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Om Søvandets faste Bestanddele.
On the Solid Matter in Sea-Water.
"Hen temmelig rige Literatur, der handler om
Søvands-J-’ undersøgelser, gaar helt tilbage til Slutningen af det
forrige Aarhundrede. De Kemikere, der fra Begyndelsen
af tog dette .Emne under Behandling, lagde naturligvis først
og fremst Vægten paa at bestemme Vandets samlede
Saltmængde eller dets tilsvarende Egenvægt i de forskjellige
Dele af Oceanet.
De første Undersøgelser i denne Retning førte snart
til den Slutning, at Havets Saltholdighed ikke var
underkastet andre Forandringer, som ved Datidens analytiske
Midler kunde paavises, end slige, der var en nødvendig
Følge af særegne forud bekjendte Naturforhold, f. Ex.
For-tyndniugen i de polare Egne ved store Ismassers Smeltning.
Denne Havets Ensartethed med Hensyn til dets samlede
Saltgehalt sandsynliggjorde naturligvis ogsaa den Antagelse,
at Forholdet mellem dets enkelte Bestanddele var af en
lignende uforanderlig Beskaffenhed. Skjønt de første
Forsøg paa at bestemme Søsaltets Sammensætning ikke førte
til saadanne Resultater, der fra Kemiens nuværende
Standpunkt vilde betegnes som overensstemmende, ser vi dog, at
allerede Marcet (Phil., trans. 1822) drager den Slutning af
sine Søvandsundersøgelser, at der kun er meget liden
Variation i Forholdet mellem Kalk, Magnesia, Klor og
Svovlsyre i Havvandet. At Havet er en ensartet Blanding, eller
at Variationerne i dets Sammensætning kun kan dreie sig
om smaa Størrelser, er senere bekræftet ved talrige
Undersøgelser. men den største Del af de Analyser, der ere
udførte i denne Retning, ere dog — lige indtil den Tid. da
Forchhammer offentliggjorde sin Afhandling om Søvandet
— temmelig værdiløse, da de ialmindelighed er behæftede "
med altfor store Feil til at kunne have nogen Betydning
fra et nyere Standpunkt betragtet. De talrige og
fortrinlige Undersøgelser. Forchhammer har udført for at komme
til Klarhed i denne Sag viser tydelig, at man skal arbeide
med stor Omhyggelighed, hvis ikke Feilene ved Analysen
skal blive større end de smaa Variationer i Havets
Sammensætning. Denne udmærkede Forsker har undersøgt
180 Vandprøver fra cle forskjellige Dele af Verdenshavet
og udført sine Analyser med en Grundighed og Nøiagtig-
Den norske Nordhavsexpedition. Schmelck: Chemi.
The first of the numerous works on ocean-water date from
. the close of the last century; and the branch of the
subject which, to the earlier authors, would appear of
paramount importance, was naturally the determination of the
total amount of salt in sea-water, or the equivalent specific
gravity of the latter, in all parts of the globe.
On instituting observations with this object in view,
it soon became apparent — to the extent at least for which
the limited means of analysis then known sufficed — that
the proportion of salt in ocean-water was not subjected to
other disturbing influences than such as could be readily
traced to physical causes: for instance, dilution, in the
Arctic regions, from the melting of enormous masses of
ice. And the remarkable uniformity prevailing in the
proportion of the total amount of salt, was plainly in favour
of the hypothesis, that a like unvarying relation should
subsist between the different constituents. The first
experiments to determine the nature of sea-water, did not indeed
give results that would now be held to exhibit close
agreement: and yet Marcet (Phil. trans. 1822) was led to
infer, that the variation in sea-water between lime,
magnesia. chlorine, and sulphuric acid is relatively very trifling.
That the ocean, so to speak, is a homogeneous fluid, or.
that the variations exhibited in its composition represent
magnitudes comparatively minute, — this view has since
been repeatedly confirmed; but the greater part by far of
the analyses performed to test it — previous to the date
at which Forchhammer published his treatise on
ocean-water — are of very questionable value, being most of them
beset with errors, which, when viewed in the light of
modern science, must be regarded as far too considerable to
admit of our attaching any real importance to their results.
The series of numerous and most successful experiments
instituted by Forchhammer, sufficiently attest the care that
is needed to keep the errors of analysis from exceeding
in magnitude the inconsiderable variations occurring in the
composition of sea-water. That distinguished observer
examined no less than 180 samples of sea-water, collected
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