Freeland tribune. (Freeland, Pa.) 1888-1921, 1900-11-30
WHY OCEANS ARE SALTY
SCIENTISTS SAY THEY WERE ONCE
ALL FRESH WATER.

If, as we have reason to hope, Lord
kelvin'S somewhat contracted period
will yield to a little stretching, Pro
fessor Joly's, on the other hand. may
take some pairing. His argument,
broadly stated, is as follows. The
ocean consisted at first Of fresh water:
it is now salt and it's saltiness is due
to the dissolved matter that is constant.
ly being carried into it by rivers. If,
then, we know the quantity of salt
which the rivers bring down each year
into the sea, it is easy to calculate how
many years they have taken to supply
the sea with all the salt it at present
contains. For several reasons it is
found necessary to restrict attention
to one only of the elements contained
in sea salt-sodium. The quantity of
sodium delivered to the sea every year
by rivers is about 160,000,000 tons, but
the quantity of sodium which the sea
contains is at least 80 millions of times
greater than this, and the period dur
ing which rivers have been carrying
sodium into the sea must, therefore, be
about 80 millions of years. Professor
Joly's estimate of the amount of So
dium in the ocean may be accepted as
sufficiently near the truth for all prac-
ticaipurposes. We may, therefore, pass
on to the other factor, the annual con-
tribution of sodium by river water.
Here there Is more room for error. Two
quantities must be ascertained-the
quantity Of water which the rivers Of
the world carry into the sea, and the
quantity or proportion of sodium pres
ent in this water. The total volume of
water discharged by rivers into the
ocean is estimated by Sir John Muir
ray as 1924 cubic miles. The estimate
being based on observations of 33
great rivers, although only approx
mate, it is no doubt sufficient to exact;
at all events such alterations as it is
likely to undergo will not greatly affect
the final result. When, however, we
pass to the last quantity to be deter
mined, the chemical composition Of av-
erage river water, we find that only a
very rough estimate is possible, and
this is the more unfortunate because
changes in this may very materially
, affect our conclusions. The average
composition is deduced from analysis
of 10 great rivers, which altogether dis
charge only 4SS cubic miles, or 7.25 per
cent. of the whole. The danger in u.s.
ing this estimate is twofold-in the first
place 7.25 is too small fraction from
which to argue to the remaining 9I.1o
per cent, and, next, the rivers which
furnish itare selected rivers i. e., they
are all of large size. The effect of this
is that the drainage of the volcanic re-
gions of the earth is not sufficiently
represented, and it is precisely this
drainage which is richest in sodium
salts. The lavas and ashes of active
volcanoes rapidly disintegrate under
the energetic action of various acid
] gases, and among the volcano eXhala-
tions sodium chloride has been
especially noticed as abundant. Again,
several considerations lead to the belief
that the supply of sodium to the ocean
has proceeded, not at a uniform, but
at a gradually diminishing rate. 1t
should not be overlooked that the pres
ent is a calm and quiet epoch in the
earth's history, following after time
of fiery activity. More than once, in
deed, has the past been distinguished
by unusual manifestations of volcanic
energy, and these must have had some
effect upon the supply of sodium to the
ocean. Finally, although the existing
ocean water has apparently but slight
effect in corroding the rocks which
form its bed yet it certainly was not
inert when it's temperature was not
far removed from the critical point.
Water begins to exert powerful de-
structive action on silicates at a tenn
perature of $50 degrees c., and during
the interval occupied in cooling from
$40 degrees to $50 degrees c., con-
siderable quantity of sodium may have
entered into solution. A review of the
facts before us seems to render some
reduction in DR.. Joly's estimate impera-
tive. A precise assessment is imDoS-
| sible, but l should be inclined myself
to take off some 10 or 30 millions Of
years. We may next take the evidence
of the stratilied rocks. Their total
maximum thickness, is as we have seer
265,000 feet, and consequently, if they
accumulated at the rate of one foot in
century, as evidence seems to sug-
| gest more than 26 millions of years
must have elapsed during their forma-
tion.-Prof. w. ]. Sollas before the
British Association.
| Cutlery in China.
The Chinese have not yet learned