CHAPTER X
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Sea Water
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CHEMISTRY
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SEA-water is salt to the taste;
very much salter than
fresh water, in which, when we drink it, we are not con—'
sciously aware that there is any salt.
Yetit is, in reality,
present, but in exceedingly minute q'uantities, for all the
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oceans derive their saltness from the fresh water which
pours down from the land in the form of rivers.
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In
ages one can imagine that the oceans were
almost fresh;
the saltness of which We are now aware
is due to the accumulation of the minute quantities washed
down from the land through countless centuries.
It has
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been estimated that there is enough salt in the oceans to
yield fourteen and a half times the bulk of the entire
continent of Europe above high-water mark
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ÏWhen sea water is eyaporated down until it is drya white
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crystalline substance, the sea salt, is left.
three
quarters of this salt consists Of sodium‘ chloride, the
being made up of small quantities of bromides,
carbonates and sulphates, of sodium, potassium, calcium
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and magnesium.
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Practically everywhere in the oceans of the world the
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:
compèSition of sea salt is to all intents and purposes the
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Same, that is the proportions to one another of the different
components
are
the
same.
But“ the actual quantity
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