with 

 an earthy fradture, and confiderable induration, inclofing the 

 bones of various animals, fome of which have the appearance 

 of being human. Thefe bones are of various fizes, and lie in 

 all direcflions, intermixed with fhells of fnails, fragments of the 

 calcareous rock, and particles of fpar ; all of which materials are 

 flill to be feen in their natural uncombined ftates, partially fcat- 

 tered over the furface of the mountain. Thefe having been 

 fwept, by heavy rains at different periods, from the furface into 

 the fituations above defcribed, and having remained for a long 

 feries of years in thofe places of reft, expofed to the permeating 

 adlion of water, have become enveloped in, and cemented by, 

 the calcareous matter which it depolits. 



The bones, in this compofition, have not the fmalleft appear- 

 ance of being petrified ; and if they have undergone any change, 

 it is more like that of calcination than that of petrifacftion, as 

 the moft folid parts of them generally admit of being cut and 

 dfcraped down with the fame eafe as chalk. 



Bones combined in fuch concretions are not peculiar to Gi- 

 braltar : They are found in fuch large quantities in the country 



of 



