372 SALINE LAGOONS. 



siderable degree of strength, "viz., to a quarter of a 

 pound of salt to one pint of water." * 



Now, in many of the natural saline lagoons, found 

 in different parts of the world, this is exactly what 

 occurs: the concentration of salt becomes very highly 

 developed by the evaporation caused by the solar 

 rays ; when this reaches what is technically known as the 

 point of saturation the water becomes no longer capable 

 of holding the whole of the salt in solution, any surplus 

 then gradually becomes deposited in a more or less pure 

 form of natural salt: in some places these deposits 

 have been known to thus form beds of this nature 

 many feet in thickness, and of a very good col- 

 our: so far however as our own experiences have 

 gone, for we have often tried it it is seldom good 

 tasted salt: that is to say the chloride of sodium 

 (or table salt) is mixed with other salts, such as 

 magnesia, etc., which impart a disagreeable flavour, and 

 also produce a purgative action. All these however, open 

 up a variety of matters of technical detail, which 

 cannot be considered here. 



The question of the migration of birds, to which 

 these great assemblages of pelicans have insensibly 

 led us, is one of very great interest and importance ; 

 well worthy of the attentive consideration of all sports- 

 men and lovers of Nature. These matters have before 

 been touched upon in various parts of this work, but 

 more particularly in our arctic section. We must 

 therefore at present confine any further observations 

 upon the subject within as narrow limits as possible ; 

 but we think a chapter upon Wildfowl and Wildfowl 



* See Linnaean Transactions, Vol. xi, p. 205, quoted by Mr. Darwin 

 in his Naturalist's Voyage. 



