The Democratic advocate., 1893-04-01
why the Sea is saltp

Why is sea water salt ? is question that
has been regarded as mystery and has
given rise TO some curious speculations, but
a little consideration on the subject must,
l think, satisfy US all that it would be very
wonderful, quite incomprehensible, if the
waters of the ocean were otherwise than
salt as they are
The following explanation was first sug-
gested to myself many years ago when
receiving my first lessons in practical chem
ical analysis. Tho problem then to be
solved was the separation of the bases
dissolved in water by precipitating them
one by one in solid condition, filtrating
away the water from the first, then from
this filtrate precipitating the second, and
so on until all were separated OF accounted
for.
But in doing this there was one base
that was always left to the last on account
Of the difficulty of combining it with any
acid that would form solid compound
difficulty so great that its presence was
determined by different method. This
base is soda, the predominating base OF sea
salt, where it is combined with hydrochloric
acid Not only is soda the most soluble of
all the mineral bases, but the mineral acid
with which it is combined forms remark
ably soluble series of salts-the chlorides.
Thus the primary fact concerning the
salinity of sea water is that it has selected
from among the stable chemical elements
the two which form the most soluble CON-
pounds. Among the earthly bases is one
which is exceptionally soluble-that is,
magnesia-and this stands next to soda in
its abundance in sea water.
Modern research has shown that the
ocean contains in solution nearly every
element that exists upon the earth, and
that these elements existe in the water in
proportions nearly corresponding to the
mean solubility of their various compounds.
Thus gold and silver and most of the other
heavy metals exist there. Sonnenstadt
found about fourteen grains of gold to the
ton of seawater, or dollars worth in less
than two tons. As the ocean covers all
the lower valleys of the earth, it receives
all the drainage from the whole OF the ex-
posed land. This drainage is the rainwater
that has fallen upon this exposed surface,
has flowed down its superficial slopes or
has sunk into porous land and descended
underground. In either case the water
must dissolve and carry with it any soluble
matter that it meets, the quantity of solid
matter which is thus appropriated being
proportionate to its solubility and the extent
of its exposure to the solvent. Rain when
it falls upon the earth is distilled water,
nearly pure (its small impurities being what
it obtains from the air), but river water
when it reaches the ocean contains measur-
able quantities of dissolved mineral and
vegetable matter. This continual addition
of dissolved mineral salts without any cor
responding abstraction by evaporation has
been going on ever since the surface of the
earth consisted of land and water.
An examination of the composition of
other bodies of water which, like ocean,
receive rivers and rivulets and have no
other outlet than that afforded by evapora-
ton, confirms this view. All of these are
more or less saline, many of them more so
than the ocean ITSELF On the great table
land of Asia, ''the roof of the world, there
is multitude of small lakes which receive
the waters of rivers and rivulets of that
region and have no outlet to the ocean,
On a map they appear like bags with a
string attached, the bag being the lake and
the string the river. All these lakes are
saline, many Of them excessively SO, simply
because they are ever receiving river water
of slight salinity aud ever giving off yapor
which has no salinity at all. There is no
wash through these lakes, as in the great
American lakes or those of Constance,
Geneva, etc,
The sea of Aral and the Caspian are
lakes without any other outlet than evapo-
ration, and they are saline accordingly.
The Dead sea, which receives the Jordan
at one end and a multitude of minor rivers
and rivulets at the other end and sides, is
noted example of extreme salinity. 1t
is, as everybody knows, sea or lake Of
brine. The total area of land draining
into the great ocean does not exceed one
fourth Of its own area, while the Dead sea
receives the above twenty times greater
than its own, and thus it fulills the de-
maud of the above stated theory by having
far greater salinity than has the great ocean.
According to this view the salinity of
the ocean must be steadily though very
slowly increasing, and there must be slowly
proceeding corresponding adaptation of
evolution among the Inhabitants, both
animal and vegetable. The study of this
subject and the effect which the increasing
salinity of the past must have had upon the
progressive notifications, Of organic life
displayed by fossils, is think, worthy of
more attention than ithas hitherto receiv-
ed from paleontoIogists.
The Economical Mule.
The mule is ready to begin work two or