SALTPETRE-WORKS. 127 



distance, of a pale yellowish colour. Further in- 

 land, during the whole ride of fourteen leagues, I 

 saw only one other vegetable production, and that 

 was a most minute yellow lichen, gi'owing on the 

 bones of the dead mules. Tliis was the first true 

 desert which I had seen : the effect on me was not 

 impressive ; but I believe this was owing to my 

 having become gradually accustomed to such scenes, 

 as I rode northward from Valparaiso, through Co- 

 quimbo, to Copiapo. The appearance of the coun- 

 try was remarkable, from being covered by a thick 

 crust of common salt, and of a stratified saliferous 

 alluvium, which seems to have been deposited as 

 the land slowly rose above the level of the sea. 

 The salt is white, very hard, and compact : it oc- 

 curs in water-worn nodules projecting from the ag- 

 glutinated sand, and is associated with much gyp- 

 sum. The appearance of this superficial mass very 

 closely resembled that of a country after snow, be- 

 fore the last dirty patches are thawed. The exist- 

 ence of this crust of a soluble substance over the 

 whole face of the country shows how extraordi- 

 narily dry the climate must have been for a long 

 period. 



At night I slept at the house of the owner of 

 one of the saltpetre-mines. The country is here as 

 unproductive as near the coast ; but water, having 

 rather a bitter and brackish taste, can be procured 

 by digging wells. The well at this house was thir- 

 ty-six yards deep : as scarcely any rain falls, it is 

 evident the water is not thus derived ; indeed, if it 

 were, it could not fail to be as salt as brine, for the 

 whole suiTOunding country is incrusted with vari- 

 ous saline substances. We must therefore conclude 

 that it percolates under ground from the Cordillera, 

 though distant many leagues. In that direction 

 there are a few small villa ses, where the inhabi- 



