194 MINERALOGICAL DESCRIPTION ' 



Th e variety of form, which this matter takes in its different 

 fituations and diredions, renders this fubten-aneous fcenery 

 flrikingly grotefqiie, and in fome places beautifully pidurefque. 

 The ftaladites of thefe caves, v^dien near the furface of the 

 mountain, are of a brownifli yellow colour ; but, as we defcend- 

 ed towards the lower caves, we found them begin to lofe their 

 darknefs of colour, which by degrees fhaded off to a whitifli 

 yellow. 



The only inhabitants of thefc caves are bats, fome of which 

 are of a larga^fize. The foil, in general, upon the moun- 

 tain of Gibraltar, is but thinly fown ; and in many parts that 

 thin covering has been waflied off by the heavy autumnal 

 rains, which have left the fuperficies of the rock, for a confider- 

 able extent, bare and open to infpetStion. . In thofe fituations, 

 an obferving eye may trace the effeds of the flow, but conflant, 

 decompofition of the r'ock, caufed by its expofure to the air, and 

 the corrofion of fea-falts, which, in the heavy gales of eaflerly 

 winds, are depofited with the fpray on every part of the moun- 

 tain. Thofe uncovered parts of the mountain rock alfo expofe to 

 the eye a phasnomenon.worthy of Tome attentioni'as ititendsrlear- 

 ly to demonftrate, that, however liigh the, furface of this rock 

 may now be elevated above the leveh of the fea, it has once 

 been the bed of agitated waters. This phsenomenon is to be 

 obferved in many partS' of the rock, land is conllantly found in: 

 the beds of tprrontstp;.'jIti<JonfiOs of ipot-like holes,, bf .vai-icms. 

 lizes, holtowed oiic of the folid rock,: and formed apparently by 

 the attrition of gravel or pebbles, fet in rhotion by the rapidity 

 of rivers, or cur'rents in the fea. One of thofe,, which had been 

 recently laid open, I examined] with attention. . I: 'ibuTidi.it; to 

 be five feet deep, and jthteer; feet iii diapeterr;; the- edge df . its 

 mouth rounded off as if .by art, and its (ides and bottorh retain- 

 ing a confiderabie degree of polifh. From its mouth,; for three 

 and a half feet down, it v/as filled, with a red' argillaceous earth, 

 .•?mT , R A •' .thmly 



