SPECIFIC GRAVITY OF SEA-WATER. 15 



They are as follow : 



Chloride of sodium .... 43^ ounces. 



Chloride of magnesium ... 6 



Chloride of potassium ... 1 J 



Bromide of magnesium . . . 21 grains. 



Sulphate of magnesia ... 7J ounces. 



Sulphate of lime 2 J 



Carbonate of lime . . . . 21 grains. 



Water 9 gallons and 5 pints. 



There cannot be a question, however, that by far 

 the simplest plan would be to evaporate sea-water 

 itself in large quantities, preserving the resulting salt 

 in closely stopped vessels, to prevent the absorption of 

 moisture, the proportion of this dry saline matter being 

 56 ~ ounces to the ten gallons of water less three 

 pints *. 



Another important point is the specific gravity of 

 the sea-water f. This should be very carefully regu- 

 lated ; for it must be borne in mind, that many of the 

 marine creatures are supplied with materials for their 

 support by a permeation of water through their tissues, 

 or over their different organs. The specific gravity 

 should not rise above 1026 at 60 Fahr., and a small 

 hydrometer should be at short periods introduced to 



* Such a preparation is in reality manufactured by Messrs. 

 Brew and Schweitzer of 71 East Street, Brighton, under the 

 title of " Marine Salts for the instantaneous production of Sea- 

 water," and may be purchased in London from Mr. William 

 Bolton, Operative and Manufacturing Chemist, 146 Holborn Bars. 



The proportion ordered to be used is six ounces to the gallon 

 of water ; to be stirred well until dissolved. 



t Warington, Ann. Nat. Hist. 1853. 



