THE VOYAGE OF THE BEAGLE 77 



for working the salinas forms the harvest of Patagones ; for 

 on it the prosperity of the place depends. Nearly the whole 

 population encamps on the bank of the river, and the people 

 are employed in drawing out the salt in bullock-waggons. 

 This salt is crystallized in great cubes, and is remarkably 

 pure: Mr. Trenham Reeks has kindly analyzed some for me, 

 and he finds in it only 0.26 of gypsum and 0.22 of earthy 

 matter. It is a singular fact, that it does not serve so well 

 for preserving meat as sea-salt from the Cape de Verd 

 islands; and a merchant at Buenos Ayres told me that he 

 considered it as fifty per cent, less valuable. Hence the 

 Cape de Verd salt is constantly imported, and is mixed with 

 that from these salinas. The purity of the Patagonian salt, 

 or absence from it of those other saline bodies found in all 

 sea-water, is the only assignable cause for this inferiority: 

 a conclusion which no one, I think, would have suspected, 

 but which is supported by the fact lately ascertained, 3 that 

 those salts answer best for preserving cheese which contain 

 most of the deliquescent chlorides. 



The border of this 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 lie 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 



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



