Of CIBRALrAR. 199 



of Dalmatia, and upon its coafls in the iflands of Cherfo and 

 Ofero, that fome naturalifls have been induced to go fo far as 

 to affert, that there has been a regular flratum of fuch matter 

 in that country, and that its prefent broken and interrupted 

 appearance has been caufed by earthquakes, or other convul- 

 fions, experienced in that part of the globe. But, of late years, 

 a traveller, (Abbe Alberto Fortis), has given a minute de- 

 fcription of the concretion in which the bones are fovmd in that 

 country : And by his account it appears, that with regard to 

 fituation, compofition and colour, it is perfecftly fimilar to that 

 fovmd at Gibraltar. By his defcription it alfo appears, that the 

 two mountain rocks of Gibraltar and Dalmatia confift of the 

 fame fpecies of calcareous ftone ; from wdiich it is to be prefu- 

 med, that the concretions in both have been formed in the fame 

 manner and about the fame periods. 



Perhaps if the iiffures and caves af the rock of Dalmatia. 

 were ftill more minutely examined, their former communica- 

 tions with the furface might yet be traced, as in thofe defcribed 

 above ; and, in that cafe, there would be at leaft a ftrong proba- 

 bility, that the luaterials of the concretions of that country have 

 been brought together by the fame accidental caufe, which, ia 

 my opinion, has tollefted thbfe found in the caverns of Gibraltar. 

 I have traced, in Gibraltar, this concretion, from the loweft part 

 of a deep perpendicular filfure, up to the furface of the moun- 

 tain.' ^ As: it approached to tiie furface, the concretion became 

 lefs firmly combined, and, when it had, no covering of the calca- 

 reous rock, a fmall degree of adhefion only remained, which was 

 evidently produced by the iargillaceous earth, in its compofition, 

 having been moiftened by rain and, baked by the fun. 



The depth, at which thefe materials had been penetrated by 

 thaf proportion of ftaladlitical matter, capable of giving to the. 

 concretion its greateft adhefion and folidity, I found to, vary ac- 

 cording, to its fitwation, and to the quantity of- jatxiitter to be com- 

 bined;. 



