OYSTER CULTURE IN ITALY. 679 



M. Louis Figuier (" Ocean World," p. 17.) informs us 

 that " The water of the Mediterranean contains more 

 salts than that of the ocean. 



The following are, according to M. Usiglio who was 

 one of a commission sent to examine the different kinds of 

 salt water in the south of France the component parts of 

 100 gallons of Mediterranean water. 



Ibs. 



Chloride of sodium .. .. .. .. 29-524 



' Chloride of potassium . . . . . . . . 0-405 



Chloride of magnesium .. .. .. 3' 2I 9 



Sulphate of magnesia .. .. .. .. 2 '477 



Chloride of calcium . . . . . . . . 6-oSo 



Sulphate of lime .. .. .. .. I 'S57 



Carbonate of lime .. .. .. .. 0-114 



Bromide of sodium . . . . . . . . '3S6 



Protoxide of iron .. .. .. . , 0-003 



43735 



The density of the water of the Mediterranean is, 

 according to M. Usiglio, 1*025 when at the temperature of 



7 o. 



The reason why the Mediterranean contains more 

 salts than that of the ocean, is because the quantity of 

 fresh water brought into it by rivers is less than that lost by 

 evaporation. The Mediterranean must therefore grow 

 salter with time, unless its water is discharged into the 

 ocean by a counter current, which would run under the 

 current coming from the Atlantic by the Straits of 

 Gibraltar." 



A gallon of sea- water contains usually 2,500 grains of 

 saline matter, of which 1,890 grains consist of common 

 salt. (" Bloxam's Chemistry.") 



