308 



Water and its Impurities, with 



as also the Ural and other large streams, decreases instead 

 of increasing in size." According to one visitor there 

 must have been here at some former period, a vast inland 

 sea extending for hundreds of miles. 



The Oceanic waters contain about, 2,500 gr. to the gall or 3J per cent 



Great Salt lake about, 14,000 " 20 



The Dead sea nearly, 20,000 " 26 



Lake Elton still more. 



Thus we find all the variation from of one per cent, 

 solids or one two thousandth of the bulk, and in these 

 more saline bodies the solids are more than one-fourth 

 of the whole. 



The Dead sea contains this immense quantity of solid 

 matter, although the Jordan which flows into it carries 

 only a small amount. All seas that have no outlet are 

 salt seas, and for this same reason I do not doubt that 

 the one exception to this rale, lake Tchad in Central Africa 

 will prove to be no exception, for more thorough explora- 

 tion will determine its outlet either upon the surface or 

 under ground. 



A word or two might be interesting as to the effects upon 

 health, of these salts in the small quantities that they 

 are met with in most of the waters supplying cities. 



There are opportunities furnished to determine this 

 with more accuracy than we often find in other investiga- 

 tions, owing to the constant nature of the water furnished 

 in any locality giving opportunity to observe the effect, if 

 any, which it has upon the health. From such investiga- 

 tion we have positive conclusions. 



" The salubrity of districts bears no relation to the 

 ^ greater or smaller quantity of saline matter in water. If 

 " distilled water could be supplied to a population in 

 " millions of gallons daily, it would be neither agreeable 

 "nor wholesome to the general public." 



It has been clearly proved (M. JBoicssingaidt), that the 

 calcareous (lime) salts of drinking waters, in connection 



