18 
THE OCEAN WOULD. 
proceeding from the successive decomposition of innumerable genera- 
tions of animals which have disappeared since the beginning of the 
world. This matter has been described by the Count Marsigli, who 
designates it sometimes under the name of glu, sometimes as an 
unctuusity. The numerous salts which exist in the sea can neither he 
deposited in its bed, nor exhaled with the vapour, to be again poured 
upon the soil in showers of rain. Particular agents retain these salts 
in solution, transform them, and prevent their accumulation. Hence 
sea water always maintains a certain degree of saltness and bitterness, 
and the ocean continues to present the chemical characters which it has 
exhibited in all times, varying only in certain localities where more or 
less fresh water is poured into the sea basin from rivers : thus the salt- 
ness of the Mediterranean is greater than that of the ocean, probably 
because it loses more water by evaporation than it receives from its fresh- 
water affluents. For the opposite reason, the Black and the Caspian Seas 
are less charged with these salts. The Dead Sea is so strongly impreg- 
nated with salt that the body of a man floats on its surface without 
sinking, like a piece of cork upon fresh water. The supposed cause is 
excessive evaporation and the absence of rivers of any importance. 
The saltness of the sea seems to be generally less towards the Poles 
than the Equator ; hut there are exceptions to this law. In the Irish 
Channel, near the Cumberland coast, the water contains salt equal to 
the fortieth of its weight ; on the coast of France, it is equal to one 
thirty-second ; in the Baltic, it is equal to a thirtieth ; at Teneriflfe, a 
twenty-eighth ; and off the coast of Spain, to a sixteenth. Again, in 
many places the sea is less salt at the surface than at the bottom. In 
the Straits of the Dardanelles, at Constantinople, the proportion 
is as seventy-two to sixty-two. In the Mediterranean, it is as thirty- 
two to twenty-nine. It is also stated that as the salt increases at a 
certain depth, the water becomes less bitter. At the mouth of the 
great rivers it is scarcely necessary to add that the water is always less 
saline than on shores which receive no supplies of fresh water ; the 
same remark applies to sea water in the vicinity of polar ice, the 
melting of which is productive of much fresh water. A recent analysis 
of the water of the Dead Sea by M. Boux gives about two pounds 
of salt to one gallon of water. No mineral water, if we except 
that of the Salt Lake of Utah, is so largely impregnated with saline 
substances ; the quantity of bromide of magnesia is 035 grammes 
