180 DESCRIPTIVE MINERALOGY. 



It appears, therefore, from the above analyses, that there is some variation in the nature as 

 well as in the proportion of the ingredients of sea water. The total amount of saline matters 

 is also different in different parts of the ocean. Thus the water of the Baltic sea is said to 

 contain y', of its weight of salt (or 1.5 percent.); that of the sea between England and 

 France contains ^'^ part (or 3.1 per cent.); and that on the coast of Spain, j'j part (or 6.1 

 per cent.) Ure. Some inland seas, however, contain a still larger proportion of saline matter. 

 The most remarkable of these is the Dead Sea, the water of which, according to Marcet, 

 contains 25.10 per cent, of salts. 



A knowledge of the relative proportion of common salt which sea water contains is of impor- 

 tance, as it is upon this that the question of the feasibility of establishing the manufacture of 

 that valuable article must often depend. From the statements which have already been made 

 in regard to the proportions of saline matter found in different seas, it may be inferred that the 

 water within the boundaries of this State is not so strongly impregnated as to render this 

 manufacture of much consequence, especially while the strongly charged brine springs of 

 Western New- York yield such an abundant supply. 



The following is the composition of a portion of sea water taken from the East river at 

 New- York, at very high tide : 



Specific gravity 1 .02038. 



1000 grains contain. 



Carbonate of lime, .... . 1.22 



Carbonate of magnesia, 0.50 



Sulphate of lime, „ 0.80 



Sulphate of magnesia, . 1.72 



Chloride of magnesium, - . 2.26 



Chloride of sodium (common salt), 20. 30 



Water, with traces of organic matter, 973 . 20 



This water would require not less than three hundred gallons for the manufacture of a bushel 

 of salt. 



On ascending the Hudson, the proportion of saline matter is of course constantly decreasing, 

 until at Newburgh the water scarcely troubles any of the ordinary tests. At the mouth of the 

 Croton river, about forty miles north of New-York, I found the specific gravity of the water 

 at high tide 1.00173, and the proportion of sahne matter in 100.000 grs. to be 000.152grs. ; 

 at low tide the specific gravity was 1 .00326, and the amount of dry saline matter 000.379 grs. 

 in 100.000 grs. of the water. 



An opinion was at one time entertained that the water of Lake Ontario was salt at the 

 bottom, but recent and carefully conducted experiments have proved that such is not the case. 

 It is found, like that of most of our inland lakes and rivers, to be nearly pure, containing only 

 minute quantities of the carbonate and sulphate of lime and chloride of calcium. 



