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14
sig ’fra en stadig Feil i hans Analyser, da han nemlig. til
Udfældning af Svovlsyren har benyttet sig af den
salpetersure Baryt, hvorved man — som senere er bevist — faar
et stærkt forurenset Bundfald.
Af den sidste og de foregaaende Tabeller fremgaar
det. at fra hvilken Side man end ser alle disse
Bestemmelser af Kalk. Magnesia og Svovlsyre, kan de ikke med
Bestemthed bevise nogen Foranderlighed i Søvandets
Sammensætning: men det bør tillige bemærkes, at de
Afvigelser, der er vanskeligst at forklare, isærdeleshed fremkommer
ved Svovlsyrebestemmelserne.
Den Antagelse, at Havet i liele sin Dybde er en
ensartet Blanding, hvori den nøiagtigste kemiske Analyse neppe
kan paa vise nogen Forskjellighed, bekræftes ved de her
foreliggende Undersøgelser i endnu høiere Grad end ved
de tidligere. Jeg har nemlig ikke nogensinde fundet saa
store Uoverensstemmelser som de. der paa enkelte Steeler
er fremkomne ved Forchhammers og andre Kemikeres
Analyser. •
Retter man nu Opmærksomheden paa de fortyndede
Vandprøver, hvis Egenvægt er under 1.O260. vil man
heller ikke her finde nogen Forandring i det konstante
Forhold mellem Bestanddelene. Station- 300. 339 og 350,
livor Egenvægt og Klorgehalt er formindskede ved
nærliggende Ismassers Smeltning, viser en nøiagtig tilsvarende
Forskjellighed for. de øvrige Bestanddeles Vedkommende.
I Station 143. eier er beliggende i Nærheden af den norske
Kyst. og hvis Overfladevand som følge heraf er noget
fortyndet,. har jeg ved to Bestemmelser fundet en temmelig
høi Kalkgehalt. medens derimod Magnesia og Svovlsyre
fuldkommen retter sig efter Klormængden. Dette fortjener
maaske en Smule Opmærksomhed, da der jo er
Omstændigheder, som taler for en Tiltagen af Kalkmængden ved
Kysterne.
I Station 256, hvor Overfladevandets Saltstyrke er
reduceret til 2.02 pCt., viser dog Forholdet mellem
Bestanddelene saa smaa Afvigelser fra det almindelige, at
disse fuldstændig kau forklares som Feil i Bestemmelserne,
der ved Vandets Fortynding naturligvis taber i
Nøiagtighed.
Kjender man Søvandets Klorgehalt. vil man af de i
Tabellerne angivne Forholdstal kunne beregne de øvrige
Bestanddele meel saa stor Nøiagtighed, at de fundne Tal
•for Kalk. Magnesia og Svovlsyre kun undtagelsesvis vil
differere mere end 0.002. 0.005 og 0.003 pCt. fra de direkte
■ Bestemmelser i Tabel 1.
Forat lette Sammenligningen meel de tidligere
Anallyser har jeg i efterfølgende Tabel paa samme Vis som
Forchhammer forbundet Klor og Svovlsyre med Kalk og
Magnesia tilj de Salte, som i Almindelighed antages at
forekomme i Søvandet. Al Kalk er regnet til Svovlsyre,
tain a. larger quantity of sulphuric acid, since he found the
proportion of that constituent between the 60th and 62nd
parallels of latitude to be 0.230 per cent. But, in all
probability, this incongruous result must be ascribed to a
constant error in his analyses, precipitating as lie did the
sulphuric acid with nitrate of baryta, which — as will be
afterwards shown — gives a niuch contaminated deposit.
From the last Table, it is sufficiently clear, that
howsoever these determinations be regarded, they cannot be
assumed to furnish absolute proof of a variable relation
subsisting between the constituent parts of sea-water; and
we must bear in mind, that of such differences as have
hitherto defied the penetration of observers, the
most-striking refer to sulphuric acid determinations.
The hypothesis which assumes the Ocean to consist
throughout its entire depth of one homogeneous fluid, in which
the most accurate of chemical analyses shall fail to detect
dissimilarity of composition, has received from the experiments’
here described probably stronger confirmation than from
any that have gone before them. Indeed none of my own <
results exhibit a want of agreement so considerable as that
met with in some of Forchhammers and other chemists*
analyses.
Again, passing to the diluted samples (with a
specific gravity under 1.0260). no disturbance will be apparent
in the constant relation subsisting between the component
parts of the water. At Stations 300, 339. and 350. where
the specific gravity and the proportion of chlorine are
reduced by the melting, in the immediate vicinity, of large
masses of ice, the other constituents exhibit a
corresponding elifference in amount. In two samples drawn at
Station 143. in close’ proximity to the Norwegian coast, where
the surface-water is accordingly somewhat diluted. I
determined a comparatively large amount of lime, whereas t\ie
proportion of magnesia and sulphuric acid was in strict
proportion to that of the chlorine. This result is.. perhaps,
deserving of notice, inasmuch as there are grounds for
assuming the amount of lime to increase near the coast.
At Station 256, where the proportion of salt in the
surface.-water is reduced to 2.02 per cent, the disturbance
in the normal relation subsisting between the Several
constituents was so slight, that it coulcl be wholly accounted
for in- each case as an error of analysis, the determinations
being by reason of the dilution of the water
proportionately less accurate.
Given the amount of chlorine in sea-water, the other
constituents may be calculated from the proportional values
given in the Tables with such accuracy, that the figures
found for lime, magnesia, and sulphuric acid will rarely
differ more than 0.002, 0.005. and 0.003 per cent from the.
direct determinations set forth in Table.I.
With a view to facilitate comparison with the earlier
analyses, I have in the annexed .Table, following the
example of Forchhammer, combined chlorine and sulphuric acid
with lime ancl magnesia, to form the salts which are.
generally assumed to occur in séa-water. Thus, all lime is
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