76 BORDERS OF SALINAS. [chap. iv. 



purity of the Patagonian salt, or absence from it of those 

 other saline bodies found in all sea-water, is the only assign- 

 able cause for this inferiority ; a conclusion which no one, 

 I think, would have suspected, but which is supported by 

 the fact lately ascertained,* that those salts answer best for 

 preserving cheese which contain most of the deliquescent 

 chlorides. 



The border of the lake is formed of mud ; and in this 

 numerous large crystals of gypsum, some of which are 

 three inches long, lie embedded ; whilst on the surface 

 others of sulphate of soda He scattered about. The Gauchos 

 call the former the "Padre del sal," and the latter the 

 **Madre;" they state that these progenitive salts always 

 occur on the borders of the salinas when the water begins to 

 evaporate. The mud is black, and has a fetid odour. I 

 could not at first imagine the cause of this ; but I afterwards 

 perceived that the froth which the wind drifted on shore was 

 coloured green, as if by confervae : I attempted to carry 

 home some of this green matter, but from an accident 

 failed. Parts of the lake seen from a short distance 

 appeared of a reddish colour, and this perhaps was owing 

 to some infusorial animalcula. The mud in many places 

 was thrown up by numbers of some kind of worm, or 

 annelidous animal. How surprising it is that any creatures 

 should be able to exist in brine, and that they should be 

 crawling among crystals of sulphate of soda and lime ! 

 And what becomes of these worms when, during the long 

 summer, the surface is hardened into a solid layer of salt ? 

 Flamingoes in considerable numbers inhabit this lake, and 

 breed here ; throughout Patagonia, in Northern Chile, and 

 at the Galapagos Islands, I met with these birds wherever 

 there were lakes of brine. I saw them here wading about 

 in search of food — probably for the worms which burrow 

 in the mud ; and these latter probably feed on infusoria or 

 confervae. Thus we have a little living world within itself, 

 adapted to these inland lakes of brine. A minute cnis- 

 taceous animal {Cancer salinus) is saidt to live in countless 



* Report of the Agricult. Chem. Assoc, in the " Agricult. Gazette," 1845, p. 93. 



t "Linnean Trans.," vol. xi., p. 205. It is remarkable how all the circum- 

 stances connected with tlie salt-lakes in Siberia and Patag:oma are similar. 

 Siberia, like Patagonia, appears to have been recently elevated above the 

 waters of the sea. In both countries the salt-lakes occupy shallow depres- 

 sions in the plains ; in both the mud on the borders is black and fetid ; beneath 

 the crust of common salt, sulphate of soda or of magnesia occurs, imperfectly 

 crystallized; and in both, the muddy sand is mixed with lentils of gypsum. 

 The 8!h<»r''(jn salt-lakes are inhabited by small crustaceous animalii ; and 



