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, Forst 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 

 videnskabelig Undersøgelse af Havet, og der har derfor 

 med Hensyn paa Udrustningen altid været lagt megen Vind 

 paa ved hensigtsmæssige Foranstaltninger og omhyggelige 

 Forberedelser at fremme dette Formaal saa meget som 

 nmligt, og det er derfor klart, at disse Expeditioner maa 

 have den største Betydning for den chemiske Undersøgelse 

 af 'Havene specielt, hvor Talen er om saadanne Observatio- 

 ner, der ligesom Bestemmelser af Gasarterne . ikke taale 

 Opsættelse, men nødvendigvis maa adføres øieblikkélig efter 

 at Vandprøven er ost, Saaledes maa aabenbart de under 

 disse Omstændigheder udforte Observationer faa storst Vægt, 

 hvor, det dreier sig om at skaffe Oplysninger om Gasarterne 

 i Sova ndet. udenat det dog derfor vil tindes paa urette 

 Plads her at give en kort Oversigt ogsaa over de herover 

 udforte ældr-e Undersøgelser. 



De tidligste Undersøgelser, der mig bekjendt ere 

 gjorte over Luften i Sovandet. udførtes i L838 af Frémy 1 

 paa nogle Vandprøver, der over et Aar forud vare bleven 

 optagne paa den franske Expedition med 'La Bonite' i L836 

 og 37. Vandproverne bestode dels af Overfladevand dels 

 af Vand fra forskjellige Djtø indtil 450 franske Favne og 

 vare optagne med et af Biot opfundet Apparat. - 



Ved Analysen af den udkogte Gas absorberede Frémy 

 Kulsyren med Kalilud og Surstoffet med Phosphor. Resul- 

 taterne ansaaes allerede af Frémy selv for upaa.lidelige og 

 de staa saa bestemt i Strid med alle nyere Angivelser, at 

 man med temmelig stor Sikkerhed kan antage, at det lange 

 Tidsrum mellein \ andprøvernes Øsning og deres Undersø- 

 gelse har gjort dem fuldstændig ubrugbåre. 



I 1^4o udforte Morren :; nogle Undersøgelser af Over- 

 fladevandet ved Saint-Malo nærmest i den Hensigt at paa- 

 vise Sollysets Indflydelse paa. den relative Sammensætning 

 af den af Våndet absorberede Luft. .Han kom i den Hen- 

 seende til det Resultat, at Surstofmængden fandtes størst 

 og Kulsyremængden mindst ved klart Snllys. hvorimod om- 

 vendt Surstofmængden fandtes mindst og Kulsyremamgden 

 størst ved mørkt overskyet Veir. Vandproverne undersøg-: 

 tes ikke paa Stedet, men sendtes til Rennes, hvor de a! 

 Morren udkogtes i Kolber paa 4.5 Litre. Den udkogte Gas 

 lededes gjenneni Kautschiikledning over i en Flaske, hvori 

 Gasarterne opsamledes over \ and. Ved Analysen s af Gasen 

 anvendte lian til Absorbtfon af Kulsyren Kalilud og for- 



1 I ' pt, rend. ii — 616. 



I ' j. Ann. 37 1 16, 



' Ann. Chim. Phys. [3] — 12 — 



riably lacked the means. Xot 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 titted out with the greatest possible care. being 

 furnished with the latest and most improVed apparatiis, 

 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, hut 

 . must be tåken immediately the sample of water has been 

 drawn. Hence. very great weight should be attached to 

 observations insfituted under such circumstauces. viz. those 

 that relate tu the determination of gaseous bodies in sea- 

 water. It will not, however, be out of place, briefly to noticé 

 some of the earlier observations undertaken with that ob- 

 ject in view. 



The earliest experiments, so far as I am aware, relat- 

 iiiL! 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 L838 

 and 1837. These samples of water consisted partlv ofsur- 

 face-water, partlv of water from various depths, the great- 

 est being 4.">0 French fathoms; and were collected with an 

 apparatus devised by Biot.- 



When analysing the gas driven off, 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 va.riance 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, clnetly with the object 

 of determining the intluence 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 

 w r as least, and that of carbonic acid greatest, with ji dark. 

 cloudy sky. The samples of water were not examined 

 .on the spot, but tåken tu Hennes, and theav hoilod by 

 Morren, in matrasses containing 4.5 litre. The gas driven 

 off during the process was conducted through a caou- 

 fcschouc tube into a phial, and there collected over 

 water. Whén analysing. the gas. Morren used a lye of 



1 Compt. rend. i>. p. lilii. 

 - l'"^'^. Ann. :IT. p. Ild. 

 3 Ann. Chim. 1'liv-. [3 . 12, p. 



