2 
ser paa Reiser at give Bidrag til Løsningen af Spørgs- 
maalet om Fordelingen af Luften i Havet, da har Anled- 
ningen dertil næsten bestandig manglet. Først ved de i 
de senere Tider hyppigt udsendte Expeditioner, hvormed 
der har været givet Chemikere Anledning til at medfølge, 
har det været muligt mere detailleret at studere disse Ting. 
Ved disse Expeditioner har Formaalet udelukkende været 
videnskahelig Undersøgelse af Havet, og der har derfor 
med Hensyn paaUdrustningen altid været lagt megen Vind 
paa ved hensigtsmæssige Foranstaltninger og omhyggelige 
Forberedelser at fremme dette Formaal saa meget som 
muligt, og det er derfor klart, at disse Expeditioner maa 
have den største Betydning for den chemiske Undersøgelse 
af Havene specielt, hvor Talen er om saadanno Observatio- 
ner, der ligcsom Bestemmelser af Gasarterne ikke taale 
Opsættelse, men nødvendigvis maa udføres øieblikkelig efter 
at Vandprøven er øst. Saaledes maa aabenbart de under 
disse Omstændigheder udførte Observationer faa størst Vægt, 
hvor det dreier sig om at skaffe Oplysmnger om Gasarterne 
i Søvandot, udenat det dog derfor vil fades paa urette 
Plads her at give en kort Oversigt ogsaa over de herover 
udførte ældre Undersøgelser. 
De tidligste Undersøgelser, der mig bekjendt ere 
gjorte over Luften i Søvandet, udførtes i 1838 af Frémy 1 
paa nogle Vandprøver, der over et Aur forud vare bleven 
optagne paa den franske Expedition med ‘La Bonite' i 1836 
og 37. Vandprøverne bestode dels af Overfladevand dels 
af Vand fra forskjellige Dyb indtil 450 franske Favne og 
vare optagne med et af Biot opfundet Apparat. 2 
Ved Analysen af den udkogte Gas absorberede Frémy 
Kulsyren med Kalilud og Surstoffet med Phosphor. Resul- 
taterne ansaaes allerede af Frémy selv for upaalidelige og 
de staa saa bestemt i Strid med alle nyere Angivelser, at 
man med temmelig stor Sikkerhed kan antage, at det lange 
Tidsrum mellom Vandprøvernés Øsning og deres I ndersø. 
gelse har gjort dem fuldstændig uhrugbare. 
1 1843 udførte Morren 3 nogle Undersøgelser af Over- 
fladevandot ved Saint-Malo nærmest i den Hensigt at paa- 
vise Sollysets Indflydølse paa den relative Sammensætning 
at den af \ andet absorberede Luft. Han kom i den Hen- 
seende til det Resultat, at Surstofmængden fandtes størst 
og Kulsyremængden mindst ved. klart Sollys, hvorimod om- 
vendt Surstofmængden fandtes mindst og Kulsyremamgden 
størst ved . mørkt overskyot Veir. Vandprøverne undersøg- 
tes ikke paa Stedet, men sendtes til Rennes, hvor de af 
Morren udkogtes i Kolber paa 4.5 Litre. Den udkogte Gas 
lededes gjennom Kautschukledning .over i en Flaske, hvori 
Gasarterne opsamledes over Vand. Ved Analysen af Gasen 
anvendte han til Absorbtion af Kulsyren Kalilud og for- 
1 Compt rend, (i — (il (i. 
* Pogg. Ann. 37 — '41 (i. 
3 Ann. Chim. Phys. [3] — 12 — 
riably lacked the means. Not till chemists had been sent 
out on the numerous Expeditions dispatched of late years 
to all quarters of the globe, was it possible to study this 
subject in detail. The sole object of such Expeditions hav- 
ing been the scientific investigation of the ocean, they were 
naturally fitted out with the greatest possible care, being 
furnished with the latest and most improved apparatus, 
and every necessary aid and appliance. It is obvious, 
therefore, that these Expeditions must largely contribute 
to our chemical knowledge of the ocean, more particu- 
larly with regard to observations which, like the deter- 
mination of gaseous bodies, will not brook delay, but 
must be taken immediately the sample of water has been 
drawn. Hence, very great weight should be attached to 
observations instituted under such circumstances, viz. those 
that relate to the determination of gaseous bodies in sea- 
water. It will not, however, be out of place, briefly to notice 
some of the earlier observations undertaken with- that ob- 
ject in view. 
The earliest experiments, so far as I am aware, relat- 
ing to the air in sea-water, were instituted in 1838, by 
Frémy, 1 with samples of water drawn more than a year 
before on the French Expedition with the •Bonite,' in 1836 
and 1837. These samples of water consisted partly of sur- 
face-water, partly of water from various depths, the great- 
est being 450 French fathoms; and were collected with an 
apparatus devised by Biot. 2 
When analysing the gas driven oft’, the carbonic acid 
was absorbed in a lye of potash, the oxygen being con- 
sumed with phosphorus. But Frémy himself did not regard 
as trustworthy the results of this process; and they have 
proved so decidedly at variance with those of all later 
observations, that his samples of water, owing to the length 
of time for which they had been preserved previous to 
examination, had no doubt become utterly worthless for 
experimental purposes.* 
In 1843, Morren 3 instituted a series of experiments 
with surface-water, near St. Malo, chiefly with the object 
of determining the influence of solar light on the compo- 
sition of the air absorbed by sea-water. He found the pro- 
portion of oxygen to be greatest, and that of carbonic acid 
least, in bright weather; whereas the proportion of oxygen 
was least, and that of carbonic acid greatest, with a dark, 
cloudy sky. The samples of water were not examined 
on the spot, hut taken to Rennes, and there boiled by 
Morren, in matrasses containing 4.5 litre. The gas driven 
oft during the process was conducted through a caou- 
tschouc tube into a phial, and there collected over 
water. When analysing the gas, Morren used a lye ol 
1 Compt. re ml. (5, p. (5 lli. 
* Pogg- Ann. 37. p. 4 Hi. 
3 Aun. Chim. Phys. [3], 12, p. f>. 
