111 .Inlv, IS.Sf).
two small viltagos arc plai’od at tlic very moullis ol the inincs.
If the tow n of Iquique appeared desolate, these, perched up
on hills, had a still more unnatural aspect. We did not
reach the saltpetre works till after sunset, having ridden all
day ai'ross an mululatiug country, a complete aiul ntter desert.
The road was strewed with the bones and dried skins of tlic
many beasts of burden, which had perished on it from tatiguc.
Excepting the Vultur aura, which preys on the carcasses,
I saw neither bird, quadruped, reptile, or insect. On tlie coast
mountains, at tlie devatiou of about 2000 feet, wlicrc during
this season the clouds generally liang, a very icw cacti were
growing in the clefts of rock ; and tlie loose sand was strewed
over witli a simple lichen, which lies on the surface quite
unattached. This plant liclongs to tlie genus Cladonia,
and somewhat resembles the reindeer lichen. In some
parts it was iu sufficient quantity to tinge tlie sand, as
seen from a distance, of a pale yellowisli colour. Further
inland, during the whole ride of fourteen leagues, I
saw only one other vegetable production, and that was a
most minute yellow lichen, growing on the hones of the dead
mules. This was the first true desert which I had seen :
the effect on me was not impressive ; but I believe this was
owing to mv having become gradually accustomed to such
scenes, as I rode northward from Valparaiso, through
Coquimbo to Copiapó. The appearance of the country
was remarkalile, from being covered by a thick crust of
common salt, and of a saliferous sandstone, which properly
deserves the name of alluvium. The salt is white, very
hard, and compact. It occurs in water-worn nodules, which
project from the agglutinated sand or soft sandstone.
The appearance of this superficial mass, very closely resembled
that of a country after snow, before the last dirty
patches have thawed. The rocks of which the mountains are
composed are saliferous ; and I imagine, the very small quantity
of rain that falls, is sufficient only to wash the salt from the
higher strata, and that afterwards it concretes in nodules and
patches, in the sandy soil of the valleys. Whatever its origin
I t* .
.luly, 18.1.5. icinu uu . 44.5
may lie, the existence of a crust of a soluble substance over the
wliole face of tbe country, show.s how extraordinarily dry the
climate must have been for a period long antecedent.
At night I slept at the house of the owner of one of the
sidtpctre rnincs. I'he country is here equally unproductive
with that near the coast; but water, tliougli having rather a
bitter and brackish taste, can he procured by digging. I ’he
well at this house was thirty-six yards deep. As scarcely
any rain falls, it is evident the water is not derived from
that source; indeed if it were, it could not fail to be as salt
as brine, for the wliole .surrounding country is incrustcd
with various saline substances. We must therefore eon-
clude that it percolates from some distant and more humid
region, probably the mountains of the higher Cordillera. In
tluit direction there are a few small villages, such as Tarapaca,
where the inhabitants, having more water, are enabled to
irrigate some little land, and produce hay, on which the
mules and asses employed in carrying the saltpetre are fed.
The nitrate of soda is sold at the ship’s side at fourteen
shillings per hundred pounds. The chief expense is the transport
to the sea-coast. The mine itself consists of a stratum
between two and three feet thick, of the hard and nearly pure
salt, lying close beneath the surface. The stratum follows the
margin of a grand basin or plain, which manifestly must once
have been either a lake or inland sea : the elevation at present
is 3300 feet above the level of the Pacific. On our return we
made a detour by the mines of Guantajaya. The village
consists solely of the houses of the miners, and the place is
utterly destitute of every necessary;—even water being
brought thirty miles on the backs of animals. At present
the mines yield little ; though formerh' they were very productive.
One has a depth of four hundred yards, and out of
it masses of silver were taken so pure, that it was only required
to melt them in order to run them into bars. II e
reached Iquique after sunset : I went on board, and then the
Beagle weighed for Lima. I was very glad to have seen
y
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