588 



ANNUAL REGISTER, ]S\6. 



suirounding hill-;, it vvonlil seem 

 more correct to consider it as a 

 mass or bed of salt filling up a 

 valley, than as constitutini;- a 

 m:)untain, n'hich according- to 

 some authors* is a league in cir- 

 cumference. These dimensions 

 could only be -btained by consi- 

 dering the neighbouring heigiits 

 as formed of this mineral ; a 

 supposition not countenanced by 

 my personal observation, iior Ijv 

 the best information whicli 1 

 could collect on the spot. 



The surfaces of the salt preci- 

 pice which have been long ex- 

 posed to the weather are not 

 smooth, but cut into innumerable 

 shallow channels, running in a 

 tortuousmanner, and divided from 

 each other by thin edges, often so 

 sharp as to cut the hands like 

 broken glass. The channelled 

 surface is evidently j)roduced by 

 the action of the winter rains, 

 which have given the whole a 

 striking resemblance to the sur- 

 face of a mass of ice, which had 

 been partially thtiwcd and again 

 frozen. 



The general colour of the ex- 

 posed surface is greyish white, 

 with here and there a tinge of 

 jiale reddish brown, fj-om the co- 

 louring matter of the superincum- 

 bent bed of clay. Towai'ds the 

 extremities of the mass of salt, 

 extremely thin layers of a jmre 

 and i)lastic clay, are insmuated 

 between layers of salt, so as to 

 give it the waved delineations 

 which often occur in some species 

 of calcsniter. The general mass 

 of salt is however of the greatest 



• Bowles' Introduction a la Ili^toria 

 Natmal de Espana ; Dillon who translates 

 him, Laborde, Ilincraire descriptif, 6cc. 



purity; and in order to be con- 

 verted into snow white culinary 

 salt requires no other process but 

 grinding. The greyish hue of 

 the external surface is owing to 

 liie rain penetrating a portion of 

 tlie salt, and by diminishing its 

 opacity, depriving it of the white- 

 ness wi»ici\ tlie fresh fracture 

 generally j)resents. At the period 

 of my visit the surface of this 

 innnense mass was properly dry, 

 and in some places, Avliere water 

 had most recently flowed, was 

 covered witii a snow white efflor- 

 escence. This circumstance, as 

 well as the sharpness of the edges 

 above mentioned, shew the little 

 hygronietric water in the atnios- 

 l)here of that country, and the 

 general purity of the salt from 

 earthy muriates. 



The fractia'c of the salt is 

 highly crystalline, and usually 

 exhibits large granular distinct 

 concretions, wliich give it some- 

 times the ajtpearance of a breccia, 

 or of containing imbedded crys- 

 tals, 



A perennial brine spring flows 

 iit tlie foot of the great precipice, 

 and afl'ords a strong proof of the 

 little effect of water on this 

 very compact salt. The aperture 

 thiough which the stream has 

 issued, for many years, is not 

 wider externally than two feet, 

 and suddenly contracts to a few 

 inches,- while the channel worn 

 in a solid floor of salt, through 

 which the stream has long flowed, 

 is not a foot in depth. This is 

 partly to be asci ibed to the water 



but, 

 the 



being saturated with salt 

 during; the 



.g, w.^ ramy season, 

 stream is much augmented, and 

 thus cannot be supposed so highly 

 charged with saline m.atter. Not- 

 withstanding 



