chap. x. of La Plata and Patagonia. 3*11 



Mr. Reeks has analysed for me some of the salt 

 from the salina near the Rio Negro, he finds it com- 

 posed entirely of chloride of sodium, with the exception 

 of 0*26 of sulphate of lime and of 0*22 of earthy matter : 

 there are no traces of iodic salts. Some salts from the 

 salina Chiquitos in the Pampean formation, is equally 

 pure. It is a singular fact, that the salt from these 

 salinas does not serve so well for preserving meat, as 

 sea-salt from the Cape de Verde Islands ; and a mer- 

 chant at Buenos Ayres told me that he considered it as 

 fifty per cent, less valuable. The purity of the Pata- 

 gonian 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 is sup- 

 ported by the fact lately ascertained, 1 that those salts 

 answer best for preserving cheese which contain most of 

 the deliquescent chlorides. 2 



With respect to the origin of the salt in the salinas, 

 the foregoing analysis seems opposed to the view enter- 

 tained by M. d'Orbigny and others, and which seems 

 so probable considering the recent elevation of this line 

 of coast, namely, that it is due to the evaporation of 

 sea-water and to the drainage from the surrounding 

 strata impregnated with sea-salt. I was informed (I 

 know not whether accurately) that on the northern side 

 of the salina on the Rio Negro, there is a small brine 

 spring which flows at all times of the year : if this be 

 so, the salt in this case at least, probably is of subter- 

 ranean origin. It at first appears very singular that 



1 ' Hort. and Agricult. Gazette,' 1845, p. 93. 



2 It would probably well answer for the merchants of Buenos 

 Ayres (considering- the great consumption there of salt for preserving 

 meat) to import the deliquescent chlorides to mix with the salt from 

 the salinas : I may call attention to the fact, that at Iquique, a large 

 quantity of muriate of lime, left in the mother-water during the 

 refinement of the nitrate of soda, is annually thrown away. 



