FOR THE PEOPLE FOR EDVCATION FOR SCIENCE
LIBRARY
OF
THE AMERICAN MUSEUM
OF
NATURAL HISTORY
DEN NORSKE NOR EH AY S- EXPEDITION
1876 — 1878.
C H E M I.
I. O'M LUFTEN 1 SOVANDET.
II. OM KULSYREN I SOVANDET.
III. OM S ALT H 0 LDI GHEDEN AF V ANDET I DET NORSKE NORDHAV.
. AF
HERCULES TORN0E.
MED 3 TRÆSNIT OG 3 KARTER.
CHRIST I A. IV I A.
GRØNDAHL & 80 NS BOGTRYK K ERI. 1880.
THE NORWEGIAN NOR TH-ATLANTIC EXPEDITION
//
CHEMISTRY.
Ssi/,4 L ( 1 ,
I. ON THE AIK IN SEA- WATER.
II. ON THE CARBONIC ACID IN SEA-WATER, HI. ON THE AMOUNT OF SALT IN THE WATER OF THE NORWEGIAN SEA.
O Y
HERCULES TORN0E.
WITH 3 WOODCUTS AND 3 MAPS.
OH K 1ST]
PRINTED BY GRØNDAHL & 80N. 1880.
»
1. Om Luften i Sovamlet.
1. On tin* Air in Sea- Water.
Allerede i lange. Aarrækker har der fra Tid til anden af forskjellige Ckemikere været foretaget Experimenter i den Hensigt-at studere Forholdene ved den atniosphæriske Lufts Absorbtion af de Vædsker, hvormed den i Naturen kommer i Berøring, men det er dog først i de seneste Aar, at dette Spørgsmaal har været gjort til Gjenstand for mere omfattende Under søgelser. hvad angaar Søvandet i de aabne Have. Rigtignok foreligger der ogsaa fra ældre Tider en- kelte Opgaver over Sammensætning og Mængden a f den i Søvandet opløste Luft, men disse ere for det Meste bundne til nogle ganske faa Puncter af Kysterne. og der. hvor Forsøgene ogsaa pmfatté Vandpirøver fra det aabne Hav, er der ofte saameget at indvende mod Materialets Indsam- ling og Opbevaring, at man. selv om Intet maatte være at udsætte‘paa Metboderue til dets Undersøgelse, ikke kunde sætte disse i Klasse med de med vore Tiders fuldkomnere Hjælpem idler udførte Observat ioner.
•Naar saaledes vort Kjendskab til Fordelingen af Luf- ten i Verdenshavene specielt for de store Dybs Vedkommende lige til de seneste Aar maa siges at have været meget mangelfuldt, da maa Grunden hertil søges i de mange Van- skeligbeder. som man allevegne møder, naar man vil under- age disse Spørgsmaal. Hvor det gjælder at bestemme Sammensætn ingen af den atniosphæriske Luft. giver Luftens Letbevægelighed Ret til af Undersøgelser udførte paa faa Puncter at slutte til den hele Atmosphære. hvad der imid- lertid ikke er Anledning til for Søvandets Vedkommende. Der fordrer Havenes langt ringere Bevægelighed et større Antal Observationer. idet der her maa stilles meget stren- gere Fordringer til den geografiske Udbredning. Enten maatte altsaa Vandprøver hjemføres fira fjerne Farvande, saaledes at de ved en længere Tids Henstand udsatte for allebaande fremmed Indvirkrring kunde blive, aldeles ubrug- bare, eller Analytikeren maatte. udsat for alle de Ulemper, som et Skibs Bevægelser medfører for vidensknbelige Un- dersøgelser, forsøge bedst muligt at udføre sine Observatio- ner ombord. Men selv naar der hos mange Chemikere fra ældre Tider kan have været Interesse for ved Undersøgel-
Deu norske Nordliavsexpedition. Tornøe: Cliomi.
Experiments have long since been instituted, from time to time, by divers chemists, with the object of investi- gating the absorption of atmospheric air by the fluids with which in the course of nature it comes in contact ; but not till of late years has this phenomenon been made the subject of exhaustive treatment in its relation to ocean- water. True, there do exist comparatively early statements respect- ing the amount and composition of the air present in sea- water. but the great majority of such are confined to a very few coastal* localities; and when, as was sometimes the case, the samples of sea-water examined had been drawn from the open sea, the mode of collecting and preserving them was frequently so open to objection that, even assum- ing the methods adopted for their examination to have been in every respect trustworthy, these early experiments will not bear comparison with those of modern date, per- formed with the far superior apparatus since devised.
Our knowledge therefore, till but a few years since, of the distribution of air in ocean-water, must be said to have continued very imperfect; and the reason is found iii the numerous difficulties everywhere encountered when proceeding to investigate so intricate a subject. From the great mobility of the atmosphere, experiments in a few localities only will suffice to determine the general com- position of air; but with sea -water the case is different. Water being far less fluid than air, many observations are obviously needed, since the greatest importance must be attached to geographical position. Hence, sam- ples of sea-water had to be brought home from 'distant regions, and in that case, by being allowed to stand over for a comparatively long period, left exposed to all manner of disturbing influences : or the observations were taken on board, and experiments performed to the best of the ana- lyst's ability, in spite of the numerous drawbacks entailed by the motion of the vessel. But, though many of the earlier chemists would, when at sea, no doubt have felt an interest in contributing tø solve the problem of the distri- bution of air in the water of the ocean, they almost inva-
l
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 Frémy1 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 Morren3 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, Morren3 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>.
3
brændte Surstofgasen med overskydende Vandstof. Han brugte. ogsaa her som Spærrevædske Vand. som paa Vor- linand var mættet ined Luft. og det kan saaledes ikke for- undre, at de Resultater, lian erholdt, vise temmelig betyde- lige Afvigelser. Surstofmængden varierer saaledes fra 39.5 til 31.0 og udgjør i Middel 34.7 °/0 af den samlede Surstof- Kvælstofmængde. medens denne varierer mellem 20.0 og 30.5 og i Middel udgjør 24.5 CC. pr. Litre af det udkogte Vand. Som man heraf ser, svarer den midlere Surstofpro- cent meget noie med det af Bunsen senere for destilleret Vand opstillede Tal. hvorimod de Tal, Morren opfører som Udtryk for den samlede Surstof-Kvæ-lstofmængde. ingen nøi- agtig fixeret Betydning have, da han intetsteds angiver den Barometerstand og Temperatur, hvortil han har redu- ceret sine Gasvolumina.
Nogle Aar senere i 1846 gjenoptog Lewy1 Morrens Undersøgelser paa nogle Vandprover, som han oste ved Langrune i Nordost for Saint-Malo, og anvendte for at kunne sammenligne sine Resultater med Morrens nøiagtig den af ham beskrevne Arbeidsmethode. Hans Resultater vise ogsaa. naar man tager Hensyn til. at Vandprøverne alle skrive sig fra samme Sted, ikke ubetydelige om end meget mindre Afvigelser, som lian ligesom Morren tilskri- ver Sollysets Indflydelse. Surstofmængden varier hos ham fra 35.4 til 32.4 og udgjør i Middel 33.6 °/o af den samlede Surstof-Kvælstofmængde, som gjennemsnitlig beløber sig til 17.3 CC. pr. Litre og ikke overskrider Grændserne 18.9 og 16.3. Heller ikke Lewy har nærmere fixeret Betydnin- gen af de opførte Gasvoliynina. Dm- har forresten i hans Tabel indsneget sig meningsfor virrende Regnefeil, som har givet Anledning til. at han er bleven misforstaaet.
I 1851 har end videre A. Hayes2 3 offentliggjort nogle Udtalelser om Fordelingen af Luften i Søvandet dog uden at vedføie sine Originalobservationer. Ifølge ham tincles i Vand fra større Dyb altid en betragtelig mindre Mængde Surstof end i OverHadevandet, en Regel, som overalt holdt stik saavel i den hede som tempererede Zone, naar und- tages i Golfstrømmen, hvor den stærke Bevægelse i Vån- det kunde antages at forstyiTe den almindelige Ligeva?gt. Han fandt ogsaa efter Storme en betydelig større Surstof- mængde i OverHadevandet.
I 1855 udførte M. F. Pisani a nogle Undersøgelser af Saltene i OverHadevandet ved Bujuk-Déré og bestemte sam- tidig de i Våndet indekoldte Gasarter. Resultaterne filides sammenstillede i nedeustaaende Tabel, hvor Volumet er reduceret til U" og 766 mm .Tryk og udtrykt som CC. pr. Litre Vand.
potash for absorbing the carbonic acid, and consumed the oxygon with a surplus of hydrogen. Here, too, the confining fluid was water, previously saturated with air; and hence it is not surprising, that the results obtained should have been found to vary considerably. Thus, for instance, the amount of oxygen varies between 39.5 and and 31.0 per cent, the mean proportion being 34.7 of the total amount of oxygen and nitrogen; while the latter ranges from 20.0 to 30.5, giving a mean proportion of 24.5“ per litre. The mean percentage of oxygen agrees, therefore, very closely with the proportion afterwards found by Bun- sen for distilled water; whereas no definite importance can be attached to Morren’s figures representing the total amount of oxygen and nitrogen, since that observer does not anywhere state to what temperature and atmospheric ■ pressure he. had reduced the volume of the gas.
Some years after, in 184(5, Lewy1 repeated Morren’s experiments, with samples of water drawn at Langrune, north-east of Saint-Malo. adopting, the better to compare his results with those of Morren, precisely the same mode of operation. The results obtained by this chemist, see- ing that the samples of water were all of them from the same locality, vary, too, considerably, though by no means to the same extent, - which he, in common with Mor- ren, ascribes to the influence of solar light. The amount of oxygen ranges from 35.4 to 32.4 -33.6 per cent, being the mean proportion of the total amount of oxygen and nitrogen, which averages 17.3“ per litre, having in no case passed the limits 18.9 and 16.3. Lewy, too, omits to give the factors determining the volume of the gas. Moreover, divers perplexing errors have slipped into his Table; and hence he has been misunderstood by some.
In 1851. A. Hayes2 published a. paper on the distri- bution of air in sea-water, without however embodying his original observations. According to the observations of that chemist, the amount of oxygen in water drawn from ' great depths is always appreciably less than that in surface- water, a rule which holds good for all seas both of the torrid and the temperate zones, with the exception of the I Gulf Stream,' where the strong current may he supposed to exert a disturbing influence. After a heavy gale of wind, too, the proportion of oxygen in the surface-water was found to be much greater.
In 1855, M. F. Pisani* instituted a series of observa- tions near Bujuk-Déré on the salts in surface-water, and also determined the gaseous bodies it contained. His results are given in the following Table, the volume being reduced to a temperature of 0° and a pressure of 760mm, expressed in cubic centimetres per litre.
1 Ann. Ckim. Phys. [3] — IT. Ann. Chem. Pharm. 58 — 320.
* Sillim. Ainer. Journ. (2| — 11 — 241.
3 Compt. rend. 41 — 532.
1 Ann. Chim. Phys. (3], 17; Ann. Chom. Pharm. 58, p. 320. * Sillim. Amer. Journ. (2), 11, p. 241.
3 Compt. rend. 41, p. 532.
1*
4
|
o -f- N pr. |
Litre |
16.0 |
I 6.2 |
|
0 -f- iV = i oo |
0°/o |
3**4 |
33-2 |
|
N°lo |
68.5 |
66.8 |
I Aaret 18(59 udgik fra England Porcupineexpeditio- nen, livor der for førete Gang foruden de øvrige videnska- bolige Arbeider ogsaa foresloges udført mere omfattende chemiske Undersøgelser. Man besluttede her at benytte den udmærkede Anledning til ved talrige Forsøg saavel med Overfladevand som Vand fra større Dyb at skaffe sig Oplysning om de Fluctuationer, som optræde saavel i de absolute som relative- Mængder af de i Søvandet opløste Gasarter. Forut undgaa de Feil, som nødvendigvis maatte indsnige sig, naar de til Gasanalyser bestemte Vandprøver opbe våredes i længere Tid før Undersøgelsen, bestemte man sig her for den Udvei at foretage Gasanalyserne ombord. Til Optagelso af do fra større Dyb stammende Vandprøver benyttedes en (meget simpel Vandhcnter bestaaende at en bul Metalcylinder med letbevægelige opadslaaende Kegle- ventiler, et Apparat, hvis Paalidelighed senere Undersøgelser giver Anledning til at bétvivle. Udkogningen og Opsam- lingen af Gasarterne forøtoges i alt Væsentligt som ved de tidligere beskrevne Forsøg, og anvendtes under Analysen til Absorbtion af Ivulsyre og Surstof Kalihydrat og pyrogal- lussur Kali. Det siger sig selv, at de paa denne Maade erholdto Resultater maatte være beheftede mod meget be- tydelige Observationsfeil, livad der , ogsaa tydeligst vises al de store AjVigelsør mellom de faf forskjellige Observatører efter. denne Fremgangsmaade udførto Bestemmelser. Som Udtryk for Sammensætningen af den af Overfladévandet udkogte Luft fandt nemlig de tro Ohemikere, som paa de tre Togter, hvori denne Expedition deltes, efter hinanden udførto cje chemiske Arbeider, tølgende Tal:1
W. L. Carpenter . . . . 31.6 °/0 0 mod 68.4 °/0 N*
Hunter 36.4 - 0 - 63.6 - N.
P. Herbert Carpenter . . . 30.5 - 0 69.5 - N.
Dotte er kun de af de enkelte Observationer udle-
dede Middelværdier, men, som man ser, er allerede Afvi- gelserne melle m disse overmaade store, medens. de enkelte Bestemmelser, som ikke tiudes opførte, varierer mcllem langt videre Grændser. Saaledes optøres som ^ dergrænd- ser for Variationerne af Surstofmængden i Cverfladevandet Maximum 45.3 og Minimum 14.0 °/0 af den samlede Gas- mængde, Kulsyren iberegnet.
Porcupineexpeditionens Ohemikere ansaa selv sine Re- sultater upaalidelige, dog mindre paa (i rund af Mangler ved Arbeidsmethoderne, end fordi, den af dem benyttede Vandhcnter tilled Undvigelsen af den Luft. som de mente kunde udvikle sig. naar Våndet fra* de større Dyb naaede op til det ved Overfladen herskende* mindre Tryk. De tog forresten sin Tilflugt .ogsaa til andre Midler for at forklare
1 Proc. Roy. Soe. !>• — 397.
|
0 N pr. |
Litre |
16.0 |
16.2 |
|
0 -(- N= ioo |
0 p.ct. |
3i-4 |
33-2 |
|
N p.ct. |
68.5 |
66.8 |
In the year 1869, the * Porcupine’ Expedition was dispatched by the British Government, and it was now pro- posed. for the first time, to institute a, series of chemical ex- periments on a more comprehensive scale than any hitherto performed. By talcing advantage of this excellent oppor- tunity to examine numerous samples of sea-water, both from the surface and from great depths, the fluctuations that occur alike in the absolute and the relative amounts of gaseous bodies in ocean -water might be effectively investigated. In order to guard against the error that must necessarily arise when the samples of water are pre- served for any length of time previous to examination, it was resolved to undertake all analyses of gas on board. For obtaining samples of water from' great depths, a very simple instrument was used, consisting ol a hollow metal cylinder, furnished with conical-shaped valves, opening above, an apparatus the trustworthiness ol which subsequent ex- periments have shown reason to doubt. The gas was boiled out and collected by a process essentially similar to that adopted for the experiments previously described, the car- bonic acid and the oxygen having been absorbed by hyd- rate of potash and pyrogallic acid. As a matter ol course, very considerable errors ol observation would attach to results obtained by this method, the best proof of which lies in the extent to which the determinations of different observers performed by this møde of operation are found to vary. For instance, the three chemists who successively accompanied the Expedition on the three voyages into which it was divided, express the composition ol the air boiled out of surface-water by the following figures:1 -
W. L. Carpenter . . . 31.6 p.ct. 0 and 68.4 p.ct. N.
Hunter 36.4 - 0 - 63.6 - N.
P. Herbert Carpenter . 30.5 0 69.5 - N.
These amounts, however, are the mean values deduced from the several observations, and yet they vary exceed- ingly: the individual determinations, which are not given, must obviously have ranged between far wider limits. Thus, the extreme limits between which the amount ol oxygen was found to vary in surface-water, is stated to have been 45.3 (maximum) and 14.0 (minimum) per cent ol the total amount of gas, including the carbonic acid.
The chemists who accompanied the ‘Porcupine’ Ex- pedition did not even themselves regard the results obtained ‘ as trustworthy,’ less however on the ground of possible defects in the modes of operation, than because the thé ap- paratus used for collecting the water admits of the escape of air which, in their opinion, may be liberated on water drawn from great depths reaching the surface, where the atmos-
1 Proc. Roy. Soc. IS, p. 397.
5
de observerede store Afvigelser. saaledes tilskreves stærke Bevægelser af Havoverfladen enten ved Storme eller paa anden Maade den Evne at forøge Surstofmængden og for- ringe Kidsyremængden, ligesom rigt Dyreliv ogsaa tilskre- ves en meget stor Indflydelse paa Sammensetningen af den i Søvandet opløste Luft.
I 1871 udgik atter igjen denne Gang fra Tyskland en Expedition til Untjersøgelse af Østersøen, hvormed som Chemiker fulgte Dr. O. Jacobsen. Med Resultaterne af de fra de tidligere Expeditions hidrøremde Gasbestemmelser for Øie besluttede ban sig hverken for den ene eller den anden af de ved Bonite eller Porcupineexpeditionen anvendte Fremgangsmaader men slog ind paa en Middelvei, den eneste, som i dette Tilfælde kunde føre til paalidelige Resultater.
Han delte Undersøgelserne i to Dele og udførte den uopsættelige Del af dem nemlig Gasarternes Udkogning strax, medens lian. indseende Umuligheden af at udføre til- fredsstillende Gasanalyser ombord paa et Fartøi i aaben Sø, opsatte deres nærmere Undersøgelse til Hjemkomsten. Désværre gav Mangelen af en til Optagelse af Dybvancls- prøver egnet paalidelig Vandhenter Anledning til. at det Iste A ars Ud bytte af denne Expedition for Gasanalysernes Vedkommende reducerede sig til blot og bart Indsamling af den Erfaring, som senere skulde komme til Anvendelse ved det Aaret efter foretagne Togt i Nordsøen. Manglerne ved den paa Porcupineexpeditionen benyttede Vandhenter kavde nemlig bevæget Jacobsen til ogsaa til Øsning af de for Gasanalyser bestemte Vandprøver at benytte en Vand- benter, der nedsænkedes, fyldt med Luft. Naar nu Appa- ratet i Dybet aabnedes, absorberedes under det der her- skende store Tryk momentant en Del af den nedbragte atmosphæriske Luft, hvorved de paa disse Vandprøver ud- førte Gasanalyser bleve saa upaalidelige, at der ikke en- gang værdigedes dem en Offentliggjørelse.
De paa Østersøtogtet i 1871 indhøstede Erfaringer, muliggjorde det imidlertid for Jacobsen ved en omhyggelig Forberedelse til den i 1872 foretagne Expedition i Nord- søeu at overvinde eller omgaa de Vanskeligheder. som havde bevirket Manglerne ved de paa Porcupineexpeditionen fore- tagne Undersøgelser, og det lykkecles ham denne Gang som Resultat af sine Arbeider at offentliggjøre en Afhandling.1 som giver en Række af vore Tiders Fordringer strengt til- fredsstillende Oplysninger om Luften i Søvandet. Til Op- tagelse af de til Gasanalyser bestemte Vandprøver fra Dy- bet tjente paa IS’ ordsøtogtet et af Dr. H. A. Meyer angivet Apparat2 * * * bestaaende af en tung Metalcylinder, som ved Udløsning i det bestemte Dyb faldt ned over to vel islebne koniske Ventiler, og derved afspærrede det mellem disse
1 Ann. Chem. Pharm. 1UT — 1: Jahresbericht der Commission zur
wissenschaftlichen Untersuchung der deutschen Meere in Kiel, 1*72
—7.1 — 43.
Jahresbericht der Commission zur wissenschaftlichen Untorsueh-
ung der deutschen Meere in Kiel 1H72 — 73 — 5.
pheric pressure is less. But they had recourse to other means whereby to explain the great differences observed, ascribing to the state of violent agitation into which the surface of the ocean is thrown bv heavy storms, or to some other adequate cause, the ability of increasing the proportion of oxygen and diminishing that of carbonic acid : an abund- ance of animal life, too, was believed to exert very great influence on the composition of the air absorbed in sea-water.
In 1871, an Expedition >vas despatched from Germany for the investigation of the Baltic, Dr. (). Jacobsen accom- panying it as chemist. Warned by the unsatisfactory results of former gas-analyses, he resolved to adopt neither of the methods resorted to on the. ‘Bonite’ and ‘Porcupine’ Expeditions, but rather to take a middle course, which indeed held out the only prospect of success.
Accordingly, he divided his observations. Experiments admitting of- no delay, such as boiling off the gas, were performed at once, whereas all analyses of gas, impossible as it is found to operate satisfactorily on board a. vessel in the open sea, were deferred till his return home. Un- fortunately, the want of a trustworthy apparatus for col- lecting samples of water from great depths, confined the results obtained on the first voyage of the Expedition, as regards analyses of gas, to the mere acquisition of experience, which, however, there was ample oppor- tunity of applying on the cruise undertaken the following year in the North Sea. The defective construction of the instrument employed for collecting water on the ‘Porcu- pine’ Expedition had induced Jacobsen to make use of an apparatus which, even when drawing water for gas-anal- yses, was sunk full of air. Now, on opening this appa- ratus at the required depth, some portion of the air it contains will, by reason of the great pressure, be momen- tarily absorbed; and hence all analyses of gas with such samples of water proved to that extent defective as to be not even deemed worthy of publication.
Meanwhile, taking advantage of the experience ac- quired in 1871 on the cruise in the Baltic, Dr. Jacobsen succeeded, after careful preparation to meet the require- ments of the Expedition undertaken in 1872 to the North Sea, in surmounting or evading the difficulties experienced on the ‘Porcupine’ Expedition, and was enabled, as the result of his labours, to publish a treatise* on the air present in sea- water recording a series of eminently satisfactory results. For collecting samples of water wherewith to undertake anal- yses of gas in water from the bottom, or from great depths, an apparatus, described by Dr. H. A. Meyer, was made use of on the cruise in the North Sea.8 It consists of a heavy I metal cylinder, which, at the required depth, will drop down on two accurately fitted conical valves, cutting off all com-
1 Ann. Chem. Pharm. 107, p. l ; Jahresbericht der Commission zur wissenschaftlichen Untersuchung der deutschen Meere in Kiel, 1^.2 -7 I 1.
1 Jahresbericht der CoininisHion zur wissenschaltlichen Untersuch- ung der deutschen Meere in Kiel, ls72 — 73, p. r».
()
beliggende Vandlag. lldløsningen foregik enten ved Appar ratets Anslag mod Bunden eller i intermediære -Dyb ved et langs Linen nedsænket Lod.
Ved Uddrivelsen af de i Våndet indeholdte Grasarter anvendte Jacobsen Bunsens Princip, idet Våndet kogtes i
munication with the outside water. The detachment was effected either by the instrument striking the bottom, or, at intermediate depths, by running a weight down the line.
For expelling the gas contained in the water, Jacob- sen made choice of Bunsen's method, boiling the water in
et ved Vanddamp frembragt Vacuum, og construerede i Forbindelse med Dr. H. Behrens i dette Øiemcd et Appa- rat, som i Simpelhed og Paalidelighed Intet lader tilbage at ønske. Apparatet, som findes afbildet i Figur l, har af Jacobsen faaet følgende Beskrivelse :
a vacuum created by steam ; and to meet the requirements of this process, he devised, with the assistance ot Dr. H. Behrens, an apparatus which in trustworthiness and sim- plicity of construction leaves nothing to be desired. This apparatus, of which a drawing is given in Fig. 1, Dr. Jacobsen has described as follows: —
<
"Die Siedekugel a låuft in ihrem unteren Theil in ein starkwandiges, genau . cylindrisches Glasrohr aus, wel- ches nnten zugeschmolzen. aber bei c mit einer seitlicken Oeffnung versehen ist. Je nachdem diese Oeffnnng bis unter den Kautschukpfropfen d hinabgedrttckt oder bis in seine Durchbohrung heraufgezogen wird, ist die Siedekugel mit dem Innern des Wasserkolbens in Verbindung oder gegen dasselbe abgeschlossen. Das Glasrobv muss sich in der glatten Durchbohrung des Kautschukpfropfens mit Rdib- ung auf- und niederbewegen , diese Reibuug dart aber nicht so stark sein, wie die zwischen dem Pfropfen und dem cylindrischen Kolbenhals. 1st einmal ein fehlerfteief Pfropfen aus vulkanisirtem Kautschuk den Glastheilen des Apparates auf das Sorgfaltigste angepasst, so lean diese Ven- tilvorrichtung unbegrenzt lange benuzt werden, ohne von ihrer volligen Zuverlåssigkeit einzubiissen.
Das Gassammelrohr b ist durch ein kurzes Kautschuk- rorchen mit der Siedekugel verbundén und zwischen die federnden Arme des messingenen Halters /eingeklemmt. Das untere Elide dieses Halters tragt eine weit stårkere Klam- mer, deren Korkfiitterung durch die starche Schraube e sehr fest um das Rohr der Siedekugel gepresst wird, so dass man, am unteren Theil des Halters anfassend, Siedekugel und Saramelrohr in dem Kautschukpfropfen auf- und nie- derschieben und damit die Oeffnung c beliebig verlegen kann.
Der Rauminhalt der Siedekugel betragt etwas mehr als das Pop pelte von dem Volumen, um welches sich die* auszukochende Wassermenge beim Erwiinnen auf 100° ausdehnt.
Bei der Benutzung des Apparates fullt man zunachst die schon im Pfropfen steckend'e und in den Halter einge- klemmte Siedekugel zur Halfte mit Wasser und schiebt den Pfropfen fiber die seitliche Oeffnung. Man ftillt nun die Kochflasche durch ein bis auf ihren Boden reichdndes Gummirohf direct aus dem Schopfapparat bis zum U$ber- laufen mit dem auszukochenden Wasser und setzt, nachdem die Oeffnung c bis eben unter den Kautschukpfropfen ver- schoben ist, diesen sehr fest in den Hals der Kochflasche ein. Zielit man nun die Siedekugel bis zur Herstellung des Verschlusses in die Hoke, so entsteht dadureh in der Kochflasche ein kleines Vacuum, in welches sofort Gas- blaschen aus dem Wasser aufsteigen. Es wird dadureh Raum geschafft fur die Ausdehnung, welche das oft sehr kalte Wasser schon in den ersten Augenblicken durch die hohere Temperatur der umgebenden Luft erfahrt, Man ftigt nun das Sammelrohr an, liber dessen beide Enden vorher kiirze Gummirohren gezogen sind, stelt die Koch- flasche in ein Wasserbad, erhitzt das Wasser in der Sie- dekugel durch eine darunter angebrachte Weihgeistflamme und erhiilt es im Sieden, bis man der vollstandigen Aus- treibung der Luft aus dem Sammelrohr gewiss sein kann. In dem Augenbliek, in welchem man mit der rechten Hand die Flamme entfernt, kneift man mit der linkeh das Ende des oberen Gummirohrs zu, verschliesst es darauf durch Hineinsteckeu der abgerundeten Spitze eines passenden Glasståbchens und schmilzt sofort bei g ab.
“Die Siedekugel a liiuft in ihrem unteren Theil in ein starkwandiges, genau cynlindrisches Glasrohr aus. wel- ches unten zugeschmolzen, aber bei c mit einer seitlichen Oeffnung versehen ist. Je nachdem diese Oeffnung bis unter den Kautschukpfropfen d hinabgedrUokt oder bis in seine Durchbohrung heraufgozogen wird, ist- die Siedekugel mit dem Innern des Wasserkolbens in Verbindung oder gegen dasselbe abgeschlossen. Das Glasrohr muss sich in der glatten Durchbohrung des Kautschukpfropfens mitReib- ung auf- und niederbewegen, diese Reibung darf aber nicht so stark sein, wie die zwischen dem Pfropfen und dem cylindrischen Kolbenhals. 1st einmal ein fehlerfreier Pfropfen aus vulkanisirtem Kautschuk den Glastheilen des Apparates auf das Sorgfaltigste angepasst, so lean diese Ven- tilvorrichtung unbegrenzt lange benutzt werden, ohne von ihrer volligen Zuverlåssigkeit einzubiissen.
Das Gassammelrohr b ist durch ein kurzes Kautsckuk- rbhrehen mit der Siedekugel verbunden und zwischen die federnden Arme des messingenen Halters/ eingeklemmt. Das untere Ende dieses Halters triigt eine want stiirkere Klam- mer, deren Korkfiitterung durch die starke Schraube e sehr fest um das Rohr der Siedekugel gepresst wird, so dass man, am untern Thc*il des Halters anfassend, Siedekugel und Sammelrohr in dem Kautschukpfropfen auf- und nie- derschiebeu und damit die Oeffnung c beliebig verlegen kann.
Der Rauminhalt der Siedekugel betragt etwas mehr als das Doppelte von dem Volumen, um welches sich die auszukochende Wassermenge beim Erwarmen auf 100° ausdehnt.
Bei der Benutzung des Apparates filllt man zuniichst die schon im Pfropfen steckende und in den Halter einge- klemmte Siedekugel zur Halite mit Wasser und schiebt den Pfropfen fiber die seitliche Oeffnung. Man fiillt nun die Kochfla-sche durch ein bis auf ihren Boden reichendes Gummirohr direct aus dem Schopfapparat bis zum Ueber- laufen mit dem auszukochenden Wasser und setzt, nachdem die Oeffnung c bis eben unter den Kautschukpfropfen ver- schoben ist, diesen sehr fest in den Hals der Kochflasche ein. Zieht man nun die Siedekugel bis zur Herstellung des Verschlusses in die Hbhe, so entsteht dadureh in der Kochflasche ein kleines Vacuum, in welches sofort Gas- blaschen aus dem Wasser aufsteigen. Es wird dadureh Raum geschafft fiii* die Ausdehnung, welche das oft sehr kalte Wasser schon in den ersten Augenblicken durch die hohere Temperatur der umgebenden Luft erfahrt. Man ftigt nun das Sammelrohr an, tiber (lessen beide Enden vorher kurze Gummirbhreii gezogen sind, stellt die Koch- flasche in ein Wasserbad, .erhitzt das Wasser in der Siede- kugel durch eine darunter angebrachte WeingeistHamme und erhiilt es im Sieden, bis man der vollstfindigen Aus- treibung der Luft aus dem Sammelrohr gewiss sein kann. In dem Augenbliek. in welchem man mit del* rechten Hand die Flamme entfernt, kneift man mit der linken das Ende des oberen Gummirohrs zu, verschliesst es darauf durch Hineinstecken der abgerundeten Spitze eines passenden Glasstiibcheus und schmilzt sofort bei g ab.
8
Nacbdem nun (lie Oeffnung c bis eben unter den Pfropfen hinabgeschoben ist, wird das Wasserbad erwiirmt und der Inhalt des Kolbens iii heftigem Sieden erhalten. Nacli einiger Zeit bat sicb im oberen Tlieil des Kolben- halses fin freier Raum gebildet, in welcben die Dampf- blasen mit Geriluscb hiiioinschlagen. Man brmgt durcb Entfernen der Wiirmequelle oder durcb kur/.es Heraushe- hon des Apparates aus dem Wasserbad e das Wasser aus der Siedékugel in den Kolben zurilck und wiederholt dieses Ervarmen und tlieilweise AbkUhlen des Kolbenhalses nocli | zwéiinal, wodurcb binnen verbiUtnissmiissig kurzer Zeit eine seln- vollstandige Austreibung der Luft bewirkt wil’d.
Es ist sehr leicbt, schliesslich das Wasser bis zur j vollstiindigen AnfUllung der Siedckugel steigen zu lassen. worauf man durcb Aufziehen derselben den Verscbluss her- stellt und das Sanimelrobr nun aucb bei h abscbmilzt.
Das Sammeln der Gase mittelst dieses Apparates inacbte aucb bei ziemlicb stark bewegter See keine Schwie- rigkeit.
GewObnhch wurden 900 CC Wasser izur Auskocli- ung verwendet.”
Ved Hjælp af dette Apparat indsméltede Jacobsen pan Nordsøtogtet 73 Luffcprøver, som efter Hjemkomsten analyseredes efter Bunsens Methode. idet Kulsyren fjernedes med Kali og Surstoffet bestemtes ved Forbræuding med overskydeiide Vamlstof. * Han sammenstiller sine Resultater i on label, hvor ban i Mbdsætning til de tidligere Forfat- tere betragter den kulsyrefrie Luft og Kulsyren- liver lor sig. 1 saaledes beregnes Surstof'og Kvælstofmængderne som Procenter af den kulsyrefrie Luft, der opløres som ( 1 pr. Litre udkogt Valid reduceret til 0"og 760 mm Tryk. Ilølge denne Tabel hersker dor en ganske mærkelig gjennomført Ensartetbed i Sammensietningen af den Luft, der er ud- drevet af de Vandprøver. som have befundet sig under samme physikalske Eorbolde, saaledes ligger Surstolprocen- j| ten i alle de 24 Lpftprøver, som stamme fra Overflade- '
Y andet, tiltrods for at de skrive sig ^ fra meget forskjellige Localiteter. mellem de meget snævre Grændser af 34.14 og 33.64. og naar denne Overensstemmelse ikke i samme Udstræk- ning er fundet at gaa igjen i de dybere Lag, da* bar dette sin Forklaring i en ujevn Circulation. Naar Surstofmæng- den overalt i Dybet er lunden lig eller noget mindre end i Overfloden, da kan det vel ikke være tvivlsomt, at dette skriver sig fra Surstoffets Eorbrug til Oxvdation al de i Søvandet forekommende organiske Plante- og Dyrerester samt til Sody renes Aandeproces. saaledes som det al Ja- cobsen udtales med følgende Ord: “Der Zusammenbang
dieses Unterschiedes ist leicbt zu denten. In dem schwere- ren Wasser, welches olme erbeblicbe Beimiscbung aus bobe-
1 Naar ,jcg her overalt hai* anvendt denne Jacobsens Fremstillings- maadc og ifølge denne omregnet de ældre Forfatteres Opgavor, hvor Gasnm*ngderne overalt ere fremstillede som Procenter af den sam- lede Sur8tof-Kv«el8tof-Kulsyrcimengde. da vil Granden hertil fremgaå af min senere Afhaiulling “Om Kulsyren i Søvandet."
Nachdera nun die Oeffnung c bfe -ebén unter den Pfropfen hinabgeschoben ist, wird das Wasserbad erwarmt und der Einbalt des Kolbens in beftigem Sieden erhalten. Nacli einiger Zeit bat sicb im oberen Theil des Kolben- halses ein freier Raum gebildet, in welcben die Dampf- blasen mit Geråuscb bineinscblagen. Man bringt durcb Entfernen der W armqcmellei oder durcb kurzes Herausbe- ben des Apparates aus dem Wasserbade das Wasser aus der Siedekugel in den Kolben zuriick und wiederbolt dieses Erwiirmen und tlieilweise AbkUhlen des Kolbenhalses nocli zw’eimal. wodurcb binnen verbaltnissmassig kurzer Zeit eine sehr vollstandige Austreibung der Luft* bewirkt wird.
Es ist sehr leicbt, schliesslich das -Wasser bis zur vollstiindigen AnfUllung der Siedekugel steigen zu lassen, worauf man durcb Aufzieben derselben den Verscbluss her- stellt und das Sanimelrobr nun aucb bei h abscbmilzt.
Das Sammeln der Gase mittelst dieses Apparates maebte aucb bei ziemlicb stark bewegter See keine Schwie-
f
rigkeit.
Gewobnlicb warden 900 CC. Wasser zur Auskocb- ung verwendet.”
With this apparatus Jacobsen collected on the cruise in the North Sea 73 samples of air, which, after the return of the Expedition, were analysed by Bunsens method, potash being used for absorbing the carbonic acid, and the oxygen consumed with a surplus of hydrogen. His
results are set forth in a Table, where, reversing the custom of earlier authors, be refers separately to the carbonic acid and the air free from that body;1 thus, for instance, the respective amounts’ of oxygen and ni- trogen will be found computed as percentages of the air free from carbonic acid, which is given in cc. per litre of the water examined, reduced to a temperature of 0° and a pressure of 760 mm. According to this Table, a truly j! remarkable uniformity prevails in the composition of the air expelled from samples of sea-water which have been j. exposed to the same physical influences; thus, for instance, the percentage of oxygen in the 24 samples of air derived from surface-water, was found, notwithstanding the collection of the latter in widely different localities, to range between the exceedingly narrow limits of 34.14 and. 33.64; and though equal agreement does not extend to the deeper- lying strata, this may be accounted for by irregular- ity of circulation. That the amount of oxygen at the bot- tom. or in great depths, should invariably prove equal to. or somewhat less than, that at the surface, is a phenom- enon the cause of which must unquestionably be as- cribed to the consumption of that gas in the oxidation of organic remains, and for the support of the res-
1 The reason that induced me to adopt exclusively Jacobsen’s mode of representation, and by the standard of that process to recompute the results of earlier observers, who invariably give the proportions of the gases determined as percentages of the total amount of oxygen, nitrogen, and carbonic acid, will appear in my next Memoir on the carbonic acid present in sea-water.
9
ren Schichten sehr lange in der Tiefe vorweilt, wird olme geniigendeir Ersatz forfcwahrend Sauerstoft' verbraucht zur Oxydation der im Wasser und besonders am Meeyesgrunde vorhandfehen oxydirbaren Stoffe, - - in wahrscheinlich wéit UntergeordnetemGrifde aucfi durch die Atlunung der Thiero."
Men de herved foranledigede Afvigelser ere ikke meget store, idet Surstofprocenten, bortseet fra- nogle faa Und- tagelser. ligger indesluttet mellem 30 og 34, saaledes at den som Regel aftager med Dybet.
Jacobsens Øbservationer, der vare udførte under de mest forskjelligartede Omstændigheder, vise ogsaa paa det Bestemteste, at . de tidligere gjorte Antagelser, om at Sol- lyset og Stormene eller i det Hele taget de meteorologiske Forholde skulde spille nogen frenjtrædende Rolle ligeoverlor den relative Saraménsætning af Overflade.vandsluftén, vare fuldstændig uhegrundede, i ethvert Fald vise de store Over- ensstemmelser, at disse Factorers Indflydelsc maatte være meget ringe.
Med Hensyn paa den absolute Mængde af den Luft, der indeholdes i de fra forskjellige Dyb . optagne Vand- prøver, da viser den sig at tiltage med Dybet, noget der imidlertid let lader sig forklare ved Temperaturens- Aftagen med Dybet, ilden at det er fornødent • at tage «sin TilHugt til de store Tryk. Der blev ogsaa paa Pomeraniacxpedi- tionen for at bevise Urigtigheden af den tidligere paa Here Steder udtalte Formodning, om at Luftgehalten i de store Dyb skulde * staa i Forhold til det der herskende større Tryk. foretaget specielle Experimenter med en af Dr*. Behrens og Jacobsen coustrueret Vaudbenter af Kåutschuk. Denne sammenklemtes først mest muligt. hvorpaa den sidste Rest Luft uddreves af den ved Hjælp afKviksølv, og ned- sænkedes derefter fuldstændig lufttom og lufttæt igjen lukket. Først i Dybet ved Apparatets, Anslag mod Bund aabnedes det, udspændtes og fyldtes med Yand, hvorpaa det atter lufttæt igjenlukket og fyldt med Vand ankom til Over-- fladen. Det viste sig nitid, at de med dette Apparat op- tagne Vandprøver ikke indeholdt mere Luft, end de ved Yandprøvens Temperatur kunde holde opløst under almin- deligt Atmosphæretryk. At dette maatte være saa. kunde man allerede være berettiget til at slutte af nogle Forsøg, som Aimé1 i 1843 udførte. Han anvendte et i den ene Ende aabent Glasrør, som nedsænkedes fyldt med Kvik- sølv og i det bestemte Dyb vendtes omkring, hvorved Kvik- sølvet i Glasrøret delvis erstattedes af\and paa en saadan Maade, at delte afspærredes af Kviksølvet. der optoges af en nedenunder anbragt passende Beholder. Som Resultat af de med* dette Apparat udførte Forsøg udtalte Ainu- den Sats, at den Mængde Luft, som indeholdtes i en bestemt Mængde Søvand, i alle Dyb var meget nær den samme.
. «Ann. Chim. Phys. [3]— 7—497. Pogg. Ann. 30—412.
Den norske Nordlmvsoxpodition. Tornoe: Chomi.
piratory process in marine animals-, as stated by Dr. .Ja- cobsen in the following words: * "Der Zusammenhang
dieses Unterschiedes ist leiebt zu deuton. In dem schwereron Wasser, welches olme erhebliche Beimischung aus hbheren Schichten sehr lange in der Tiefe verweilt, wird olme ge- niigenden Ersatz fortwiibrend SauerstotV verbraucht zur Oxydation der im Wasser und besonders am Moeresgrunde vorbandenen oxydirbaren Stoffe. in wahrscheinlich weit untergeordnetem Grade auch durch die Atlunung dor Tbier.e,'’
But the differences thus occasioned are not very great, since the percentage of oxygen, with but few exceptions, ranges from 30 to 34. as a rule diminishing with the depth.
Moreover, Jacobsen’s .observations, instituted under circumstances the most diverse, furnish incontestable proof, that the views of earlier authors, according to which the (‘fleet of solar light and storms, or indeed meteorological influence generally, was assumed to play an important part in modifying the [composition of the air in surface-water, were wholly unfounded; nay, the extent to which the results based on that hypothesis are found to vary, will of itself show the comparative insignificance of such factors.
As regards the absolute amount of air contained in samples of water collected from different strata, this is found to increase with the depth, — a fact sufficiently obvious from . the temperature diminishing as the depth increases, without needing to seek an explanation in the greater pressure. And with the object of showing that the proportion of air present in sea-water at great depths, is not, as assumed by some, to any appreciable extent dependent on the greater pressure prevailing there, a special series of ex- periments was instituted on the ‘Pomerania’ Expedition, with an apparatus Jfor collecting water constructed of caoutschouc by Drs. Behrens and Jacobsen. This instru- ment was first pressed flat, and then sunk, after the air still remaining in it had been expelled by means of mercury, perfectly air-tight. On its striking the bottom, it opened and tilled with water, after which it again closed, and was then f brought up to the surface, air-tight as before. The samples of water collected in this apparatus were never found to contain more air than would be absorbed, with the same temperature, at the surface. That such must be the case, there was indeed reason to infer from the experiments instituted by Aimé1 in 1843. Aimé made use of a glass tube, which, open at the upper extremity, was sunk full of mercury, and at the required depth inverted, caus- ing part of the mercury in the tube to be replaced by water, in such manner that the mercury, flowing into a receiver of proper size and shape, prevented its escape. As the result of the experiments performed with this in- strument. Ainu* ventured to assume, that the proportion of air contained in a given quantity of sea-water, is at all depths very nearly the same.
«Ann. Chim. Phys. [3], 7, p. 107; Fogg. Ann. 30, p. 412..
10
I A ar fit 1873 udgik atter fra England en Expedition, | Challépgere^peditionen. som i et Tidsruin at 3 Aar skulde undersøge hande de æquatøriale og antarktiske b afvande. Med denne Expedition fulgte som Cliemiker J. Y. Bu- chanan. som besluttede sig til at anvende de pan Pomerania- expeditionen benyttede Methoder og Apparater saa godt som uden Modifikationer. Resultaterne at hans Under- søgelser ere, saavidt jeg ved, endnu ikke offentliggjorte i sine Enkelthedgr. medens der dog er gjort nogle foreløbige Meddelelser, hvoretter man vjl kunne danne sig -et Be- greb om de Slutninger, hvortil haus Observationer ville føre.
Han finder1, at >Surstofmængden i Overfiadevandet varierer mel lem 33 og 35 % af den samlede- Surstof- Kvælstofmængdø, soaledes at den grørste Mærigde . cr 1'undet (baade relativt og ahsolut) i Vandprøver øste i Nærheden af den sydlige Polarcirkel og den mindste i Pasatvind- egnene. Hvad augaar de under Overfiaden liggende Lag, da hav han observeret det nuerkelige Factum, at Surstof- procentøn nltager nedover indtil etDyh af 300 Favne, hvor den opnaar et Minimum for atter igjen at stige, saaledes som det fremgaar af følgende Tabel.
|
Dybdo i engelske FavnO; |
0 |
25 | 50 |
loo ! |
200 |
300 j 400 j |
8oo |
Der- over. |
|
-{- A7 _ = l oo 1 ■ 0 % |
33*7 ! |
33-4 32-2 |
30.2 |
33-4 |
n-4 15-5 |
22.6 |
23-5 |
Om den absolute Mængde af de af hans Vandprøver udkogte Gasarter findes paa dette Sted Intet, hvorimod der senere er bleven offentliggjort følgende Tabel2.
|
Dybde i Pod. |
CC. 0 per Litre. |
Midlere Tempe- ratur i °C. ' '• |
CC. N per Litre A',. • |
CC. iV per Litre destill. Vnnd ved Temperat. r. Bunsen AV |
A j — A , _ |
|
600 |
4.24 |
• i4-"6 |
1 1.26 |
n-75 |
O.49 |
|
1200 |
3-59 |
13- 0 |
II. 71 |
1 1.92 |
0.2 I |
|
1800 |
1.67 |
6- 9 |
13.OO |
. 13-45 |
0-45’ |
|
2400 |
2.41 |
5- i |
J3.!0 |
14.00 |
0.90 |
|
4800 |
4.06 |
2. 6 |
13.82 |
15.00 |
1. 14 |
|
derover. |
— |
i- 5 |
r 4-37 |
15.40 |
1.03 |
Hermed er i Korthed gjengivet det Vigtigste af de til Dato fremkomne Bidrag til Løsningen af Spørgsmaalet om Luften i Søvandet.
I Yaaren 1876. da man i Norge var beskjæftiget med I'drustningen af den Expedition, som var besluttet udsendt for i Sommermaanederne * af Aarene 1 87 15 — 77 og 78 at
‘The Voyage of the •‘Challenger.’ Tin* ‘Atlantic." 2 :>(>(>.
* Ber. Berl. chcnu Ges. 11 —410.
In the year 1873, another Expedition was dispatched, from England, with H. M. 8. 'Challenger.' its object being the investigation, during, a period of 3 years, both of the Equatorial and the Antarctic Seas. As chemist to this Expe- dition. had been secured the services of J. Y. Buchanan, who • resolved to adopt the methods and apparatus employed on the •Pomerania' Expedition, almost without’ modifica- tion. The results of his labours are not yet. I believe, published in detail; preliminary papers have, however, ap- peared, from which we can form some general idea of his results.
Buchanan found1 the proportion of oxygen in surface- water to vary between 33 and 35 per cent of the total amount of oxygen and nitrogen; it was greatest (both re- latively and absolutely) in the samples of water drawn near the Antarctic Circle, and smallest in those collected within .the region of the trade winds. As regards the pro- portion of oxygen in water below the surface,, he ob- served the very remarkable fact, that it generally dimiushes down to a depth of 300 fathoms, where, a minimum is reached, and then begins to increase, as shown by the following Table.
|
• Depth in English Fathoms. |
0 |
25 |
50 |
100 |
200 |
300 |
400 |
800 |
Great- er Dptlis. |
|
<> A =*100 0 p. Ct. |
•33-7 |
33-4 |
32.2 |
30.2 |
33-4 |
11.4 |
15-5 |
22.6 |
23-5 |
With respect to the absolute amounts of the gases boiled out of the different samples of watei\ nothing is stated in the work alluded to. but the following Table 2 has since appeared.
|
Depth in Feet. |
CC. 0 per Litre |
Mean Tempera- ture in'C. t. |
CC. A7 . per Litre AY |
CC. # per 1 Litre dis- tilled Water, at Temp. t . Bunsen -v- |
n3-n, |
|
600 |
4.24 |
"f* ' O' |
1 1.26 |
11-75 |
0.49 |
|
1200 |
3-59 |
13- 0 |
II. 71 |
I I.92 |
0.2 I |
|
1800 |
1.67 |
6. 9 |
13-00 |
13-45 |
o-45 . |
|
2400 |
2.41 |
5- i |
i3-io |
14.00 |
0.90 |
|
4800 |
4.06 |
2- 5 |
13.82 |
15.00 |
1. 14 |
|
Greater Depths. |
— : |
i- 5 |
14-37 |
15-40 |
1.03 |
A brief account has now Jieen .given of what had pre- viously been accomplished as regards the solution of the problem presented by the air in sea-water.
In the spring of 1§76. when fitting out the Norwegian Expedition, which had for . its object the investigation, during the summer months of 1876, 1877. and 1878. of
1 The Voyage of the. ‘Challenger." The ‘Atlantic.’ 2, p. 300. 1 Bor. Berl. chein. Ges. 11, p. 410.
11
undersøge det mellem Norge, Færøerne, Island, Jan Mayen og Spitsbergen beliggende Hav, vare heller ikke de paa den engelske Challengerexpcdition udførte Observationer offentliggjorte, saaat de Data. der den Gang forelaa, i Rig- holdighed paa ingen Maade kunde sammenlignes med dem, som nu staa til Raadighed. Især var det med Hensyn paa den geografiske Udbredning, at Observationerne ikke kunde give synderlg omfattende Oplysnipger, idet det eneste Hav, som endnu var gruiidigt undersøgt, nemlig Nordsøeu, bande med Hensyn paa Dybde og øvrige .physikalske Forholde iifveg i hoi Grad fra det store Verdenshav, forsaavidt man kjendte det. Da der først var. fattet Beslutning, om* at der ogsaa paa den norske Nordhavsexpedition skulde udføres' chemiske Undersøgelser af samme Art som paa de tidligere Expedi- tioner, maatte det derfor for Hr. S. Svendsen, hvem disse Arbeider oprindelig vare overdragne, fremstille sig som en meget vigtig, ja man kan sige, som den viktigste Opgave at tilveiebringe de fornødne Opiysninger om Gasarterne i Søvandet. hvad angaar den Del af Verdenshavet, som Norge havde paataget sig at gjøre til Gjenstand for videnskabelig Undersøgelse. Med Hensyn paa de Midler, der skulde be- nyttes til Løsningen af denne Opgave, da kunde Valget af disse ikke falde vanskeligt, da de af Dr. Jacobsen benyt- tede Methoder og Apparater strax maatte udpege sig som de hensigtsmæssigste fremfor Alt, livad der for Resten stod til Raadighed. selv om ikke Hensynet til Resultatcrnes Sammeulignelighed havde gjort deres Anvendelse ønskelig. Svendsen besluttede derfor uden Modificationer at optage de paa Pomeraniaexpeditionen benyttede Arbeidsmetlmder. og var det i Henseende til Expeditionens Udrustring et stort Held, at Professor Dr. Jacobsen velvilligen tilbød sig at anskaffe de til de chemiske Undersøgelser fornødne Apparater.
Det var dog ikke alle de ved Pomeraniaexpeditionen benyttede Apparater, som ogsaa kom til Anvendelse paa den norske Nordhavsexpedition. idet man der besluttede at anvende en af Capitain Wille construeret Vand henter, som især i en Henseende maatte være at foretnekke for den af Dr. H. A. Meyer angivne. Paa denne maatte nemlig, naar den skulde optage Vandprøver fra intennediære Dyb, Cylinderen udløses ved et langs Linen nedsamket Lod. som aldeles udelukkede Muligbeden af paa Linen samtidig j at have anbragt Thermømetre eller deslige, saaledes som det uden mindste Ulempe . kan forenes med Brugen af Willes Vandhenter.
Willes Vandhenter, som rindes afbildet i Fig. 2. er af Opfinderen bleven beskrevet paa følgende Maade:
“Vandprøven indesluttes' i dette Instrument i et for Pladsens Skyld spiralformig bøiot Rør, der under Ned- firiugeu i Våndet holdes aabent i* begge Ender, saaledes at Våndet frit kan strømme igjennem; men naar Instrumentet ophales et kort Stykke, lukkes Enderne af Røret med to Ventiler, hvorved det da i Røret staaende Vand afstænges og kan bringes op.
the sea lying between Norway, the Feroe Islands, Iceland, Jan Mayen, and Spitzbergou, the results of the observa- tions instituted on the •Challenger' Expedition had not yet been made public; and bonce the data then obtained were few compared to those of which we are now in possession. It was more particularly with respect to geographical distribution, that the information former ob- servations could supply had proved but meagre, inasmuch J as the only sea thoroughly investigated, viz the Ger- man Ocean, was found to differ widely in regard to depth and other physical conditions from the Atlantic and Pacific, so far at least as our knowledge of ‘both may be said to extend. . The resolution once formed, bf instituting on the Norwegian North- Atlantic Expedition a series of chem-
iical experiments similar to those performed on former Expeditions, Mr. S. Svendsen, the» gentleman on whom the execution of this task was to have devolved, could not but regard as an important, nuy the most important, part of his labours, accurate determinations of the. gases pre- sent in that tract of the Atlantic Ocean which the Nor-
iwegian Exjjedition was to make the subject of scientific investigation. Respecting the means whereby to solve this problem, no difficulty could be experienced in making a choice, since Dr. Jacobsen's- methods and apparatus must at once suggest themselves as by far the best, even apart from the consideration, that, for the better comparing of his results with those obtained, their adoption was desi- rable. Svendsen, therefore, decided in favour of the pro- cess without modification resorted to on the •Pom- erania Expedition; and it was a fortunate concurrence, that Professor Jacobsen should kindly volunteer his assist- ance in procuring the various apparatus necessary for the chemical experiments.
All the apparatus made use of on the •Pomerania' Expedition, were not, however, adopted on the* Norwegian North-Atlantic Expedition ; the . instrument, for instance, employed to collect water, which, particularly in one respect, must be held preferable to that described by Dr. H. A. Meyer, had been constructed by Captain Wille R. N. When drawing water from intermediate depths, the cylin- der in the latter is detached by running a weight down the line, which precludes the possibilty of having a ther- mometer, or any other instrument, attached to it, an ad- vantage which may. without the slightest drawback, be combined with Wille’s apparatus.
Willed. instrument for collecting water, of which Fig. 2 is a represention. has been described by the inventor as follows: —
“The samples of water 'drawn with this instrument are, to save space, brought up in a spiral tube, which, when sunk through the water, is kept open at both ends, to admit of the free passage of tin* fluid; but, on the instrument, at the required -depth, being hauled in a few fathoms, the ends of the tube are closed by means of two valves, and the water .it contains, thus prevented from escaping, may be brought to the surface.
■L
12
Fig. 2.
.l/f af naturlig Størrelse.
(One-ciyhth of the Actual Size.) •
13
■ Tegningen fremstiller Instrumentet klar til Nedfiring; Tampen af Lodlinen hexes i øverste Øiebolt (a) og Loddet i den nedre (b). I nder Nedffringen løfter Vandtrykket Propellerne op, saa at Taggerne i Underkant af Propel- bosset (c) kommer klor af Taggerne i Muffen, gjennem hvil- ken Ventilstangen (d) gaar, og om de. ikke kommer ganske klare, skor Propellens Omdreining mnd Skraaplanerne, saa at Muffen og \ entilstangen bliver staaénde stille. Naar Instrumentet derimod under Ophalingen bevieges opad. driver \ audtrykket Propellerne ned, de dreies rundt den anden \ ei og tager Mufierne med sig. Yentilstiengerne. der ikke kan dreie sig rundt, men styres af Tværstykkerne (e), skrues da, tilligemed de med Kautschuk overtrukne Ventiler, mod Ventilsæderne i Enderne af Røret, og naar dé ere. næsten lukkede, glipper den sidste Skruegjænge paa Ventilstangen ud af Skruegjængerne i Muffen, og Spiral- fjædrene (/) klappe da Ventilerne i, medens Propellerne og Mufferne gaa løse rundt om den glatte Del af Yentil- stængerne, og frembyder saoledes meget liden Modstand under Resten af Lndhivningen. Instrumentet lukker sig efter omtrent 7 Favnes (13* Meters) Indhaling. . Ringen om Midten og Skjærmerne rundt Propellerne beskytte Instrumentet, saaledes at det ilden Skade kan ligge paa Bunden.
For at' konstatere, om der var Overskud a f Luft i de nedre Vandlag, blev der over Svikbullet paaskruet et gjennomboret Laag (f/), der ved Hjælp af et Stykke Gummi- slange forenédes til et i den ene ' Ende lukket Glasrør. Naar Våndet under Npdfiringen strønunede ind i Vand- røret, løb det ogsaa ned i Glasrøret, af hvilket Luften saa- ledes blev udjnget. Naar Instrumentet kom ombord, ende- •vendtes det. saa at . Kranen kom ned og Glasrøret op. Man bevægede nu Vandhenteren lidt frem og tilbage med den øvre Ende. og hvis der havde været Overskud af Luft. maatte denne have arbeidet sig op og vist sig i Toppen af Glasrøret. men dette viste sig stadig fuldt lige til Tops, og blev derfor i* den sidste Tid ikke paasnt."
Instrumentet kan tømmes gjennem Tappekranen (h) og leverer en Vandprøve paa circa 5 Litre.
Udførelsen af de chemisko Arbeider ombord paa den norske Nordhavsexpedition overtoges altsaa først i Følge den oprindelige Plan af Hr. Svendsen, som gjorde Togtet i 1870 med. men blev senere, da denne af Helbredshensyn bad sig fritaget, overdraget Forfatteren, der saaledes har udført de paa de to sidste Togter gjorte Observationer del- vis med Assistance af Hr. L. Schmelck, sonr sidste Sommer medfulgte Expeditionen. og som for Tiden er beskjæftiget med Bearbeidelsen af en anden Del af det paa Expeditionens Togter til chemisk Undersøgelse indsamlede Materiale.
The figure shows the instrument ready for sinking. The end of the sounding-line is made fast to the upper eve- holt (<0. and the lead to the lower (/>). On the down- ward passage, the pressure of the water lifts up the pro- pellers. enabling the cogs in the under surface of the base of the latter (e) to get clear of the cogs in the bush, through which passes the rod of the valve ( d)\ and if not quite clear, the propeller revolves with the inclined planes, the bush and the rod of the valve remaining stationary as before. On the other hand, when the instrument, on being hauled in. is given an upward motion, the pres- sure of the water forces down the propellers, which then revolve in the opposite direction, carrying along with them the bushes. The. rods of the valves, which cannot revolve, being kept in position bv transverse pieces (e), are, tqgether with the valves covered with caoutschouc, screwed against the ends of the tube. Now. when the latter are almost closed, tin* last twist of the screw on the rod of the valve slips out of the corresponding twist of the screw on the bush, and the spiral springs (/) instantly press down the valves, the propellers and the bushes revolving independently round the smooth portion of the rods, thus presenting but little resistance to the water during the refnainder of the upward passage. The instrument closes on being hauled' in about 7 fathoms (13 metres). The ring round the middle, and the shields protecting the propellers, prevent the instrument from sustaining injury on its striking the bottom.
With a view to ascertain whether tin* proportion of air were, really greater in the lower strata, a perforated cover ((f) was screwed over the spigot-hole, and • con- nected by means of a piece of caoutschouc hose with a glass tube, open at one end. Now. when the water on the .downward passage flowed into the spiral tube, it also de> sconded into the glass tube, expelling the air. * So soon as the instrument came on board, it was inverted, the . stop-cock therefore pointing down, and the glass tube up. The upper end of the apparatus being now moved a little backwards and forwards, the surplus of air. if any had been present, must obviously have forced its way up- wards. and have appeared, in the form of bubbles, at the top of the tube, which, however, was invariably found to b$ quite full, and therefore not attached to the appa- ratus when the fact would no longer admit of doubt.”
' The stopcock (h) serves to empty the instrument, which will hold about 5 litres of water.
The chemical work to be done on board was. as stated above, originally undertaken by Mi*. S. Svendsen, who went out on the first cruise, in 1870; but. his health failing, Mr. Svendsen was succeeded by the author, who had therefore to take the observations instituted in 1877 and 1878. partly with the assistance of Mr. L. Schmelck. that gentleman having accompanied the Expedition on the last cruise. (Mr. Schmelck is now engaged in working uj> other materials collected on the Expedition for chemical investigation).
u
Da jeg Vaaren 1 H77 blev opfordret til at .overtage disse Arbeider, var der kun givet mig faa Dages Varsel, saaat jeg havdc de største Vanskeligheder med- at. *faa ud- ført selv de aller uødtørftigste Forberedelser, og naar det alligevel lykkedes at ffla.Alt tilfredsstillende ordnet for Afreisen, da skyldes dette udelnkkende den Beredvilliglied, hvormed Hr. Professor Waage bistod mig blandt Andet o g- saa med Indredningen af detcbemiske Laboratorium ombord.
Det paa Expeditionens første Togt i 187(5 fremher- skende ualmindeligt stormfulde Veir gjorde det i boi Grad vanskeligt ja næsten ugjørligt at udføre de cbemiske Obser- vationer ombord, og det Udbytte, som af Svendsen lijembragtes fra første Togt. indskrænkede sig derfor i denne Branclie til 17 Luftprøver, bvoraf- desuden 3 ved Ulield senere gik tabt. Det rolige Veir. som de to sidste Aar begunstigede Expe- ditionens Arbeider. tillod mig derimod paa de Togter. hvor- med der var* givet mig Anledning til at medfølge, at ind- smelte et større Antal, idet der for disse Aars Vedkom- mende erholdtes 80 Luftbestemmelser af de bjembragte Luftprøver, bvoraf 9 vare. indsmeltede af Hr. Schmelck. Naar Udbyttet ikke er blevet støiTe, da bar dette sin ti rund i. at talrige Observationer gik tabt nogle faa ved Ulield under Analysen men de Heste ved Ulield Under Indsmelt- ningen. Saaledes var .der til Brug paa sidste Togt fra lvUobler & Solme i Ilmenau sendt mig nogle Luftopsam- lingsrør. bvoraf over 75 °/0 tiltrods for den omliyggeligste Behandling sprang enten under Indsmeltningen eller effcer samme, Luftprøverne ere alle analyserede ved det afFranck- laiul og Ward1 augivne Gasanalyseappnrat. saaledes at Kul- • syren er fjernet med Kalilud og Surstoffet bestemt ved Porbrænding med Vandstof. De 14 førstnævnte Prøver ere analyserede af Hr. Svendsen de øvrige 80 af forfat- teren. De erholdte Resultater findes sammenstillede i •Tabel I, hvortil kan bemærkes følgende: De i Tabellen opførto Temperaturangivelser ere mig meddelte af Pro- fessor Mcrtin. Ved Angivelse af de Dybder, hvorfra Vand- prøverne ere bentede, er ikke taget Hensyn til. at Vnnd- benteren først lukker sig effcer circa 7 Favnes Indbivning. Ved de med * betegnode 10 Nummere var der. i de til Luftprovornes Opbevarelse benyttede Glasror smaa Feil, uden at jeg dog bar fundet mig foranlediget til at tilla>gge disse mindre Vægt end de Øvrige, da man vel ikke kan tamke sig Muligbeden af en Læ kage, uden at den, naar Glasrørene i 'Here Maaneder opbevaredes under . en Trvk- diflerent§ mellera det ydre og indre Gastryk af circa 300 til 400""", maatte liaVe øvet en incerkbar Virkning paa deii indesluttede Lufts Sammensætning. Jeg kan såa meget trøstigere tage dem med i Beregjiingerne. hvor det gjælder at opstille de almindelige Slutninger, som de ikke i syn- derlig Grad ville bidrage til at forrykke 1'dseendet af de endelige Resultater. Alle Gasvolumina findés i Tabellen udtrykte i CC. per Litre udkogt Søvand reduceret til 0° og.
7 60’"m Barometerstand.
1 Chem. Soc. Jour». *22— :U3. 1809.
When, in the spring of 1877. I was requested to undertake these labours. I had but a few days’ notice, and experienced, therefore, very great difficulty in making even the most necessary preparations; uor would it indeed have been possible to- get everything satisfactorily arranged in so short a time but for the readiness with which Pro- fessor Waage came forward to assist me; for instance, in fitting up the chemical laboratory on board.
The exceptionally heavy weather on the first cruise in 1876, rendered it in the highest degree difficult, nay well nigh impracticable, to perform the necessary experi- ments on board ; and hence the chemical work done by Svend- sen on the first voyage was,' with regard to gas-determina- tions. confined to collecting 17 samples of air, 3 of which however were subsequently lost. On the two- last cruises of the Expedition the weather proved much more favourable, and I succeeded in obtaining a larger number of samples (9 of them collected by Mr. Schmelck), with which, when brought home. 80 air-determinations were performed. A more satisfactory result would, however, have been obtained but for the loss of numerous samples, some few from accident when- analysing the gass, but the great majority by reason of the difficulty experienced in sealing. Thus, for instance, on the last voyage 75 per cent of the glass tubes for collecting air, procured from. Kucbler & Solme in Ilme- nau, notwithstanding the greatest care cracked either during the sealing-process or after its completion. The samples of air were all of them analysed in the apparatus described by Francklnnd and Ward,1 the carbonic acid having been absorbed in a lye of potash and the oxygen determined by consuming it with hydrogen. The first 14 samples were analysed by Mr. Svendsen, the remaining 80 by myself. The results obtained will be found in Table I. The -temperatures in the Table were given by Professor Molm. When stating the depth's from which the samples of water were drawn, regard has not been bad to the fact.' that the instrument used for collecting them does not close till it has been hauled in about 7 fathoms. The asterisk marking 10 of the. determinations signifies that, the glass tubes used for preserving these samples of air bad small de- fects. To these determinations, however. I have not attached' )ess weight than to the others; for it is impossible to con- ceive that a leakage, after the glass tubes had been exposed for month's together to a difference of pressure amounting to 300mm— 400mm, viz. that existing between the air inside and the atmosphere without, should npt have had an ap- preciable effect on the composition of the air they contained. Moreover, I hesitate the less to include them as factors when seeking to arrive at general conclusions, since they cannot to any considerable extent disturb the char- acter ot the final results. The volumes are given in cubic centimetres per .litre of the sea-water examined, reduced to a temperature of 0° and a pressure of 760'”m.
1 Chem. Soc. Journv 22, p. ;Ji3; 1S60.
Tab el X.
If)
|
Dvlnle hvorfra Pro- |
||||||||||
|
Længdo fra Greenwich. |
ven hentet. ■ |
|||||||||
|
No. |
Stat. No. |
Nordlig Brodde. |
(Depth from which the Sam- ple» were collected.) |
O + K cc. |
A’ GC. |
0 4- s = 100 |
Tempe- ratur. |
Anmrorkuingor. |
||
|
( hurth Latitude.) |
Eng&lske |
0 v |
||||||||
|
(Longitude from |
Meter. |
per Litre. |
per Litre. |
Celsius. |
(Hem arks.) |
|||||
|
. |
Greenwich.) |
1' avne. |
(0 per cent.) |
|||||||
|
(English Fathoms ■ ) |
(Metres.) |
|||||||||
|
i |
Huso |
O |
0 |
17.4 |
ii-3 |
35* * |
10.5 |
|||
|
2 |
14 |
02 4 |
20 44 -5 E. |
226 |
413 |
20.1 |
13.8 |
3 * - * |
6.1 |
|
|
3 |
32 |
63 10 |
4 5 1 -3 |
430 |
786 |
I9.O |
13.0 |
3 * -7 |
— 0.6 |
|
|
' 4 |
33 |
63 5 |
3 0 |
O |
0 |
18.9 |
12.4 |
34-4 |
11. 8 |
|
|
5 |
33 |
63 5 |
3 0 |
525 |
960 |
17-3 |
1 1.7 |
32.6 |
— 1. 1 |
|
|
6 |
35 |
63 ? |
1 26 W. |
O |
0 |
17.0 |
1 1. 1 |
35-0 |
10.4 |
|
|
7 |
35 |
63 7 |
1 26 |
721 |
1319 |
18.4 |
12.4 |
32.6 |
—0.9 |
|
|
8 |
37 |
62 28.3 |
2 29 |
309 |
565 |
18.5 |
12.4 |
32-8 |
0. 1 |
|
|
9 |
•37 |
• 62 28.3 |
2 29 |
69O |
1262 |
18.3 |
12.3 |
32.7 |
— 1 . 1 |
|
|
IO |
40 |
63 22.5 |
5 29 |
O |
0 |
*7* |
1 1. 1 |
35-2 |
9-7 |
|
|
1 1 |
40 |
63 22.5 |
5 29 |
515 |
942 |
20.5 |
1 } 9 |
3 2. A |
—P-4 |
|
|
12 |
5i |
65 53 |
7 18 |
515 |
942 |
20.6 |
*3-9* |
32-3 |
— 0.6 |
• |
|
l3 |
5i |
65 53 |
7 18 |
I 163 |
21.27 |
20.9 |
* 4- * |
32.7 |
— 1. 1 |
• |
|
*4 |
52 |
65 47.5 |
3 7 |
l86l |
3403 |
; |
32.2 |
— 1.2 |
||
|
• 15 |
95 |
60 42 |
. 4 13-7 E. |
1 75 |
320 |
— |
— |
32 4 |
5-« |
|
|
16 |
96 |
66 8.5 |
3 0 |
805 |
1472 |
— |
— |
52.3 |
— -i. 1 |
. |
|
«7 |
125 |
67 52.5 |
5 12 |
700 |
1280 |
20-5 |
1-3-7 |
33-0 |
— 1. 1 |
|
|
18 |
125 |
67 52.5 |
5 12 |
700 |
1280 |
20.0 |
*3 3 |
33-6 |
— 1 .1 |
• |
|
*9 |
*52 |
67 18 |
12 46 |
125 |
229 |
— |
3 1 -o |
4.1 |
||
|
20 |
162 |
.68 23 |
10 20 |
795 |
1454 |
20.6 |
13-9 |
32.6 |
* — 1.2 |
|
|
21 |
162 |
68 23 |
0 <N c |
795 |
1 454 |
’ 194 |
12.9 |
33-7 |
— 1.2 |
IMkoffl oder uogon Tide Unnetaixl. (Ilollcd After the lapeo of a eliort Interral.) |
|
22 |
J7i |
69 18 |
14 29 |
642 |
1174 |
19.6 |
13.0 |
33-5 |
— I .O |
|
|
23 |
179 |
69 32 |
I I IO |
1607 |
2 939 |
— |
— - |
32-1 |
— 1.2 |
|
|
2 4 |
«83 |
69 59*5 |
6 15 |
0 |
0 |
20.2 |
12.9 |
36.1 |
8.6 |
|
|
25 |
183 |
69 59-5 |
6 15 |
0 |
0 |
— |
36.1 |
8.6 |
||
|
26 |
184 |
70 4 |
9 50 |
1 547 |
2829 |
21-5 |
14.6 |
32.0 |
— i-3 |
|
|
27 |
iS4 |
70 4 |
9 50 . |
600 |
1097 |
20.7 |
1 4. 1 |
32.1 |
0.0 |
|
|
28 |
189 |
69 41 |
15 42 |
. 0 |
0 |
18.4 |
12.0 |
35-o |
9.6 |
|
|
29 |
189 |
69 41 |
15 42 |
860 |
1573 |
21-5 |
14.6 |
32.0 |
1 . 1 |
|
|
30 |
200 |
71 25 15 40.5 Imlloliet til MnlAiigciiQord. |
620 |
1134 |
19.9 |
12.8 |
35-8 |
— 1.0 |
l ilkotfi offer ft — «1 Timor* Hcuataud (Moiled aflor tin* lnp«/* of ft or II Lours.) |
|
|
31 |
* |
(Entrnncc la tlic Malniigrii KJoril.) |
0 |
0 |
— |
35-5 |
8.5 ? |
|||
|
32 |
213 |
70" 23 |
2" 30 |
0 |
0 |
18.6 . |
12. 1 |
■34-9 |
. 8.2 |
|
|
33 |
213 |
70 23 |
2 30 |
1760 |
• 3219 |
19.6 |
12.9 |
34-0 |
1.2 |
|
|
34 |
213 |
70 23 |
2 30 |
1760 |
3219 |
— |
• 33-8 |
— 1.2 |
||
|
35 |
215 |
70 53 |
2 0 W. |
0 |
0 |
— |
. . — |
34-8 |
8.0 |
■ . |
|
36 |
215 |
70 53 |
2 0 |
• 700 |
1280 |
20.1 |
13-6 |
22.4 |
—0.6 |
|
|
37 |
215 |
70 53 |
2 0 |
1665 |
3045 |
19.2 |
12.9 |
.}2.8 |
— 1.2 |
|
|
38 |
226 |
70 59 |
7 5i |
0 |
0 |
— |
— |
33-7 |
3-o |
|
|
39 |
226 |
70.59 |
7 5i |
340 |
622 |
— |
— |
32-7 |
- 0.6 |
|
|
40 |
— |
69 20 |
1 r r8 |
O |
0 |
20.7 |
*3-3 |
35-8 |
4-3 |
|
|
4i |
— • |
69 20 |
n 18 |
0 |
0 |
-- |
35-4 |
4-3 |
||
|
42 |
243 |
68 32.5 |
6 26 |
0 |
0 |
20.0 |
*3- * |
34-7 |
7.8 |
|
|
43 |
243 |
68 32.5 |
6 26 |
600 |
1097 |
22.1 |
15.0 |
52.2 |
0.8 |
|
|
44 |
243 |
68 32.5 |
6 26 |
1385 |
2533 |
22.6 |
15 -3 |
32-5 |
— i-3 |
|
|
45 |
2 47 |
68 5-5 |
2 24 E. |
0 |
0 |
•19-3 |
— |
— - |
9.4 |
|
|
46 |
2 47 |
68- 5-5 |
2 24 |
■ 500 ‘ |
•914 |
— |
' — |
32-3 |
—0.4 |
|
|
47 |
249 |
68 1 2 |
6 35 |
1063 |
1944- |
21.4 |
1 4-5 |
323 |
— i-3 |
|
|
48 |
252 |
Hi'nilenfor SkrnavTin. (South of Skraavou.) |
0 |
0 |
18.2 |
11 -9 |
34-7 |
14.0? |
||
|
49 |
253 |
SkJitirntAriQord. (Tho Skjrorttnd Fjord.) |
263 |
481 |
20.9 |
13-8 |
34-2 |
3-2 |
||
|
50 |
254 |
67"27 |
13" 25' |
0 |
0 |
18.2 |
11 -9 |
34-8 |
1 0.0 |
|
|
5* |
254 |
07 27 |
13 25 |
70 |
128 |
21.3 |
14.2 |
33-2 |
4.8 |
|
|
52 |
254 |
67 27 |
13 25 |
140 |
256 |
19-5 |
132 |
32.4 |
5-8 |
|
|
53 |
264 |
70 56 |
‘ 35 37 |
0 |
0 |
. 20.6 |
13-3 |
35-5 |
5-2 |
|
|
54 |
264 |
70 56 |
35 37 |
86 |
*57. |
20.7 |
*3-8 |
33 * |
1.9 |
|
|
55 |
2 75 |
74 8 |
.31 12 |
0 |
0 |
20.5. |
*3-3 |
34-9 |
2.9 |
|
|
56 |
2 75 |
74 8 |
31 12 |
1 47 |
269 |
2 1.9 |
14.6 |
33-4 |
—0.4 |
|
|
57 |
278' |
74 i-5 |
22 2*7 |
■0 |
0 |
20.4 |
* 3-3 |
35-0 |
. 4-2 |
|
|
58 |
278 |
74 »-5 |
22 27 |
230 |
421 |
20.7 |
13-8 |
33.3 |
0.9 |
1C»
No.
59
60 ■6 1 62 6.3'
64
65
66
67
68 6g+ 7°* 7i* 72 73*
74
75
76
77
78
79
80
81
82
83
84
85
86 87 88* 80
90
91*
92*
93*
94*
No.
283.
283-
286
286
293
295
295 2 95
296
297 301.
303
304
304 •321 32. I*‘ 323 323 332 332 335 335 339 342 342 345 I 345 347 347 349 I 350
! 350
j 352 j 352 1 359 362
|
T Nordlig Uredde. (North Latitude.) |
Længde fra Greenwich. '(/.qriffiluile from Orrenwlt/l.) |
Dybde hvorfra Pro- ven hentet. (J)rpth /ram which the Sam-' plrt were collected.) Engelske Favne. Meter. (ICnglilh 1 Metres.) |
0 4- -V x;c. per Litre. |
’.V CC. per Litre. |
0 4- iV = 100 0 % ( U per cent.) |
Tempe- ratur. Celsius. |
Anmærkninger. (Jtemarks.) - » ~ |
|
|
73° 47 -5
73 47 5 72 57 72 57
7 1 7
71 59 71 55
71 59
72 15-5 72 36.5
74 1
75 >2
75 3
75 3
74 56.5
74 56.5 72 53-5 72 53-5
1 75 56
75 56
76 16.5 76 16,5 76 30 76 33 76 33 76 42.5 76 42-5
76 40.5
76 40-5 76 30 76 26
76 26
77 56 77 56 78. 2 79 59
1 40 21 14 21 14 32 14 32 2 1 11 1 1 40 11 30 1 1 40 8 9
5 12
1 20
3 2
4 51. 4' 5i
19 30 19 30 21 51 21 5 1 ' 1 1 36
1 1 36 14 39
14 39
15 39
13 18 13 18 10 9
10 9
7 47 7 47
2 57 o 29 o 29
3 29 3 29 9 25 5 40
W.
E.
W,
o o o
447’ I
95 !
o.
600 1 1 10 100 1280 o
150
300
1735
o
25
o
o
1149 1 1 49 o . 179
37
o
523
300
300
o
1429
1487
300
1686
300
1686
o
o
o
o
817
174
o
1097
2030
183
2341
o
274
549
3173
o
46
o
o
•2IOI 2 101 O
32 7 68 o
956
549
549
o
2613
2719
549
3083
. 549 3083 o o
|
19.8 |
12.8. |
35-4 ' |
7-2 |
|
19-5 |
1 2.6 |
35-3 |
7-2 |
|
20.6 1 |
13.2 |
35-8 |
7.2 |
|
2 1.8 |
14.8 | |
• 3 1 9 |
— 0.8 |
|
19.6 1 |
13.0 |
33-5 |
5,1 1 |
|
20.2 |
12.8 | |
’ 36.7 |
7.0 |
|
2 1 ‘4 |
14.6 |
3i-7 |
—0.8 1 |
|
2 1-5 I |
14.6 |
32.1 |
— 1-3 |
|
20.4 1 |
13-4 |
* 34-2 |
*■' 1 |
|
21.3 |
13-8'. ! |
35 1 |
-1-4 |
|
21'9 |
14.1 j |
35-6 |
2.2 |
|
22.6 |
t4-7 |
33-1 |
— 1- 1 |
|
21-7 |
M-7 1 |
32.2 |
— 0.8 j |
|
21.6 |
14.6 |
32.2 |
— 1-5 |
|
' 2-3.8 |
• 15-4 |
35-2 |
05 1 |
|
23-7 |
15 3 |
35-4 |
0.2 |
|
i9-3 |
12.3 |
36-5 |
7.8 |
|
‘ — |
35-8 |
7-8 |
|
|
21.9. |
14.8 |
32.2. |
—1-5 |
|
22.0 ' |
150 |
31.8 |
— i-5 |
|
20.8 |
13-3 |
36.2 |
5-4 |
|
2 1.0 |
14.0 |
33-1 |
1 .0 |
|
2 1. '6 |
142 |
34-i |
0.9 |
|
21.8 |
1 4. 1 |
35-3 |
6.2 |
|
20.8 |
13.8 |
33-8 |
— 1.0 |
|
20.9 |
1 13-7 |
• 34-4 |
1.0 |
|
21.5 |
142 |
33-9 |
1.0 |
|
20.9 |
13-4 |
35-7 |
4-4 |
|
21.4 |
13-9 |
35-1 |
— i-3 |
|
21.7 |
14.6 |
32-5 |
— i-5 |
|
21.9 |
14-7 |
32-7 |
— 1 . 1 |
|
22.9 |
i*5-3 |
■ 3 3 -.3 |
— i-5 |
|
2 1.9 |
14.8 |
32-5 |
— 0.8 |
|
22.4 |
151 |
32.8 |
— i*5 |
|
— |
-- |
35' 7 |
4-3 |
|
20 3 |
13.0 |
35-8 |
5-2 |
|
ke II |
The samples of water |
udtrykkelig er anført, udkogte stvax efter derés Optagels'e.
Som man ser, ligner denne Tabel overmaade meget deh åf Dr. Jacobsen opstillede,. bvad man ogsaa paa For- Inuuid kunde vente, da de undersøgto Districter tuldstamdig gaa over i hinanden, og naar Differentserne mellom de af Hr. Svendsen og mig opforte Tal ere noget storro, da kommer dette ligefrem af det af os bearbeidede Felts større Ud- strækning og deraf følgende større Uensartethed i de phy-
verse is .suittu. uum-u ~ -<=
As will be seen, this Table agrees very closely with that prepared by Dr. Jacobsen, which was indeed to be expected, since the tracts investigated coalesce; and the somewhat greater differences exhibited by Mr. Svend- sen’s and my own figures arise Simply lrom tbe region explored by the Expedition having been more extensive, involving greater 'dissimilarity in the physical conditions.
sikalske Forholde.
Hvad dor er most ioinefaldende. er dot paafaldende Phænomen,. at der med Hensyn paa den relative Sarnmen- sætning af den i OverHadevandet indeholdte Lult paa den norske Nordhavsexpedition er fundot betydeligt større Sur- stofgehalt end af Dr. Jacobsen for Nordsøen opstillet, sna- ledes er Surstofprocenten i Overfiaden i Nordsøen bestemt til i Middel 33.93 °/0 af den samlede Luftmængde, medens den for det af den norske Expedition i 1870 og 77 under- søgte Strøg søndenfor den 70de Breddegrad, beløber sig
With regard to the relative composition of the air in surface-water, the proportion of oxygen was. strange to say, on the Norwegian North- Atlantic Expedition lound to be considerably greater than that given by Dr. Jacobsen for the North Sea. The mean proportion of oxygen in the surface-water of the North Sea he determined to be 33.93 per cent of the total amount of air, whereas the mean proportion for the tract of the North- Atlantic stretching south of the 70th parallel of latitude, that investigated by the
17
til i Middel 34.96 og for det i 1878 undersøgte melleni 70de og 80de Breddegrad beliggende Strøg til 35.64 -°/0<- Fuldstøendigt tilsvarende er- det' af Buchanan fuudet at være paa den sydlige Halvkugle. idet Syrstofprocenten i Overfladen ' der varierer fra omkring 33 i Æ(jvator egnene til ca. .35 omkring den ’sydlige Polarcirkel.
Dette lod med temmelig stor Bestemthod formode, at de for destilleret Vand gjældende; af Bunsen opstillede, Absorbtionscoefficienter ikke skulde være gyldige for Søvand, idet det. naar Oveyflådévandsluftens Sammensætning fandj.es at variere med Blinklen, maatte være det Naturligste at skrive disse Variationer paa Temperaturforandringen^*. Det vil imidlertid ikke føre til ligget rimeligt Resultat, om man
foreliggende Obsefvationer forsøgo at .udlede en Lov for Absorbtionscoefficienternes Variationer med Temperaturen. Man vil da finde, at de enkelte Observationer staa ikke ubetydeligt i. Strid med hinande.n, idet der. for Surstof- mængdernes Vedkommende overalt optræder meget større Afvigelser, end man kan -antage begrundede i Observations- feil. D.et kunde dog ikke synes tilraadeligt at lade det bero hermed og forsøge at di^cutere- de foreliggende Ob- servationer udeir nøiere Kjendskab fil Absorbtionscoeftici- enternes Afhængighed af Temperaturen, og jeg besluttede derfor at bestemipe saavel Sammensætning som Mængde af .den i Søvandet ved forskjellige Temperaturer opløste Luft.
Først gjordes en Del Forsøg, hvorved Søvandet i et Bad af constant Temperatur søgtes mættet ved flere Timers Gjennemledning. af Luft, (saaledes som Bunsen har gaaet frem ved sine Besjemmelser1), hvorefter den opløste Luft uddrcves og analyseredes paa den før beskrevne Maade. De paa denne Maade mættede Vandprøver afgave bestan- dig Luftmamgder, som uden Hensyn til .den Temperatur, hvorved Våndet var .mættet. viste nogenlunde nær den samme Sammensætning (med 34.9 °/o Surstof mod' (55.1 °/0 Kvælstof), medeus de ofte temmelig stærkfc afvigende Tal. som udtrykte de absolute Mængder af opløste (laser, tyde- ligt viste, at . der paa denne Maade ikke var opnaaet fuld- stændig Mætning.
Professor Waage foreslog mig derfor at gjentage disse * Forsøg med nbgen Variation i den Maade. hvorpaa Ma*t- ningen ivæfksattes, og hår jeg som Følge déraf ved de senere Forsøg benyttet følgende Fremgangsmaade. En pas- sende Portion Søvand af nogenlunde høi Egenvægt rystedcs med Luft i en rummefig Kolbe i et Tidsrum fra 1 til 2 Timer under stadig Vexlen af den i Kolben værende Luft og hensattes derpaa i nogle ' Timer ganske rolig, idet Tem- peraturen saavel under Kystningen som senere holdtes fuld- stændig constant. Forat -overbevise mig om. at jeg har opnaaet fuldstændig Mætning, bar jeg nærmet mig Mæt-
Norwegian Expedition in 1876 and 1877. amounts to 34.96. and for that lying between the 70th and 80th parallels of latitude, to 35.64 per cent. Buchanan observed precisely tlu* same phenomenon in thy southern hemisphere, the proportion of oxygen varying from about 33 per cent in the Equatorial Seas to about 35 per cent in tlu* vicinity of the Antarctic Circle.
Reasoning on these data, there -were strong grounds to- assume, that tlu* coefficients of absorption given by Bunsen for distilled water could not apply to sea-water ; for, the composition of the air in surface-water having been found to. vary with the latitude, the most probable cause of this' phenomenon would seem to he temperature. Mean- while. we shall not arrive at a satisfactory result by regard- ing temperature as the variable factor, and by seek- ing from the observations here sot forth to discover a law. according to which the coefficients of absorption vary with the temperature. The individual observations would in that case be found ' to clash, inasmuch as the variation with regard to oxygen is invariably greater than can he assumed to arise from errors of oliservation. However,, it did not seem advisable to leave the question as it stood, and proceed to the discussion of the results without having further investigated the relation of the coeffi- cients of absorption to the temperature : and 1 resolved, there- fore. on determining alike the composition and the amount • Of the air absorbed by sea-water at different temperatures.
A series of experiments were first instituted with a .view to saturate sea-water wjtli air. viz. by placing it in a bath of constant temperature, and for the space of several hours uninterruptedly conducting through it a current of air,’ — tlu* mode of operation adopted by Bunsen for his determinations, 1 — after which the air ab- sorbed in the water was driven off, and analysed by the process previously ■ described. The samples of water satu- rated in this manner invariably yielded quantities of air which, irrespective of the temperature at which the water had been saturated, were found to be very nearly uni- form in composition, viz. 34.9 per cent oxygen and 65. 1 per cent nitrogen, whereas’ the figures, often widely divergent, ■expressing tlu* absolute quantities of the gaseous bodies absorbed* gave sufficient proof that by this method complete saturation had not been attained. *
At Professor Waago’s suggestion, 1 repeated these experiments, varying slightly the means by which satura- tion was sought to he effected, and have since adopted tlu* following mode of operation. A quantity of sea-water, ol considerable specific gravity, is shaken, along with air, in a roomy matrass for one or two hours, the air in the matrass being frequently renewed, and then left perfectly still for a few hours, at the precise temperature preserved during its continual agitation. To be quite sure that 1 have really succeeded in saturating the water, I approach- the point of saturation as it were from opposite, directions:
1 Bunsen. Gasoiu. Metkoden — 1
‘ Bunsen, Gnsom. MethodCn. |>. Bin.
l.s
ningspunctet fra begge Sider, idet jeg paa. den ene Side har behandlet Vand. som paa Forhaand var utilstrækkeligt m ættet med Luft ved vedkommende Temperatur, og paa den anden Side først har mættet Våndet ved en betydelig lavere Temperatur’ for deretter,, som ovenfor beskrevet, at ryste det med Luft ved don Temperatur, hvorved det øn- skedes mættet. Den Barometerstand, hvorved Vandprø- verne ere m retted e; er nltijl bleven observeret. . og ere de uddrevne Gasmængder reducerede til Mætning ved 760 m'". idet de absorberode Volumina. ere satte proportionate med Trykket. ' Resultaterne ere sammenstillede i nedenstaaende Tabel, hvor Gasmæhgderiie ere udtrykte som CC. pr. Litre udkogt Vand reduceret til 0" og 760 mw Tryk. Dé med fede Typer trykkede Tal hidrore fra de Vandprover. der i Forveien have været mættede med Luft ved en lavere Temperatur. Ved de med Klammer sammenføiede Tal ere begge Luftprøver udkogte af samme Vaudprøve.
|
e-c. |
5°C. |
... r. |
I5° |
0. |
|
|
0 N |
0 \ |
u |
jX |
0 |
N |
|
\ 7-76 I 14..36 |
\ 6.85 13-20 |
6.31 |
12.14 |
1 5-6o |
10.79 |
|
) 7.85 1 14-56 |
| 6. go 13-30 |
\ 6 30 |
1206 |
1 5-79 |
1 1.20 |
|
7-7i 14-3.1 |
\ 6 97 13.16 |
i 625 |
12 04 |
5.70 |
1 1 04 |
|
— - 1 — |
| YOI 13.20 |
— |
— |
Som Middel værdier erholder man heraf:
|
°c. |
0 |
5 |
10 |
15 |
|
0 |
7-77 |
6-93 |
6.2 Q |
5-70 |
|
N |
• 14.41 |
13.22 |
I2.08 |
I I .OI |
|
0 N = 100 0 °/o |
35-03 |
34-39 |
34.24 |
34-n |
Til yderligere Control paa Jligtighøden al denne Ta- bel kensattes en Vandprøve i uproppet Kolbe ved 0° i 7 Døgn, hvorpaa den deri opløste Luft udkogtes og analyse- redes, og viste den uddrevne Gas sig at være omtrentlig af samme Sammensætning som ovenfor angivet nemlig 35.18 *y0 0 mod 64.82. 0/0iV. Af den samlede Luttmængde erholdtes her ingen Maaling. da desværre en liden Blære under Overfyldningen i Evdiometret gik tabt, den reste- rende Del maalte 21.71 CC. Som man af .denne Tabel vil kunne se. er den Kvælstofmængde, som 1 Litre Søvand absorberer af (hm atmosphæriske Luft, ligetil proportional med Temperaturen og lader sig udtrykt i CC. meget nøie fremstille ved Formelen
N= 14.4 — 0.23 tf hvoraf map istedetfor de
observerede Værclior . 14.41 13.22 12.08 11.01
kan beregne .... 14.40 13.25 12.10 10.95.
Hvad iingaar den absorberede Surstofmængde. da er Forholdet ikke længere saa -simpelt, idet den Curve, Uer betegner Variationen med Temperaturen, ikke længere er en røt men en svagt krummet Linie. som paa Strøgot fra 0 til 10°., hvorom der her nærmest er .Tale, lader sig ud- trykke ved Formelen
on the one hand. operating with water that has been im- perfectly saturated at a given temperature, and on the other, saturating that water at a much lower temperature; and not till then, proceeding to shake it' along with air at the temperature for „ which saturation is • sought to be at- tained. The atmospheric pressure- at which, tlie samples ot water were saturated, was always noted down, and the quantity of gas driven off reduced to the point ol satura- tion at 760mm, the volumes absorbed being put propor- tional with the pressure. The results are set forth in the following Table, the amounts of gas being expressed in cubic centimetres per litre of the water examined, re-- duced £o a temperature of 0° and a pressure oi 760wm. The figures printed in thick type refer to samples of water previously saturated with air at a lower tempera- ture. those in brackets are determinations performed with the same sample of water.
|
0*0. |
5°C- |
IO° |
C. |
i5° C. |
|||
|
O |
N |
0 |
N |
0 |
A |
0 '■ A |
|
|
\ 7-76 |
14-36 |
\ 6-8 3 |
13.20 |
6.31 |
12.14 |
| 5- 60 |
i°-7g |
|
1 7-85 |
14.56 |
) 6. go |
13-30 |
\ 6.30 |
12 06 |
1 5-79 |
1 1.20 |
|
7-7i |
14-31 |
\ 6.97 |
13.16 |
1 6.25 |
12.04 |
5.70 |
1 1 04 |
|
— / | — ■ |
1 7 01 |
13.20 |
' — v |
— ’ |
— |
— ; |
The mean proportions are accordingly : —
|
0. |
o° |
5° |
10" |
15° |
|
0 |
7-77 |
6.g3 |
6.2g |
5-7'o |
|
A |
14.41 |
.13-22 |
12.08 • |
1 1 .0 1 |
|
0 -f- Ar= 100 0 p.ct. |
35-03 |
34-39 |
34-2 4 |
34-1.1 |
With the object of testing still further the accuracy of this Table, a sample ’of-. water was allowed to stand over in an open matrass at a temperature of 0° for the space of 7 days, when the air absorbed by it was boiled out and analysed: but the composition of the gas driven off proved to be almost the same .as that specified above, viz. 35.18 per cent oxygen and 64.82 per cent nitrogen. Ot the total amount of air no measurement was obtained, a.small bubble of gas having unfortunately escaped when transferring the air into the eudiometer; the remaining portion mea- sured- ■ As appears from this Table, the quant-
ity of nitrogen absorbed from the atmosphere by 1 litre of sea-water is strictly proportional to the temperature, and may be very accurately expressed in cubic centimetres by the formula —
N— 14.4 — 0.232,
which, in place of
the ’ values observed, 14.41 13.22 12.08 11.01
gives ... . . . . -14.40 13.25 12.10 10.95
With regard to the amount of oxygen absorbed, the proportion is- less easily .expressed, since the curve indi- cating the variation with the temperature will no longer be a straight, but a slightly curved line, which, from 0° to 10°, tin- interval most important here, may be ex- pressed by the formula —
19
0 — 7.79 — 0.2 1 -j- 0.005 ti.
som lStedefcfbr do observerede Værdter 7.77 6.93 6.29 glVei 7.79 6.92 6.29
Men Hensyn paa den relative Sammensætning af den absorberede Luft cia er den ikke. saaJedes «J,,. rf Bunsen foi destilleret Vand fundet. uafhamgig af Temperaturen lien varierer med denne, saaledes at Surstofprocenten paa Strøget Ira 0° til 15° forandrer sig med en hel Procent.
Botragter man Resultaterne af disse Forsøg som Norm, viser det sig, at den relativt til den samlede Luftmængde meget hoie Surstofgehalt, som er observeret i ( Jverfladon i den nordlige Halvdel af det undersøgte Hav. i Virkolm- . heden skriver sig fra en Overmanning med Surstof og ikke som man ogsaa kunde tænkt, fra en maugelfuld Mætniug med J\ vælstof, idet der nuerkeligt nok her tindes en Sur- . stofgebalt» ^er meget hyppigt overskrider den af disse For- søg beregnede med 0.5 CC. og derover. Det vil. sige. der optræder saa store Afvigelser, at de paa ingen Maade. kunne tilskrives Observationsfeil. og det viser sig; saaledes. ‘ at Sur- stofgehalten i Overfladen ikke alene afhænger af Tryk og Temperatur, men rimeligvis ogsaa maa paavirkes af en eller Here andre ubekjendte Aarsager.
Naar det gjælder nærmere at studere Surstofmamgdens Variation med Dybden, falder det bekvemmest at udtrykke den som Procenter af den samlede Luftmængde. da den absolute Luftmængde varierer i meget st.erkere Grad med temperaturen end Luftens relative* Sammensætning. og mail vil saaledes ved at benytte denne Udtryksmaade opnaa at gjøre sig i betydeligt større Udstrækning uafhængig af Temperaturens Indfiy deise.
Ordner man de paa denne Maade udtrykte Tal efter Dybden, viser det sig, at der med Hensyn paa Surstof- procentens Størrelse i de forskjellige Dyb existerer en ‘tem- melig udpræget Lovmæssighed. som nærmere kan karak- teriseres af nedenstaaende Tabel, der er uddraget af samt- lige Observations;, naar undtages.de to. hvor Udkogniugen ikke foretoges strax men først efter nogen Tids Henstand.
|
Dybdeintervaller. |
Antal Observa- tioner. |
Midlere- Dybde. |
Midlere Surstøf- procent. |
|
|
Engelsk»* . * Favne. |
Meter. |
Engelske • Favne. ] Meter- |
||
|
O |
O |
28 |
O 0 |
35- 31 |
|
O — 1 00 |
0—183 |
6 |
.69 126 |
.3.3-9 3 |
|
ioo — 300 |
1 83 -549 |
14 |
210 I 384 |
.32,84 |
|
300—600 |
549—1097 |
16 |
420 768 |
32.50 |
|
600 — 1000 |
1097-1829 |
1 1 |
684 1251 |
32.58 |
|
i ood— 1 400 - - . |
1829— 2560 |
6 |
II92 2l.Su |
32.78 |
|
1400— 17601 |
256o— 3219 |
10 J |
1646 3010 J |
32.89 |
De enkelte Observationers Afvigelser fra den ved denne Tabel bestemte Regel ere i Bétragtning af det under- søgte Felts- store Udstrækning hverken mange eller syn- derlig store, 'idet kun 10. Nø. 2. 19. 38. 49. 64. 68. 83.
0 = 7.79 — 0 .2. f -f 0.005 1
?1VHl.g ‘ ‘ 7^79 6.92 6.29
m place ot the values observed . 7.77. 6.93 6.29
'Hi'iiei', the relative- composition of the air absorbed is no . as Hanson found to be the case with distilled water independent of temperature, hut varies with that factor' the percentage of oxygen, for instance, differing as much as 1 per cent between 0° and 15°.
Now. assuming the results of these experiments to furnish’ a normal standard, the relatively large proportion Ol oxygen as compared with the total amount of air present m the surface-water of the northern tracts of the sea in- vestigated. will he found to aviso from supersaturation with oxygen, and not. as might he supposed, from imperfect saturation with nitrogen, seeing that the proportion of oxygen exceeded that computed from these experiments by as much as. or even more than. 0.5 for a difference sa considerable does not admit of being’ ascribed to errors of observation. On the basis of these facts, the proportion ol oxygen m surface-water is shown to depend not only on pressure and temperature, but. probably, also oii the ef- fect of one or more, causes as vet unknown.
When investigating the degree in which tin- proper lion of oxygen varies with the depth, it will be most convenient to express the .difference as a percentage of the total amount of air. the absolute amount of air varying to a much greater extent with the temperature than does its relative compo- sition; besides, with this mode of expression considerably less regard need be hud to the influence of temperature.
If the figures representing, the results thus expressed m-e arranged according to depth, the proportion of oxygen present in the different strata will he found to exhibit very considerable uniformity, as appears from the following Table, based as it is bn the whole series of determinations, with the exception of two, the Water with which the latter were performed not having been boiled at once,* but allowed to stand over for some time previous to examination.
|
Intervals of Depth. |
Number |
Mean |
Depth. |
Mean Per- |
|
|
English Fathoms. |
■ Metres. |
of Obser- vations. |
English Fathom*. |
, Metres. |
centage of Oxygen. |
|
• 0 |
0 |
28 |
0 |
.0 |
35-31 |
|
0 — 100 |
0— 1 s 3 |
6 |
• 69 |
f 126 |
33-9.3 |
|
100 — 300 |
183 S)u |
14 |
2 10 |
384 |
32.84 |
|
300 — 600 |
549—1097 |
16 |
.420 |
768 |
32.50 |
|
600 — 1000 |
IO97 I#2<) |
1 1 |
684 |
12^1. |
32.58 |
|
1000 14001829—^560! |
6 |
1 192 |
2180 |
32.78' |
|
|
1400 - 1760 2650-32 19I |
10 |
1646 |
3010 | |
32.89 |
Considering the great extent, of. the region investi- gated. the deviation of the individual observations from the standard given in this Table is neither frequent nor con- siderable. 10 only. viz. Nos. 2. 19. 38. 49. 64. 68. 83. 84.
• 3*
20
84, 85 og 8,7. fjerne sig om mere end 1 Procent fra dot al- mindeligc Resultat, medens man af samtlige Observationer kan bestemme en enkelt Observations sandsynlige Afvigelse fra den efter doiino Tabel optrukne Curve til + 0.52 °/ 0, on Afvigelse saa liden, at eii ikke ringe Del af deii kan skrives paa Observationsfeil.
De største Uoverensstemmelser optræde talrigst i et Dyb fra 300—600 Favne (540 1097 Meter) men brides,
ogsaa enkeltvis i større Dyb.
Fra Buhden liidrører i de større Dyb kun to Lult- prøvef mod væsentlig for hoi Surstofprocent nemlig No. 68 og 87, optagne fra. to Puncter, som mærkeligt nok begge ligge paa on Linje paralel med og' tøt ved Grænd- sen mellem den nordover strygendo varme • Strøm og den sydover forbi Jan Mayen gaaende ' Polarstrøm. Bortser man imidlertid fra disse Vie wæsentligste Foverensstemmelser, ioin bidrage til at give Curyen et om end meget svagt M inimum i 300— 400 Favnes (549 — 732 Meters) Dyb, vil man i Kortlied kunne udtale Regelen for Surstofprocentens. Aftagen med Dybet saaledes: Surstofprocenteri er i Over- laden gjennemsnitlig 35.3 og aftager derpaa først liur- tigt senere langsommere til hfenimod 32.5 i 300 Favnes (549 Meters) Dyb, hvorira den med stigende Dyb holder sig paa det Nærmeste constant. Det kan bemærkes, at af de her undersøgte Vandprøver 40 ere øste lige ved Hav- lmiiden. Man. vil imidlertid forgjajves bestradie sig for at opdage nogen Forskjellighed i Egeiiskaber mellem disse og' de fra ligestore interriiediære .Dyb optagne.
Hvoy det gjælder at studere Variationerne af den absolute Luftmængde, maa det synes naturligt som Maal lor denne at benytte den opløste lvvælstof,' idet den ob- serverede Luftmængde paa Grund af det vedvarende For- brug af Surstof i de dybere liggende Lag bestandig kan forudsættes at være mere eller mindre forskjellig fra den Mængde, som vilde absorberes i Overfladen under direote Paavirkning af Atmospluvren. K vælstofmængden kan der- imod paa Grund af denpe Gasarts størkt udpr'rogede In- differentisme ligeoverfor andre Legemer udjeir. synderlig Feil antages.ua fbængig af locale Tilfældigbeder. ,
Anvendes saaledes Kvælstofmængden som Maal * for den i Søvandet opløste- Luft, viser der sig i Fordelingen ogsaa her en udprægøt Lovimessigbed, naar undtages, at der i de af Svendsen paa det første Togt udførte Obser- vationer-overalt or tumlet en mindre Kvadstofmængde, end man efter alle øvrige foreliggende Observationer skulde vente. Bortser man imidlertid fra disse paa første Togt udførte 14 Observationer, vil man se, at alle de Øvrige paa fan Undtagelser nær meget, vel stemipe overens med de Tal. man kan beregne efter den ved de oveuciterede Forsøg bestemte Formel
85, and 87* exhibiting a difference of more than 1 per cent as compared with the t general result, whereas the probable deviation of a single observation from the curve drawn according to this Table may be computed at + 0.52 per cent, a deviation so small as to arise, probably,, in no slight degree from errors of observation.
The greatest discrepancies refer chiefly to a depth of 300 — ooo fathoms (549 — 1097 metres); now and again,
• however, they were met with in water obtained from greater depths.
In only two of the samples of air expelled froip bottom-water drawn where the depth was great, did the percentage of oxygen prove much too high, viz. in Nos. 68' and 87, the samples of water yielding them having beei^ obtained from two spots which, strange to say, are in a line running parallel * and . in close proximity to the bound- ary, between the warm current Hewing north .and the cold Arctic current Howing south past the Island of Jail Mayen. Now, if we exclude from these differences the chief of those that contribute towards giving the curve a very slight but appreciable minimum at a. depth of from 300 to 400 fathoms *(540 — 732 metres), the. yule according to which the proportion of oxygen is found to diminish with the depth may be expressed as follows: — The proportion of oxygen, which at the surface is 35.3 per cent, begins at
ionce and continues to diminish, at first rapidly and after- wards at a slower rate, till it hqs reached 32.5 per cent, j at tin1 depth of 300 fathoms (549 metres), from whence it 1 keeps almost constant. I will not omit to observe, that of the samples of water examined 40 had been drawn from the bottom: is was, however, impossible to detect any dif- ference in composition between these and the samples. ob- tained from equal intermediate depths.
When investigating the variation in the absolute amount of air, it will ' obviously be advisable to make use <jf the nitrogen absorbed, since the quantity of air observed in the deeper strata may, by reason of the steady consump- tion of oxygen, he assumed to differ more or less from that which would he absorbed . at the surface .under the direct inHuence of the atmosphere, whereas nitrogen, from the very slight affinity evinced bv that gas for other bodies, may, without involving appreciable error, be regarded as proof against 'the accidents of locality.
If. therefore, the amount of nitrogen be adopted as •the standard- of measurement for the air absorbed in sea- water. a marked uniformity will here, too, be found to cha- racterise the distribution, as determined by the observa- tions described, with the exception however of Svendsen s, on the first voyage, by which the amount of nitrogen was found to be less than all subsequently instituted observations gave reason to expect. Excluding, then, the 14 observa- tions from the first voyage, all of the others, with hut few | • exceptions, agree closely with the figures which may he ' found by the formula stated above —
N= 1.4.4 7— 0.23 t.
N= 14.4 — 0.23 1.
21
Man friar nemlig af Observationerno følgende Mid- delværdier :
|
Dybdeintervaller. Engelske Vn Meter, r avne. , . |
Middcl- temp. nC. |
Midlore Kvu-lstof- mrcngde observoret |
Kvielstof- jnqpngde beregnet. |
Dif- ferent». |
|
|
O |
0 |
6.4 |
13-07 |
12.93 |
—o' 1 4 |
|
0 1 oo |
1 •o co T 0 |
. ’2-7 ’ |
13.98 |
I3-78 |
— 0.20 |
|
too — 300 |
183—549 |
1.0 |
14-15 |
14.17 |
0.02 |
|
300 — 600 |
349—1097 |
— 0.6 |
14-54 |
14-34 |
0.00 |
|
600 — 1000 |
1097—1829 |
— 0.8 |
14.04 |
1458 |
0-54 |
|
1000—1760 |
1829— 3219 |
— 1.4 |
14.38 |
14-72 |
O.34 |
Naar den midlere Kvælstofmængde lier i de dy here Lag er funded noget lavere' end man skulde tente, da har dette sin Grund i. at der ved de 5 Observationer No. 17.
22, 33, 3(1 og 37. alle hidrørende fra Vandprøvér fra det i 1877 undefsøgte Strøg, er fundet en ca. 1.5 CC., lavere Gehalt, end de ved sin Temperatur Vilde kunne optage ved almiudtfligt Atmosphæretryk. Forresten vil elter alle de øvrige Observationer at dømme ogsaa r de større Dyb Kvælstofmængden findes at stemme overens med den af | Formelen beregnede.
En lignende Sammenligning 1 er af Buchanan gjort mellem de af ham for de sydlige Have fundne Tal og de af Bunsen for destilleret Vand opstillede. I)er optræder ved denne Sammenligning især ved de lavere Temperaturer ikke ubetydelige Djfferentser paa lige op til over 1 CC. pr. Litre, men disse vil ved Sammenligning med de efter Forfatterens ’Formel beregnede Tal saa godt som bortfakle, idet man faar :
|
Dybde i Fod. . |
Midlere Temperatur. °C. |
Kva-lstof- imengde efter Buchanan. |
Ivvaelstof- • mængde efter Formelen. |
Difi'crents. |
|
• 600 |
14.6 |
1 1.26 |
11.04 |
— 0.22 |
|
1200 |
13.0. |
11.71 |
11.41 |
—O.3O |
|
1800 |
6.9 |
13.00 .. |
. 12.81 |
— 0.19 |
|
2400 |
5-i |
13-10 . |
13-23 |
0.13* |
|
4800 |
2,5 |
13.82 |
13.82 |
0.00 |
|
derover |
i-5 |
14-37 |
14-05 |
— -0.32 |
Det frekigaar heraf, at Kvælstofmængden, saaledes som det allerede af Dr. .Jacobsen og Andre er antaget? ikke i mindste Maade retter sig efter de i de store Dyb herskende Tryk men kun afhænger af Temperaturen. Den eneste rimelige Fortolkning udelukker Muligheden for,-- at Tryk- og Temperaturdifferentser i de under Overfladen
|
as will be mean values |
seen from |
the following Table showing the |
|||
|
Intervals of Depth. |
Mean |
Mean \ mount |
Amount of |
Dif- |
|
|
English . Fathoms. |
Metres. |
°C. |
of Nitr. observed. |
\ itrogen computed. |
foronco. |
|
O |
O |
6'. 4 |
‘3-07 |
12-93 |
—0.14 |
|
0^ 100 |
0 — 183 |
2-7 |
13.98 |
13-78 |
— 0.20 |
|
100 — 300 |
183—549 |
1.0 |
14-15 |
14.17 |
0 02 |
|
. 300 — 600 |
549 1097 |
— 0.6 |
14-54. |
«4-54 |
0.00 |
|
600 — 1000 |
1097 *829 |
—0.8 |
14.04 |
14-58 |
0.54 |
|
1000 1760 |
1829 3219 |
— 1.4 |
14-38 |
14.72 |
0-34 |
The mean quantity of nitrogen in the deeper strata proved, accordingly, somewhat lower than there was reason to expect; hut this arose from the proportion determined by 5 of the observations, viz. Nos. 17. 22. 33. 3(5, and 37 ;ill of them referring to samples of water obtained from , the tract of ocean investigated in 1877 having been about l.fr less than could be absorbed at the same •temperature under ordinary atmospheric pressure. For the rest, judging from all the other observations, the proportion of nitrogen observed, even at greater depths, will be found to agree with that computed by the formula, 4 similar comparison1 was instituted by Buchanan between his results for the water of the Southern Sums and the figures found by Bunsen for distilled water. The differences resulting from this comparison, , more especially for a low temperature, are considerable, the greatest reach- ing l cc per litre; but, on comparing them with the figures given -by the author’s formula, they will lie found almost to vanish, as appears. from the following Table.
|
Dopth in Feet. |
Mean Temperature. °C. |
Amount of Nitrogen ac- cord. to Buchanan. |
Amount of Nitrogen comp, by the Formula. |
Difference. |
|
600 |
14.6 |
1 1.26 |
1 1.04 |
— 0.22 |
|
1200 |
13-0 |
11-71 |
11. 41 |
—0.30 |
|
1800 |
6-9 |
13.00 |
12.81 |
—0.19 |
|
2400 |
5-i |
13-10 |
13-23 |
0.13 |
|
4800 |
’ 2.5 |
13-82 |
13.82 |
0.00 |
|
Greater Depths. |
1-5 |
14-37 |
14.05 |
—0.32 |
Hence the amount of nitrogen, as previously assumed by Dr. Jacobsen and others, can in ho wise be affected by the increase of pressure at great -depths, but must ob- viously be dependent on temperature, alone. The results of these observations exclude, therefore, the possibility of ditfere.nces in temperature and pressure at depths below
1 Ber. Berl. chem. Ges. — 11 — -110.
Bor. Berl. chcnf. (ion.- 11, p. 110.
22
liggende Lag skulde kunne hidføre en anden Fordeling af Luften end den. der allerede existeror fra den Tid. da Våndet sidste Gang befandt sig i Overfladen udsat lor tri Paavirkning af AtniQsphæren. Luften vil saaledes kun gjennem Vandets Circulation kunne naa ned i Dybet, og nogen Udjevning af Luftmængderne vil der kun kunne ske gjennem Blanding af de forskjelligartede Vandinrengder. en Blanding, som under Forudsætning at at der ikke ogsaa foregaar ()|)\annning eller Afkjoling. ikke vil kunne for- rykke det rette Forhold melleni Temperatur og Kvælstof- nnengde. da Kvælstofmængdons1 \ ariation med Temperatu- ren fremstilles ved* en ret Lihie.
Man vil altsaa, dersom disse Forudsætninger holde Stik, ved en Kvielstofbestemmelse i de dybere liggende Vandlag kunne om end meget raat bestemme, om disse have været Gjenstand for en væseiitlig Opvarmning eller Atkjoling. siden de sidst befandt sig i OverHaden. forudsat at man kan negligere Virkningerne af Atmosplneretrykkets Forandringer og andre mulige '1‘ilfaddigheder. som under Absorbtionen i OverHaden vil kunne gjøre sin Tndflydelse gjeldende.
Grupperer man de her offentliggjorte Observationer efter Vandprøvernos Temperatur, viser, det sig, at Ivvæl- stolinængden meget nøie' svarer til den efter denne Tempe- ratur af Formelen beregnede, det vil sige. Vandprøvernes Temperatur skulde ikke i væseiitlig Grad have forandret sig, siden de sidst befandt sig i Overfladen. M:tp faar nemlig :
|
Temporatur- interval. |
Midlore Temperatur. |
Midlore Kviidstof- nuengde. |
. Beregnet Kvælstof- inængde. |
Diflerents. |
|
under o" |
1. 1 |
M-32. . |
14-65 |
6.33 |
|
0—3 ' |
1.2 |
14.19 |
14.12 |
— 0.07 |
|
3-6 |
4.6 |
CC rr3 rr> |
13-34 |
— O.04 |
|
6—9 |
7-5 |
I 2.90 |
12.67 |
—O.13 |
|
over 9 |
I 1.2 |
1 1 -93 |
1 1.82 |
— 0. 1 1 |
the surface causing a distribution of the air different to that which existed when the water was last at the- surface, in direct contact with the atmosphere. Hence the air. cannot penetrate to such depths save by the circulation of the water, and an adjustment of the amounts of air can be effected solely by the mixing of the water different in composition, which will not, however, unless we assume a simultaneous increase or decrease of heat, disturb the true relation between the temperature and the amount of nitrogen, since the variation of the latter with the temper- ature is expressed by a right line.
If. then, these assumptions are found to hold good, it will be possible, when computing the proportion of nitro- gen in the lower strata of the water, to determine — very roughly indeed — .whether the latter have experienced any increase or decrease of heat since they were last at the surface, provided we can ignore the effect of change in the atmospheric pressure and of other accidental circum- stances’, which, durjng the process of absorption, may have made their influence felt.
On grouping together according to the temperature of the samples of water examined, the observations published in this Memoir, the proportion of nitrogen will be found to agree very closely with that computed by the formula, showing, as appears from the following Table, that the temperature could have varied but little since the water had been last at the surface.
|
Intervals of Temperature. |
Mean Temperature. |
Mean Amount of Nitrogen. |
Computed Amount . of Nitrogen. |
Difference. |
|
below O0 |
— i°.i |
14.32 |
14.65 |
0-33 |
|
0—3 |
1.2 |
14-19 |
I +.12 |
—0.07 |
|
3—6 |
4-6., |
I3.38 |
13.34 |
—0.04 |
|
6—9 |
7-5 |
12.90 |
12.67 |
-O.13 |
|
above 9 |
. 1 1.2 |
U.93 |
I 1.82 |
-0.11 |
At Overensstemmelsen for Temperaturerne under 0° ikke er saa fuldstændig som ellers, skyldes ogsaa her de ovenfor nævnto 5 Observationer alle udførte paa Togtet i 1877. Beregner man derimod den midlere Temperatur og Kvælstofmængde for dette Interval af ile paa sidste Aars Togt gjorte Observationer. erholder man til Middeltempe- raturen 1.2 Kvadstofunengdeii 14.59 CC. altsaa kun 0.09 CC. mindre end beregnet.
Benyttes paa samme Maade de af l)r. Jacobsen of- fentligjortc Observationer til et Overslag over Kvælstof- mamgden i Nordsøen. erholder man med runde Tal:
For the temperatures under 0*' the agreement is in- deed not so close; but here, too, the cause may he traced to the aforesaid 5 observations from the voyage in 1877. H'. however, we compute the mean temperature, and the amount of nitrogen for that interval by the results of the observations instituted on the last voyage, the mean tem- perature w ill be — 1.2 and the amount of nitrogen 14.59 •*, or only 0.09 ee less than that computed by the formula. 1 A similar comifutation w ith the observations published by Dr. Jacobsen for estimating the amount of nitrogen in the. water of the iCorth Sea, will give, in round numbers, the following results: —
|
Temperatur- intorval. |
Midlere Temperatur. |
Midlere Kvælstof» mængde. |
Beregnet Kvælstof- mivngde. |
Different». |
|
under io° |
6°-5 |
13-2 |
12. Q |
P-3 |
|
10—15 |
1 2 .1 |
12.0 |
1 1.6 |
-0.4 |
|
?5 — 20 |
16 .9 |
1 1.0 |
10.51 |
—0.5 |
Her Andes altsaa overalt en Kvælstofgehalt svarende til en noget lavere Temperatur end den obsérvetede og det i §t<rrkest Grad lor de høiere Temperaturer, eller da Tem- peraturen aftager med Dybden, for de øverst liggende Vandlag. Naar' man erindrer, at Jacobsens Observation» ere udførté r Ettersommeren og for det Meste paa Vand- prøver fra saa smaa Dyb,. at Luft- og Yandtempernjturens aarlige Variation kan tenkes at have gjort sig gjældende, vil dette ikke være saa vanskeligt at forklare' gjennom \ andets Opvarmniug i Sonimermaanederne, modems Kvæl- stofinængden maa antages at rette sig efter en Temperatur mindst lige saa lav som den aarlige Middeltemperatur.
At lignende Phænomener ikke ogsaa ere observerede’ i de øvre Lag af det af den ilorske Nordhavsexpedition undersøgte Hav. har sin simple Forklaringsgrund deri, at Lufttemperaturen der selv om Sommeren ikke er høiere end Overfladetériiperaturen hellere omvendt.
. ' Don for Intervallet fra 0 til 15° udledede Formel er her forud- sat at, giælde ogsaa fra 15 til 20".
|
Intervals T 0f 1 omperaturo. |
Meau Temperature. |
Mean Amount, uf Nitrpgen. |
Computed Amount of Nitrogen. |
Difference. |
|
bolow 1 0" |
6°-5 |
13-2 |
—0.5 |
|
|
0 [ |
12 .i |
12.0 |
1 1 |
O- 1 |
|
15—20 |
16 .9 |
1 1.0 |
IO.5 1 |
°*5 |
The proportion of nitrogen in this Table * corresponds accordingly to a somewhat lower temperature tlmu that observed, especially for the higher temperatures, or rather, since the temperature diminishes' with the depth for the upper strata of the water. If. however,, we bear in mind that. Jacobsen’s observations were instituted at the latter end oi summer, and the majority with samples of water obtained from such trifling depths that the annual .variation m the temperature of air and water probably exerted some influence, this will not he difficult to account for.
| by reason of the heat stored in the water during the summer months, whereas the amount of nitrogen must he regulated by a temperature at least as low as the mean annual temperature.
Tlmt similar phenomena were not observed in the upper
strata of the water throughout the ti'act of ocean investigated on the Norwegian North-Atlantie Expedition, arises simply •irom the tact, that the temperature of the air in those regions does not even in summer exceed tlmt of the water at the surface,, nay the reverse is rather the case.
1 Hie formula deduced for the interval from 0° to |.V is hore an. sumed to be correct for that .emending from i:.n to 2Q°.
II. Om Kiilsyrcu i Søvaiidet.
A f a.lli* do Chéffiikere. som før (len tyske Pomerania- expeditioni 1 872 anstillede Undersøgelser over Luften i Søvnndet, blev der ioruden Bestemmelser af Surstof- K vælstofinængden ogsaé samtidig udført Maalinger at den under Udkogningen •uddroYiie Kulsyre. og de ■ Qvantiteter, man paa denne Maadø fandt. bleve ogsaa bestandig opførte. blandt Resultaterue som den samlede Mængda Kulsyre. der var opløst i Søvnndet enten fri som G^sart eller bun- den til Carbonator som sure Salte. De Resultater, som ad denne Vei erholdtes. vise imidlertid bestandig overmaade store Uoverensstemmelser ikke alene mellem de torskjellige Forfattere men ogsaa mellem (b* enkelte Observationer bos en og samme I'Jxperimeiitator, hvor man dog maatte bave _ antaget, at en ston e ' Ensartethed i Forsøgenes Udforelse skulde have udjevnet Differentsérne.
80111 Exempel paa. hvor vidt Uoverensstemmelserne i de leldre Opgaver strække sig. kan anføres Følgende:
I en Liter Overfladevand fandt
|
Frémy . . . . • |
... 2.2 til 2.8 CC |
Kulsyre *. o |
|
Morren . . . . • • |
. . . 1.6 „ 3.9 |
- |
|
Lewy . . . . . |
. ’ . . 2.4 „ 3.9 - |
— 3. |
|
Pisani ...... |
. . . 6!0 „ 8.1 - |
|
|
Hunter |
. . . 0-.8- „ 5.9 - |
5< |
|
Desudeji faudtes |
eftor en noget anden |
Fremgangs- |
maade af
Bischof 39.0 CG.
.Vogel 55.6 til 1 L6.3 — . 7.
Ved alle disse a-ldre Undersogelser. hvor der ved l d- kogningerue var anvendt tuldt Atmosplueretnk. og b\oi
II. Oil the Carbonic Acid in Sea-water.
The several chemists who. previous . to the German -Pom- erania Expedition (1872), bad instituted observations 011 the air present in sea-water, when measuring the amount of the oxygen and nitrogen also collected the carbonic acid driven off during the process of boiling; and the quantities determined were invariably .set down among the results as the total amount of carbonic acid actually existing in the water, either free as gas or contained, to a less extent, also 111 bicarbonates. The results thus attained vary however to a remarkable extent, and not only as between the different experimentalists individually, — the like is also the case with the observations, of one and the same person, although greater uniformity in the mode of operation should ap- parently have tended to eliminate error.
The. following Table will show the . wide difference prevailing between the formulae' of early authors.
Amount of Carbonic Acid in 1 Litre ‘of Surface-water.
Frémy . . . • * • •, • ■
Morren . . . . . . • • • . •
Lewi'. . ... . • • •
Pisaui . . . •• • • • •
Hunter
The proportion as found process was as follows
Bischof
‘ Vogel . . . . v . . . .
. ... 2.2 to 2.8 CC. l *. ... 1.6 „ $.9 - -. ... 2.4 „ 3.9 — 3, . . 6.0 „ 8.1 — 4 *.
. 0.8 „ 5.9 — \ by a- somewhat different
.... 39.0 CC: 6.
. 55.6 to 116.3 — 7.
Hence, it appears that the quantity of carbonic acid given off under these early experiments, for which the boil-
1 Coiupt. rend. (>— Old.
Ohim. l’liw '.) — 12 — ■ 5. *
a Ann. - - [3] — 17. . Ann. Chem. Ph'nrm. 58 — 328.
4Compt. rend. *11 — .r>32.
6 Jahrosbericht 1861) — 1279.
0 Chem. Geologic 1 Autl. 2 — 1130. • •
7 Sclrweigg. .Journ. 8 — 351.
\Compt. rend. 0, p. 016.
1 Ånn. Chim. Phys. (3J 12, p. 5.
» — — — [3] 17. Ann. Chem. Pharm. -58, p. 328.
4 Compt. rend: 41. p. 532, *
•’’Liebigs Jahrbericht i860, p. 1279.
“Chem. Geologic '1 Autl. 2, p. 1130.
7 Schweigg. Journ! S, p. 351.
25
derfor Temperaturen steg over 100°. undveg altsaa altid vel maalelige og ofte endog temmelig betydelige Mængder Kulsyre.
Ved de påa Pomeraniaexpeditionen i 1871 udførte Lufthestemmelser *, hvor den tidligere beskrevne Methode med Gasarternes Udkogning under et, ved Vanddamp frem- bragt \ acuum anvendtes. sænkedes imidlertid Temperaturen ikke ubetydeligt, og det viste sig da. at man ved denne Temperatur temmelig ofte kun fik næsten umaalelig smau Qvantiteter Kulsyre uddrevet sammen med den øvrige Luft. medens de tidligere Uoverensstemmelser mellem flere med samme Vandprøve. gjentagne Udkogninger ogsaa lier gik igjen.
Jacobsen fandt sig derfor ved dette mærkelige Phæ- nomen foranlediget til nærmere at andersøgé Kulsyrens Absorbtionsforhold ligeoverfor Søvand.
Gjennem de Forsøg, som han i denne Anledning an- stillede, wiste det sig da. at man ad andre Veie kunde paavise aldeles uventet store Qvantiteter Kulsyre i det samme Vand. hvoraf man ved en i flere Timer fortsat Ud- kogning efter Bunsens Methode kun kunde erholde meget smaa Mængder. Åfdestilleredes nemlig Søyandet i en kul- eyrefri Luftstrøm uden Luftfortynding i en Retorte, undveg der den hele Tid Kulsyre. lige indtil den hele Mængde Vædske var afdestilleret. saaledes at man først ved rigelig Udskillelse af Salte kunde være fuldstændig sikker paa at have erholdt det samlede Udbytte af Kulsyre uddrevet.
Der lod sig under Udkogningen ikke paavise noget Punct. hvor man kunde tale om en Grændse mellem fri og surt hunden Kulsyre.
Paa denne Maade uddrev nu Jacobsen ved fuldstæn- dig Afdestillation af 1j4i Litre Søvand i en kulsyrefri Luft- strøm den hele Mængde Kulsyre og opsamlede den efter Pettenkoffers Princip i en afmaalt Mængde titreret Baryt- vand, som efter endt Operation retitreredes med Oxalsyre, og beregnedes efter disse den samlede Kulsyremængde, som for ufortyndet Nordsøvand opgives til omkring 100 Mgr. per Litre.
Samtidig bestemtes ogsaa i Residuet fra Inddampning a/ circa ID Litre af det samme Vand den i de neutrale Carbonater indelioldte Kulsyre til i Middel kun omkring 10 Mgr. per Litre.
Ifølge disse Observationer kunde altsaa kun en meget liden Brøkdel af den ved Destillationen uddrevne Kulsyre betragtes som surt hunden, og Jacobsen imødegaar derfor i sin Afhandling bestemt den af Vierthaler2 gjorte Antagelse, at al den ved Kogning afSøvandet uddrevne Kulsyre skulde være surt hunden. Han anser sig endvidere aldeles sikker for under Inddampningen ikke at have erholdt decomponeret nogen Del af de i Søvandét iudeholdte neutrale Carbonater, idet hau udtrykkelig siger: ‘*Die ganze Menge der nicht
1 Ann. Chem. Pharm. 167 — 1.
8 Wien. Acad. Ber. [2] — 56 — 479.
Den norske Nordhavsexpedition. Tornoe: Cheim.
ing-process was conducted with lull atmospheric pressure, or at a temperature of more than 100° C., invariably proved appreciable, nay sometimes rather large.
When performing the air-determinations 1 on the ‘Pom- erania’ Expedition in 1871 (by the method, previously described, of boiling out the gaseous elements in a vacuum created by steam), the temperature kept considerably lower, and the quantity of carbonic acid expelled with the other atmospheric element» at a comparatively low temperature was often immeasurably small : moreover, the variable char- acter of the results, alluded to above, on repeating the boiling-process with the same sample of water again as- serted itself.
Struck by this remarkable phenomenon, Jacobsen determined to investigate anew the absorptive capacity of sea-water in relation to carbonic acid.
The experiments of that chemist undertaken with the above ebject in view afforded conclusive proof of the fact, that large quantities ol carbonic acid were still present in water from which a very small amount only could be ex- pelled after several hours’ protracted boiling by Bunsen’s method. On distilling in a retort sorb-water exposed to a current of air free from carbonic acid, but not varified. carbonic acid is found to escape so long as any portion ol the fluid remains undistilled, an abundance of solid deposit however being the only indication that all or nearly all the carbonic acid present in the water has been driven off.
During the process of boiling no particular moment could be determined marking the escape of the carbonic acid present as gas and of that which has combined with carbonates to form bicarbonates.
In this manner, by distillation in a current of air free from carbonic acid, .Jacobsen succeeded in expelling the whole amount of carbonic acid contained in ‘/i litre of sea-water, and collected it, by Pettenkoffer's method, in a given quantity of titrated baryta water of known strength, which, on the operation being terminated, he retitrated with oxalic acid, computing accordingly the total amount of carbonic acid driven off in the process. Undiluted North Sea water contains according to Jacobsen’s results about 100^r per litre.
The amount of carbonic acid contained by the neutral * carbonates in the residuary deposit from the evaporation of 10 litres of the [same water, was also calculated, and found to average only about 10m<?r per litre.
According to these observations, a very small propor- tion only of the carbonic acid driven off by distillation could have been present in bicarbonates ; and hence Ja- cobsen emphatically opposes Vierthaler’s assumption,2 that the carbonic acid boiled out of sea-water occurs in that form. Moreover, he feels quite sure that no portion of the neutral carbonates in the water examined was de- composed during the process of boiling. "Die ganze Menge." he says, i(der nicht mit Basen zu neutralen Salzen verbun-
1 Ann. Chem. Pharm. 167, p. 1.
8 Wien. Acad. Bcr. [2] 50, p. 479.
4
mit Basen zu neutralen Salzen verbundefien KohVenstCnre erha.lt man aus dem Meerwasser, wenn dieses unter Durch- leiten eines Stromes kohlonsiiurefreier Luft bis zur reich- lichen Abscheidung von Chlorn atrium verkocbt wild;'
Det maatte saaledes fremstille sig som et hoist mær- keligt PhaSnomen, at den Kulsyre, som dog maatte tænkes oj)løst. i Søvandet paa en eller anden Maade som fri Gas- art. ikke skulde lade sig uddrive ved Udkogning efter Bun- sens Metbode, og at den endogsaa ved Udkogning under fuklt Atmosphæretryk og i en kulsyrefri Luftstrøm skulde undvige saa langsomt, at man først ved Concentration til omkring l/io h f det oprindelige Volum crholdt den sidste Rest uddrevet
Forat kunne forklare disse Mærkeligheder tillægger Jacobsen Søvandet en eiendommelig Evne til med mpgen Kraft at kunne tilbageholde sin KulsyrQ, en Mening, som han efter nærmere at have fremført sine Grunde mod den af YierthaJér gjorte Antagelse udtrykker med følgende Ord: •«Wie man aber aucli eine Deutung’der starkeh Absorptions- wirkung des Meerwasser^, auf die atmosphårische Kohlen- siiure versucben moge, jedenfalls kann man die Kohlensilure nicbt iu demselben Sinne, wie Sauerstoff und Stick stoff, als absorbirtes freies Gas darin annehmen. Man mag einst- weilen von eiiiem eigentbumlichen Zustande der Bindung sprecben, bei welcbem die Kohlensåure selbst durch stun- denlanges Kocben nur selir unvoUståndig ausgestrieben wird. Das Vorbandeusein ungebeuerer Mengen Kohlensåure im Meerwasser, in einem solcben Zustande, wo sie der Ath- raungsluft der Seethiere nicbt olme Weiteres zugezahlt wer- den kann, obne andererseits der Vegetation des Meeres unzugånglich zu sein, ist jedenfalls fur das maritime Thier- und Pflanzenleben von hbchster Bedeutung.”
Jacobsen antager nærmest at maatte henlægge denne eiendommelige Absorbtionsevne hos Søvandet til den deri opløste Chlormagnesium og henviser i saa Henseende til Egenskaber hos en Chlormagnesiumopløsning, der indehol- der en i Kulsyre opløst Mamgde killsur Kalk. En saadan Opløsning kan ifølge ham henstaa i ugevis ja endog koges uden at blakkes, først ved meget langt fortsat Concentra- tion udskiller der sig ren kulsur Magnesia.
Denne Jacobsens Anskuelsesmaade blev senere saa godt som uforandret optagen af den engelske Challenger- expeditions Chemiker, J. Y. Buchanan, som udførte en Række Forsøg1 for nærmere at bestemme, hvilket eller hvilke af Saltene i Søvandet der skulde være i Besiddelse af denne Evne saaledes at kunne tilbageholde Kulsyren. Han kom i den Henseende til det paafaldende Resultat, at de fleste Salte, som han undersøgte, i mere eller mindre Grad skulde være i Besiddelse af denne Egenskab dog mest Sulfaterne, saaledes at denne Søvandets stærke Ab- sorbtionsevne ligeoverfor Kulsyren af ham benbigdcs fra Chlormagnesium til Sulfaterne. Ved de af ham udførte
• 26 _
denen Kohlensåure erbiilt man aits dem Meerwasser. wenn dieses unter Durchleiten eines Stromes kohlensaurefreier Luft bis zur reichlichen Abscheidung von Chlornatrium ver- kocbt wird.”*
Hence it could not but strike the experimentalist as a remarkable phenomenon, that the carbonic acid, which in some way or other must' have been held absorbed by the sea-water in a free gaseous form, should not admit of being boiled out by Bunsen s method, and that even when the boiling-process was conducted with full atmospheric pressure in a current of air free from carbonic acid, it should escape so slowly, that concentration to the extent of about one-tenth of the original volume proved necessary to obtain it all.
To account for this perplexing phenomenon, Jacob- sen ascribed to sea-water a peculiar property of retaining its carbonic acid, an assumption which, after setting forth more at large the grounds that led him to oppose Vier- thaler's hypothesis, he enounces in the following terms: — “Wie man aber auch eine Deutuug der starkeh Absorptions- wirkung des Meerwassers auf die atmospharische 'Kohlen- såure versuchen moge, jedenfalls kann man die Kohlensåure nicht in demselben Sinne, wie Sauerstoff und Stickstoff, als absorbirtes freies Gas darin annehmen. Man mag einst- weileu von einem eigenthttmlichen Zustande der Bindung sprcchen. bei welchem die Kohlensilure selbst durch stun- denlanges Kochen nur sehr unvollstandig ausgestrieben wird. Das Vorbandeusein ungebeuerer Mengen Kohlensåure im Meerwasser. in einem solchen Zustande, wo sie der Ath- mungsluft der Seethiere nicht okne Weiteres zugezahlt wer- den kann, olme andererseits der Vegetation des Meeres unzugiinglick zu sein, ist jedenfalls fur das maritime Thier- und Pflanzenleben von hocbster (Bedeutung.”
Jacobsen is of opinion, that this peculair absorptive power must be derived from the chloride of magnesia pres- ent in sea-water, and draws attention to certain properties possessed by a solution of chloride of magnesia' containing carbonate of lime dissolved in carbonic acid. A solution of this kind may, according to bis statement, be left ex- posed for weeks together, nay be boiled even, without be- coming turbid; nor can it be made to part with pure carbonate of magnesia till after protracted concentration.
Jacobsen’s hypothesis was subsequently adopted, almost without modification, by J. Y. Buchanan, chemist to the ‘Challenger’ Expedition, who instituted a series of experi- ments1 with a view to determine which of the salts present in sea-water had this property of retaining car- bonic acid. He arrived at the surprising conclusion, that most of the salts examined were in some degree distinguished by this property, chiefly however the sulphates; and the remarkable power possessed by sea-water of retaining car- bonic acid he transferred accordingly from chloride of mag- nesia to the sulphates. Hence, when performing carbonic aeid determinations he always precipitated the sulphuric
Proc. Royal Soc. 22
102 og 483.
'Proc. Royal Soc. 22, pp. 192 and 483.
Kulsyrebestemmelser pleiede lian derfor altid for Opera- tionens Begyndelse at udfælde Svovlsyren raed concentreret Ohlorbariumopløsning, forat Kulsyren lettere skulde und- vige, men anvendte forresten den af Dr. Jacobsen angivne Methode, hvorved han har bestemt Kulsyren i Søvandet i de sydlige Have til i Middel 43.26 Mgr. per Litre1.
Da jeg Vaaren 1877 opfordredes til at gaa ud som Chemiker paa den norske Nordhavsexpeditions 2det Togt, var der kun levnet mig nogle faa Dage til Forberedelser, og det følger derfor af sig selv, at jeg ikke paa nogen Maade dengang kunde kave befattet mig med vidtløftigere Forundersøgelser, og jeg maatte saaledes uden selv at kunne prøve optage de tidligere Methoder uforandrede. Paa Togtet i 1877 anvendtes derfor den af Dr. Jacobsen angivne Methode. og bestemtes efter denne gjennem en Række omhyggelig udførté Observationer Kulsyregehalten i det da undersøgte Hav til omkring 100 Mgr. per Litre* Der viste sig imidlertid ved Gjentagelse af samme Observa- tion bestandig Uoverensstemmelser, som ofte vare ikke ube- tydelige og engang endog løb op til hele 12 Mgr. per Litre.
Dels herved dels ved andre Omstændigheder vaktes min Mistanke om Tilforladeligheden af den af Dr. Jacob- sen i Forslag bragte Methode.
Det syntes mig paa Forhaand overnlaade urimeligt, at der hos Søvandet skulde findes en saadan mærkelig Evne til rent mekanisk at tilbageholde den ene Gasart, medens den ingensomhelst Virkning skulde udøve paa de Andre. Heller ikke var der nogensinde gjort noget Forsøg paa at sætte dette Phænomen i Forbindelse med bekjendte chemi- ske Egenskaber hos nogen af de i Søvandet indeholdte Stoffe.
Ved et Tilfælde kom jeg en Dag -til at forsøge Sø- vandets Reaktion paa Lakmus og Rosolsyre og fandt til min store Forundring, at det reagerede bestemt og tyde- ligt alkalisk, livad jeg siden har bragt i Erfaring, at alle- rede v. Bibra2 og senere E. Guignet og A. Telles3 har observeret.
Efter mine Forsøg viser to ligestore Prøver af en efter Gottliebs1 Fremgangmaade frisk tilberedt -Lakmus- opløsuing. hvoraf den Ene tilsættes en tilstrækkélig Mængde Søvand og den Anden et ligestort Volum rent destilleret Vand, ikke ubetydelige Farvedifferentser. Ligeledes an- tager en med meget fortyndet Oxalsyre svagt udsyret pas- sende Portion rent Vand, hvori paa Forhaand er opløst en Draabe Rosolsyre, ved Tilsætning af Søvand strax den bekjendte rødlig-violette Farve.
Paa denne Maade undersøgtes paa Expeditionens sidste Togt, hvor der var fuld Anledning til at erholde Vand- prøverne ganske friske,., et meget stort Antal af disse og uden Undtagelse med det samme ovenbeskrevne Resultat.
1 Ber. Berl. chem. Ges. 11 — 410.
* Ann Chem. Pharm. 77 — 00.
8 Compt. rend. S3 — 019.
4 Journ. fiir pract. Chem. 107 — 488.
acid, before commencing the operation, by adding to the water a saturated solution of chloride of barium, in order to facilitate the liberation of the carbonic acid, but. with this exception, adopted the method devised by Dr. Jacobsen, and determined the mean amount of. carbonic acid present in the water of the Southern Seas to hi* 43.26 mt>r per litre. 1 •
When invited, in the spring of 1877, to go out as • chemist to the Norwegian North- Atlantic Expedition, on the second cruise, I had but a few days in which to make the necessary preparations, and consequently no time being left me for preliminary experiments, I was compelled to adopt unchanged the earlier methods, without testing the accuracy of their results. On the cruise in 1877. I therefore ap- plied Dr. Jacobsen’s method, and determined by a series of careful observations the amount of carbonic acid present in the water of the tract then investigated to be about 100m^per litre. But, on repeating the. operation with the same sample of water, the results were always found to vary, aud frequently indeed considerably ; nay, on one occa- sion the difference amounted to as much as 1 2m^r per litre.
Partly for this reason, and partly from other circum- stances. I was led to question the trustworthiness of Jacobsen’s method.
Now it struck me at once as highly improbable that sea-water should possess so remarkable a power of retain- ing mechanically one gas, and yet. in this respect, exert no influence whatever on others. Nor had any attempt been made to connect this phenomenon with known chemical properties distinguishing the substances contained* in sea- water.
Quite accidentally, I was one day Ted to investigate the effect of sea-water as a reagent on litmus and rosolic acid, and found its reaction, to my great surprise, dist- inctly alkaline, which, indeed, as I subsequently learnt, had been already observed, first by von Bibra8 and later by E. Guignet and A. Telles.3
According to my experiments, two equal measures of a solution of litmus, freshly prepared by Gottlieb’s method,4 one of which has added to it a sufficient quantity of sea- water and the other an equal volume of pure distilled water, exhibit considerable difference in colour. Moreover, a proportionate mixture of highly dilute oxalic acid and pure water, the latter having been previously treated with a drop of rosolic acid, will, on the addition of sea-water, immediately assume the well known reddish-violet hue.
In this manner were examined on the last cruise of the Expedition, which afforded excellent opportunities of obtaining the water quite fresh, a very large number of samples, and invariably with the results described above.
1 Ber. Berl. chem. Ges. 11, p. 410.
8 Ann. Chem. Pharm. 77, p. 00.
8 Compt. rend. *3, p. 010.
* Journ. fiir pract. Chem. 107, p. 488.
1*
28
Dette syntes ogsaa meget vanskeligt at forklare, saa- fremt det virkelig skulde forholde sig som åf Enkelte paa- staaet, at der i Søvandet skulde findes et meget stort Overskud af fri Kulsyre ved Siden af en meget liden Qvantitet af sure Carbonater. Det maatte aabenbart synes meget rimeligere at forklare de at Dr. Jacobsen gjorte Observationer derved, at Søvandet under den langvarige Kogning ved on eller anden chcmisk Reaction gav Slip paa noget af sin neutralt bundne Kulsyre.
For at komme paa det Rene med, om dette virkelig forholdt sig saa, gik jeg frem paa følgende Maade:
200 CC. Søvand (af sp. Vregt 1.0267 ved 17.°5 C. i Forhold til destilleret Vand af samme Temperatur) afdestil- leredes næsten til Tørhed i en kulsyrefri Luftstrøm, og op- fangedes den undvigende Kulsyre i 25 CC. af en Baryt- opløsning, hvoraf 1 CC. svarede til 4.0204 Mgr. Kulsyre. Ved Retitration med Oxalsyre viste det sig, at 19.97 CC. af det anvendte Barytvand var uneutraliseret. hvoraf den undvegne Kulsyre beregnedes til 20.2 Mgr. Residuet paa- heldtes nu friskt udkogt Vand, som atter afdestilleredes, hvorved endnu et ubctydeligt Spor af Kulsyre erholdtes. Sluttelig tilsattes circa 0.5 Gr. fuldkommen ren friskt ud- glødet Soda, hvorpaa det Hele atter forty ndedes med kul- syrefrit Vand til Søvandets oprindelige Volum og saa al- destilleredes i en kulsyrefri Luftstrøm.
Allerede fra det Øieblik af, daYædskfen var koiiunen i Kog, begyndte strax en saa voldsom Kulsyreudvikling, at det i Forlaget anbragte Barytvand slap store Mængder uabsorberede igjennein, og det viste sig efter endt Opera- tion, at kun 1.3* CC. Barytvand var forblevet uneutralise- ret. Heraf beregne» den absorberede Del af den undvegne Kulsyre til 95.3 Mgr., medens desforuden meget betydelige Mængder gik igjennom, idet nemlig Barytvandet i et ufor- migt Ror, som var anbragt foran Forlaget, fuldstændigt var forbrugt.
Efter Forslag af Professor Waage gjentoges Forsøget med varmt fældt, ved 100° tørret kulsur Kalk. hvoraf det ogsaa lykkedes at uddrive ikke ubetydelige om end meget mindre Mængder Kulsyre, hvorimod der ved et Forsøg med fint pulveriseret Marmor ikke erholdtes noget sikkert Resultat.
Betydningen af disse -Observationer kunde ikke være tvivlsom. da det hermed paa det Tydeligste var godtgjort, at den i Søvandet forhaaudenværende Saltblanding ved Kog- hede decomponerede neutrale Carbonater, og dermed ogsaa, at alle de hidindtil gjorte Kulsyrebestemmelser med Hen- syn paa sin Hensigt at bestemme den i Søvandet inde- holdte frie og surt bundne Kulsyre vare forfeilede. Hvad angaar de før Publicationen af Dr. .Jacobsens Afhandling om Luften i Søvandet udførte Kulsyrebestemmelser. da er det eu Selvfølge, at de alle uden llndtagelse maatte være i enhver Henseende fuldstændig værdiløse, idet der ved dem intetsteds er kommen til Anvendelse en Afdestillation til Tørhed eller en saa vidtdreven Concentration, at man
This fact would obviously be most difficult ol expla- nation ifi as some have affirmed, sea-water does actually contain a very large surplus of free carbonic acid along with an exceedingly small proportion of bicarbonates. A more plausible hypothesis by which to explain Dr. Jacobsens observations were surely the assumption, that during the protracted process of boiling some ol the neutral carbon- ates present in sea- water had been decomposed.
With the object of ascertaining whether such was really the case, I went to work as follows.
Two hundred c.centim. of sea-water (sp. grav. 1.0267? temp. 17.°5 C., as computed with distilled water ol the same temperature) were distilled almost to dryness in a current of air free from oarbonic acid, and the carbonic acid collected in 25 cc of baryta, water, 1IC of which re- presented 4.0204'"*"' carbonic acid. On being retitrated .with oxalic acid 19.97 M of the baryta water were found not to be saturated, and 20.2 w*r carbonic acid had accord- ingly befen driven oft. Water freshly boiled was now poured on the residue, and then . evaporated, the result yielding a slight trace of carbonic acid; finally, about. 0.5 purified and freshly heated soda was added, • and the whole com- pound again diluted with water, from which all carbonic acid had been expelled, to the original volume of the sample, and then distilled in a current of air free from carbonic acid.
From the very moment at which the fluid began to boil, so rapid was the liberation of carbonic acid that large quantities passed unabsorbed through the baryta water; and, on the operation being terminated, 1.3 " only of the baryta water had not been neutralised. Hence the absorbed portion of the carbonic acid was calculated at 95.3 exclusive of which a very considerable quantity, as before stated, passed off into the atmosphere, the baryta water, placed in a glass tube (resembling in form the letter U) connected with the receiver, being surcharged with the gas.
At Professor Waage’s suggestion I repeated the ex- periment with carbonate of lime, precipitated warm and dried at a temperature of 100° C., and succeeded in expel- ling carbonic acid in considerable, though not so large, quantities as before, whereas an experiment with finely pulverised marble gave no positive result.
The importance of these observations was not to be questioned, aft'ording as they did conclusive proof that the saline mixture in sea-water, on the temperature being raised to the boiling point, decomposed neutral carbonates, and likewise that all carbonic acid determinations hitherto at- tempted with the object of measuring the carbonic acid present in sea-water were faulty. As regards the car- bonic acid determinations performed previous to the publi- cation of Dr. Jacobsen’s Memoir on the presence of air in sea-water, such must as a matter of course be wholly worthless, the method of distillation to dryness having in no case been adopted, or that of concentrating the fluid till further evaporation ceased to expel carbonic acid. The
29
ikke ved fortsat Inddampning skulde kunne have erholdt et større Udbytte af Kulsyre. De af Dr. Jacobsen og J. Y. Buchanan udførte Observatiouer kunde derimod ikke saa ligefrem forkastes, idet der jo kunde tænkes Muligked for, at det ved de af dem benyttede Methoder kunde have lykkedes ved den langvarige Kogning at uddrive ogsaa al neutralbunden Kulsyre. i hvilket Fald de af dem opførte Tal i en anden Henseende kunde faa Betydning nemlig som Udtryk for den samlede Sum af den i Sø våndet inde- holdte Kulsyre.
Desværre lagde dere Omstændigkeder Hindringer i Veien for Afslutningen af mine Forsøg over disse Gjen- stande i Vinteren 1877 — 78, dels var min Tid optagetmed andre Arbeider, dels lod min Helbred den største Del af Vinteren adskilligt tilbage at ønske, saaat mine Forsøg in- genlunde liavde den ønskelige Fremgang, og jeg blev der- for nødt til at gaa ud ogsaa paa Togtet i 1878 uden nogen paalidelig Methode til Bestemmelse af den i Søvandet inde- lioldte Kulsyre. Da jeg efter endt Togt om Høsten vendte tilbage, gjenoptog jeg imidlertid atter mine Undersøgelser og bragte dem til Afslutning.
Gjehnem en netop da af C. Rorchers offentliggjort Afhandling1 om Bestemmelsen af Kulsyren i naturlige Mi- neralvande blev jeg gjort opmærksom paa det for Bestem- melse af Kulsyren i Carbouater af Alexander Glassen angivne Apparat,- som jeg senere i stor Udstrækning har benyttet.
Apparatet i den Form, hvori det her er kommen til Anvendelse, tindes sammenstillet i Figur 3.
A er 2 med Natronkalk fyldte uformige Rør, B inde- holder Barytvand. C er en Erlenmeyers Kolbe paa circa 0.5 Litre, der gjenuem et ved Bunden udmundende Rør communicerer m,ed B, medens et lige under Kautschuk- proppen udmundende sætter den i Forbindelse med Kjøle- leren D, hvis indre Del efter Glassen bestaar af et 27 — 30 mm vidt Glasrør. hvortil i øvre og nedre Ende er loddet Rør med respective 15 og 'lmm Diameter. Forlaget E er fuldstændig af samme Construction som det af Jacobsen benyttede og er oventil forsynet med det af P. Wagner3 foreslaaede med Glaskugler fyldte Rør F.
Ved a, hvor cler tindes en Indsnevring, er anbragt en noget større Glaskugle, som temmelig nøie dækker pver det nederste snevre Rør. Idet det til Opsamling af Kul- syren anvendte titrerede Barytvand heldes ned gjennem F, .fjernes Proppen b, indtil det Meste af Barytvandet har passeret a, men sættes derpaa hurtigt i, saaledes at der over de nederste Glaskugler bliver staaende noget Baryt- vand til en Høide af omtrent 50 mm over a. Dersom nu
series of observations instituted by Dr. .lacobsen and J. Y. Buchanan cannot however be wholly rejected, since the protracted boiling characteristic of the method they adopted may possibly have driven otf all the carbonic acid contained in the carbonates, in which cast* their figures would acquire importance as expressive of the total amount of carbonic acid present in the sea-water examined.
Unfortunately, divers untoward circumstances conspired to prevent my terminating in the winter of 1877 —78 the series of experiments l had begun with the object of elu- cidating this intricate subject; my time, for instance, came to be unexpectedly occupied in other ways, and during the greater part of that period I suffered from ill-health. Mv observations, therefore, not having progressed so favourably as I at first had reason to anticipate, I was again obliged to set out on the Expedition, in 1878, without having fixed on any reliable method for determining the carbonic acid present in sea-water. On my return however to Chris- tiania in the autumn of that year, I recommenced the said experiments, and succeeded in bringing them to a satisfac- tory termination.
A paper by G. Borchers, which had just appealed,1 on the determination af carbonic acid in mineral water, drew my attention to the apparatus — of which 1 have since made frequent use — devised by Alex. Glassen2 for determining carbonic acid in carbonates.
Figure 3 represents this apparatus as constructed for my experiments.
A 2 glass tubes, resembling in form the letter U, filled with soda-lime; B a vessel for baryta water: C an Erlenmeyer flat-bottomed matrass, containing about 0.5 litre, which by means of a tube terminating at tin* bottom is made to communicate with B. a similar tube, issuing im- mediately beneath* the caoutschouc stopper, putting it like- wise in communication with the cooler D, the inner por- tion of which, according to Glassen, should consist of a glass tube from 27'"m to 30mOT in diameter, with tubes, measuring respectively 15 mm and lmm in diameter, sealed to its upper and lower extreinitfes. The receiver E has precisely the same form as that adopted by Jacobsen, and is furnished above with a glass tube, F, filled with glass balls, as suggested by P. Wagner.3
At the point a, where the tube suddenly narrows, is introduced a somewhat larger glass ball, to fill up, as near as may be, the opening of the lower or slender portion of the tube. When the titrated baryta water, which absorbs the carbonic acid, is being poured down through F, the stopper b has to be taken out, but must he quickly replaced, before the whole of the fluid has passed a, in order that the glass balls to a height of about 50"m abovt* a
1 Journ. fur pract. Chem. 125 — 353.
2 Fresenius Zeitschrift 15 - 288.
3 Fresenius Zeitschrift 9 — 445,
1 Journ. fur pract. Chem. 125, p. 353. 1 Fresenius Zeitschrift 15, p. 288.
3 Fresenius Zeitschrift 9, p. 445.
30
den nederste Glaskugle slutter godt, vil den gjennem a passerende Luft spaltes i en Mængde meget fine Blærer, som ved at stige op inellem de afBarytvand omgivne Glas- kugler bliver fuldstændig kulsyreiri. Det uformige Kor 0 indeholder Barytvand, H fører til Aspiratoren.
may be immersed in baryta water. Now. assuming the large glass ball to fit well, the air will pass a in the form of minute bubbles, which, having to ascend between the glass balls surrounded by baryta water, must part with the || whole of its carbonic acid. The tube 0 contains baryta j water; H leads to the aspirator.
Den af Classen foreslaaede Kjøler virker saa udmær- ketf. at man i meget laug Tid kan koge fortyndet Saltsyre i Kolben, uden at det mindste Spor af Chlor kan paavises i Forlaget, fprudsat at den gjennemlcdede Luftstrøm ikke gives for stor Hastighed, kvad der imidlertid heller ikke er fornødent.
The cooler devised by Glassen is so excellent, that diluted hydrochloric acid may be boiled in the matrass for a very considerable length of time without a trace of acid being detected in the receiver, provided that too great rapidity be not given- to the current of air; this, however-, is quite unnecessary.
31
Naar Søvandet i dette Apparat kogtes med fortyndet Svovlsyre i en kulsyrefri Luftstrøm, lindveg Kulsvren meget hurtigt, idet 15 Minutters Kogning fuldstændig strak til for at bringe al Kulsyre over i Forlaget. Søvandets Sul- fater viste altsaa i alle Fald ikke ved Tilstedeværelsen af tri Syre de af J. Y. Buchanan observerede Egenskaber. Naar den paa denne Maade uddrevne Kulsyremængde op- samledes og bestemtes, viste den sig altid at stemme nogen- lunde med, hvad man efter den af Dr. Jacobsen anvendte Metkode kunde erholde uddrevet,* idet de optrædende Af- vigelser snart vare positive snart negative men i Regelen ikke større, end at de for den største Del maatte kunne tilskrives Observationsfeil. Ved den af Buchanan i For- slag bragte Udfældning af Svovlsyren erholdt jeg derimod bestandig betydelig for lave Resultater, hvorom senere.
For samtidig i en og samme Portion at kunne be- stemme baade den neutralbundne og den samlede M&ngde Kulsyre. anvendte jeg følgende Fremgangsmaade.
Efterat Apparatet fuldstændig var befriet for kulsyre- holdig Luft, anbragtes i Forlaget paa den før. beskrevne Maade 25 CC. Barytvand, hvoraf hver CC. svarede til 4.129 .Mgr. Kulsyre, hvorefter der i Kolben C heldtes 367.7 CC. af det til Undersøgelse bestemte Søvand tillige- med 10 CC. af en Svovlsyre, hvoraf hver CC. svarede til 4.099 Mgr. Kulsyre. Indholdét i Kolben ophededes nu under Gjennemleduing af en meget langsom Luftstrøm til Koghede og lioldtes i Kog i uggen Tid. Efter Forløb af kenimod 15 Minutter fjernedes atter Varmekilden og Væd- sken afkjøledes, idet Luftstrømmen lidt efter lidt gaves en noget større Hnstigked, hvorved den endnu ikke absorberede Kulsyre meget hurtigt bragtes over i Forlaget.
Efter endt Operation bragtes de i F værende Glas- kugler tilligemed det ved Rørets Vægge heftende Baryt- vand ned i Forlaget E, hvorpaadet Hele retitreredes med en Oxalsyre, hvoraf hver CC. svarede til 3.976 Mgr. Kul- syre, idet alkoholisk Curcuma tjente som Index. Ligeledes skylledes den ved de indre Va^gge af Kjøleren heftende Vædske ved lidt kulsyrefrit destilleret Vand ned i Kolben, hvori den overskydende Syre neutraliseredes med en Natron- lud, hvoraf hver CC. svarede til 2.928 Mgr. CO», idet Rosolsyre tjente som Index.
Som Resultat af disse Titreringer erholdtes den sam- lede Kulsyremængde bestemt til omkring 97 Mgr. og den neutralbundne til gjeunemsnitlig lienimod 53 Mgr. pr. Litre. De 44 Mgr. Kulsyre, som udgjør Differentsen mellem den samlede Kulsyremængde og den neutralbundne, kan aaben- bart ikke forekomme i Søvandet som fri Gasart, men inaa forene sig med de allerede færdigdannede Carbonater under Dannelsen af Bicarbonater. og det viser sig altsaa, at de af Dr. Jacobsen gjorte Observationer meget naturligt lade sig forklare derved, at Søvandet ikke indeholder det mind- ste Spor af fri Kulsyre men hele 53 Mgr. neutralbunden og kun omkring 44 Mgr. surtbunden Kulsyre pr. Litre.
On boiling sea- water along with diluted sulphuric acid, exposed to a current of air free from carbonic acid, in this apparatus, carbonic acid escaped very rapidly, the space of 15 minutes sufficing to collect the whole of it in the receiver. The sulphates in sea-water — at least when free acids were present — did not, accordingly, exhibit the properties ascribed to them by .1. Y. .Buchanan. On col- lecting and determining the carbonic acid driven off by this process, the amount was invariably found to agree with that which could be liberated by Dr. Jacobsen’s method, the differences observed having been sometimes positive and sometimes negative, but as a rule not greater than would admit of imputing them chiefly to errors of observation. On precipitating the sulphuric acid as suggested by Buchanan, the results obtained were invariably too low; but to this subject I shall afterwards return.
In order to determine both the proportion of carbonic acid torming the neutral carbonates and the whole amount of carbonic acid contained in one and the same sample of sea-water, I adopted the following mode of procedure.
After expelling from the apparatus all air in which carbonic acid was present, 25" of baryta water were introduced, as previously described, into the receiver, each c.centim. representing 4.1 29 mvr carbonic acid; 367.7" of the sea-water to be examined were then poured into the mat- rass (C). along with 10° of sulphuric acid, each c.centim. of which represented 4.099 m,Jr carbonic acid. The contents of the matrass were now heated, during exposure to a very slow current of air, up to the boiling-point, and kept for some time at that temperature. After the lapse of about 15 minutes, the source of heat was removed and .the fluid cooled, the rapidity of the current of air being slightly increased, causing the carbonic acid not yet absorbed to pass off quickly into the receiver.
The operation being terminated, the glass balls in the tube F, along with the baryta water adhering to the wqlls of the tube, were introduced into the receiver E , and the whole of its contents retitrated with oxalic acid, each c.centim. of which represented 3.976 mvr ‘carbonic acid, a solution of alcoholic curcuma serving as the index. The fluid adhering to the walls of the -cooler was likewise washed down into the matrass with a little distilled water free from carbonic acid, and the surplus acid neutralised by the ad- dition of soda-lye, each c.centim. of which represented 2.928m',r CO 2. rosolic acid serving as the* index.
As the result of this titration, the total amount of carbonic acid was found to be about 97",!'r and the pro- portion forming neutral carbonates to average about b‘dmjr per litre. Now, the difference, 44m^r, cannot occur free as gas, but will unite with the carbonates to form bicar- bonates; and hence Dr. Jacobsen's- observations could be readily explained on the assumption that sea-water contains no trace even of free carbonic acid, but as much as 53rai,r per litre of carbonic acid forming carbonates and only about 44 m,Jr per litre of carbonic acid forming bicar- bonates.
Som man ser. ev den lier til Bestemmelse nt den neutralbundne Kulsyre anvendte Methode i alt væsentligt den samme, som allerede for flere A ar tilbage er beskre- ven af Dr. Mohr. 1 Forskjellen stikker kun deri. at jeg har anvendt Classfens Kjøler og desuden ombyttet Salpeter- syren med Svovlsyre. I)et syntes mig nemlig ikke tilraa- deligt at anvende Salpetersyre ligeoverfor et saa stærkt cblorboldigt Mineralvand som Søvand, hvori der desuden fandtes en vel mærkbar om end temmelig liden Qvantitet oxyderbare Stoffe.
Elter denne Fremgangsmaade har jeg senere ved 78 Observntioner bestemt Kulsyren i 64 forskjellige Vandprø- ver temmelig jevnt fordelte over det af den norske Nord- havexpedition undersøgte Felt. Resultaterne Andes sam- menstillede i Tabel 11. . •
Først skal i Korthed berøres de Feil. hvormed de i Tabellen opførte Tal kan tænkes beheftede.
Om man vikle antage. at den i Søvandet indeholdte Kiselsyre ikke forekom opløst som fri Syre, men forefandtes bundet til Baser i Form af Silicater. en Antagelse af me- get tvivlsom Berettigelse, vilde man aabenbart efter den ovenfor beskrevne Methode fan noget feilagtige Resultater, idet den til Kiselsyre bundne Mængde Baser vilde Andes som hunden til Kulsyren. Fornt kunne danne mig en Forestilling om, hvorvidt den Feil. som man under denne Forudsætning skulde kunne begaa, nogensinde vil kunne tænkes at faa særlig Betydning, har jeg bestemt Kiselsyre- mængden i forskjellige af de hjembragte Vandprøver, idet følgende .Fremgangsmaade er kømmen til Anvendelse. 0.5 Litre Søvand inddampedes med lidt Saltsyre i en Platina- skaal først over fri Ild senere paa Yandbad til Tørhed og tørredes ved 110° — 120° C. Saltene udtoges derpaa og pulveriseredes bedst muligt i en vel poleret Agatrive- skaal. hvorpaa de atter tørredes ved samme Temperatur, og sluttelig bragtes over i et passende Kar og tilsattes ca. 200 CO. saltsyreholdigt Vand, hvorved al Gips fuld- stamdigt opløstes. De paa denne Maade udskilte Kisel- Syremængder vare altid meget smaa og maatte nærmést blive at betegne som Spor. idet de. hvor jeg forsøgte at veie dem. kun beløb sig til Brøkdele af Mgr. i den an- vendte Portion Vand. Dette stemmer paa det Nøieste med. hvad Thorpe og Morton nylig har fundet i det irske Hav,2 hvorimod de ældre Opgaver giver noget større Tal. Og man vil saaledes se, at der ingensomhelst Rimelighed er for. at den i Søvandet indeholdte Kiselsyremængde skulde bidrage til i mærkelig Grad at gjøre de fundne Resultater upaalidelige.
Naar man skal danne sig en Mening om Nøiagtighe- den af disse Observationer. er det imidlertid nødvendigt at tage Hensyn til en anden Omstændighed, som kunde tænkes at have liavt sin Indflydelse paa Resultaterne.
As will be seen, the method adopted lor the determ- ination of the carbonic acid forming carbonates, was es- sentially the same as that described by Dr. Mohr1 several years previously. The only difference lay in my having employed Classen’s cooler and made choice of sulphuric acid in preference to nitric. It did not seem advisable to use nitric acid when examining a mineral water so rich in chlorine as is sea-water, and which besides contains a quantity, small indeed but appreciable, of organic matter.
By this process I subsequently determined the car- bonic acid in 64 different samples of sea-water, drawn at comparatively regular intervals from the tract of ocean in- vestigated on the Norwegian North- Atlantic Expedition; the number of observations amounted to 78. The results are given in Table II.
I will flrst say a few words respecting the errors that may possibly affect the accuracy of the flgures set down in the Table.
Assuming the silicic arid in sea-water not to occur as a free acid, but combined with bases in the form of silicates, an .hypothesis of very doubtful value, the results obtained by the method described above would be obviously to some extent inaccurate, inasmuch as the bases com- bined with silicic acid must in that case have behaved as if originally combined with carbonic acid. In order to ascertain what importance could possibly be attached to an error arising on such an assumption, I determined the amount of silicic acid in divert of the samples of sea-water brought home with me, adopting for that purpose the- following method. Five-tenths of a litre of sea-water mixed with a little hydrochloric acid were evaporated to dryness in a platinum dish, at Arst over a common Are and then in a water-bath, and dried at a temperature of 110° — 120“ C. The salts were then taken out and transferred to a well polished agate dish, in which they were Anely pulverised, and again dried at the same temperature ; Anally they were placed in a suitable vessel, and mixed with about 200 « of water containing hydrochloric acid, which thoroughly dis- solved all the gypsum. The amounts of silicic acid thus precipitated were invariably very small, indeed but little more than traces; for. on attempting to weigh them, they proved to be but fractions of a milligramme. This result agrees exactly with the observations of Thorpe and Morton on water from the Irish Sea,2 whereas the flgures in ear- lier statements are somewhat higher. Ht*nce, there is no reason whatever to assume, that the silicic acid present in sea-water should to any considerable extent influence the results obtained.
When judging of the accuracy of these observations, regard must, however, be bad to another circumstance that might possibly in some measure affect the results. The water examined did not consist of freshly drawn samples,
1 Mohr Titrirmethode 3te AuH. — 524. 4 Ann. Chem. Pharm. 158 — 122.
1 Mohr’s Titrirmethoden 3te Aufl. p. 524. 4 Ann. Chem. Pharm. 158, p. 122.
I
I
I
1 1
II
2i
2
2.
2y
2.
2
2;
2i
2 C
3<
31
. 3^
35
3-1
35
3^
37
3*
39
40
4i
42
43
44
45
46
47
48
49
50
5i
52
53
54
55
56
57
58
33
Ltengde
fra
Greenwich.
i'en.
r 18' 3 7 3 7
O 33 o 33 33 33
6 15
6 15
9 50 9 50 9 50
14 41
15 42 *5 42 15 42
2 o o o 8 5i
7 5i 7 5i 7 5i 7 5i 10 10 10 10 [ 1 26 [ 1 26 7 7 6 2 2
2
2
51
* 5i l 5i > -’7 i 5 1
W.
E.
W.
-5
25
26 5 5
2 24 2 24 15 37 5 37
1 1 2
2 58
1 40 1 30
1 30 1 40 5 12 5 12
i 50.5
3 23
3 22 3 2
E.
W.
E.
Tornoe: Clieuii.
|
Dybde hvorfra Prø ven hentet. (Depth /rom which the San pie * were collected.) |
• Tempe- |
Xeutral- bunden Kul sy re. j (Carbonic lAcid/ormin 1 Carbonates. \ Mgr. per Litre |
Surf lum den Ivulsyro. |
/ Annuerkningor. (Utmark».) |
|
|
Engelske Favne. (English Fathoms.) |
i Meter. | (Metres.) |
Celsius. |
forming IU carbonates. Mgr. per Litre |
||
|
O |
0 |
? |
52.3 |
41. 1 |
|
|
I I63 |
2 127 |
— 1. 1 |
52.6 |
46.7 |
|
|
l86l |
3403 |
— 1.2 |
527 |
46.9 |
|
|
l86l |
3403 |
— 1.2 |
52.9 |
46. 1 |
|
|
1539 |
2814 |
— i-3 |
53-i |
43-8 |
|
|
O |
O |
10.5 |
54-3 |
40.4 |
|
|
i8q |
346 |
6.2 |
53-8 |
43-3 |
|
|
0 |
O |
8.2 |
53-4 |
41-5 |
|
|
1600 |
2g26 |
— 1.2 |
52.6 |
44.8 |
|
|
0 |
O |
8.6 |
53-5 |
44-8 |
|
|
1547 |
2829 |
— i-3 |
53-0 |
45-5 |
|
|
600 |
IOQ7 |
0.0 |
52.4 |
44-7 |
|
|
0 |
0 |
7.6 |
53-8 |
40.9 |
|
|
1335 |
2441 |
— 1. 1 |
53-8 |
43 1 |
|
|
860 |
1573 |
— 1. 1 |
53-o |
45-5 |
|
|
860 |
1573 |
— 1. 1 |
52.7 |
43-6 |
|
|
0 |
0 |
9.6 |
54-2 |
41.8 |
|
|
0 |
0 |
8 0 |
54-2 |
41.4 |
|
|
200 |
366 |
2:8 |
52.6 |
||
|
200 |
366 |
2.8 |
52.6 |
46.8 |
|
|
0 |
0 |
4.6 |
52-7 |
413 |
|
|
340 |
622 |
— 0.6 |
54-3 |
46.4 |
|
|
340 |
622 |
—0.6 |
54-6 |
46.0 |
|
|
340 |
622 |
—0.6 |
54-7 |
— |
|
|
0 |
0 |
30 |
52.2 |
40.7 |
|
|
0 |
0 |
3-0 |
52.2 • |
41.6 |
• |
|
0 |
0 |
3-0 |
53-4 |
42 4 |
|
|
0 |
0 |
3-o |
54-5 |
39-7 |
|
|
0 |
0 |
4.2 |
55 0 |
44-4 |
|
|
0 |
0 |
4-2 |
55-4 |
— |
|
|
0 |
0 |
6.0 |
53-0 |
45-0 |
|
|
0 |
0 |
6.0 |
53-o |
43-9 |
|
|
1385 |
*533 |
— i-3 |
53-7 |
42.4 |
|
|
0 |
0 |
9-0 |
53-8 |
45-2 |
|
|
0 |
0 |
90 |
53-8 |
44.2 |
|
|
500 |
914 |
—0.4 |
53-9 |
47-3 |
|
|
0 |
0 |
9.4 |
54-0 |
47.2 1 |
|
|
0 |
0 |
5-2 |
51-8 |
42-3 ! |
|
|
86 |
157 |
1.9 |
52.6 |
43-2 |
|
|
0 • |
0 |
2.9 |
53-0 |
45-3 ! |
|
|
0 |
0 |
. 6.8 |
52-6 |
43 2 |
|
|
0 |
0 |
7.0 |
52.8 |
42.4 I |
|
|
100 |
183 |
3-2 |
51-9 |
42.8 i |
|
|
600 |
L097 |
—0.8 ; |
52.6 |
43-7 |
|
|
1 1 10 |
2030 |
1 -3 | |
53.8 j |
43-i |
|
|
0 |
0 |
4.6 |
52.6 |
43-7 |
|
|
1280 |
2341 |
— i-4 |
52.1 ! |
43-4 |
|
|
1500 |
2743 |
— i-5 1 |
52.2 , |
42.9 |
• * |
|
0 |
0 |
*•7 |
48.6 |
43-4 |
I«l ll(r« veil Kam.-ii nf OrimlAiidtlion. Or* «11 In lunne. Iluto iiroilmlty to the Greenland Ice.) |
|
0 |
0 |
‘•7 |
48.4 1 |
42.0 |
|
|
0 |
0 . |
3-3 |
52.2 |
47-9 |
|
|
. 0 |
0 |
3-3 I |
51.8 |
48.0 |
|
|
150 |
274 |
— 1,1 |
518 1 |
43-0 |
|
|
300 |
549 |
— 0.8 |
52.2 |
42.5 |
|
|
.300 |
549 |
— 0.8 | |
52.3 |
45-1 , |
|
|
1 735 |
3173 |
— i-5 1 |
52.4 ; |
43-9 |
|
|
1334 |
2440 |
— i-3 |
52.0 |
40.5 ( |
|
|
223 i. |
408 |
i-5 |
53-1 ! |
42.1 | |
34
|
No. |
Stat. No. |
Nordlig Bredde. (North Latitude.) |
Længde fra Greenwich. ( Longitude from Green with.) |
Dybde hvorfra Pro- ven hentet. (Depth from which the Sam- ples were collected.) Engelske ! Favne. Meter. ( English (Metres.) Fathoms.) . | |
Tempe- ratur. Celsius. |
Xeutral- bunden Kulsyre. (Carbonic Acid forming Carbonates ■) Mgr. per Litre.- |
Surtbun- den Kulsyre. (Carbon. Acid forming Di- carbonates.) Mgr. per Litre. |
Anmærkninger. (Itcmarks.) |
|
|
59 |
335 |
76° 16'. 5 |
1 4° 39' E- |
O |
0 |
5-4 |
53-4 |
42.7 |
|
|
6o |
347 |
76 40.5 |
7 47 |
1429 |
2613 |
— i-3 |
52.2 |
41.6 |
• |
|
6i |
347 |
76 40.5 |
7 47 |
O |
0 |
4-4 |
52.6 |
41.0 |
|
|
6 2 |
3 49 |
76 30 |
2 57 ** |
I487 |
2719 |
— i-5 |
51.6 |
43-5 |
|
|
^3 |
350 |
76 26 |
O 20) w. |
0 |
0 |
3-0 |
54-0 |
47.2 |
|
|
350 |
76 26 |
O 20) |
300 |
549 |
— 1. 1 |
53-2 |
45-8 |
||
|
65 |
350 |
76 26 |
0 29 |
300 |
549 |
— 1 . 1 |
53-3 |
46.0 |
* |
|
66 |
350 |
76 26 |
0 29 |
1686 |
3083 |
— i-5 |
5*-9 |
43-9 |
|
|
67 |
35* |
77 49-5 |
0 9 |
0 |
0 |
3-3 |
5i-9 |
42.8 |
* |
|
68 |
352 |
77 5b |
3 29 E- |
0 |
0 |
3-9 |
52.3 |
4i-5 |
|
|
69 |
352 |
77 56 |
3 29 |
300 |
549 |
— 0.8 |
52.6 |
46.0 |
|
|
70 |
355 |
78 0 |
8 32 |
0 |
0 |
4-9 |
52-4 |
43-2 |
|
|
7i |
355 |
78 0 |
8 32 |
948 |
1734 |
— 1 .3 |
51.8 |
44.6 |
|
|
72 |
361 |
79 8.5 |
5 28 |
0 |
0 |
4.2 |
52-4 |
42.7 |
|
|
73 |
361 |
79 8.5 |
5 28 |
905 |
ib55 |
— 1.2 |
5 1 -9 |
46.1 |
|
|
74 |
362 |
79 59 |
5 40 |
0 |
0 |
5-2 |
52.6 |
43-2 |
|
|
75 |
362 |
79 59 |
5 40 |
459 |
839 |
J.O |
5 1 -8 |
44.6 |
|
|
76 |
363 |
80 0 |
8 15 |
260 |
475 |
1. 1 |
52-9 |
44.0 |
|
|
77 |
368 |
78 43 |
8 .20 |
3*5 |
567 |
1.6 |
52.9 |
42.4 |
|
|
78 |
373 |
78 10 |
14 26 |
120 |
219 |
0.8 |
5 * -4 |
44-4 |
Forsøgeuo ere nemlig ikke blevne udførte paa \ andprø- verno strax elter deres Optagelse men først, etterat de have lienstaaet i kortere eller længere Tid. Angaaende Tidsrommet, hvori de enkelte Vandprøver have lienstaaet før Bestemmelsen, kan anføres Følgende: No. 1. en Vand- prøve, som Hr. Dampskibsfører E. Rostrup viste mig den Velvillie at skaffe mig, har kun lienstaaet nogle Dage, de øvrige Prøver have benstaaet. No. 2 — 6 i ca. '2lj\ Aar,
7 — 37 i ca. I1 Aar og 38—78 i 2 til 4 Maaneder paa et kjøligt Sted opbevarede paa Flasker, der vare forsynede med vel islebne (ilasproppe. Der aabner sig altsaa en Midighed for. at der ved Oxydation af de i Søvandet væ- rende, aldrig manglende, organiske Bestanddele kunde have dannet sig en mindre Qvantitet Kulsyre paa Bekostning al den opløste Surstofmængde, en Proces, der naturligvis kun har Indflydelse paa den surt bundne Kulsyre, saafremt ikke Oxydationen skulde skride saa vidt frem. at ogsaa Surstoffet i Svovlsyren skulde medgaa til Dannelsen al , Kulsyre, i hvilket Fald den dannede Kulsyre maatte træde ind som neutralbundén istedetfor den destruerede Mængde Svovlsyre. En saa vidt fremskreden Oxydation kan imid- lertid ikke tænkes mulig, medmindre man til Prop i Fla- skerne anvender Kork, da den i Søvandet opløste Surstof- gas et mere end tilstnekkelig til at oxydere alle de op- rindelig tilstedeværende organiske Bestanddele. Det kan ogsaa bemærkes. at det ikke i nogen af de undersøgte Y andprover har været muligt at paavise det mindste Spor af Svovlvandstof. For saa nogenlundé at lixere de Mæng- der Kulsyre, som paa denne Maade skulde kunne dannes,, har jeg anmodet min Ven Schmelck, som har været beskjæf- tiget med Undersøgelse af de faste Bestanddele i Våndet i det af Expeditionen befarede Hav, og som saaledes ogsaa har
having all of it been allowed to stand over for a longer or shorter period. With respect to the interval that had elapsed before commencing the determinations, the. follow- ing particulars can be’ given: — No. 1. a sample of sea- water which Captain E. Rostrup had the kindness to procure me, did not stand over for more than a few days; of the remaining samples, Nos. 2 — .6 were . preserved for about two years and a quarter, Nos. 7 — 37 for about one year and a quarter, and Nos. 38 -78 from two to four months', all of them in a cool spot, and in bottles furnished with ground glass stoppers. Hence it is just possible that oxidation of the organic matter never absent in sea- water may have produced a small quantity of carbonic acid, by reducing the amount of oxygen, a process which of course could only affect the carbonic acid forming bi- carbonates, unless indeed oxidation were so far advanced, that the oxygen in the sulphuric acid should also contri- bute to the formation of carbonic acid, in which case such carbonic acid would reimplace the sulphuric acid decom- posed. But this advanced stage of oxidation is clearly im- possible unless the bottles are corked, since the oxygen in sea-water is more than sufficient to oxidize all organic matter originally present. 1 can also observe, that in none of the samples of water examined was it possible to detect the slightest trace of sulphuretted hydrogen. With the object of determining approximately what proportion of carbonic acid could result from this process, I requested my friend Mr. Schmelck — whose labours have been chiefly confined to the examination of the solid matter present in the water of the seas explored on the Expedition, and who accord- ingly instituted a series of experiments to ascertain the amount of organic substances it contained — to furnish
35
udtort en Ra*kke Forsøg til Bestemmelse af de organiske Stoffes Mængde, om at meddele mig de foraødtfe Data. Ifølge ham ere de organiske Stoffes Mængde kun under- kastet meget srnaa Variationer, og affarver 1 Litre So- vand gjennemsnitlig 3 Mgr. Kamæleon, som under Forud- sætning af Reduction til Oxydulsalt kun kan afgive hen- imod 0.8 Mgr. Surstof, hvoraf det lettelig vil kunne indsees, at den dannede Mængde Kulsyre ikke kan være meget stor. naar Surstofforbruget selv ved en saa energisk Oxyda- tion som ved Anvendelse af Kamadeon er saa lidet. .Og hvad der især tyder paa. at den Oxydation. som kan foregaa ved jVandprøvens Henstand under ordinære For- holde, fuldstændig maa kunne negligeres, er den Om- stændighed, at Schmelck har fundet Søvandets Evne til at affarve Kamæleon ligestor. hvadenten Yandprøven under- søges' frisk eller først efter aarelang Henstand.
At noget afKulsyren ved den lauge Henstand skulde være fordampet, er der heller ingen Rimelighed for. naar man erindrer, at Søvandet er en alkalisk Vædske, som ikke indeholder det mindste Spor af fri Kulsyre, og som med saadan Kraft holder paa sin surt bundne Kulsyre'. at den i timevis kan koges i det af Jacobsen angivne Luft- udkogningsapparat med det Resultat, at kun en meget liden Brøkdel uddrives. Der er aabenbart større Fare for det Modsatte. nemlig at der skulde kunne absorberes noget af Atmosphærens Kulsyre. men for Undgaaelseu af denne Feilkilde er der sørget ved omhyggelig Opbevaring paa velproppede Flasker.
Resultaterne synes heller ikke at tyde paa. at Hen- standen skulde have været til Skade for VandprøverneS Brugbarked. idet de alle uden Hensyn til den meget for- skjellige Yarighed af det Tidsrum. hvori de have henstaaet, vise nogenlunde det samme Resultat, og jeg tror saaledes ikke at tage meget Feil. naar jeg anser de af mig udførte Observationer som. i alt Væsentligt ligesaa gode, som om de havdé været udførte ombord paa friskt optagne Yand- prøver.
Hvad angaar de af selve Methoden og Experimenta- tionen flydende Observationsfeil, da vil de hyppigt udførte Controlhesteminelser kunne give de fornødne Bidrag til Bedømmelsen af deres Størrelse, saaledes tr ved 13 Con- trolbestemmelser for .den neutralt bundne Kulsyres Yed- kommende den gjennemsnitlige halve Differents mellem 2 paa samme Yaudprøvc udførte Observationer bestemt til 0.11 Mgr. per Litre (Maximum 0.6) og for den surt bundne Kulsyres Yedkommende til 0.59 Mgr. per Litre (Maximum 1.35). Foruden den variable Feil vil der imidlertid . i sidste Tilfælde ogsaa være en constant, idet det ikke lader sig undgaa. at man ved Arbeide i en kulsyreholdig Atmosphære vil erholde noget om end meget lidet for hoie Resultater. Naar Feilene ved Bestemmelsen af den surt bundne Kulsyre er lunden at være størst, da er G runden dertil for en stor Del at søge deri, at man ved Retitration med Natronlud. især naar Rosolsyre anvendes som Index, erholder en meget skarp Endereaction. raedens dette paa lang Yei ikke i samme Grad er Tilfælde. hvor Barvt re-
ine with the necessary data. According to his ohserations. the amount of organic matter varies but very slightly. 1 litre of sea-water discolouring on an average 3m*p per- manganate ot potash: and this quantity, assuming extreme reduction, cannot give off more than about 0.8”'?r of oxygen. Hence it is obvious that the amount of carbonic acid can- not be very large, considering the limited consumption of ; oxygen even with the use of permanganate of potash. But that the oxidation which can ordinarily result from allow- ing the water to stand over may be altogether ignored, is more particularly indicated by the fact of Schmelck hav- ing found the property in sea-water of discolouring perman- I gaijate ot potash to he invariably the same, whether the samples are freshly drawn or have been preserved for years together.
Nor is there reason to assume, that any portion of the carbonic acid should have escaped by evaporation dur- ing the long interval, if we bear in mind that sea-water is an alkaline fluid, which does not contain the smallest trace of free carbonic acid, and which retains that present in bicarbonates with such vigour., that it may he boiled for hours together in the apparatus devised by Jacobsen for boiling out air and not part with more than a mere frac- tion. Nay, there is obviously danger of the reverse, viz. that some of the carbonic acid present in the atmosphere will be absorbed; but that source of error was effectually avoided by keeping the water iu bottles provided with tight-fltting glass stoppers.
Judging, too. from the results, which were very nearly the samé for all the samples, irrespective of the difference in the length of the period during which they had been preserved, the interval that had elapsed previous to examin- ation did not appear to have had any injurious effect on the water for experimental purposes; and hence I feel tolerably convinced that my observations in all essential particulars are as reliable as if they had, been conducted | on board with freshly drawn water.
With respect to the errors of observation involved in the method itself, numerous test-determinations will serve as an approximate standard by which to compute their magnitude; thus, for instance, half the difference between two observations with the same sample of water was found, for the carbonic acid forming carbonates, to be 0.1 1'"'7'' per litre (maximum 0.6). and for the carbonic acid forming bi- carbonates to be 0.59"^r per litre (maximum 1.35). Exclusive of the variable error there will also, in the latter case, be a constant one, inasmuch as the results of experiments performed in an atmosphere containing carbonic acid must necessarily be somewhat, if hut a very little, too high. When the error in the determination of the carbonic acid forming bicarbonates is found to he greatest, the reason will be chiefly this, that retitration with soda-lye. more espe- cially if rosolic acid has been selected as the index, gives rise to a very decided -terminal reaction, which does not result on the baryta water being titrated with oxalic acid : the reaction is then muph less obvious. It must be likewise
titreres med Oxalsyre. Tillige bør det erindres, at de som Udtrvk for den surt bundne Kulsyre opførte Tal indebolde Feilene saavel i Bestemmelsen af den neutralt bundne som den samlede Kulsyremængde.
Som man let vil overbevise sig om. vise de i Tabellen opførte Tal især for den neutralt bundne Kulsyres Ved- kommende en mærkelig ( )verensstemmelse, naar nemlig 2 Observationer. begge udførte paa en "V andprove bentet lige ved Grønlandsisen, undtnges, ligger i alle de øvrige 133 Vandprøver den neutralt bundne Kulsyre mellein Grænd- serne 51.4 og 55.4 Mgr. per Litre, saaledes at den største Difte rents kun beløber sig til 4 Mgr.. hvad der maa siges at være meget lidet i Betragtning af. at disse Tal .ere fremkomne ved Undersøgelse ai et Hav paa betydeligt over 200 geografiske Mile i UdStrækniug saavel i syd og nord som øst og vest. Hvad derimod den surt bundne Kulsyre angaar. da ere de optrædende Differentser betydelig større og beløbe sig i Ydertilfældene til omkring 8 Mgr. pr. Litre.
Jeg bar længe bestræbt mig for at opdage nogen Lovmæssigbed i disse Variationer. uden at det dog saaledes som for Luftens Vedkommende bar lykkes at erbolde klare og paalidelige Resultater, i saa Henseende og det ligegyl- digt. bvadenten man vælger Dy-bdeforholdene eller den geografiske Beliggeidied til IJdgangspunkt for sin Betragtning.
Da saaledes ingen Del af det undersøgte Felt ud- mærker sig fremfor den. anden ved nogen tydelig Forskjel- ligbed i Kulsyregebalt, og da de optrædende Differentser overalt ere smqa. ville de erboldte Resultater naturligst være at benytte til Udiedning af GjennemsnitsværUier, der kunne o])fores som Udtrvk for Kulsyregebalten i det under- søgte Hav i sin Helbed betragtet. De Gjennemsnitsværdier, som saaledes blive at opstille . som Hovedresultater, ere lor den neutralt bundne Kulsyres ^ edkommende
52.78 + 0.083 Mgr. pr. Litre
med en sandsynlig Afvigelse herfra af en enkelt Observa- tion af + 0.(562 Mgr. pr. Litre og for den surt bundne Kulsyres Vedkommende
43.64 + 0.16 Mgr. pr. Litre
med en sandsynlig Afvigelse berfra af en enkelt Observa- tion af + 1.20. Mgr. pr. Litre.
Da det først var bragt paa det Rene. at de af Dr. Jacobsen iagttagno Egenskaber hos Søvandet skrev sig der- fra. at den i Søvandet existerende Saltblanding ved Kog- hede decomponerede neutrale Carbonater. maatte det ogsaa fremstille sig som en meget interessant Opgave at finde den nærmere Forklaring dertil.
Den nærmestliggende Tanke, som i denne Anledning først paatvang sig mig, var den at soge G runden i* Chlor- magnesiumens bekjendte Egenskaber. At denne under Kogningen selv ved Tilstedeværelsen af Overskud afCblor- natrium skulde have Tilbøieligbed til lidt efter lidt at spalte sig, og at der af den dannede Saltsyre skulde kunne u d drives noget Kulsyre, kunde jo ikke synes umuligt. Der
borne in mind, that the figures representing the carbonic acid forming bicarbonates also include the error in both titrations.
A glance at the Table will show that the . figures therein set-down, more particularly those representing the carbonic acid forming carbonates, exhibit a remarkable uni- formity : save in 2 observations, both with a sample of water drawn in close proximity to the ice oft the coast of Green- land. the carbonic acid forming carbonates determined in the remaining 63 samples lies between the limits 5 1 A"'ar and 55.4»"<jr per litre and the greatest difference amounts there- fore to only 4'"0r, which must be regarded as very small, considering that the said figures refer to the examina- tion of water from a tract of ocean which, measured both from north to south and from east to west, extends for considerably more than 200 geographical miles. As regards the carbonic acid forming bicarbonates, the dif- ferences in the amounts determined are, however, much greater, reaching S""jr per litre.
I have long had my attention directed to the possible discovery of a law controlling these variations, similar to • that which 1 found to regulate those of air, but have not yet succeeded in obtaining conclusive results; and it is quite immaterial whether depth or geographical position bo made the basis of investigation.
The water in no part of the ocean-tract explored being characterised by properties plainly distinguishing it from that of any other, and the differences in the results obtained having invariably proved small, the latter will obviously serve for the computation of average formulae representing the amount of carbonic acid present in the water of the sea investigated. These average formulae, set down accordingly as the final results, were ‘found to be —
52.78 + O.083w*,r per litre
for the carbonic acid forming carbonates, with a probable error in a single observation of + 0.662 per litre; and
43.64 + 0. 1 'ém*r per litre
for the carbonic acid forming bicarbonates, with a probable error in a single observation of + l.26"‘°r- per litre.
Having now obtained conclusive proof that the pro- perties observed by Dr. Jacobsen in sea-water were the result of the property possessed by the saline compounds present therein of decomposing at the boiling-point neutral carbonates, the next step was to find a satisfactory explana- tion of the interesting phenomenon.
My first thought in this direction was to seek the cause in the known properties of chloride of magnesia. Assuming this body to have a tendency of gradually de- composing during the process of boiling, carbonic acid might possibly be driven oft’ by the hydrochloric acid formed. Against such an hypothesis, however, various objections may be raised. Dr. Jacobsen and others having shown that sea-
37
lader sig imidlertid reise Indvendinger mod denne Betragt- ningsmaade, idet det af. Dr. Jacobsen med Flere er paa- vist, at So vand lader sig inddampe til Tørlied og Saltene endog tørre ved en Temperatur af 180° C.. uden at nogeu synderlig Mængde Saltsyre forflygtiger sig. og det er i Virkeliglieden heller ikke fornødent at ty til Chlormagne- siumens Dissociation for at tinde den rimeligste Forklarings- grund. Man behøver blot at holde sig til den kulsure Magnesia og dens Egenskaber, saaledes som de ere kjendte al Arbeider udførte af de mest berømte Chemikere.
Ifølge Angivelser af Berzelius, 1 * H. Kose/ Fritzsche,3 Norgaard4 og L. .Joulin’ er den ved høiere Temperatur dannede kulsure Magnesia altid mere eller mindre basisk, ja ifølge Berzelius og H. Rose er Selv de ved Blanding af Magnesiaopløsninger med kulsure Alkalier i Kulden dan- nede Bundfald mere kulsyrefattige end mættet kulsur Mag- j nesia.. Der tindes om den kulsure Magnesia et meget stort Antal ti kleis meget modstridende Angivelser, og der er, ettersom Fremstillingsmaaden er varieret. erholdt meget | forsk, jelligt sammensatte Salte, hvis procentiske Sammeil- sætning itølge Analyserne stemme meget claarligt overens- med den af de opstillede Formler beregnede. Disse For- bindelser ere ogsaa af enkelte Forfattere betragtede som basiske Salte af variabel Sammensætning og ansees af L. .louliu endog for en* Blanding af vexlende Mængder Oxyd og Carbonat. Det vilde føre for langt her ’at gjeiir nemgaa de talrige over dette Eiune forfattede Athaudlinger, og jeg skal derfor indskrænke mig til at henvise til Gmelin- Krauts Handbuch der Chemie 6te Aufl. 2 432. hvor det \ æsentligste tindes i Uddrag. Det maa dog være mig til- ladt at citere nogle Udtalelser af H. Rose. som jeg nylig blev opraærksom paa, Udtalelser. som vise at Videnskaben allerede meget henge har været i Besiddelse af Materiale til Forklaringen at de at Dr. .Jacobsen gjorte Observatio- ner. H. Rose siger (Pogg. Ann. [3] — 23 — 41 7) Følgende:
"Als das Gesetz der einfacheu chemischen Proportionen aufgestellt und hinreichend durch Versuche bewiesen wor- den war. ergab sich die Neutralitiit zweier sich zei'setzender Salzauflosungen als eine gauz nattirliche Folge des Ge- setzes der bestimmten Yerhaltnisse. in denen sich alle Kor- per, also auchi Siiuren und Basen, mit einander verbinden.
Aber das Gesetz, dass durch Zersetzuug zweier neu- traler Salze nach ihrer Auffosung in \ Vasser wiederum zwei neutrale Salze entstehen, ist nicht richtig, wenigstens nicht in der Allgemeinheit, wie es bisher olme den gering- steu Widorspruch angenommen worden ist.
Es ist bemerkenswerth, dass die so ausserordentlich vielen Ausnahmen, die bei diesem Gesetze statttinden. nicht friiher aufgefallen sind, obgleich mehrere derselben schon seit lauger Zeit bekannt waren. Nur eine fast einzeln steilende
1 Berzelius Johresbericht 17 — 158.
8 Pogg. Ann. §3 — 435.
s Pogg. Ann. 37 — 310.
4 K. Danske Vid. Selsk. Skrift. (5| — 2 — 54 (1850).
4 Ann. Ohim. Phys. (4J — 30 — 271. »
water admits of being evaporated to dryness, and the re- sidue even dried at a temperature of 180° C. without vo- latilising any considerable quantity of hydrochloric acid. But it is -not necessary to seek in the properties of chloride of magnesia the most plausible means of explanation : we need only keep to the carbonate and its properties, as determined by the most renowned Chemists.
According to the statements of Berzelius, 1 H. Rose,8 Fritzsche,3 Nbrgaard,4 and L. Joulin/' carbonate of mag- nesia formed at a high temperature invariably contains less carbonic acid than the neutral salt; nay, according to Berzelius and Rose the precipitate resulting from the mixture ot carbonate ot potash, when cold, with solutions of magnesia, contains less carbonic acid than saturated car- bonate ol magnesia. For carbonate of magnesia we have a very large number ol conflicting statements, and the compounds obtained have been found to vary greatly with the mode of operation, the proportion of their constituents, too. often agreeing but very indifferently with that computed by tlie lormula*. By some authors these combinations have been' regarded as basic salts, varying in tlieir com- ponent parts; nay by L. Joulin, as consisting of incon- stant mixtures of some oxide and carbonate. I lack space here to notice the numerous memoirs treating of this subject, and shall therefore merely refer the reader to Gmelin-Kraut's -Handbuch der Chemie' (Ote Auflage, 2. p. 432), in which copious extracts from them will be found. I cannot however retrain lrom quoting certain remarks by H. Rose, on which a short time since I happened to light.
remarks showing science to have' been long in pos- session of materials amply sufficient to explain Dr. .Ja- cobsen's observations. In I’ogg. Ann.. [31 23. p. 417, H. Rose observes as follows: — '
"Als das Gesetz der einfachen chemischen Proportionen aufgestellt und hinreichend durch Versuche bewiesen wor- den war. ergab sich die Neutralitiit zweier sich zersetzender Salzauffosungen als eine ganz natiirliche Folge des Ge- setzes der bestimmten Verhiiltnisse. in denen sich a lie Kor- per. also auch Siiuren und Basen, mit einander verbinden.
Aber das Gesetz. dass durch Zersetzung zweier neu- traler Salze nach ihrer AuHbsung in Wasser wiederum zwei neutrale Salze entstehen. ist nicht richtig, wenigstens , nicht in der Allgemeinheit, wie es bisher ohne den gering- sten Widorspruch angenommen worden ist. *
Es ist bemerkenswerth, dass die so ausserordentlich vielen Ausnahmen, die bei diesem Gesetze statttinden, nicht friiher aufgefallen sind, obgleich mehrere derselben schon seit langer Zeit bekannt waren. Nur eine fast einzeln stehende
1 Berzelius Jahresbericht, 17. p. 158.
8 Pogg. Ann. 83, p. 435.
3 Pugg. Ann. 37, p. 310.
4 K. Danske Vid.' Selsk.-»Skrift [5] 2. p. 54 il>*50). a Ann. Chim. Phys. [4j 30, p. 271.
Ausnahme erregte vor l&ngerer Zeit ein allgemeines Auf- sehen. Als man faml. dass eine Aufidsung von gewbhnlichem phosphorsaureiu Natron, wejcbe fiir sicli gerbthetes Lackmus- papier bliint. mit einer A.ufldsung von salpetersaurem Silber- owd. welche das Lackmuspapier unveråndert hisst, versetzt, einen Niederscblag von gelbem phosphoysaurem Silberoxyd und einc* Fliissigkeit giebt. welche geblilutes Lackmuspapier rbthet, konnte diese Erscheinung nicht friiher genugend er- klart werden, als bis die interessanten Untersucbungen von Clarke, und die sinnreiche Deutiing derselben durcb Gra- ham bekannt wurde.
Aber vor weit langerer Zeit schon hatte man Er- scheinungen beobachtet. die eben so riithselbaft waren, als der beschriebene Fall. Man hatte schon ott bemerkt, dass aus der Aufidsung eines neutralen kohlensauren Alkalis (lurch Zersetzung vermittelst einer Aufidsung eines neutralen Salzes von Magnesia, von Zinkoxyd oder von einem andern iihnlicb zusammengesetzten Metalloxyd Kohlensåuregas ent- wickelt werde, besonders wenn die Fållung des kohlen- sauren Oxydsin der Wiirme geschieht. und eine grosse Reilie von Versuchen. die man besonders in neuerer Zeit auge- stellt hat. hat orgeben. dass die moisten der kohlensauren unldslichen Salze. welche man durcb Zersetzung nentraler Salzaufldsungen erhlilt, nicht die entsprechende Zusammen- setzung des kohlensauren Alkalis haben, das zu ibrer Er- zeugung angewandt women ist. Sie enthalteh weniger Kohlensiiurc, aber obgleich die Untersucbungen oft von sehr bewabrten Chemikern angestellt worden sind, so bat man ihre Zusammensetzung- sehr wenig ubereinstimmend gefunden."
H. Rose har ogsaa ved Forsøg, som ban sammesteds beskriver, lundet, at varmt fældt basisk kulsur Magnesia indeholder mindre Kulsyre. naar den efter Fældningen ko- ges nogen Tid. end naar den strax gjøres til Gjenstand for Analyse.
Det kan efter dette ikke være tvivlsomt. at den kul- sure Magnesia ved høiere Temperaturer decomponeres og antager meget forskjellige Sainmensætninger, eftersom den koges kortere eller længere Tid. Rigtignok er det ikke nogensteds ved de tidligere Forsøg paavist. at man paa denne Maade kan faa Magnesia fuldstændig befi.net for Kulsyre,- men man maa ogsaa ber tage Hensyn til. at man ved de tidligere Forsøg visselig overalt har arbeidet med temmelig store Mængder Bundfald. der naturligvis ikke med samme Lethed som Smaaportioner vil kunne er- holdes decomponerede.
Forat paavise, at smaa Mængder kulsur Magnesia ved Kogning lader sig omvandle til fuldstændig rent Oxyd. gik jeg frem paa følgende Maade. Af fuldstændig ren friskt udglødet Soda afveiedes 0.422 Gr. og opløstes i 100 OC. kulsyrefrit destilleret Vand. ligeledes tilberedtes en \‘d °/o indeholdende Opløsning af almindelig ren svovlsur Mag- nesia, som i Forveien ved gjentagne ( hnkrystallisatibner var befriet for alle Forurensninger. En Blanding af 15 CC. af Sodaopløsningen med 50 ('C. af Bittersaltopløsningen fortyndet med iioget over 1 :l Litre friskt udkogt endnu varmt Vand kogtes i en kolsyrefri Luftstrøm i ('lassens
Ausnahme erregte. vor langerer Zeit ein allgemeines Auf- sehen. Als man fand. dass eine Aufjbsung von gewohnlicbem phospborsaurem Natron, welche fur sicli gerothetes Lackmus- papier blaut. mit. einer Auflosung von salpetersaurem Silber- oxyd, welche das Lackmuspapier unveråndert liisst. versetzt, einen Niederscblag von gelbem phosphorsaureiu Silberoxyd und eine Fliissigkeit giebt, welche geblåutes Lackmuspapier rothet. konnte diese Erscheinung nicht friiber geniigend er- ldiirt werden. als bis die interessanten Vntersuchungen von Clarke, und die sinnreiche Deutung derselben (lurch Gra- ham bekannt wuyde.
Aber vor weit liingerer Zeit schon hatte man Er- scheinungen beobachtet. die eben so rathselhaft wareu, als der beschriebene Fall. Man hatte schon oit bemerkt. dass aus der Auflosung eines neutralen kohlensauren Alkalis durcb Zersetzung vermittelst einer Auflosung eines neutralen Salzes von Magnesia, von Zinkoxyd oder von einem andern
iahnlich zusammengesetzten Metalloxyd Kohlensiiuregas ent- wickelt werde. besonders wenn die Fålluug des kohlen- II sauren Oxyds in der Warme geschieht, und eine gi;osse Reilie von Versuchen, die man besonders in neuerer Zeit ange- stellt hat. hat ergeben. dass die meisteu der kohlensauren unlbslichen Salze. welche man durch Zersetzung neutraler ! Salzauflosungen erhalt, nicht die entsprechende Zusammen- setzung des kohlensauren Alkalis * haben, das zu ilirer Er- zeugung angewandt worden ist. Sie enthalten weniger Koblensåure, aber obgleich die UntersucbuAgen oft von sehr bewåhrten Chemikern angestellt worden sind. so hat man ihre Zusammensetzung sehr wenig ubereinstimmend l| gefunden.”
Moreover. H. Rose also found, by experiments which be has described in the same paper, that basic carbonate of magnesia, precipitated warm, contains less carbonic acid when boiled for some time after precipitation than when at once subjected to analysis.
’ From what lias been stated above, carbonate of mag- nesia is evidently decomposed at a high temperature, and enters into a variety of very different combinations accord- ing to the duraton of the boiling-process. True, none of the earlier experiments have shown that all the car- bonic acid present in magnesia can be expelled by this method; but those experiments were conducted, we must remember, with a comparatively large amount of precipitate, which necessarily proves less easy to decompose than do small quantities.
In order to show that small quantities of carbonate yf magnesia may be transformed by boiliug into pure oxide. I went to work as follows. In 100 cc of distilled water free from carbonic acid were dissolved 0.422 ''r of freshly heated carbonate of soda; a solution was likewise prepared containing 1 3 per cent of ordinary sulphate of magnesia, which by repeated crystallization had been previously freed from all impurities. A mixture consisting of 15fC of the solution of soda and 50 cr of a solution of Epsom salts diluted with a little more than lU of a litre of freshly boiled water, still warm, was boiled in Classen's ap-
39
Apparat i omkring 2 Timer, idet den undvigende Kulsyre som før opfangedes og besteintes ved titreret Jiarytvand. I den anvendte Mængdfe Sodaopløsning var iudeholdt G3.3 Mgr. Soda svarende til 20. 3 Mgr. Kulsyre, medens der ved to Experimenter paa denne Maade fandtes uddrevet den ene Gang 26.8 og den anden 27.7 Mgr. Ved Kor- søgets Gjentagelse med en lidt større Qvantitet paariy ind- veiet Soda fandtes uddrevet 34.1 Mgr. Kulsyre istedetfor beregnet 33.2. Under Kogningen var Oplosningen i Be- gyndelsén fuldstændig klar. hvorpaa der efter circa l/o Ti- mes Forløb begyndte at fremkomme et Bundtald a f Mag- nesia. hvori der trods al anvendt Moie ikke lykkedes mig at paavise det minffste Spor af Kulsyre. Den basisk kul- sure Magnesia er nemlig ifølge H. Rose og Flere ikke ubetydelig opløselig saavel i Vand som i forskjellige Salte, saaledes at der af smaa Mamgder intet Bundtald fremkom- mer, og det er derfor ikke paafaldende. at Oxydet ved saa fortyndede Opløsninger; som her ere anvendte, ikke udfældes, førend det ved Kogningen er befriét for sin Kulsyre.
lvoges Søvn nd under Concentration, kan man meget let komme til at overse denne Udski Helse af Magnesia, idet denne først indtræder efter nogen Tids Forlob. saa- ledes at man kan antage Blnkningen fremkommen ved Ud- fældning afGjps i den concentreredé Vædske. Udskillelsen vil ogsaa, naar Inddampningen foregå ar i aabent Kar. for- sinkes betydeligt, idet Kulsyrens Undvigen foregaar meget langsommere i en kulsyreholdig Atmosphære end i en kul- syrefri Luftstrøm, og det kan derfor ikke forundre, at denne Udfældning af Magnesia .af kogende Søvand, saavidt mig bekjendt. ikke tidligere er observer et, naar undtages, at Usiglio 1 i det tørrede Residum hai* paavist fri Magnesia. Dersom man imidlertid koger Søvand uden Concentration i en kulsyrefri Atmosphære med omvendt Kjøler, saaledes som det let kan ske ved Classens Apparat, fremtræder Phænomenet meget tydeligt paa samme Maade som ved Kogning af en Blanding af Soda og Bittersalt, idet der efter circa */s Times Kogning begynder at udskille sig et Bundfald bestaaende af ren kulsyre- og kalkfri Magnesia ved Siden af et lidet Spor af Kiselsyre hidrørende fra det benyttede Glaskar. Om man samtidig opfanger og bestem- mer den undvigende Kulsyre, viser det sig, at den Yillig- .lied. hvormed Kulsyrén undviger, ikke saameget afhænger af Concentrationsgradeu som af Varigheden at det Tids- rum, hvori Kogningen fortsadtes, da ogsaa paa denne Maade circa 2 Timers Kogning strækker til for at skaffe en tuld- stændig kulsyrefri Vædske.
Det vil forhaabentlig hermed kunne ansees luldstæn- dig godtgjort, at Søvandets Evne til ved Kogning at decom-
. ■
Jouru. flir pract. Clicm. 40 — 100.
paratus for 2 hours exposed to a current' of air free from carbonic acid, the carbonic acid driven off being collected and determined as before by titrated baryta water. The portion of the solution of ' carbonate of soda employed contained 03.3 m,Jf of that substance, representing 26.3 ms,r carbonic acid; and two experiments performed by this method gave respectively 26.8,n;;’ and 27.7 as the amount of .the latter driven off. On repeating the experiment with a somewhat larger quantity of carbonate of soda, carefully weighed, 34.1'"0r were found to have been liber- ated. whereas the exact proportion would have been 33.2'"<'r. During the process of boiling, the fluid at first continued perflectly clear: but after the lapse of about half an hour magnesia began to be precipitated, in which with the most delicate tests I failed to detect the smallest .trace of carbonic acid. According to H. Rose and other authors basic carbonate of magnesia is to a considerable extent soluble alike in water and in solutions of divers salts, so that small quantities give no precipitate and hence it is not surprising that with a solution so diluted as that made use of for these experiments, the oxide should not have been precipitated before it had given off all its car- bonic acid.
If sea-water he boiled during concentration, this precipitation of magnesia may be easily overlooked, since it does not take place till after the lapse of some time, and the turbidness of the concentrated fluid might there- fore be ascribed to the deposit of gypsum. When the water, too, is evaporated in an open dish, the precipitation will be considerably retarded, since the carbonic acid es- capes much more slowly in an atmosphere containing car- bonic acid than in a current of air from which all car- bonic acid has been expelled : and this accounts for the precipitation of magnesia in boiled sea-water, so far as I am aware, not having been previously observed, except at least by Usiglio, 1 who detected the presence of free magnesia in the dried residue. When: however, sea-water is boiled without being concentrated in an atmosphere free from carbonic acid, and with the cooler inverted, which it easily may be with Classen’s apparatus, the phenomenon appears with great distinctness, as is tin* case on boiling a mixture of soda and Epsom salts; for after about half an hour's boiling a precipitate begins to form, consisting of pure magnesia, with no admixture of lime and carbonic acid and a trace only of silicic acid, the latter arising from the glass vessel employed in the operation. If the carbonic acid be simultaneously collected and determined, the readiness with which it escapes is found to depend not so much on the degree of concentration as on the duration of the boiling-process, about 2 hours proving amply sufficient to obtain a fluid tree from the smallest trace of carbonic acid.
From what has been stated, there is. we think, con- clusive proof, that the property possessed by sea-water of
1 Journ. fur pract Chein. 40, p. 100.
40
ponere neutrale Carbonater maa blive at tilskrive gradvise Omsætiiinger mellem de i Søvaudet existerende kulsure Salte og Maguesiaforbindelseme. og de ai Dr. Jacobsen hos So våndet iagttagne Kgenskaber maa derfor ogsaa i mere eller mindre Grad tilligge alle andre magnesiaholdige Mineral vånde, eller naar man hegger Roses ovenciterede Udtalelser til Grund. alle Saltopløsninger. forsaavidt de foruden Alkalier og Jordalkalier tillige indeholder opløse- lige Salte ai' nogen af de svagere Baser, som med Kulsyren danner ubestandige Forbindelser. Denne Omstændighed vil saaledes uden videre stemple saa godt som alle de til Bestemmelse af Forholdet mellem den frie og bundne Kul- syre j Mineralvande anvendte talrige Metlioder som niere og mindre upaalidelige ligeoverfor magnesiaholdige Mine- ralvaude, idet man ved dem til Bestemmelse af neutral- 1, mulen Kulsyre enten anvender Residuet fra Inddampning eller paa anden Maade benytter sig af Koguing. hvor den efter det forhen udviklede vil være utilladelig.
Det vil sluttelig ikke være paa urette Sted kortelig at berøre de Synsmaader. som fra ældre Tider bar været gjort gjældende, livad angaar de i Sovandet indéholdte Carbonater.
Efter de Fremgangsmaader, hvorved disse af ældre Forfattere ere bestemte, kunde de naturligvis Sun erholdes udskilte i Form af kulsur Kalk eller, som af enkelte ogsaa fundet. lidt kulsur Magnesia, men deraf følger ingenlunde, at de med Nødvendighed oprindelig skulde forekommet i Søvaudet under denne Form. ja dette er saa langt i ra sikkert, at jeg meget mere skulde være tilbøielig til at tro, at saa ikke er Tiliælde. Koger man nemlig Søvand i det af Dr. Jacobsen beskrevne Luftudkogningsapparat, undviger der. som allerede før bennerket. meget siuaa Qvantiteter Kulsyre. idet man kan fortsætte Kogningen med vexlende Afkjøling en hel Time uden at faa uddrevet mere end en Brøkdel af Milligram pr. Litre. Kogepuuctet vil her i Begyndelsen ligge meget lavt, men stiger, efterhaanden som den undvigende Luft og den dannede Yaiuldamp forøger Trykket, meget liurtigt. saaledes at jeg allerede under den første Halvdel af Operationen bar observeret en Tempera- ratur af 89" C. Naar saaledes de i Søvaudet indeholdte sure Carbonater vise en saa haardnakket Modstand mod Decomposition, at de i en hel Time skulde saa godt som aldeles uden Virkning kunne udsættes for en Temperatur af omkring 90° C.. da synes mig denne Egenskab at passe noget bedre paa surt kulsurt Natron end paa sur kulsur Kalk. og det vilde desuden falde vanskeligt at forklare Sovandets tydelige alkaliske Reaction, medmindre man kunde ajitage. at Carbonaterne i det Mindste for en ikke ringe Del bestod af Alkalisalte.
Med Hensyn paa Qvantiteten af de i Sovandet fore- kommende kulsure Salte, da stemme de derover existerende Opgaver meget daarligt overens, de lyde i Regelen paa Spor undertiden endog paa lutet, medens * der af enkelte igjen er opført forholdsvis store Mængder. Saaledes linder
decomposing when boiled neutral carbonates, arises from the slow reciprocal action of the carbonates and salts of magnesia it contains, and the properties observed by Dr. Jacobsen in sea-water must therefore to a greater or less extent distinguish all mineral waters containing magnesia compounds, or. according to Rose, in bis statements quoted above, all solutions of salts, provided they contain, exclusive of sodium, potassium, lime, barium, and strontium, also soluble salts of some one of the weaker bases, which along with carbonic acid form inconstant combinations. Hence, this circumstance clearly shows, that ol the nu- merous methods devised for determining, in mineral waters, the relative proportion of free carbolic acid and that present in carbonates nearly all are, when magnesia is present, unreliable, since for the determination of the carbonic acid present in carbonates, either the residue from evaporation Or'some other result ol boiling is had recourse to. which has been shown to be inadmissible.
Finally, it will not be out of place to notice the views originally entertained with regard to the carbonates present in sea-water.
By the process according to which the earlier chem- ists determined these compounds, they could of course ob- tain them only in the form of carbonate of lime, or. as found by some observers, along with a little, carbonate ol magnesia; but from this it does not by any means follow that they necessarily occur in that form in sea-water ; nay,
I am myself inclined to believe that such is not the case. Oil boiling sea-water in the apparatus described by Dr. Jacobsen, very small quantities only of carbonic acid are found to escape; the fluid may be alternately boiled and cooled for an hour together without liberating more than a fraction of a milligramme per litre. The boiling-point with this method will at first be very low. hut. on the pressure being increased by the escape of the air and the formation of steam, rapidly rise; even in the first halt ol the operation I have observed a temperature of 89" C. The. vigorous resistance to decomposition thus exhibited by the bicarbonates in sea-water, which admits of their being exposed almost without effect for an hour together to a temperature of nearly 90" C., would rather seem to indi- cate bicarbonate of soda than bicarbonate of lime; and besides, the decided alkaline reaction of sea-water would be difficult to explain unless by assuming the carbonates — or a considerable portion of them at least — to consist ol I carbonate of soda and potash.
With regard to the proportion of carbonates present in sea-water, the results as yet obtained agree but very indifferently ; the majority of observers have detected traces only or none whatever, whereas some allege to have found comparatively large quantities, as will be seen from the following Table.
41
von Bibra1 Intet.
Robinet og Lefort2 i clet rode Hav Spor,
Pisani3 ved Bujuk-Déré i Bosporus 0.1569 Gr. pr. Litre, C. Knauss4 0.011 Gr. pr. Litre.
Thorpe og Morton5 i det irske Hav 0;04754 i 1000 Dele
Yand,
Dr. Jacobsen i Nordsøen 0.018 — 0.028 Gr. pr. Litre. Vierthaler6 i Adriaterhavet 0.315 Gr. pr. Litre,
F. WibeD i det joniske Hav Intet
og Buchanan8 i de sydlige Have enten Intet eller og meget
smaa Mængder.
Saa store Forskjellighéder vilde natUrligvis være meget paafaldende, i Fald man kunde anse Resultaterne af disse Observationer for aldeles correcte, .kvad der imidlertid ikke er muligt, da alle uden Undtagelse ere udførte efter Me- * thoder, som kun for aldeles specielle Sammensætninger af Havvandet kunde føre til nogenlunde rigtige Resultater.
Ved de tidligere i denne Afliandling beskrevne For- søg er det godtgjort, at Søvandet (under enhver Omstændig- hed det af Forfatteren undersøgte) ved Kogning i kulsyre- fri Luft taber al neutralbunden Kulsyre, og det mua end- videre ved de af v. Bibra og Buchanan udførte Observa- vationer ansees fuldt bevist, at almindeligt Oceanvand ved Inddampning til Tørhed selv i en kulsyreholdig Atmosphære undertiden kan give et fuldstændig kulsyrefrit Residuum, medens det kanske ligesaa . ofte ikke vil være Tilfælde, idet der ofte af Buchanan og altid af Jacobsen er fundet Car- bouater i Residuet. Hvor den neutralbundne Kulsyre un- der Inddampningen bortdrives, vil der til Gjengjæld altid udfældes (Jen æqvivalente Mængde. Magnesia, som, naar Residuet henstaar i kulsyreholdig Luft før Bestemmelsen, vil kunne gjeuoptage en Del Kulsyre, og det er derfor let forklarligt, at man ved Anvendelse af Inddampning vil kunne erholde meget forskjellige Resultater selv i Søvand af fuldstændig identisk Sammensætning.
En til Bestemmelse af Carbonaterne hyppig anvendt Methode er den, hvorefter Søvandet koges i ca. 1 Time under stadig Fornyelse af det fordunstede Vand, hvorefter det udskilte Bundfald frafiltreres og veies, saaledes som Viertkaler og Uere har gjort, medens T. E. Thorpe og E. H. Morton af den i Søvandet opriudelig indeholdte Kalkmængde og den i Va*dsken efter Frafiltration af dot ved Kogningen udskilte Bundfald tilbageværende beregner den kulsure Kalks Mængde.
1 Ann. Chem. Pharm. 77 — 90.
9 Compt. rend. 02 — 430.
9 Compt. rend. 41 — 032.
* Petersb. Acad. Bull. 2 — 203 (1800).
6 Ann. Chem. Pharm. 158 — 122.
6 Wien. Acad. Ber. [2] — 50 — 479.
7 Ber. Berl. chem. Ges. 0 — 184. s Proc. Roy. Soc. 24 — 604.
Don norske Nordhavaexpedition. Tornoe: Cliomi.
Von Bibra:1 none.
Robinet and Lefort,2 in the Red Sea: traces.
Pisani,8 near Bujuk-Déré in the Bosporus: 0.1 569^ per litre. C. Knauss:1 0.01 l-'7r per litre.
Thorpe and Morton,6 in the Irish Sea: 0.04754 in 1000
parts of water.
Dr. Jacobsen, in the North Sea: 0.018 — 0.028:'' per litre. Vierthaler,® in the Adriatic Sea: 0.315'" per litre.
F. Wibel,7 in the Ionian Sea: none.
Buchanan,3 in the Southern Seas: none at all or traces
only.
Differences so considerable would indeed be extraor- dinary, assuming the results of the observations to be quite correct; tins, however, is simply impossible, since they were all without exception obtained by methods none of which, save for sea-water of a particular composition, can lead to results even approximately reliable.
By the experiments previously described in this Me- moir, it has been shown that sea-water — at least that examined by the author — can, by boiling in an atmosphere free from carbonic acid, be made to part with all of its carbonic acid that is present in carbonates; and moreover, the observations, of v. Bibra and Buchanan have furnished conclusive proof, that ordinary ooean-water when evaporated to dryness even in a atmosphere containing carbonic acid, sometimes gives a residue in which no trace of carbonic acid can be detected, but the reverse will, perhaps, no less frequently prove to be the case, seeing that Buchanan, has often, and Jacobsen always, found carbonates present in the residue. When the neutral carbonates are decom- posed during the process of evaporation, an equivalent pro- portion of magnesia will invariably be precipitated, which, on the residue being allowed to stand over previous to determination in an atmosphere containing carbonic acid, may possibly absorb some carbonic acid; and hence, when recourse is had to evaporation, very different results may obviously be obtained even with water identical in com- position.
A method frequently adopted for determining the proportion of carbonates, is to boil the searwater for about an hour, while steadily adding freshwater in place of that evaporated, after which the precipitate is filtered off and weighed, as done by Vierthaler and others; T. E. Thorpe and E. H. Morton calculate the proportion of carbonate of lime by comparing the amount of lime - originally present in the water with that contained in the fluid after filtering off the precipitate.
1 Ann. Chem. Pharm. 77, j>. 90.
* Comp. rend. 62, p. 436.
3 Comp. rend. 41, p. 532.
4 Petersb. Acad. Bull. 2, p. 203 (I860).
6 Ann. Chem. Pharm.. 158, p. 122.
0 Wien. Acad. Bcr. [2] 56, p. 479.
7 Bcr. Berl. chem. Gos. 6, p. 184.
8 Proc. Roy. Soc. 24. p. 604.
6
Det er af samme Grund som ovenfor klart, at denne Fremgangsmaadc for almindeligt Oceanvands Vedkommende vil føre til aldeles værdiløse Resultater, uden at det dog med Sikkerhed kan paastaaes, at dette i samme Udstræk- ning skulde være Tilfælde for det af Viertkaler undersøgte Vand, som har en fra almindeligt Søvand meget forskjellig Sammensætning. Efter de talrige og værdifulde Analyser af Søvand. som vi skylde Professor Forckkammer.. indehol- der Våndet i de store Verdenshave uden synderlig store Variationer i de enkelte Bestanddeles indbyrdes Forhold | gjennemsnitlig
Chlor-f Brom 1.895 %
Svovlsyre ( S03 ) 0.225 -
Magnesia 0.210 -
Kalk 0.056 -
medens Vierthaler i Adriaterhavet har fundet
Chlor -f Brom . 2.264 °/o
Svovlsyre 0.262 -
Magnesia 0.237 -
Kalk 0.371 -
Denne uforholdsmæssig store Forøgelse af Kalkmæng- den uden tilsvarende Forøgelse af Svovlsyremængden vil bidrage til. at det af Vierthaler undersøgte Vand vil have en meget større Tilbøielighed til ved Kogning at udskille kulsur Kalk, hvad der i ikke ringe Grad kan tænkes at forrykke de almindelige Phænomener.
Hvad angaar de af Thorpe og Morton ujdførte Obser- vationer, da er der i en Henseende en væsentlig Forskjel mellem de af disse Forfattere og de af mig erholdtb Re- sultater. Jeg havde, alleredé før jeg blev opmærksom paa. den af dem offentliggjorte Aihandling, lagt Mærke til, at der af Søvand ved Kogning i en kulsvrefri Luftstrøm i Classens Apparat udfældtes et Bundfald af Magnesia, inde- holdende lidt fra Glasset hidrørende. Kiselsyre, men jeg havde aldrig deri kunnet paavise hverken Kulsyre eller Kalk og det, uanseet om Kogningén afbrødes paa et tidligere eller senere Stadium, hvadenten den neutralbundne Kulsyre var helt eller kun delvis bortdrevet. Rigtignok anfører Thorpe og Morton intetsteds udtrykkelig, at de have under- søgt det udskilte Bundfald paa Kalk, men det fremgaar indirecte med stor Bestemthed, af hvad der forresten er bemærket, at saa maa have været Tilfælde.
At Vierthaler kunde faa udfældt kulsur Kalk af et saa abnormt sammensat Søvand som det i Adriaterhavet flydende, kunde ikke vække Forundring, men at det samme landtes at være Tilfælde med Våndet i det irske Hav, som ved livlige Strømme stadig optager friske Vandmængder fra det store \ erdenshav, og som i sin Sammensætning viser sig saa analogt det af den norske Nordhavsexpedition un- defsøgte, forekom mig meget paafaldende. Jeg har derfor gjentaget Thorpe og Mortons Forsøg aldeles uforandrede paa flere al de fra den norske Expedition hjembragte Vand- prøver, men erholdt altid det samme Resultat, at det i det udskilte Bundfald trods al anvendt Møie ikke lykkedes at paavise Spor hverken af Kulsyre eller Kalk. Af det for- hen l dviklede vil det fremgaa, at man af de ældre Angi-
For the same reason, as explained above, the said process with ordinary ocean-water will give results absolutely worthless; this cannot however be affirmed with certainty of Viertlialer's observations, the water lie examined having been very different in composition from ordinary sea-water. Ac- cording to the numerous and valuable analyses of sea-water for which we are indebted to Professor Forchhammer, the water of the great oceans, the component parts of which vary but little in their relative proportion, is generally found to contain —
Chlorine -f- Bromine 1.895 per cent.
Sulphuric Acid (SO$) 0.225 - —
Magnesia 0.210 - —
Lime ; 0.056 - —
whereas the water of the Adriatic Sea, according to Vier- thaler's observations, contains —
Chlorine -j- Bromine 2.264 per cent.
Sulphuric Acid 0.262 - —
Magnesia 0.237 - —
Lime . 0.37 1 - —
This disproportionately large amount of lime without a corresponding increase in the amount of sulphuric acid will give the water examined by Vierthaler a tendency, when boiled, to precipitate carbonate of lime, which must to a considerable extent have a disturbing influence on the phenomena.
With regard to the series of observations instituted by Thorpe and Morton, there is. in one respect, an essential difference between their results and mine. Previous to my reading their Memoir, 1 had become aware of the fact, that, on boiling sea-water exposed to a current of air free from carbonic acid in Classen’s apparatus, there results a precip- itate of magnesia, containing a little silicic ac*id, derived from the glass; but I have never succeeded in detecting therein the presence of carbonic acid or lime: the result is precisely the same whether the boiling be interrupted at an early or a late stage of the process, or whether all or part only of the carbonates be decomposed. True, Thorpe and Morton nowhere distinctly state their having examined the precipitate for lime; but from what is ob- served in other respects, this must obviously have been the case.
That Vierthaler should* have succeeded in precipitat- ing carbonate of lime from water so exceptionally composed as is that of the Adriatic Sea, cannot surprise us; but that the same result should have been obtained with water from the Irish Sea, which by reason of rapid currents is continually receiving a large influx of water from the Atlantic Ocean, and which in its composition exhibits so great an analogy with that examined on the Norwegian North -Atlantic Expedition, does, to me, indeed appear slange. ^ 1 have therefore repeated the experiments insti- tuted by Thorpe and Morton, adopting their method with- out the slightest modification; hut the results obtained were invariably the same: even with the most delicate tests I failed to detect the smallest traces of carbonic acid or
43
velser Intet med Bestémthed kan slutte om Carbonaternes Mængde i de store Verdenshave. Det synes dog, som om de af Buchanan udførte Bestemmelser af Kulsyren i At- lanterhavet, (hvorved han iuddamper efter forudgaaende Til- sætning af Chlorbarium og tilslut med stærk Saltsyre for- gjæves har bestræbt sig for at paavise Kulsyre i Residuet), med Sikkerhed skulde fastsætte en ovre Grændse for den tilstedeværende Carbonatmængde, mon dette er i Virkeiig- heden ikke Tilfælde.
Som bekjendt beskytter uopløselige Sulfater Carbona- ter mod Decomposition endog, naar til Uddrivelse af Kul- syren anvendes saa radicale Midler som concentreret Svovl- syre, saaledes at man endog af den Grund har fuudet det fornødent at modificere den af Fresen i us og Will angivne Methode til Bestemmelse af Kulsyren i neutrale Carbonater.1 * De af Buchanan foretagne 1'ndersøgelser efter Kulsyre i Residuet kan derfor ikke betragtes som Bevis for, at den ikke skulde have været tilstede, og det fremgaar ogsaa tydeligt af hans egne Udtalelser. at han selv har været af samme Mening.
Forat faa Rede paa. hvorvidt en ved Kogniug bevir- ket Decomposition af de i Søvandet indeholdte neutrale Carbonater foregaar i større Udstrækning ogsaa, naar der i Vædsken findes uopløselige Sulfater, har jeg udført nogle Forsøg efter den af Buchanan foreslaaede Fremgangsmaade.
Af nogle V andprøver, som, udersøgte efter den af mig be- . nyttede Methode, viste sig at indeholde en Sum af surt- og neutralbunden Kulsyre af 96 Mgr. pr. Litre og der- over, erholdtes ved Inddampning til Tørhed efter Tilsæt- ning af Chlorbarium uddrevet kun henimod 50 Mgr., ved en enkelt Undtagelse erholdtes engang over 50 Mgr.' pr. Litre. Det vil sige, den uddrevne Kulsyremængde var j ikke synderlig høiere end den af Buchanan for Våndet i Æqvatoregnene angivne og beløb sig til kun faa Mgr. over, livad den surtbundne Kulsyre efter paalidelige Observa- tioner skulde beløbe sig til, de endnu i Residuet tilbage- værende Carbonater lykkedes det heller ikke mig at paavise.
Spørgsmaalet om Carbonaternes Mængde i de sydlige Have maa derfor endnu betragtes som a a bent.
Forhaabentlig resterer endnu en Del af de fra Chal- lengerexpeditionens Togter hjembragte Vandprøver, og man vil i saa Fald ved Undersøgelse af disse kunne give Bi- drag til Besvarelsen af disse Spørgsmaal.
Etterat Ovenstaaende var nedskrevet paa Norsk, men førend det endnu var oversat paa Tysk, ankom hertil 2det og 3die Hefte for 1879 af Fresenius’ Zeitschrift fur anal. Chem.. hvori E. Bohlig offentliggjør en Afhandling,8 hvoraf det sees, at han ved Arbeide med naturlige Mineralvande har observeret Omsætninger mel lem kulsur Kalk og svovl-
of lime. From what has been already explained, it is ob- vious that nothing definite can be inferred from earlier statements respecting the proportion of carbonates in the water of the great oceans. The carbonic acid determina- tions performed by Buchanan with water from the Atlantic Ocean (he had recourse to evaporation, adding first chloride of barium, and then attempting, unsuccessfully, to detect carbonic acid in the residue by means of strong hydro- chloric acid) would appear to fix. a limit for the maximum amount of carbonates contained in sea-water; but such is not really the case.
The presence of insoluble sulphates serving, as is known, to protect carbonates against decomposition, even when concentrated sulphuric acid is made use of to expel the carbonic acid, it was necessary for this reason alone to modify the process devised by Fresenius and Will for determining carbonic acid in neutral carbonates.1 Hence, the experiments performed by Buchanan with a view to detect carbonic acid in the residue, cannot be regarded as affording conclusive proof of its absence; indeed, he himself,
as appears from his statements, is clearly of the same opinion.
.
In order to ascertain whether the decomposition by boiling of the neutral carbonates in sea-water also took place to a considerable extent when insoluble sulphates i were present in that fluid, I made a few experiments by Buchanan’s process. From several samples of sea-water which, examined by the method 1 adopted, were found to contain 90ro,/l of carbonic acid per litre, l succeeded, by evaporation to dryness, after adding a solution of chloride of barium, in liberating about only, with a solitary exception, when the amount exceeded 50 n,jr per litre. The proportion of carbonic acid expelled was accordingly not much greater than that determined by Buchanan in water from the Equatorial Seas, and but a few millegrammes in excess of what the carbonic acid forming bicarbonates, ac- cording to trustworthy observations, should have been; of the carbonates said to be still present in the residue, 1 failed to detect any trace.
• The amount of the carbonates contained in the water of- the Southern Seas must, therefore, be still regarded as an open question.
It is to be hoped, that some of the samples of water collected on the ‘Challenger’ Expedition still remain, in which case their examination will serve to throw further light on the subject. *
After this Memoir had been written in Norwegian, but previous to its translation into German, the 2nd and 3rd Parts of Fresenius' Zeitschrift fill* anal. Chemie lor 1879 came to hand, in which E. Bohlig’ has published a paper8 on transformations, observed by him in mineral waters, resulting from the reciprocal action ol carbonate ot
(i*
1 Fresenius. Qvant. Analyse. Me Aufl. 3(i4 1)1).
a Fresenius' Zeitschrift, IS — 19f>.
1 Fresenius. Qvant. Analyse, Me Aufl. 3(14. bb. • * Fresenius' Zeitschrift, is, p. 10‘>.
44
sur Magnesia, som fuldstændig svare til, livad jeg efter de foran beskrevne Observationer har fundet for Søvands Ved- kommende. Disse Omsætninger kunne saaledes, idet de ere iagttagno af to af hinanden uafkængigt arbeidende Che- mikere, uden videre Begrundelse outages fuldstændig laotiske.
Det vil af dette Bohligs Arbeide sees, at han allerede Sommeren 1878 over det samme Thema bar publiceret en Afliandling,1 som jeg ikke tidligere bar været opmærksom paa. Den vilde dog ikke bavt nogen væsentlig Indflydelse paa mine Indersøgelser, saasom de vigtigste af de Obser- vationer. der har fort mig frem til de samme Resultater, som Boklig først bar beskrevet, allerede vare udførte 3 — 4 Maaneder, førend hans første Afliandling forelaa trykket.
lime and sulphate of magnesia, which precisely agree with those I have described as occurring in .sea-water. These transformations- having accordingly been observed by two chemists working independently of each other, may with-, out further proof be accepted as facts.
From the said paper, it appears that Bohlig pub- lished a treatise on the same subject in the summer of 1878,1 to which my attention bad not previously been directed. It would not, however, have materially in- fluenced my experiments, the most important of the obser- vations that led me to the results which Bohlig was the first to describe, having been instituted 3 or 4 months before his^ first treatise bad left the press.
' .Fresenius’ Zeitschrift. 17 — 301.
1 Fresenius’ Zeitscbl ift, 17, p. 301.
III. Om Saltholdigheden at' Vandet
111. On the Amount of Salt in the Water of the Norwegian Sea,
i det norske Nordhav.
Hvor det gjælder at tilveiebringe Oplysninger om Varia- tionerne af Saltmængderne i Havvandét, kan man til sine Saltbestem meiser . benytte flere forskjellige Metliocjor, som hver især tidligere bar fundet udstrakt Anvendelse. Den nærmest liggende af disse bestaar i Vandets Afdamp- ning og derpaa følgende Tørring og Veining af de som Residuum tilbageblivende Salte, en Fremgangsmaade, som rigtignok directe fører til Manlet, men som til Gjengjæld ogsaa fordrer temmelig meget Arbeide. Som mere iudi- rectc men ogsaa ulige mindre besværlige Metboder kan Ogsaå anvendes Bestemmelse af Havvandets Cblormængde1 eller Egenvægt, livoraf man gjennem passende bestemte Coefflcienter kan beregne den samlede Saltmæugde, forud- sat. at man kan antage et constant indbyrdes Forbold mellem de i Søvandet indeboldte faste Bestanddele. Den første af disse Metboder medfører foruden Besværligbeder ved Udførelsen ogsaa den Ulempe, at den ikke lader sig anvende ombord pan et Fartøi i aaben Sø. hvor Skibets Be.vægelser forbyder Brugen af Vægt, medens Egenvægts- bestemmelser ved Hjælp af Aræometré og volumetriske Cblor- bestemmelser meget letvindt og med temmelig stor Nøiag- tigbed kan udføres ombord selv i temmelig uroligt Veir.
Hvor man derfor ikke tror sig sikker paa at kunne opbevare Vandprøverne i lffingere Tidsrum uden derved :ft risikere, at de undergaa Forandringer, som kunde ytre en skadelig Indflydelse paa Resultatenie af de erholdte Salt- bestemmelser og. hvor man som Følge deraf maa begge Hovedvægten paa en hurtig Undersøgelse af Vandprøverne i frisk Tilstand, bliver man saaledes udelukkende henvist til Brugen af Cblorbestemmelser eller Egenvægtsbestemmel- ser som Maal for den samlede Saltgehalt.
Paa det første, af den norske Expeditions Togter blev af Svendsen, hvem de cbemiske Observationer deugang vare
1 Saåvel her som overalt senere forstaaes ved Chlormtengde don samlede Chlor- og Brommrengde.
ben seeking to investigate the degree in which the proportion of salt varies in sea-water, choice may be made for performing the salt-determinations between several methods, each of which has in turn been extensively adopted. The most simple process, is first to evaporate the water, and then dry and weigh. the salts left in the residue, a mode of operation which, though leading direct to the desired result, involves considerable labour. ' Two other methods, not so direct, but far less tedious, consist in determining either the specific gravity of the water or the amount of chlorine 1 it contains, from which, by means of proper coefficients, the total amount of salt may be com- puted, provided always that a constant proportion can be assumed to exist between the solid constituents of sea-water. The first process is attended, irrespective of the trouble- some mode of operation, with another drawback, viz. the impractibility of adopting it on board ship in the open . sea, where the motion of the vessel altogether precludes the use of the balance, whereas both specific gravity determinations, with the hydrometer, and volumetric determinations of chlorine, may be performed at sea with the greatest ease, and very considerable accuracy, even in comparatively rough weather.
Hence, when there is reason to fear that the samples of water cannot be preserved for any length of time with- out exposing them to chemical change, which might exert a disturbing influence on the results; and whenever, accord- ingly, weight must be chiefly attached to their immediate examination, the only practicable standard of measurement for computing the total amount of salt will lx? that furnished by determinations of chlorine or of specific gravity.
On the first voyage of the Norwegian Expedition, Svendsen, who then, as previously stated, did the chemical
1 By “the amount of chlorine,” here and elsewhere throughout this Memoir, is understood the total amount of chlorine and bromine.
overdrawn*, til Undersøgelser- over Saltgehalten udelukkende anvendt Egenvægtsbesteramelser, hvorimod jeg paa de to sidste Togter ved Siden af disse ogsaa har udført et større Antal Chlortitreringer for -gjennem denne Control at give . Resultaterne en større SikkcrlW-
Til Undersøgelser over den i Søvandet indeholdte Chlormængde medhavdes paa de to sidste Togter foruden Sølvopløsning af saadan Styrke, at 1 CC. af denne omtrent svarede til 1 CC. Søvand, ogsaa 2 paa første Togt ind- saralede Vandprøver, bestemte til som Normaler at tjene til den nøjagtigere Fastsættelse af Sølvopløsningens Styike. Disse Normalers Chlormængde i Procenter blev ved om- hyggeligt udførte Veiningsanalyser hvert Aar bestemt saavel før Expeditionens Udreise som efter dens Hjemkomst be- standig med meget nær det samme Resultat, hvorhos tillige deres Egenvægter ved Hjælp al‘ Aræometret ombord af- læstes. Til Brug ved alle ombord udførte Chlortitreringer tjente kim to Biiretter af lignende Construction og Stør- relse. de samme, som af Stipendiat A. Helland anvendtes ved de Bestemmelser af Chlormængderne i Overfladevandet i Atlanterhavet, som denne foretog i Aaret 1875 paa en Reise til Grønland, de bleve af ham den Gang calibrerede ved Hjælp af Kviksølv og befundne særdeles tjenlige for. Øieraedet.
Ved Biiretternes' Brug fyldtes den ene med Sølvop- losning den anden med det til Undersøgelse bestemte Sø- vand. hvoretter en passende Portion Søvand fra den ene under Omrystning tilsattes Sølvopløsning fra den anden, indtil al Chlor var udfældt, idet chrbmsurt Kali tjente som Index. Begge Biiretters Stand aflæstes nu, og nogle Draa- ber Søvand tilsattes atter til Aftarvning, hvorefter paany fulgte Tilsætning af Sølvopløsning og Aflæsning af Biiret- ternes Stand o. s. v. Gjennem en Række af 4 a 5 paa hina mlen følgende lignende Aflæsninger erholdtes paa denne Maade de fornødne Data til Beregning af det Volum Sø- vand. som i hvert enkelt Tilfælde svarede til 1 CC. Sølv- opløsning.
Paa denne Maade sammenlignedes paa den ene Side Søvandsprøverne og paa den anden Side ogsaa fra Tid til anden de medbragte Normaler med Sølvopløsningen. idet der altid sørgedes for. at Vandprøvernes og Opløsningernes Temperatur ikke fjernede sig synderlig meget fra hinanden. Biiretterne bleve for at tilveiebringe en bedst mulig Aflob- ning hyppig rensede med concentreret Svovlsyre.
Af de gjennem disse Observationer erholdte Tal er senere Søvandets' Chlormængde beregnet efter følgende Formel
KSP
3)= u
hvori p betegner den undersøgte Vandprøves Chlormængde i Procentei\ k det Antal CC. af samme, der svare til 1 CC. Sølvopløsning ♦ og s dens Egenvægt ved 17. 5 C'.. P Middeltallet mellem de før Udreisen og efter Hjemkomsten i Normalen fundne Chlormængdef, K det Antal CC., som af denne svarer til 1 CC. Sølvopløsning og S dens Egen-
work, made exclusive use of specific gravity determinations; but for a considerable number of my own observations, on the last two cruises, I also adopted titration for chlorine as a means of testing the general accuracy of the results.
For estimating the amount of chlorine in sea-water,
I took with me. on the two last cruises, besides a solution of silver of such strength that 1 ec of the fluid about corre- sponded to 1“ of sea-water, also 2 samples of water col- lected on the first voyage, to serve as a normal standard by which to determine the strength of the solution of , silver. Each year, both previous to the departure of the Expedition and after its return, the chlorine in these standard samples was carefully determined by weighing, and the percentage calculated accordingly, their specific gravity too, as shown by the areometer on board, having been like- wise noted down. For all chlorine-titrations performed at sea, there were only two burettes in use, similar alike in size and construction. — those used by Mr. Helland for determ- ining the amount of chlorine in the surface-water of the Atlantic on a voyage to Greenland in 1875 ; he had cali- brated them by means of mercury, and they proved excel- lently adapted for the purpose.
When using the burettes, one was filled with solution of silver and the other with the sea-water selected for examination, after which solution of silver was added to a proper quantity of the sea-water, while shaking the flask in which the titration was performed till all chlorine had been precipitated, chromate of potassium serving as the index. The height of the fluid in both burettes was now read, and a few drops of sea-water added to the mix- ture. to discolour it, after which solution of silver was again added, and the height of the fluids read as before, &c. After the height had been thus read 4 or 5 times in succession, the necessary data were obtained for computing the volume of sea-water, which in each individual case cor- responded to 1" solution of silver;
In' this manner, were compared on the one hand •the freshly drawn samples of sea-water, and on the other, from time to time, also the standard samples, with the solution of silver, care being taken to keep the samples of water and the solution as near as possible at the same tempera- ture. In order to prevent any portion of the fluid from adhering to the burettes, they were frequently rinsed with concentrated sulphuric acid.
With the figures obtained from these observations, the amount of chlorine in sea-water was afterwards determined by the following formula —
KSP
v - ~ i- ir
in which p signifies the percentage of chlorine in the sample of water examined, k the proportion in cubic cen- timetres representing lec of the solution of silver, and s the specific gravity of the water at 17° 5 C. ; P the mean between the amounts of chlorine found in the standard sample before the departure and after the return of the
47
vægt ved 17° 5 ('. Disse Obsorvationer bleve dog selv paa de to sidste Togtcr ikke anstilledc i samme Udstræk- ning som Egenvægtsbestemmelserne, der ogsaa oprindelig vare bestemte til i første Række at tjene som Maal for den samlede Saltgehalt.
Expeditionen var for Egenvægtsbestemmelser forsynet med flere Sæt Glasaræometre fra Dr. Kiichler i Ilmenau,
li 7° 5
indrettede til at vise Søvandets Egen vægt ved ^iV h saa-
ledes at et Sæt viste Egenvægter fra 1 til 1.007. et andet fra 1.006 til 1.013, et tredie fra 1.012 til 1.019, et fjerde fra 1.018 til 1.025 og et femte fra 1.024 til 1.031. Aræo- metrene vare inddelte i Delstreger af Yærdi 0.0002, medens Afstanden mellém disse Delstreger paa Scalaen beløb sig til meget nær 1.5""", saaledes at man raaatte kunne aflæse udeii stor Feil det 5te Decimal. Under Aflæsningen af Vandprø vernes specifiske Vægt anbragtes disse i en i dob- belt Slingrebøile opbængt Glascylinder, hvis indre Diameter belob sig til ointreut det tredobbelte af Aræometrets Cor-
pus. hvorefter dette dvkkedes i Vædsken
omhyggeligt renset og
aftorret ned- og tillodes at svømme frit i nogen Tid. indtil det liavde antaget Vandets Temperatur. Aflæs- ningen foretoges nu langs den undre Rand af Vædskens Niveau, idet samtidig Vandets Temperatur iagttoges paa et controlleret Thermometer, inddelt i Delstreger af Værdi 0. " 2.
Paa Grund af det af Expeditionen benyttede Damp- skibs fortrinlige Egenskaber som Soskib voldte disse Obser- vationer i nogenlunde roligt Veir ingensomhelst Vanskelig- heder, selv naar Kursen sattes ret mod Vinden, hvorimod Skibets Duvning i meget liaardt Veir altid ytrede sig i mærkbare om end smaa Bevægelser hos Aræometret. Hvor Vandproverne optoges i saa uroligt Veir, at Bestemmelsen paa Grund deraf kunde medføre forøgct Usikkerhed, bleve de altid hensatte nogle Dage, indtil de kunde undersøges under mere gunstige Villen ar.
Disse saaledes aflæste Egenvægter maa imidlertid i 2 Henseender forbedres, idet man paa den ene Side maa an- vende passende Correctioner for at faa de ved meget for- skjellige Temperaturer aflæste Egenvægter reducerede til den fælles Nor malte mperatur 17.° 5, og paa den anden Side maa befrie dem for Aræometrenes constante Feil.
Hvad for det Første Correctionerne for Temperaturen angaar. da give de af flere Videnskabsmænd udførte Be- stemmelser af Søvandets Volumforandring med Temperaturen Midlerne til at beregne disse, idet baade Hubbard s, L. F.
Expedition, Å those amounts in cubic centimetres corres- ponding to lw of the solution of silver, and S the specific gravity of the standard sample at 17" 5 C. These obser- vations. however, were not instituted even on the two last voyages to the same extent as those based on determina- tions of specific gravity, the method by which, as origin- ally agreed upon, the total amount of salt was to bo chiefly computed.
For performing specific gravity determinations, the Ex- pedition had been supplied by Dr. Kiichler of Ilmenau with divers sets of glass areometers, adapted to show the
1 7 ' 5
specific gravity of sea-water at ^ one set indicating
specific gravities from 1 to 1.007. another from 1.006 to 1.013, a third from 1.012 to 1.019, a fourth from 1.018 to 1.025, and a fifth from 1.024 to 1.031. The areometers were graduated in degrees of 0.0002, the interspaces on the scale measuring however very nearly 1.5"""; and hence you could read oft' with comparative accuracy to the fifth decimal. When about to read the specific gravity, the samples of water were poured into a glass cylinder sus- pended in gimbals, the inner diameter of the cylinder being triple that of the areometer, which, carefully wiped and dried, was immersed in the fluid and suffered to float freely for some time till of the same temperature as the water. The specific gravity was now read in the ordinary way, the temperature of the water, as shown by a tested thermometer graduated in fifths of a degree Centigrade, being simultaneously observed.
The steamer selected for the Expedition being an excellent sea-boat, these observations were attended with no difficulty whatever in moderately fair weather, even when steaming dead against the wind; pitching, however, was found to have a distinctly disturbing effect on the areometer, and therefore all samples of water drawn when it was in any way violent, so as to give reason for appre- hending greater uncertainty in the determinations if per- formed at once, were stored for a few days, till the weather had improved.
These readings of specific gravity have, however, a two- fold need of correction, arising on the one hand from the very different temperatures at which the specific gravities were read, involving the t necessity of their reduction by proper corrections to the normal, temperature 17" 5, and on the other, the constant error of the areometer, which has also to be eliminated.
As regards the corrections for temperature, these may be computed by the determinations performed by di- vers men of science of the extent to which the volume of sea-water varies with the temperature, Hubbard,* L. F.
1 Naar her so in ofte senere brugea Bctcgningsmaaden Egenvægt ved
<° ’
, da menes dermed Egenvægt ved t° i Forhold til destillerct Vand
af T" som Enhed. Alle Ttfmperaturangivelser i denne AflmiuMing ere udtrykte i Grader Celsius.
a Maury’s Sailing Directions 1858, — 1 — 237.
1 The expression, specific gravity at ?,0 ) signifies specific gravity at
t° , with distilled water of T° as the unit of comparison. All statements of temperature in this Memoir are given in degrees Celsius.
1 Maury's Sailing Directions, 1858, 1, p. 237.
48
Ekman1 og Thorpe og Riicker8. har givet meget fuldstæn- dige Tabeller over Søvandets Volumina ved forskjellige Temperaturer, hvorhos tillige ogsaa Dr. Karsten» bar op- stillet en Correctionstabel. hvoretter man kan reducere de ved vilkaarlige Temperaturer aflæste Bgenvægter til 17.°5. Sammenstiller man de Correctioner. som efter disse Iagt- tagelser kunne beregnes, erholder man imidlertid især for de lavere Temperaturer meget daarligt overensstemmende Yærdier. idet der kan optræde Difterenter, der endog kan overskride 0.0004, mellem <le af Ekmann's og Hubbard’s Observationer beregnede Correctioner. hersker der den største Overensstemmelse, men ogsaa her gaar Different- serne paa enkelte Puncter op til meget nær 0.0001. I Betragtning af disse tildels temmelig betydelige Uoverens- stemmelser mellem de liidtil publicerede Undersøgelser af denne Art kunde det ikke findes ubeføiet endnu engang at gjenoptage Bestemmelserne af Søvandets Volumina ved forskjellige Temperaturer, og jeg besluttede mig derfor til gjenuem egne Undersøgelser at forvisse mig om. hvilken af de opstillede Tabeller der bedst svarede til Udvidelsen af det i det norske Nordhav flydende Vand. Dels i dette Øjeined dels for at bestemme de benyttede Aræometres Correctioner og de Constanter, hvormed Chlorprocenterne og Decimalerne i Egenvægten maatte multipliceres for at give Saltmængden. har jeg anstillet Undersøgelser med føl- gende Vaudprøver,
|
Bredde. |
Længde |
Dybde |
||
|
Station. |
fra Greenwich. |
Eng. Fra. |
Meter. |
|
|
245 |
68° 2 1 ' |
2° 5' v. |
O |
O |
|
247 |
O' 00 Cn Cn |
2 24 0. |
500 |
941 |
|
253 |
Skjærstadfjord. |
0 |
0 |
|
|
254 |
67" 27' |
13" 25' |
0 |
0 |
|
284 |
73 1 |
12 58 |
0 |
0 |
|
300 |
73 10 |
3 22 V. |
0 |
0 |
|
349 |
76 30 |
2 57 0- |
1487 |
27 x9 |
|
362 |
79 59 |
5 40 |
0 |
0 |
hvilke jeg for Kortheds Skyld i den Orden, hvori de her findes opforte. vil betegne med I. II o. s. v. indtil A III. Til Bestemmelse af Søvandets Udvidelse benyttede jeg et Sprengels Pyknometer4, forarbeidet af to Stykker meget tynde Glasrør af et og samme Rør med en indvendig Dia- meter af omtyent 13mra. 'Rørene vare nedentil sammenlod- dede ved Hjælp af et snævert kort u-formig bøiet Glasrør og oventil paaloddede knæformig bøiede solide Oapillarrør med meget fin Aabning. Ved Paalodn ingen at disse Glas- rør blev der saa meget som muligt draget Omsorg lor. at kun en liden Del af de videre Rør udsattes for Opvarm- ning over Blæselampen, fornt ikke Apparatet derved [skulde
1 Kongl. Svenska Vétenskapsak. Handlingar 1870 — 1.
2 Proc. Roy. Soc., ‘24 — 159.
a Tafeln zur Berechnung der Beobachtungen aii den Kiistensta- lionen u. -s. w. Kivi 1874.
4 Pogg. Ann. 150 — 459.
Ekman1, and Thorpe and Rucker2 * having prepared com- prehensive Tables to show the volume of sea-water at diffe- rent temperatures; Dr. Karsten8, too. has published a Table of Corrections by which specific gravities read at any tem- perature may be reduced to 17.°5. Meanwhile, on comparing together the corrections computed from these observations, the values obtained, more especially lor low temperatures, are found to agree but very indifferently, the difference in some cases exceeding even 0.0004. The agreement is closest between the corrections computed from Ekman s and Hubbard's observations; but here, too. the difference for some temperatures amounts to very nearly 0.000 1. ( ou- sidering. therefore, the want of uniformity, in some cases very considerable, exhibited by such observations of this kind as had till then been made public, it could not be deemed superfluous to investigate anew by a further series of experiments the variation in volume which sea-water is found to undergo at different temperatures; and hente I determined on ascertaining from the results of my own ob- servations which of the aforesaid Tables corresponded best with the expansion of the water in the Norwegian Sea. Partly with this object in view, and partly in order to determine the corrections for the areometers and the con- stants by which the percentages of chlorine and the deci- mals of specific gravity had to be multiplied when com- puting the amount of salt. I examined the following sam- ples of water: —
|
Latitude. • |
Longitude |
Depth |
|||
|
Station. |
from |
Greenw. |
Eng.Fath. |
Metres. |
|
|
245 |
68" 2? |
2 0 |
5'W. |
O |
0 |
|
247 |
68 5.5 |
2 |
24 E. |
500 |
941 |
|
253 |
The Skjærstad Fjord. |
0 |
0 |
||
|
254 |
67° 27' |
J3° |
25' |
0 |
0 |
|
284 |
73 1 |
12 |
58 |
0 |
0 |
|
300 |
73 Jo |
3 |
22 W. |
0 |
. 0 |
|
349 |
76 30 |
2 |
57 E. |
1487 |
2719 |
|
362 |
79 59 |
5 |
40 |
0 |
0 |
which I will indicate, for the sake of brevity, by the Roman numbers from I to VIII. and in the order in which they are given here. For determining the expansion of the sea- water. I made use of Sprengels pycnometer;4 the instru- ment was constructed of two pieces of glass tubing, cut oft from the same length, with an inner diameter of about 13”"". These tubes were sealed together at their lower ends by means of a short, narrow glass tube, bent into the form of the letter U. and had strong knee-shaped capillary tubes sealed on to their upper extremities. AVhen sealing on these glass tubes, the greatest care was taken to confine the heat from the glass-blower’s lamp to as small a portion
1 Kongl. Svenska Vetenekapsak. Handlingar 1870, 1.
2 Proc. Roy. Soc., 24; p. 159.
Tafeln zur Berechnung der Beobadijungen an den Kiistensta- tionen u. s. w. Kiel 1874.
4 Pogg. Ann. 150, p. 459.
49
antage en anden I’dvidelsescoefficient end den, det anvendte Glasrør oprindelig havde. Pyknometret blev først omkring 4 Maaneder, efterat det var blæst. taget i Brug til de Forsøg, som her skulle beskrives; forat ikke den for alle Glasgjenstande eiendommelige Contraction gjennem de første Maaneder efter deres Blæsning skulde bidrage til i mærke-r lig Grad at forandre dets Volum under Observationernes Udførelse. Pyknometret benyttedes ved de første Forsøg uden nogen Sikkerhedskugle, men maatte senere, hvor det fyldtes ved lavere Temperaturer, forsynes med en saadan, indrettet til at trsekkes ind over det videre Capillarrør. Apparatet uden Sikkerhedskugle vil jeg for Kortheds Skyld betegne som Pyknometer No. 1 og med Sikkerhedskugle som Pyknometer No. 2. Ved Hjælp af disse udførtes føl- geiule Forsøg i den Orden, hvori de her findes opførte.
/
|
Pyknometer med Indhold. |
Vffigt Gr. |
I Luft af sp. Vægt. |
||||||
|
I. |
Pykn. No. 1 |
tomt .... |
15.9222 |
0.001200 |
||||
|
2. |
— |
- |
1 |
15-9223 |
0.001200 |
|||
|
3- |
— |
- |
1 |
med rent Vand af |
i7-°5 |
44-3153 |
0.001200 |
|
|
4- |
— |
- |
1 |
r » n |
n |
i7- 5 |
44-3156 |
0.00 1201 |
|
5- |
— |
- |
1 |
m »i j» |
11 |
T7- 5 |
44-3I5I |
0.00 1201 |
|
6. |
— |
- |
1 |
„ HI ... . |
11 |
l7- 5 |
44.8097 |
0.00 1201 |
|
7- |
— |
- |
1 |
.. ILI ... . |
1.7* 5 |
44.8693 |
0.001201 |
|
|
8. |
— |
- |
1 |
,. VII |
1 7 • 5 |
45.0742 |
0.001 200 |
|
|
9- |
— |
- |
1 |
,. VII . . . . |
„ |
•l7’ 5 |
45-0738 |
0.001200 |
|
IO. |
— |
- |
2 .torat |
18.5665 |
0.001 194 |
|||
|
1 1 . |
— |
- |
2 |
med I . . . . |
af |
o.° |
47.7869 |
0.00 1 1 98 |
|
12. |
— |
- |
2 |
,. I . . . . |
n |
0. |
47-78.73 |
0.001 198 |
|
13- |
— |
- |
2 |
„ I |
J! |
0. |
47.7871 |
0.001 199 |
|
1 4- |
• — |
- |
2 |
, . I |
11 |
I7’°5 |
47.7249 |
0.001 201 |
|
15- |
— |
- |
2 |
„ I • • • • |
» |
*7- 5 |
47.7246 |
0.00 12.01 |
|
16. |
— |
- |
2 |
I |
J1 |
20. |
47-7085 |
0.001 198 |
|
17- |
— |
- |
2 |
I . . V . |
j; |
20. |
47.7087 |
0.001 198 |
|
18. |
— |
- |
2 |
.. I . . . . |
j? |
8. |
47.7696 |
0.00 1200 |
|
iq. |
— |
- |
2 |
» I — |
11 |
8. |
47.7702 |
0.001 200 |
|
20. |
— |
- |
2 |
„ I . . . . |
»? |
4- |
47.7810 |
0.001 200 |
|
2 I . |
— |
- |
2 |
r I |
)• |
.4. |
47.7808 |
0.001 200 |
|
22. |
— |
- |
2 |
„ I |
V |
J3- |
47-7487 |
0.001 198 |
|
23- |
— |
- |
2 |
„ I |
11 |
13- |
47-7484 |
0.001 198 |
|
24. |
— |
- |
2 |
med rent Vand ,. |
0. |
46.9773 |
0.001 191 |
|
|
25- |
— |
- |
2 |
11 11 11 |
•• |
0. |
46.9776 |
0.001 191 |
|
26. |
— |
- |
2 |
tomt |
18.5658 |
0.001 191 |
||
|
27. |
— |
- |
i |
15.9216 |
0.001 191 |
|||
|
28. |
— |
- |
2 |
11 • • • • • |
18.5656 |
0.001 231 |
||
|
29. |
— |
- |
1 |
,, • • • • • |
I5-92I3 |
0.001231 |
Til Bestemmelse af Udvidelsescoefficienten af def an- vendte Glas forarbeidedes af det samme Glasrør et andet engrenet Pyknometer nedentil tilsmeltet og oventil forsynet med et Capillarrør, idet der ogsaa her sørgedes for Op- varmning af en saa liden Del al Iioret som muligt. V ed
Den norske Nordhavsexpeditio». Torpoe: CJiemi.
as possible of the wider tubes, lest it should give to the apparatus a coefficient of expansion different to that which the glass tubes originally had. The pycnometer was not made use of for the experiments to be described here, till about 4 months after the tubes of which it consisted had been sealed together; for the contraction peculiar to all articles of glass throughout the first few months after they have been blown might otherwise have occasioned an appreciable change in its volume during the progress of the observations. For the first experiments, the pycno- meter was used without a receiver, but subsequently, ‘when filled at a lower temperature, one had to be provided, adapted so as to admit of its being drawn over the capil- lary tube. The apparatus when used without a receiver I shall designate, for the sake of brevity ‘Pycnometer No. 1. and when used with a receiver, ‘Pycnometer No. 2.’ By means of this instrument the following experiments were
|
performed, |
in |
tin |
order in |
Avhicli |
they are here |
arranged. |
||
|
Weight |
In Air |
|||||||
|
P> |
c-nometer with Contents. |
in |
with a Sp. |
|||||
|
Grammes. [ |
Gr. of |
|||||||
|
1. |
Pycn. |
Xo. |
1 |
empty . |
' * ‘1 |
15.9222 |
0.001200 |
|
|
2. |
— |
- |
1 |
» |
I5-9223 |
0.001200 |
||
|
3- |
— |
- |
1 |
with pure |
water of |
i7-°5 |
44-3153 |
0.061200 |
|
4- |
— • |
- |
1 |
11 11 |
11 .11 |
17- 5 |
44.3l56j |
0.001 201 |
|
5- |
— |
- |
i- |
1! >5 |
>• 11 |
17- 5 |
44-315I |
0.001 201 |
|
6. |
— |
- |
1 |
III. |
17- 5 |
44.8097 |
0.00 1 20 1 |
|
|
7- |
— |
- |
1 |
.. III. |
17- 5 |
44.8093 |
0.001 201 |
|
|
8. |
— |
- |
1 |
.. vn. |
17- 5 |
45.0742 |
0.001200 |
|
|
9- |
• — |
- |
1 |
,. VII. |
. . . ,. |
»7- 5 |
45-0738 |
0.001 200 |
|
10. |
_ — |
- |
2 |
empty . |
18.5665 |
0.001 194 |
||
|
1 1. |
— |
- |
2 |
with I . |
. . of |
o.° |
47.7869 |
0.001 198 |
|
12. |
— |
- |
2 |
„ I. |
. . . ,. |
0. |
47-7873 |
0.001 198 |
|
i3- |
— |
- |
2 |
,. I. |
0. |
47.7871 |
0.001 199 |
|
|
14. |
— |
- |
2 |
„ I • |
...... |
i7-°5 |
47-7249 |
0.00 I 20 1 |
|
15- |
— |
- |
2 |
I. |
• • ■ y. |
17-5 |
47.7246 |
0.001201 |
|
16. |
— |
- |
2 |
,- I- |
. . . ,. |
20. |
47.7085 |
0.001 198 |
|
17- |
— |
- |
2 |
„ I- |
. . . |
20. |
47.7087 |
0.001 198 |
|
18. |
— |
- |
2 |
,.' I. |
. . . |
8. |
47.7696 |
0.001200 |
|
19. |
— |
* |
2 |
I • |
. . . |
8. |
47.7702 |
0.001 200 |
|
20. |
— |
- |
2 |
,. I . |
. . . ,. |
4- |
47.7810 |
0.001200 |
|
2 i. |
— |
- |
2 |
„ I- |
. . . „ |
4- |
47.7898 |
0.001 200 |
|
22. |
— |
- |
2 |
,• I- |
13- |
47-7487 |
0.001198 |
|
|
23- |
* — |
- |
2 |
I- |
13- |
47-7484 |
0.001 198 |
|
|
2 4- |
— |
- |
2 |
with pure |
water ,. |
0. |
46.9773 |
0.001 1 91 |
|
2-5- |
- - |
2 |
»• V |
>• >• |
0. |
46.9776 |
0.001 191 |
|
|
26. |
— |
- |
2 |
empty . |
18.5658 |
1 0.001 191 |
||
|
2 7- |
— |
- |
1 |
— |
15.9216 |
0.001 191 |
||
|
28. |
— |
2 |
■ — |
18.5656 |
0.001 23 1 |
|||
|
29. |
— |
- |
1 |
— . . |
15-9-2 13 |
| 0.001 23 1 |
For determining the coefficient of expansion of the glass, a single-branched pycnometer was constructed, of the same length 6f glass tubing, with the lower opening sealed up and the upper extremity bearing a capillary tube, care being taken, as before, not to heat a greater part of the large tube than
50
Hjælp af dette Apparat, som ved et Stykke Kautschukror var forbundet med et lidet Reservoir, bestemt til Optagøjjle af den ved mulig Opvarmning udskudte Del af Indholdet, bestemtes jm Ildvidelsescoefficienten af det anvendte Glas- rør med renset Kviksølv. som nogen Tid før Forsøgenes Udførelse under Udkogning paafyldtes Pyknometret. Med dette Apparat, som jeg vil betegne som Pyknometer No. 3. udførtes til den Ende følgende Veininger.
absolutely unavoidable. With this apparatus, which was connected by a caoutschouc tube with a small receiver for collecting any portion of the contents that, in the event of the instrument becoming warmer might possibly be expelled, the coefficient of expansion of the glass tube was now determined by means of purified mercury, which, shortly before the commencement of the experiment, had, when boiling out the air, been introduced into the pycnometer. With this apparatus, which I will designate ‘Pycnometer No. 3/ were performed the following determinations of weight: —
|
Pyknometer mod Indhold. |
Vægt Gr. |
I Luft af sp. Vregt. |
Pycnometer with Contend. |
Weight in Grammes. |
In Air with a Sp. Gr. of |
||||
|
30. |
Pykn. No. 3 tomt |
10.8654 |
0.0012 14 |
30- |
PyCn. No. 3 empty .... |
10.8654 |
0.0012 14 |
||
|
3 !• |
- 3 » |
10.8653 |
0.0012 14 |
31- |
— - 3 » • • • • |
10.8653 |
0.0012 14 |
||
|
32. |
- 3 med Kviksolv |
af o° |
I95'9265 |
0.0012 1 5 |
32. |
— - 3 with mercury |
of o° |
495-9265 |
0.0012 15 |
|
33- |
3 n n |
» 0 |
I95-9265 |
0.0012 15 |
33- |
— - 3 » |
» 0 |
I95-9265 |
0.0012 15 |
|
34- |
- 3 v » |
„ 20 |
I95-3588 |
0.001205 |
34- |
— - 3 » |
,, 20 |
I95-3588 |
0.001205 |
|
35- |
3 11 55 |
,, 20 |
195-3592- |
0.001205 |
.35- |
— - 3 >• n |
20 |
195-3592 |
0.001205 |
|
36. |
3 55 55 |
» r5 |
195-4993- |
0.001205 |
.36. |
- 3 » » |
11 15 |
195-4993 |
0.001205 |
|
37- |
3 » n |
» 0 |
195.9276 |
0.001205 |
37- |
- 3 r ' ■ « |
» 0 |
195.9276 |
0. 001 205 |
|
38. |
- 3 tomt |
10.8650 |
0.001203 |
38. |
— - 3 .empty |
10.8650 |
0.001203 |
||
|
39- |
- 3 med rent V and af 40 |
24.4621 |
0.001202 |
39- |
— - 3 with pure water |
51 -4° |
24.462 1 |
0.001202 |
|
|
40. |
3 » n • n |
» 4 |
t 24.4634 |
0 O' 0 q 6 |
40. |
3 r 51 51 |
55 4 |
24.4634 |
0.00 1 190 |
|
Alle disse Veininger. ere |
udforte |
efter Substitutions- |
These weight-determinations |
were |
all performed ac- |
methoden ved Afiæsning af Svingninger paa en Vregt, hvis Følsomhed uden Belastning beløb sig til 1.4 Mgr. pr. Delstreg og for stigende Belastning temmelig jevnt aftog indtil 1.9 Mgr. ved 200 Gr. Belastning. Til disse saavel som alle finere Veininger, som jeg har foretaget i Anled- ning af disse Arbeider, benyttedes en Platina lodsats fra Deleuil i Paris, hvis Correctioner jeg i Forveien havde be- stemt ved flere vel overensstemmende Veininger paa en af P. Bunge forarbeidet fortrinlig Vægt, hvis Følsomhed for de her omhandlede Belastninger beløb sig til omkring 0.14 Mgr. Ved Veiuingerne iagttoges altid Temperatur og Ba- rometerstaud af Luften i Veieværelset, hvorimod dens Fug- tighedsgrad i Mangel af Observation passende ansattes, en Mangel, der ikke har nogen mærkbar Indflydelse paa For- søgenes Paalidelighed, da selv en saa grov Feil i Ansæt- telsen af Luftens relative Fugtighed som 25 °/0 under de her omhandlede Forhold kuii virker paa det endelige Resultat med en liden Feil i 6te Decimal. Efter disse Data er Luf- tens specifiske Va*gt under Veiuingerne paa vanlig :Maade beregnet og ppført i Tabellen. Pyknometret blev for Jiver særskilt opført Veining indstillct paany for Temperaturen . 0° i finstødt Is og forøvrigt i Våndbad. hvis Temperatur under stadig Omrøring holdtes constant, ligesom det mindst en Gang for hver anden Veining tømtes og fyldtés igjen med det Søvand, hvis Volum skulde bestemmes. Ingen Indstilling toges for god, med mindre det lykkedes i mindst lo Minutter at holde Temperaturen såa constant, at Ther- mometret ingensindé viste Variationer af O/ l eller derover. Til Brug ved Aflæsniug af Vandbadets Temperatur tjente
cording to the substitution method, by reading the oscilla- tions of a balance, the sensibility of which, when not' loaded, amounted to \Amar for every division of the scale, diminishing, on being loaded with successive weights, at a comparatively uniform rate down to 1.9m*r, when loaded with 200^r. For the above-mentioned as for all accurate weight-determinations involved in these labours, I made use of a set of platina weights procured* from Deleuil in Paris, the corrections of which I had previous to start- ing on the Expedition computed from a series of closely agreeing determinations of weight performed with an ex- cellent balance (made by P. Bunge), its sensibility when loaded to the extent here specified being nearly 0.14ws'r. When performing the weight-determinations, the tempera- ture and the atmospheric pressure in the room were al- ways observed, but the relative humidity not having been found by observation had to be roughly estimated, a source of inaccuracy which however can exert no appreciable in- fluence, on the trustworthiness of the experiments, seeing that an error ol even 25 per cent in the computation of the relative humidity of the atmosphere would affect the final result only by occasioning a very small .error in the 6th decimal. From .these data, the specific gravity ol the air during the process of weighing was computed in the usual manner, and entered in the Table. For each successive determination, the pycnometer was plaeed in finely crushed ice, to give it the temperature of 0°, and lor every other required, in a water-bath, which by constant stirring was kept at an equable temperature ; it was emptied.
*51
et Thermometer, inddelt i Delstreger af Yærdi 0.‘2 med en Længde af O-Ofr"""., hvis CoiTectioner bestemtes ved gjentagne Sammenligninger med det herværende meteoro- logiske Instituts Normalthermometer. som til det Brug velvillig blev mig laant af Iiistitutots- Bestyrer. Professor Dr. Molm.
Af Observationerne 32' til 37 kan først Udvidelsen af det til Pyknometrenc benyttede Glasrør beregnes, og man erholder, naar de af Wiillner1 beregnede Yærdier for Ivviksolvets Udvidelse lægges til Grund, som Udtryk for Glassets midlere Udvidelsescoefficient mellem 0° og 15° 0,0000267 og mellem 0° og 20° 0.0000274. Man kan desuden ogsaa benytte Observationerne 3, 4 og 5 i For- bindelse med 24 og 25 til Be-regning af Glassets Udvidelse og erholder, naar man anvender de [af Hallstrom- og Ro- setti3 bestemte Yærdier for Yandets Udvidelse. meget vel overensstemmende Tal, som i Middel ' fastsætte Glassets midlere Udvidelsescoefficient mellem 0° og 17.°5 til 0.0000275. Efterat man heraf har bestemt en passende Yærdi for Glas- sets Udvidelse, hvorved naturligvis de med Kviksølv ud- førte Bestemmelser fortrinsvis maa komme i Betragtning, kan man nu skride til Udledelsen af de videre Resultater af Forsøgene. Man maa imidlertid her tage Hensyn til, at Observationerne 1. 2, 10, 26. 27. 28 og 29 tydeligt bevise, at Pyknometret under Forsøgene har tabt omkring 0.7 Mgr. i Y ægt, hvad der rimeligvis skriver sig fra Op- løsuiug af en Del af Glasset paa de ydre Vægge paa Grund af den stadige Omrøring i Badet. Den herved foraarsagede tJsikkerhed kan dog betydelig reduceres, naar man beregner Pyknometrets Vægt til enhver Tid under Forudsætning af, at Vægttahet er proportionalt med Ob- servationernes Antal, idet Usikk.erheden da knapt nok vil, influere paa 5te Decimal. Under denne Forudsætning har jeg senere beregnet følgende Resultater, idet jeg paa en- kelte Steder har tilladt mig smaa Aproximationcr, som imidlertid kim kan virke paa de endelige Yærdier med en liden Feil i 6te Decimal.
Egen vægt ved j-
• 17.°5 17. "5 17.5 1 7.5 0° w
af ril 1.01739. af YH 1,02669. af I 1.02691. af I 1.02845. *
too, at least once for every other determination, and again filled with the sea-water the volume of which had to be found. These observations were in no case considered satisfactory unless the temperature of the water-bath had been kept comparatively uniform for at least 15 minutes, the greatest variation indicated by the thermometer during that interval never having exceeded 0.°1. For reading the temperature of the water-bath, a thermometer graduated in divisons of 0.°2, measuring each 0.68mm, was made use of, the instrument having been previously corrected by frequent comparison with ’the standard thermometer of the Norwegian Meteorological Institute, which the Director. Professor H. Molm, had kindly lent me for that purpose.
Nos. 32—37 are the first of the observations by which the expansion of the glass in the pycnometer may be computed; and, taking the values found by Wiillner1 for the expansion of mercury as the basis of calculation, the mean coefficient of expansion of the glass between 0° and 15° will be 0.0000267, and between 0" and 20°, 0.0000274. Moreover, Nos. 3. 4. and 5, in conjunction with. Nos. 24 and 25, will also serve for determining the expansion of the glass; and. adopting the values computed by Hallstrbm* * and Rosetti3 for the expansion of water, very closely agreeing results will he obtained, the figures expressing the average mean coefficient of expansion of the glass be- tween 0° and 17.°5 being 0. 0000275. After a proportionate value of the expansion of the glass has been found, for computing which preference should he given to the de- terminations performed with mercury, we may proceed to deduce the further results of the experiments. Mean- while. regard must be had to the fact, of. which the obser- vations 1. 2. 10. 26, 27, 28. and 29 afford conclusive proof, that the pycnometer had lost about 0.7m‘?r in weight during tlu* progress of the experiments, some portion of the outer surface of the glass having probably been dissolved, a result of the constant motion of the water surrounding the instru- ment when in the water-bath. The uncertainty this occa- sions may however be very considerably reduced by com- puting the weight of the pycnometer for every experiment on the assumption that the loss of weight is proportional to the number of observations; in that case it will hardly influence the 5th decimal. On the basis of this assump- tion, I subsequently computed the following results, intro- ducing, here and there slight approximations, which, however, can affect the -final result only by occasioning a small error in the 6th decimal.
Specific Gravity at of III 1.01739. •'
of vn 1.02669.
I 1.02691.
I 1.02845.
1 7.°o . 17.°5 it. ;> 0°
0°
of
of
1 Pogg. Ann. 153 — 440.
x Disse Yærdier ere ogsaa af Ekman benyttede til Bestemmelse af Udvidelsen af det Dilatometer, som denne til sine Forsøg over Sø- vandets Udvidelse har anvendt.
* Ann. Chim. Phys. [4] — IT — 372.
1 Pogg. Ann. 153, p. 440.
* These values were also adopted by Ekman for determining the expansion of the dilatometer which he used when investigating the expansion of sea-water.
3 Ann. Chim. Phys. [4], IT, p. 372.
og som Control paa det benyttede Kviksølvs Renlied dettes Egenvægt ved ^ , til 13.5963
samt Søvandets Volumina ved forskjellige Temperaturer til
and, as a test of purity, the specific gravity of the mer- cury at was found to be 13.5963, and the volume of sea-water at different temperatures —
|
tn |
0 4 | 8 |
i3 j 17-5 j 2c |
t° * |
0 |
4 |
. 8 |
»3 |
17-5 |
20 |
|
V, af I |
1.000000, 1.000308 1.000794 |
1.001654 1.002605! 1.003227 |
Vt of I |
1. 000000 |
00 0 0 0 0 |
1.000794 |
1.001654 |
1.002605 |
1.003227 |
Til Udjevning af den efter disse Observationer op- trukne Curve har jeg benyttet de mindste Kvadraters Methode, idet jeg har sat Ligningen for Søvandets Volum ved t" under Formen
For smoothing the curve laid down from these obser- vations, I adopted the method of the least squares, giving the equation for the volume of the sea-water at *° the form —
Vt=\ + at-{-U* + ct\'
V, - 1 + at + 6*2 +
Betingelsesligningerne blive
a -f- 4‘ b -f 16 c — O.OOUU77 = 0
a -f- 8 6 -f- 64 c — 0.00009925 = 0
a 4 13 6 + 169 c — 0.00012723 = 0
a 4 17.56 -\- 306.25c — 0.000148857 = 0
a + 20 b 400 c — 0.00016135 s 0
The conditional equations will be —
a- 4 6 + 16 c — 0.000077 =0
a _|_ 8 5 -f 64 c — 0.00009925 = 0 0+13 6+169 c — 0.00012723 =0 ' a -f- 17.56 4 306.25c — 0.000148857 = 0 a + 20 6 + 400 c — 0.00016135 =0
hvoraf Systemerne
ha 4 '62.5 6 4 955.25c— 0.000.613687 = 0
62.5.0. 4 955.256+ 16132.37c — 0.008588 = 0
955.25« 4 16132.376 4 286702 c — 0.1392135 = 0
som ved Elimination giver
from which are deduced —
5a 4 62.5 6 4 955.25c — 0.000613687 = 0
62. 5ø 4 955.256 4 161 32.37c — 0.008588 =0
955.25ø 4 16132.376 4 286702 c — 0. 1392135 = 0
and these equations give by elimination —
0 = 0.0000527328
b- 0.00000617375 r = — 0.000000037516
a—. 0.0000527328
h- 0.000006 L 7375 c- — 0.000000037516
eller ved Afrunding
V, = 1 4 0.000052733* 4 0.000006 1 738* 2 — 0.00000003752*3.
Efter denne Formel har jeg beregpet følgende Tabel, hvori Sovandets Volum findes opført for .liver hel Grad ogsaa for Tempera tur erne under 0°, uagtet Formelens Gyl- dighed for dette Strog ikke er stottet ved nogen Observa- tion.
or, rounded off.
Vt= 1 40.000052733* 40.0000061738*- — 0.00000003752*a.
By means of this formula I determined the. results set forth in the following Table, which shows the volume of sea-water, computed for every degree, including temper- . atures below 0°, although the applicability of the formula to the latter has not been ascertained from observation.
|
*" |
vt |
*° |
vt . |
*° |
F, |
|
— 4 |
0.99989 |
5 |
1. 0004 1 |
14 |
1.00185 |
|
—3 |
0.99990 |
6 |
1.00053 |
*5 |
1.00205 |
|
— 2 |
0.99992 |
7 |
1.00066 |
16 |
1.00227 |
|
— 1 |
0.99995 |
8 |
1.00080 |
•7 |
1.00250 |
|
0 |
1. 00000 |
9 |
1.00095 |
*7-5 |
1.00261 |
|
. 1 |
1.00006 |
10 |
• 1. 001 11 |
18 |
• 1.00273 |
|
2 |
1. 000 1 3 |
1 1 |
1.00128 |
>9 |
1.00297 |
|
3 |
1.0002 1 |
12 |
•1. 00 1 46 |
20 |
1.00322 |
|
• '4 |
1.00031 |
13 |
1.00165 |
|
*° |
vt |
*° |
*° |
vt |
|
|
—4 |
0.99989 |
. 5 |
1.0004 1 |
14 |
1.00185 |
|
—3 |
0.99990 |
6 |
1.00053 |
15 |
1.00205 |
|
— 2 |
0.99992 |
7 |
1.00066 |
16 |
1.0022.7 |
|
— 1 |
0.99995 |
8 |
1.00080 |
17 |
1.00250 |
|
0 |
1. 00000 |
9 |
1.00095 |
17-5 |
1.00261 |
|
1 |
1.00006 |
10 |
1. 001 1 1 |
18 |
1.00273 |
|
2 |
1. 000 1 3 |
1 1 |
1.00128 |
19 |
1.00297 |
|
3 |
1.0002 1 |
12 |
1.00146 |
20 |
1.00322 |
|
4 |
1.0003 1 |
13 |
1.00165 |
Til Sammenligning fcidsættes" her de af Ekmau fundne Værdier for Volumet af 4 Vandprøvef A, B, C og D af
lo"
respective Egenvægter ved - 1.01603, .1.01982, 1.02306,
og 1.02695.
For comparison with these figures, are annexed the values found by Ekman for the volume of 4 samples of
sea-water. A, B, C, and I) , their specific gravity at
being respectively 1.01603, 1.01982, 1.02806, and 1.02695.
|
t° |
Vt af A |
V, a f B |
Vt af C |
Vt af D |
t° |
Vt- of A |
V of B |
Vt of C I |
Vt of D |
|
—5 |
1. 000 1 45 . |
1.00006 1 |
0.999983 |
0.99990 2 |
— 5 |
1. 000 1 45 |
1. 00006 1 |
0.999983 |
0.999902 |
|
—4 |
1.000087 |
1.000020 |
0-999959 |
0.999894 |
—4 |
1.000087 |
1.000020 |
.0.999959 |
0.999894 |
|
—3 ’ |
1.000044 |
0.999994 |
0.999948 • |
- 0.999904 |
—3 |
1.000044 |
0.999994 |
0.999948 |
0.999904 |
|
— 2 |
1 .000015 |
0.999983 |
0-999953 |
0.999922 |
— 2 |
1.000015 |
0.999983 |
0-999953 |
0.999922 |
|
— I |
1. 00000 1 |
0.999985 |
0.999969 |
0-990955 |
— ^ i |
1.000001 |
0.999985 |
0.999969 |
0.999955 |
|
O |
1. 000000 |
1. 000000 |
1 .000000 |
1 .000000 |
0 |
1 .000000 |
1. 000000 |
I.OOOOQO |
1 .000000 |
|
i |
1 .000019 |
1.000035 |
1.000043 |
1.000062 |
1 |
1 .0000 1 9 |
1.000035 |
I.OOOO43 |
1.000062 |
|
2 |
1.000047 |
1.000083 |
1. 000 1 00 |
1.000136 |
2 |
1.000047 |
1.000083 |
I. OOO I OO |
1.000136 |
|
3 |
1.000096 |
1. 000 1 42 |
1. 000 1 68 |
1.000220 |
3 |
1.060096 |
1. 000 1 42 |
i. 000 1 68 |
1.000220 |
|
4 |
1. 000 1 54 |
1.0002 13 |
1.000249 |
1.0003 15 |
4 |
1. 000 1 54 |
1 .0002 1 3' |
1.000249. |
1. 0003 1 5 |
|
5 |
1 .000223 |
1. 000296 |
1.000344 |
I;00042 I |
5 |
1.000223 |
1.000296 |
1.000344 |
1.00042 1 |
|
6 |
1.000305 |
1.000390 |
1 .000450 |
I OOO537 |
6 |
1.000305 |
1.000390 |
1.000450 |
1.000537 |
|
7 |
1.000399 |
1.000495 |
1 006567 |
I.OO0664 |
7 |
. 1.000399 |
1.000495 |
1.006567 |
1.000664 |
|
8 |
1.000504 |
1.000612 |
1.000696 |
1. 00080I |
8 . |
1.000504 |
1.000612 |
1.000696 |
, 1. 00080 1 |
|
9 |
1.00062 1 |
1.Q00739 |
1.000836 |
I.OOO948 |
9 |
1.00062 1 |
1.000739 |
1.000836 |
1.000948 |
|
IO |
1.000749 |
1.000877 |
1.000985 |
I. OO IIO4 |
10 |
1.000749 |
1.000877 |
, 1.000985 |
1 .001 104 |
|
1 1 |
1.000888 |
1.001026 |
1.001 145 |
I.OOI272 |
1 1 |
1.000888 |
1.001026 |
1. 00 1 145 |
1. 00 1 27 2 |
|
12 |
1 .001038 |
1.001185 |
1.001315 |
I.OOI449 |
12 |
1.001038 |
1.001 185 |
1-001315 |
1.001449 |
|
‘3 |
1. 00 1 199 |
1. 00 1 354 |
1. 00 1 495 |
I.OO.1635 |
13 |
1. 00 1 199 |
1.001354 |
1.001495 |
1.001635 |
|
14 |
1. 001370 |
1001533 |
1.001683 |
I.OOI83I |
14 |
1. 001370 |
1001533 |
1.001683 |
1.00183 1 |
|
15 |
1.001551 |
1.0017 IQ |
1. 00 1 880 |
1.002038 |
«5 |
1-001551 |
I ;00 I7I9 |
1. 001880 |
1.002038 |
|
16 |
1. 00 1 742 |
I. OOI925 |
1.092085 |
1.002250 |
16 |
1. 001742 |
I. OOI925 |
1.002085 |
1.002250 |
|
17 |
1.001943 |
1.002 I34 |
1.902299 |
I.OO2473 |
17 |
1. 00 1943 |
1.002 I34 |
1.002299 |
1.002473 |
|
18 |
1-002153 |
1.002353 |
1.002520 |
I.OO2705 |
. 18 |
1-002153 |
I0O2353 |
1.002520 |
1.002705 |
|
«9 |
1.002373 |
I.OO2582 |
1.002749 |
I.OO2946 |
19 |
1.002373 |
1.002582 |
1 .002749 |
1.002946 |
|
20 |
1.002601 |
1.002819 |
1.002984 |
1.003 195 . |
20 |
1.002601 |
1.002819 |
1.002984 |
1.003 195 |
|
2 1 |
1.002839 |
.1 .003002 |
1.003227 |
IOO3453 |
2 1 |
1.002839 |
1.003062 |
1.003227 |
* 1.003453 |
|
2_2 |
1.003085 |
I.00332I' |
1.003474 |
1.003 7' 19 |
22 |
1.003085 |
I 00332 I |
1.003474 |
1.003719 |
|
1.003340 |
I.OO3588 |
1.003728 |
1.003993 |
' 23 |
i 003340 |
I.OO3588 |
1.003728 |
1.003993 |
|
|
24 |
1.003602 |
I.OO3861 |
1.003988 |
1.004275 |
24 |
1.003602 |
I.OO3861 |
1.003988 |
1.004275 |
|
25 |
1-003875 |
1.004 144 |
1.004253 |
1.004565 |
25 |
1.003875 |
1. 004 I 44 |
1.004253 |
1.004565 |
For den af mig undersogte Vaudprøve I er elter de forhen beskrevne Observationer fundet Egenvmgten 1.02691
ved l < ‘° eller 1.02707 reduccrét til ■)? . medens Ekman 17,°5 lo
for Vandprøven D bar fundet Egenvægten 1.02695 ved
15"
15"
og det fremgaar saaledes,
at Undersøgelserne for disse
Vandprøvers Vedkommende meget godt kunne gjøres til Gjenstand for Sammenligning. En saadan Sammenligning viser let, at der »paa alle Puncter selv for Temperaturerne
under 0° existerer en tilfredsstillende Overensstemmelse, idet Dilferentserne i Kegplen ikke overstige 0.00001 og lor de høiere Temperaturer, hvor de antage sin største A ærdi, kun gaa op til omtrent 0.000025, en Uoverensstemmelse, som, naar Hensyn tages til Forskjellen medlem Vandprø- vernes Egenvægter, end yderligere kan reduceres. Med de ovenfor nævnte af andre Chemikere udførte Undérsøgelser
According to the observations previously described the specific gravity of sample l , was, at j-,,-- 1.02691, or;
reduced to . 1.02707, and Ekman found the specific lo°
1 0°
gravity of sample D to be 1.02695 at ^ .0 . Hence the re- sults, so far at least as these samples are concerned, very well admit of being compared ; satisfactory agreement exists even for temperatures below 0", since the •difierence does not as . a rule exceed 0. 00001. and lor the highest tcmpei- atures , at which it is greatest, it amounts to only 0.000025; nay, these figures may be still further reduced by taking into account the specific gravities of the samples. With the results of the above-mentioned observations in- stituted by other chemists, those here described, agree but indifferently. According to the formula deduced by
54
stemme de her beskrevne Resultater kun maadeligt overens. Ifølge den af Wackerbarth efter Ekmans Observationer beregnede Formel er Temperaturen for Tæthedsmaximum hos Søvand af Egenvægt 1.02707 = — 4.' "04. medens Lig- ningen ^ = 0 med de af mig fundne Coefficienter giver Temperaturen — 4." 45.
Paa Grund af denne gjennemførte Overensstemmelse mellem Ekmans og mine Resultater, har jeg ikke fundet det fornødent at bestemme Udvidelsen af Vandprøver af lavere Egenvægt, men har uden videre anvendt Ekmans Observationer paa de faa Puncter, hvor jeg til Reduction af de paa den norske Nordhavsexpedition aflæste Egenvæg- .ter har havt Brug for dem. Yed Hjælp af de ovenfor op- førte Værdier for Søvandets Volumina ved forskjellige Temperaturer kan man nu beregne de Correctioner, hvor- med de ved vilkaarlige Temperaturer aflæste Egenvægter
1 7 °5
maa forbedres forat reduceres til ' . Correctionerne .
1 <.°o
hvori ogsaa indgaar et Led. der afhænger af Aræometrenes IJdvidelsescoefflcient.1 Andes sammenstillede i nedénstaaende Ta bel.
|
t° |
Correction |
t° |
Correction |
|
0 |
— 0.00224 |
12 |
— 0.00104 |
|
2 |
— 0.002 14 |
— 0.00069 |
|
|
4 |
— 0.00201 |
l6 |
— 0.0003 1 |
|
6 |
— 0.00183 |
l8 |
0.0001 1 |
|
8 |
— 0.001 61 |
20 |
0.00056 |
|
10 |
—0.00134 |
Hvor den Temperatur, hvorved Aflæsniugeh foretages, ikke fjerner sig meget fra Normaltemperaturen 17.°5, kan disse Correctioner, der strengt taget kun gjælde for Søvand af Egenvægt omkring 1.027. ogsaa uden mærkelig Feil an- vendes i or \ andprøver af en derfra temmelig forskjellig Egenvægt. Hvor derimod den Temperatur, hvorved Aflæs- ningen foretages, ligger langt fra 17.°5, ere disse Correc- tioner kun gyldige for et meget begrændset Interval.
Elterat saaledes de aflæste Egenvægter ved Anbrin- gelse af disse Correctioner ere reducerede til Normaltem- peraturen. staar det endnu tilbage at befrie dem for de ved de benyttede Aræometre heftende constante Feil.
Til Aflæsning af saa godt som alle paa Expeditionen bestemte Egenvægter benyttedes kun 3 Aræometre, to paa tørste Togt og et paa de to sidste. Af de to først nævnte, tier af Svendsen for Udreisen vare udvalgte af de øvrige, fordi de -havde vist sig at stemme særdeles vel ovetfens, er desværre det ene senere bleven knust, det andet er endnu i Behold og er. sammen med det paa sidste Togt benyttede bleven corrigeret af mig.
1 Som saadan benyttedes 0.000020.
A. Wackerbarth from Ekmans observations, the tempera- ture for the maximum density of sea-water with a specific
gravity of 1.02707 is — 4. "04, whereas the equation ~ = 0
gives, with my coefficients, a temperature of — 4.°45.
Relying, then . on the close agreement between Ekman’s results and my own. I have not determined the expansion in samples of sea- water with a lower specific gravity, but have adopted Ekman’s observations, for reducing, when needful, the specific gravities read on the Norwegian North- Atlantic Expedition. By means of the values, tabulated above, for the volume of sea-water at I . different temperatures, the corrections which serve to reduce
1 7 "5
specific gravities read at. any given temperature to 7~-
1 i ,°o
may be computed. These corrections, into which the coef- ficient of expansion of the areometer1 enters as- a factor, are given in the following Table.
|
t° |
Corrections |
t° |
Corrections |
|
0 |
— 0.00224 |
12 |
— 0.00104 |
|
2 |
— 0.002 1 4 |
14 |
— 0.00069 |
|
4 |
— 0.002O1 |
16 |
— 0.0003 1 |
|
6 |
— 0.00183 |
18 |
0.0001 1 |
|
8 |
— 0.001 61 |
20 |
0.00056 |
|
10 |
— 0.00134 |
When the temperature is not far removed from the normal temperature, 17. "5, these corrections, which, strictly speaking, apply only to sea-Vater with a specific gravity ol about 1.027, may, without involving . any appreciable error in the result, be likewise adopted for samples of water whose specific gravity differs considerably from that expressed by the above formula; but when, on the other hand, the temperature at which the specific gravity is read and that of 17.° 5 lie far apart, the interval for which these corrections will serve is but very limited.
After reducing by means of these corrections the specific gravities to the normal temperature, there still remains to eliminate the constant error of the areometer.
For reading almost all of the specific gravities determ- med on the Expedition, only 3 areometers were made use of. two on the first cruise and one oil the two last. Of the two former, which, having been found to agree uncom- monly well, Mr. Svendsen had selected previous to his departure, one was unfortunately afterwards broken; the other is still in perfect order, and was, together with that made use of on the last voyage; corrected by myself.
1 That adopted was 0.00002(1.
55
Correctionernes Bestemmelse -udførtes ved Hjælp af 1 Yandprøverne I og YII, hvis Egenvægter tidligere ere be- stemte til 1.02691 og 1.02669 ved ^5 , For det paa
tørste Togt anvendte Araeometer erholdtes sa«a)edes gjennem 5 Aflæsninger i I Oorfectionen —0.00023 og gjennem 12 Aflæsninger i VII ligeledes —0.00023. Paa samme Maade bestemtes det andet Aræometérs Gorrectioner ved 5 Aflæs- ningei- i I til —0.00037 og ved 8 Aflæsninger i VII til — 0.00038. Under disse Aflæsninger var Vædsken altid bragt til 17. "5 eller en meget nærliggende Temperatur, hvorfra Aflæsningerne efter de forheu gjengivne Correctio- ner reduceredes til Normaltemperatureu. Gjennem flere Rækker Aflæsninger i Vandprøyen 1 ved forskjellige Tem- peraturer har jeg tillige forvisset mig om, at den ved Be- I .regning af Correctionstabellén benyttede Udvidelsescoefficient for Aræometrene er passende valgt.
Hermed er givet de fornødne Data til Reduction af de paa den norske Nordhavsexpedition aflæste Egenvægter, og jeg gaar dernæst over til Bestemmelsen af Relationerne mellem Saltgehalten, Chlormængden og Egenvægten.
Til Bestemmelse af Saltmængden har, saavidt jeg ved, tidligere kuu været benyttet den simpleste Methode, bestaa- ende i Afdamphing af Våndet og Residuets Tørring ved en passende Temperatur, som af de forskjellige Chemikere er bleven valgt noget jorskjelligt fra 150° — 180°. Denne Methode har jeg imidlertid af flere Grunde fiindet lidet I tilfredsstillende, livad man ogsaa paa Forhaand maatte vente. Efter Graham 1 og andre taber nemlig den svovlsure Mag- nesia. om hvis Tilstedeværelse i Søvandet der vel ikke kan reises Tvivl. først ved en Temperatur* af over 200° sit sidste Molekyl Vand, medens man paa den anden Side allerede ved en Temperatur af betydeligt under 200° maa befrygte en delvis Decomposition af den i Saltene tilstede- værende Chlormagnesium. Efter de Forsøg, som jeg an- stillede, viste det sig, at Saltene selv efterat være tørrede ca. 20 Timer i Luftbad ved en Temperatur fra 170° — 180° endnu indeholdt ikke ubetydelige Mængder Vand (om- kring 15 Mgr. pr. Gr. Salt), medens de tørrede ved lidt lavere Temperatur indeholdt noget mere. Samtidig under- søgtes ogsaa Saltene paa fri Magnesia, hvorved jeg i Strid med ældre Angivelser fandt, at de bestandig selv ved Tør- ring ved 160" til 170" indeholdt uventet store Qvantiteter, saaat der for hvert Gr. tørret Salt faudtes en Magnesia- mængde tilstrækkelig til at neutralisere over. 20 Mgr. HC1 (ved Tørring ved 180" fandt jeg .endog en enkelt Gang 40 Mgr.). Bestemmelsen af den frie Magnesia foretoges ved Saltenes Opløsning i en afmaalt Mængde titreret Svovlsyre og der- paa følgende Retitration med forty ndet Natron lud af be- kjendt Styrke. Ved Anvendelse af Rosolsyre som Index erholdtes her en meget skarp Endereaction.
The determination of the corrections was performed with the water of samples I and VII. whose specific grav- * 17.°5 , , , .
Ry at had been found to be respectively 1.02691 and
1.02669. For the areometer used on the first voyage 5 readings with the water of sample I gave the correction — 0.00023, and 12 readings with the water of sample YII likewise — 0.00023; in the same manner, the corrections for the other areometer were determined, by 5 readings with the water of sample l. to be — 6.00037, and, by 8 readings with the water of sample VI 1, to be —0.00038. For these readings, the fluid was always brought to 17.*5, or as near that temperature as possible, the readings having in the. latter case to be reduced, by means of the correc- tions given above, to the normal temperature. Several series of readings with the water of sample I, at different temperatures, convinced me that the coefficient of expan- sion for the areometer which 1 had computed for prepar- ing the Table of Corrections was practically correct.
Having now specified the data necessary for reducing the specific gravities read on the Norwegian North- Atlantic Expedition. I shall proceed to determine the relation be- tween the specific gravity of sea-water and the amount of salt and chlorine it contains.
For determining the amount of salt, the only method formerly resorted to was, so far as I am aware, the sim- plest, viz. that of evaporating the water and then drying the residue at a proper temperature, which has been vari- ously fixed by different chemists at from 150" to 180°. This method, however, has proved in several respects de- fective, as was indeed to be expected. According to Gra- ham1 and others, sulphate of magnesia, the presence of which in sea-water can hardly admit of doubt, does not part with its last molecule of water till exposed to a temp- erature of more than 200" whereas, on the other hand, it is highly probable that partial decomposition of the chloride of magnesium contained in the salt takes place consider- ably below 200°. Even after the salts had been dried for about 20 hours in an air-bath at a temperature of 170" — 180", they were still found to contain, according to my experiments, a considerable quantity of water (about l5M'/r salt per gramme); dried at a lower temperature, the amount was somewhat greater. L also tested the salts for free magnesia, and found, in direct opposition to earlier statements, that, even when dried at 160°— 170", they in- variably contained a very large amount, the quantity of magnesia to every gramme of dried salt being sufficient to neutralize more than 20m,/' MCI (once, when dried at 180", even 40 m',r). For determining the free magnesia, tin* salts were dissolved in a given quantity of titrated sulphuric acid, and the fluid then retitrated with dilute soda-lye of known strength. With rosolic acid as the index, the final reaction was very decided.
1 Phil. Mag. .1. <i. p. 422.
Phil. Mag. J. (i - 4 22.
56
Forat undgaa de her omtalte Feil, beuyttedes til Be- stemmelse af Saltmængden i Sovandet følgende Fremgangs- maade.
I en med tætsluttende Laag forsynet tyk, veiet Por- cellaiudigel indveiedés 30 til 40 Gr. Sovand. som afdunste- des paa Vandbad. Efterat Saltene fare nogenlunde vel tørrede, ophededes Digelen med JLaaget paa ca. 5 Minutter over eu Bunsens Lampe, afkjøledes og veiedes paauy. Der- efter bestemtes paa den forud beskrevne Maade den ved Decomposition af Chlormagnesium dannede frie Magnesia, hvorved de til Beregning af den samlede Saltgehalt for- nødne Data erholdtes.
T en tidligere Afhandling1 har jeg paavist, at Car- bonaterne i Sovandet ved Kogning omsætter sig til kulsur Magnesia, som ved Inddampning eller under enhver Om- stamdighed ved Glødning efterlader Magnesia, og man skulde altsaa strengt taget for den saaledes dannede Del af den frie Magnesia beregne en anden Correction end for den ved Decomposition af Chlormagnesium dannede Hoved- mængde. Den Feil, man begaar, ved at undlade dette er imidlertid baade meget nær constant og desuden saa liden, at den uden videre kan negligeres, idet den kun bidrager til at formindske den samlede Saltgehalt med omkring 0.0015 °/o. Det er saaledes fuldstændig tilstrækkeligt til den ved Vein ingen fundne Mængde tørret Salt at' addere 1.375* Gange den ved Titreringen bestemte Mængde fri Magnesia, lor af det saaledes fremkomne Tal at beregne Saltgehalten i Procenter.
Mod denne Methode kan der dog reises Indvendinger. idet det kunde befrygtes, at mindre QVantiteter ( 'lilorna- trium, Chlormagnesium eller Chlorkalium under Glodningen kunde forflygtiges, eller at en Del a f den svov-Isure Mag- nesia ved den hoie Temperatur kunde decoiuponeres og give Anledning til Tab af Svovlsyre. Man kan imidlertid let forvisse sig om, at dette ved Anvendelse af en tyk Porcel- laindigel med tætsluttende Laag ikke bevirker nogen Feil af mærkbar Indflydelse. Saaledes fandt jeg, at 1.2 Gr. af en passende Blanding af Chlorkalium og Chlornatrium ved D/i Times starkest mulig Glødning over en Bunsens Lampe i den samme Digel, som jeg benyttede til mine Saltbestem- melser, kun tabte 2 Mgr. i Vægt. det vil sige, Blandingen tabte ved Glodningen ikke fuldt 0.14 Mgr. pr. 5 Minutter. Ligeledes paavistes ved Bestemmelse af Svovlsyre og Mag- nesia saavel i det benyttede Sovand som i det glodede Residuum, at man selv ved en meget længere fortsat Glod- ning end . den. der udfordres forat skatte fuldstændig vand- frit Salt. ikke risikerer nogen skadelig Feil foranlediget ved Forflygtigelse af Chlormagnesium eller Decomposition af svovlsur Magnesia.
* •‘Om Kulsyren i Søvatjilet" Side 40 øverst.
In order to guard against the above-mentioned errors, the following mode of operation was adopted for determin- ing the amount of salt in sea-water.
From 30'"' to 4lCr of sea-water were introduced into a thick porcelain crucible of known weight, furnished with a tight-fittting cover, and evaporated on a water-bath. So soon as the salt was sufficiently dry, the crucible, with the cover on. was heated for about 5 minutes over one of Bunsen’s gas-burners, then cooled and weighed with its contents. The free magnesia liberated by the decomposi- tion of the chloride of magnesium was now determined in the manner previously described, and the last factor neces- sary for computing the total amount of salt accordingly found.
In a former paper1 I drew attention to the fact, that the carbonates present in sea-water are transformed during the process of boiling into carbonate of magnesia, which after evaporation, or. at least, on the salt being thoroughly heated, leaves a residue of magnesia; and hence the pro- portion of free magnesia thus formed would, strictly speak- ing. seem to involve the need of a correction different from that adopted for the principal amount liberated by the decomposition of the chloride of magnesium. But the error * which arises from applying the same correction to both is. on the one hand, very nearly constant, and. on the other, so small as to admit of being safely ignored, seeing that it reduces the total amount of salt only abtiut 0.0015 per cent. It is. therefore, amply sufficient, if to the amount of dried salt found by weighing he added 1.375 times the amount of the free magnesia determined by titration : the figure thus obtained will ser.ve to compute the percentage of salt.
This method certainly is so far open to objection, that small quantities of cldoride of sodium, chloride of magnesium, or chloride of potassium may be volatilized during the- process of heating, or some portion of the sul- phate of magnesia be decomposed at the high temperature, and thus occasion a loss of sulphuric acid. The error, however, arising from this source will not exert any ap- preciable influence on the result, provided the crucible used for the operation be of thick porcelain, and have a tight-fitting cover. Thus, for instance. I found that 1.2-',r of a proportionate hnixture of chloride of potassium and chloride of sodium, on being heated for the space of an hour and a quarter over one of Bunsen's gas-burners in the crucible I had used for my salt-determinations, lost only in weight, or 0.14m*r every 5 minutes. More- over, it was manifest on determining the sulphuric acid and magnesia both in the water itself and in the heated residue, that» even in the event of the heating-process being much more protracted than • is necessary to obtain salt free liom the smallest trace of water, no serious error can result from the volatilization oi chloride of magnesium or the decomposition of sulphate of magnesia.
s “On the.Cnrbonic Acid in Sea- Water,” p. 40.
57
At Methoden giver indbyrdes vel overensstemmende Resultater, viser de talrige Saltbestemmllser, som udførtes med samme Vandprøver. Saaledes fandtes ved neden- staaende Forsøg
Proc. Salt i II
— — - III
— — - IV
— — - VI
3.525
(3.517
12.303
(2.299
1 3.386 (3.385
|3.530
(3.533
(3.276
13.279
(3.514
Proc. Salt i VII '3.516- 3.515
— — - VHI
3.501
3.507
3.508 3.500
3.502 3.506
3.500
3.501
Resultater ne ere, som man ser, allerede lier temmelig vel overensstemmende, men kunde visselig gives en endnu større Nøiagtighed, 0111 man vilde arbeide med noget større Quantiteter Søvand.
For Vandprøverne III og VII er Egenvægten ved
1 T "0
- allerede tidligere ved Hjælp al' Pyknometer bestemt 17.°5
.til respective 1.01739 og 1.02669, for Vandprøvériie IV. V, VI og VIII er den funden ved gjentagne Afiæsninger pan et af de corrigerede Aræometre, medens den lor Prøven II kun blev' bestemt ved en enkelt AHæsning. Ligeledes bestemtes meget ombyggeligt samtlige Vandprøvers Chlor- mængdér. Heraf kan
Saltmængden
Chlorcoefficienten =r
Egen wægtscoeffici enten =
Chlormængden Saltmængden
Egenvægten — 1 beregnes, saaledes som det er gjort i nedeustaaende Tabel.
|
No. |
Egcimegt , IT.0.') . veil it.0:. |
Chlor- mængde 0 JO |
Salt- mængde * % |
Egen- vregts- coefficient. |
Chlor- coefficient. |
|
II |
1.02670 |
C947 |
3-521 |
I3I.9 |
i.8p8 |
|
III |
1.0173Q |
1. 271 |
2.301 |
132.3 |
1. 810 |
|
IV |
1.02573 |
1.868 |
3-386 |
131.6 |
1.813 |
|
A' |
1 .02676 |
I-956 |
3-532 |
132.O |
1.806 |
|
VI |
1 .02488 |
1.809 |
3-278 |
00 |
1.812 |
|
VII |
1.02669 |
1.947 |
3.5I5 |
131.7 |
1.805 |
|
vm |
1.02655 |
i'.938 |
3-503 |
1*31.9 |
1.808 |
Som det heraf fremgaar. er bnade Ohlor- og Egen- vægtscoefficienterne tiltrods for Saltgehalternes Forskjellig- hed overalt .meget nær constant©, saa at Variationerne
Don norske Nordlmvsoxpoditiou. Toruoe: Cliemi.
That «the results obtained by this method must be regarded as agreeing very closely inter sc, is shown by tile numerous salt- determinations performed with the same samples' of water.
Is ■>*>•)' (3.514
Per cent, of Salt in II Percent, of Salt in VII 3.516
3'517 3.515
- — - III
IV
V
2.303
(2.299
(3.386
(3.385
) 3.530 1 3.533
- Vlll
3.276
- - VI 1
3.279
3.Q01 3.507 • 3.508 3.500 3.502 3.506
3.500
3.501
These figures, it will be seen, differ but little inter se , and by increasing the quantity of water greater accuracy could no doubt be attained.
For samples III and VII. the specific gravity at
17.05
respectively 1.01739 and 1.02669, bad been pre- viously determined by means of the pycnometer ; for samples IV, V. VI, and VIII, it was found by repeated readings of one of the corrected areometers, whereas for sample II it was determined by one reading only. The amount of chlorine, too.* in each sample was carefully determined. From these data may be computed the
Amount of Salt
Coethcient of Chlorine =r
Amount of Chlorine
and the
Amount of Salt
Coefficient of Specific Gravity = Gl,,vitv ,
as set forth in the following Table.
|
No. |
Spec. Grav. . 17.°f» at 17.°o |
Percentage of Chlorine. |
Percentage of Salt. |
Coefficient of Spec. Grav. |
Coofficicn of Chlorine |
|
II |
1.02670 |
I.947 |
3-521 |
I3I-9 |
I.808 |
|
. Ill |
1-OI739 |
1. 271 |
2.301 |
I32.3- |
1.8 10 |
|
IV |
1.02573 |
1.868 |
3-386 |
131.6 |
1.813 |
|
v. |
1.026^6 |
1.956 |
3-532 |
132.O |
1 .806 |
|
^vT |
1 .02488 |
1.809 |
3.278. |
131.8 |
1 .8 12 |
|
vii |
1.02669 |
1-947 |
3.515 |
I3I-7 |
1 .805 |
|
vm |
1.02655 |
1 .938 |
3-503 |
I3I.9 |
1.808 |
It thus appears, that the coefficients both of chlo- rine and specific* gravity, notwithstanding the difference in the percentage of salt, are always very nearly constant;
rimelfgst bliver at tilskrive ObseVvationsfeil. Som Chlor- coefficient kan lieraf opstillcs
1.809 + 0,00076
med en sandsynlig Feil af en enkelt Bestemmelse al + 0.002 og som Egenvægtscoefficient
131.9 4- 0:058
and. hence the variation in the results should most prob- ably be ascribed to errors of observation. The .coefficient of chlorine may accordingly be taken at —
1.809 + 0.00076
with a probable error in a single determination of +. 0.002, and the coefficient of specific gravity, at —
131.9 + 0.058
med en sandsynlig Feil af en enkelt Bestemmelse.al + 0.15.
Disse Værdier stemme især for Chlorcoefficientens Vedkommende ganske vel overens med tidligere fundne Værdier, saaledes' har baade Forchhammer og Ekman i Middel fundet 1.811. mcdéns de af Andre opstiUede Egen- vægtscoefficienter overalt ere noget mindre end den af mig fundne..
Ved Hjælp af disse Coefficienter har jeg af de paa Expeditionens Togter udførte Chlor- og Egenvægtsbestem- melser beregnet Vandprøvernes Saltgehalt og sammen med Originalobservationerne opført dem i nedenstaaende Ta bel.
Egenvægterne ere i Regelen kun aflæste med 4 Deci- maler, det 5te er kun opført, hvor det havde en Værdi nær 5, saa at det kunde være Tvivl underkastet, om der ved Afrunding skulde formindskes eller forhøies. I de reduce- rede Egenvægter findes ligeledes kun opført 4 Decimaler, hvor det uden Tvivl kunde algjøres, til hvilken Side Afrundingfen skulde finde Sted, hvorimod der i modsat Fald ogsaa der er tilføiet et 5te. De mod * betegnede Egenvægter ere aflæste paa Aræometre, hvis Correction ikke er bleven bestemt. Til Optagelse af de til Under- søgelse af Saltholdigheden bestemte Vandprøver er foruden det tidligere beskrevne, af Wille construerede, Apparat og- saa paa grundere Vand ofte benyttet den af Ekman an- givne fortrinlige Vandhenter, som imidlertid ifølge den Frem- gangsmaade, hvorefter Dyblodninger paa den norske Ex- pedition foretoges, ikke egnede sig til Brug ved større Dyb.
Ved Velvillie af Professor Mohn har jeg faaet op- givet de undersøgté Vandprøvers Temperatur i Havet, hvor- ved det er bleven muligt ogsaa at tilløie en Rubrik for deres Egenvægter ved denne Temperatur i Forhold til rent Vand af 4°. 1 Af de i Tabellen gjengivne Observa- tioner ere . alle indtil No. 149 udførte paa . Iste Togt af Svendsen,, alle fra 149 til 225 paa 2det Togt af mig, de øvrige ere udførte paa sidste Togt af Schiuelck og mig i Fællesskab, .saaledes at det største Antal skyldes Sclmielck. der dette Apr medfulgte Expeditionen.
1 Rent Vand af 4° er ved denno Reduction valgt, som Enhed, fordi «len allerede tidligere er anvendt af .J. V. Huchanan (Proc. Roy. Soc. 2-1 Ved Beregning af Egcnvægternes Værdi
ved Havets Temperatur i Forhold til Vand af 4° er Forhol- det Jncllem Volumet af rent Vand ved 4° og 17.0.‘> sat = 0.098708.
with a probable error in a single determination of +0.15.
These values agree closely, in particular as regards the coefficient of chlorine, with those previously found. Thus, for instance, the mean value found both by Forcli- hanmier and Ekman was 1.811. whereas the coefficient of specific gravity given by . former observers is somewhat lower than mine.
By means of these coefficients I have computed from [ the determinations of chlorine and specific gravity the amount of salt in the samples of water collected on the Expedition, and have set down the observations and their results in the accompanying Table, which calls for a brief explanation.
The specific gravities are as a rule not read to more than 4 decimals, a fifth being added only in the event of its having a value of 5. in which case it is often doubtful whether, when rounding off the figures, there should be increase or diminishment. The reduced specific gravities, too. are expresed with 4 decimals only, wherever it was mani- fest in which direction the rounding off had to be made; when such is not the case, a fifth has been added. An asterisk at the side of a specific gravity denotes that the latter was determined with an areometer • for which no correction had been found. Besides the instrument devised by Wille, of which a description has been given, Ekman's excellent apparatus was likewise made use of, in compara- tively shallow localities, for collecting the samples of sea- water in which to determine the amount of salt: the mode of sounding practised on the Norwegian North-Atlautic Expedition would not admit of its adoption for greater depths.
Professor Mohn has kindly furnished me with the temperatures of the samples of water in situ, which lias enabled me to give an aditional column for the specific gravities at those temperatures as compared with pure water of 4". 1 Of the observations given in the Table, those extending from No. 1 to No. 149 were performed on the first voyage, by Mr. Svendsen; those extending from No. 149 to No. 225, on the second voyage, by myself; the remainder were taken on the last voyage, by Mr. Schmelck and myself conjointly, the greater number, however, by Mr. i Sclpnelck, who that year accompanied the Expedition.
1 Pure water of 4° was chosen as the unit of reduction, J. Y. Bu- chanan having previously adopted ‘it as such (Proc. of Roy. Sne. 24, ]). When computing the specifio gravities at the
temperature of the sea, as compared with water of 4°, the ratio existing between the volume of pure water at 4° and 17.°.'» was assumed to be 0.99870S.
59
Tab. ru,
|
No. |
Stat. No. |
Nordlig Bredde. (North Latitude.) |
Længde ( fra •* Green- wich. (Longitude .from . Greenudch.) |
Dybde hvorfra Pro- ven hentet. Depth from which t/ie Sam- ple* were collected.) |
|||
|
Engelske Favne. (English fi'athonis-) |
Meter. (Metres.) |
||||||
|
i |
|
Esefjord |
Sogn. |
O |
O |
||
|
2 |
|
Do. |
I |
2 |
|||
|
3 |
— |
Do. |
2 |
4 |
|||
|
4 |
— |
Do. |
3 |
5 |
|||
|
5 |
— |
Do. |
4 |
7 |
|||
|
6 |
— |
Do. |
5 |
9 |
|||
|
7 |
— |
Do. |
6 |
1 1 |
|||
|
8 |
1 |
Do.. |
7 |
«3 |
|||
|
9 |
2 |
61 ° |
9/6 |
6' |
3 1 - 9 |
672 |
1229 |
|
IO |
— • 1 |
Fjærland. |
0 |
0 |
|||
|
1 1 |
— |
Esefjord. |
0 |
0 |
|||
|
12 |
— |
Do. |
i |
•2 |
|||
|
13 |
6 1 0 |
5-'2 |
5 " |
i5-'3 E. |
618 |
1 130 |
|
|
14 |
Husø |
* 0 |
0 |
||||
|
"15 |
J |
Do. |
0 |
0 |
|||
|
1 6 |
Do. |
0 |
0 |
||||
|
17 |
— |
• |
Do. |
6 |
1 1 |
||
|
18 |
— |
'Do. |
6 |
1 1 |
|||
|
iQ |
— |
Do. |
41' E. |
0 |
0 |
||
|
20 |
— |
61 0 |
25' |
3° |
0 |
0 |
|
|
2 1 |
10 |
61 |
41. 1 |
3 |
18.5 |
0 |
0 |
|
22 |
12 |
61 |
53-3 |
3 |
0 |
0 |
0 |
|
23 |
14 |
62 |
4 |
2 |
44-5 |
0 |
0 |
|
24 |
14 |
62 |
4 |
2 |
44-5 |
226 |
4U |
|
25 |
16 |
62 |
23-9 |
2 |
!7 |
0 |
0 |
|
26 |
17 |
62 |
33 |
2 |
4 |
0 |
0 |
|
2 7 |
18 |
62 |
44-5 |
J |
48- |
0 |
0 |
|
28 |
— |
62 |
39 |
2 |
8 |
0 |
0 |
|
29 |
. — |
62 |
.29 |
2 |
34 |
0 |
0 |
|
•30 |
19. |
62 |
23-5 |
2 |
50 |
0 |
0 |
|
3i |
20 |
62 |
1 6-3 |
3 |
8 |
0 |
0 |
|
32 |
2 1 |
62 |
14-7 |
3 |
27-5 |
0 |
0 |
|
33 |
22 |
62 |
13-2 |
3 |
40.5 |
0 |
0 |
|
34 |
— |
62 |
52-5 |
5 |
5i-5 |
0 |
0 |
|
35 |
6 2 . |
56 |
6 |
j6 |
0 |
p |
|
|
35 |
Christiansund. |
0 |
0 |
||||
|
37 |
— |
63' |
10' |
6' |
30' |
0 |
0 |
|
38 |
24 |
63 |
IO |
5 |
57-5 |
0 |
0 |
|
39 |
24 |
63 |
10 . |
5 |
57-5 |
90 |
165 |
|
40 |
— |
63 |
10 |
5 |
19 |
0 |
0 |
|
4i |
1 26 |
63 |
10 |
5 |
16 |
0 |
0 |
|
42 |
. • — |
63 |
7-i |
5 |
17 |
0 |
0 |
|
43 |
— |
63 |
10 |
4 |
56 |
0 |
0 |
|
44 |
32 |
f>3 |
IO |
4 |
5 1 -3 |
430 |
786 |
|
45 |
— |
63 |
9 |
3 |
56 |
0 |
0 |
|
46 |
— |
63 |
6 |
3 |
1 |
0 |
0 |
|
47 |
33 |
63 |
5 |
3 |
0 |
525 |
960 |
|
48 |
— |
63 |
5 |
2 |
57 |
0 |
0 |
|
49 |
— |
63 |
4 • |
2 |
. 5'2 |
0 |
0 |
|
50 |
• — |
63 |
3 |
2 |
43 |
0 |
0 |
|
51 |
— |
63 |
3 |
2 |
10 |
0 |
0 |
|
52 53 |
34 |
53 63 |
5 5 |
1 0 |
7 52-5 |
0 587 |
0 *' 1073 |
|
54 |
1 — |
63 |
3 |
0 |
54 |
0 |
0 |
|
55 |
— |
62 |
• 48 |
1 |
5i |
0 |
0 |
|
56 |
1 — |
62 |
44 |
2 |
IO |
0 |
0 |
|
Temperatur. |
Egenvftjgter. |
Saltmiengdo. |
|||||
|
f Salt |
|||||||
|
Athestc Egon- 's'ægtor. (Specific Gravity read.) |
(Temperature.) |
(Specific Gravity.) |
measured,) |
||||
|
Under Afkesnin- gen. |
I H a vet. |
Ved 1 7." r> , 17.? 5 |
Veil t4u |
miengde. j .Imotinl of Chlorine.) |
Etter Arnao- metor. |
Efter Chlor- nrengclo. |
|
|
II- Am reail.) |
(In ’.Vilii.) |
At if. 0 £ .5 |
. i" |
(Jiy the 1 Areometer.) | |
(Jly the Amount of Chlorine.) |
||
|
I-OI5I* |
14-8 |
— |
1.01465 |
— |
1 -93 |
. * — |
|
|
1 .0234 ; |
13-7 |
— |
I.0227 |
— |
— |
2-99 |
— |
|
I.O237* |
12.5 |
— |
1.0228 |
— |
— |
3.01 |
|
|
1. 0241* |
13.0 |
' |
IO233 |
— |
— |
307 |
|
|
I.O242 * |
13 8 |
— |
»-0235 |
— |
3-> 0 j |
— |
|
|
1.02 40* |
17-3 |
— |
IO2395 |
. |
3.16 1 |
— |
|
|
1.0245* |
17.0 |
— |
1.0244 |
— |
3-22 |
||
|
1.02 49* |
20.0 |
, — ‘ |
1-02545 |
— |
— |
3-36 |
— |
|
I.O27O |
16.7 |
6.7 |
1.0266 |
I.0274 | |
— |
3-5-1 |
|
|
I .OI.18* |
9.2 |
— |
1.0107 |
— |
— |
1.41 |
— |
|
1.0147* |
L2.0 |
— |
1.0139 |
— |
1.46 1 |
— |
|
|
r.0188* |
12-5 |
— |
1. 01 80 |
— |
— |
2-37 |
_ |
|
1.0280 . |
I 1.0 |
6.6 |
1.0266 |
I.0274 |
— |
3-5i |
— |
|
i.0262 |
9-7 |
— |
1.0246 |
— |
— |
3-24 j |
— |
|
1.0262 |
9.9 |
— |
1.02465 |
— |
— |
3-25 |
— |
|
1.0262 |
10.2 |
— |
1.0247 |
■ — |
— |
3-26 |
— |
|
1.0261 |
10.7 |
— |
1.02465 |
— |
— |
3-25 |
— |
|
1.0258 |
15.6 |
— |
1.0252 |
1 |
3-32 . |
— |
|
|
1.0262 |
10.9 |
— |
1.0248 |
— - |
— |
3--2 7 |
|
|
1.0254 |
16.8 |
— |
1.0250 |
— |
— |
3 30 |
* — |
|
1-0253 |
16.2 |
i»-5 |
1.0248 |
1.0248 |
— |
3-27 |
— |
|
1 0270 |
18.0 |
1 1. 1 |
1.0269 |
1.0270 |
3-55 |
— |
|
|
1.0265 |
19.9 |
9.9 |
1.0268 |
1 .027 1 |
— |
3-53 |
— |
|
1.0268 |
18.6 |
6. 1 |
1.0268 |
1.0277 |
— |
3 53 |
|
|
1.0275 |
154 |
10.9 |
1.02685 |
1.0270 |
— |
3-54 |
— |
|
1.027 1 |
17-5 |
1 1.2 |
1.0269 |
1.0269 |
|
3-55 |
— |
|
1.0270 |
18.4 |
1 1 .6 |
1.0270 |
1.02695 |
— |
3-56 |
— 1 |
|
1.0270 • |
17.9 |
1.2.5 |
1.0269 |
1.0267 |
, 3-55 |
— |
|
|
1-0273 |
16.2 |
12,5 |
1.0268 |
1 .0266 |
• |
3-53 |
|
|
1 .0262 |
1 7*5 |
1 1.0 |
1.0260 |
1.02605 |
— |
3-43 |
— |
|
1.0256 |
18.7 |
11.2 |
1 .0256 |
1.0257 |
— |
3-38 |
|
|
1-025*1 |
17.8 |
134 |
1-02495 |
1-02455 |
3-29 |
||
|
1-0254 |
18.0 |
12.6 |
10253 |
1.02505 |
3-34 |
||
|
1.0252 |
19-5 |
12. 1 |
1.0254 |
10253 |
3-35 |
||
|
1-02 53 |
18.4 |
12.8 |
10253 |
1.0250 |
3 34 |
||
|
1-0255 |
17-5 |
L — |
10253 |
— |
I 3-34 | 3-36 |
||
|
1.0260 |
16.2 |
10.0 |
I 1-0255 |
1.0257 |
|||
|
1.0262 |
17-5 |
11. 7 |
1.0260 |
1.0259 |
— |
3-43 |
|
|
1 .0262 |
•7-5 |
6.9 |
1.0260 |
1 .0267 |
1 |
.3-43 |
|
|
1.0266 |
17.2 |
1 1.2 |
1.0263 |
1 .0264 |
— |
1 3-47 |
|
|
1 .0261 |
17.6 |
11. 8 |
1.0259 |
1.0258 |
— |
3-4i |
— |
|
1 .0264 |
18.6 |
1 1.7 |
1.0264 |
1 1.0264 |
— |
3-48 |
|
|
1 .0264 |
>7-5 |
1 1 .6 |
1.0262 |
1.0261 |
— |
3-46 |
|
|
1.0270 |
17.0 |
— 0.6 |
1.0267 |
1.0281 |
3-52 |
||
|
1.0265 |
16.2 |
1 1.2 |
■ 1.0260 |
1.0260 |
3-43 |
||
|
i .0260 |
. 15-8 |
1 1.8 |
1-0254 |
1-02535 |
3-35 |
||
|
1.0279 1.027 1 |
15.0 1 5-2 |
I — 1 1.6 |
1.0272 1 .0264 |
1 .0286 1.0264 |
— |
3-59 3<48 . |
— |
|
1.0269 |
14.6 |
12.3 |
1.0261 |
1.0259 |
3-44 |
||
|
1.0266 |
17-3 |
1 1.9 |
1.0263 |
1.0262 |
3-47 |
||
|
1-0275 |
1 4-3 |
12.0 |
1.02665 |
K0265 |
3-52 |
||
|
1.0278 |
14-7 |
*«•5 |
1.0270 |
1.0270 |
• 3-56 |
||
|
1.0277 |
15.0 |
— 1.0 |
1.0270 |
1.0284 |
3-56 |
||
|
1.0277 |
14.8 |
12.0 |
1.02695 |
1.0268 |
3-55 |
||
|
1.0273 |
I 16.3 |
1 .11-9 |
1.0268 |
1.0267 |
3-53 |
||
|
1.0272 |
1 16. 1 |
I I.4 |
1.0267 |
1.0267 |
1 3-52 |
60
|
62 0 |
37' |
2' |
37' |
|
|
— |
62 |
40-5 |
1 |
58 |
|
— |
62 |
45 |
1 |
13 |
|
— |
63 |
2 |
1 |
12 |
|
— |
63 |
3 |
1 |
14 |
|
— ■ |
63 |
4 |
1 |
19 |
|
— |
63 |
6 |
1 |
24 |
|
63 |
8 |
i |
26 |
|
|
— • |
63 |
12 |
1 |
26 |
|
— |
63 |
14 |
1 |
27. |
|
— |
63 |
17 |
1 |
28 |
|
— |
63 |
18 |
1 |
.23 |
|
— |
63 |
45. |
0 |
57 |
|
— |
63 |
46 |
1 |
0 |
|
— |
63 |
26 |
1 |
28 |
|
— |
1 63 |
18 |
I 1 |
38 |
|
— |
1 6 3 |
8 |
1 |
58 |
|
— |
62 |
58 |
2 |
58 |
|
— • |
! 62 |
46 |
3 |
34 |
|
— |
62 |
34 ‘ |
4 |
• 28 |
|
— |
62 |
20 |
1 5 |
28 |
|
— |
62 |
5 |
1 6 |
22 |
37
37
40
40
40
40
Tliorshavn.
Do.
Do.
Kanina Nonlpyiit- (Sorllicrn KatromHy «'< NanUo.)
Do.
62° 28'. 3 62 28.3
62 15
&2 23 62 28 62 37
62 50
62 57
63 12
63 22
63 22.5 63 22.5 63 22.5 I 5 2q 63 22.5 ! 5 2g
Reikjavik.
MI.Hrll af V»*o1>»ir1- (Tlie Mlildlo of V*
63" 49'
— 63 37
22" 52' 21 58
|
102 1 — 63 |
42 . |
22 |
25 |
|
103 — ^3 |
25 |
2 1 |
° |
|
104 — j 63 |
13 |
19 |
54 |
|
105 1 — 63 |
6 * |
18 |
43 |
|
106 1 — i 63 |
7 |
•«7 |
3» |
|
107 1 —63 |
7 |
16 |
20 |
|
108 1 — | 63- |
8 |
15 |
9 ' ! |
|
109 — | 63 |
8 |
13 |
59 |
|
! 10 , — | 63 |
20 |
13 |
22 |
|
in 45 . 63 |
28 |
12 |
58 |
|
1 12 — 1 63 |
38 |
12 |
35 |
|
1 Staerk Rcgn. |
.Heavy Rain.) |
|
Dybde hvorfra Pro- |
|||||||||||||||
|
ven hentet. |
Temperatur. |
Egenvægter. |
Saltmængde. |
||||||||||||
|
Nordlig |
Længde fra |
{Depth from which the Sam- ples were collected.) |
All reste |
(Temperature.) |
(Specific |
Gravity.) |
(Xtnotiiil 0/ Salt measured.) |
||||||||
|
Stat. 'No. |
Bredde. (Mo nil |
Green- wich. |
Egen- vægter. |
Chlor- nuengde. |
|||||||||||
|
No. |
Under |
Ved |
Ved tn |
Eftor |
Eftor |
||||||||||
|
Latitude.) |
( Longitude from Greenwich.) |
Favne. |
Meter. (Metres.) |
(Specific Gravity read.) |
AHæsnin- gen. |
Havet. |
17.° 5 |
( .1 mount of Chlorine.) |
Areo- meter. |
Chlor- mængde. |
|||||
|
Fathoms.) |
(When read. |
(In Situ) t° |
J7o 5 |
(by the Areometer.) |
(by the Amount oj |
||||||||||
|
11» 6 |
4o |
Chlorine.) |
|||||||||||||
|
>>3 |
— |
63° |
57' |
I I |
52' w. |
O |
O |
1.0277 |
13.6 |
10.2 |
I .0267 |
I O269 |
|
3-52 |
|
|
114 |
— |
64 |
14 |
I I |
12 |
O |
O |
1.0277 |
14.0 |
9-5 |
I.O268 |
1.027 I |
— |
3- 53 |
|
|
1 15 |
48 |
64 |
36 |
IO |
21.5 |
0 |
0 |
1.0279 |
>1-5 |
5 3 |
I.O2655 |
1.0275 |
— |
3-50 |
‘ |
|
1 10 |
64 |
44 |
IO |
4 |
0 |
0 |
I O27O |
>7 5 |
7.0 |
1.0268 |
1.0275 |
— |
3 53 |
— |
|
|
117 |
— |
65 |
0 |
9 |
24 |
0 |
0 |
I.O269 |
18.0 |
7-4 |
I .0268 |
1.02 75 |
— |
3-53 ' |
- |
|
1 18 |
• — |
65 |
2 1 |
8 |
36 |
0 |
O |
I .0271 |
16.8 |
7.8 |
I .0267 |
1.0273 |
• |
352 |
— |
|
1 19 |
— |
65 |
39 |
7 |
53 |
0 |
O |
I .027 I |
150 |
7.2 |
I.O264 |
I 02705 |
— |
3- 48 |
— |
|
120 |
5i |
65 |
53 |
7 |
18 |
0 |
0 |
1.0272 |
15.0 |
8.0 |
1.0265 |
1.02705 |
— |
3-50 |
— |
|
1 2 1 |
5i |
65 |
53 |
7 |
18 |
515 |
942 |
1.0272 |
16.0 |
— 0.6 |
I.O2665 |
1 O28I |
— |
3-52 |
— |
|
122 |
5i |
65 |
53 |
7 |
18 |
1163 |
2 127 |
I.O272 |
16.0 |
— 1. 1 |
I.O2665 |
I .028 I |
— |
3-52 |
— |
|
>23 |
— |
65 |
5i |
5 |
36 |
0 |
0 |
I .0269 |
.18.2 |
8.4 |
I .0268 |
>02735 |
■ |
3-53 |
— |
|
124 |
— |
65 |
49 |
4 |
18 |
0 |
0 |
I .0270 |
17.6 |
9-3 |
I .0268 |
1.0272 |
— |
3 53 |
— |
|
125 |
52 |
65 |
47-5 |
3 |
7 |
0 |
O |
I O27O |
17.6 |
9-7 |
1.0268 |
1 .027 1 |
— |
3-53 |
— |
|
126 |
52 |
65 |
47-5 |
3 |
7 |
515 |
942 |
I O27O |
17.4 |
—0.4 |
I.O2675 |
1.0282 |
— |
3-53 |
— |
|
127 |
52 |
65 |
47-5 |
3 |
7 |
1861 |
3403 |
I O280 |
12.0 |
— 1.2 |
I .O267 |
1.0282 |
' |
3-52 |
— |
|
128 |
— |
64 |
47 |
4 |
24 E. |
0 |
0 |
1.0274 |
>\3-9 |
1 1.0 |
I.O2645 |
1.02655 |
— |
3-49 |
— |
|
1 29 |
— |
64 |
47 |
4 |
24 |
0 |
O |
I O264 |
19-5 |
1 1.0 |
I .0266 |
1 .0267 |
* |
3-5 1 |
— . |
|
130 |
' — |
64 |
49 |
4 |
46 |
0 |
0 |
1.0263 |
19.0 |
10.8 |
1.0264 |
1.0265 |
— |
3-48 |
— |
|
131 |
— |
64 |
46 |
5 |
38 |
0 |
0 |
I .0270 |
18.0 |
1 1.2 |
1 .O269 |
1.02695 |
— |
3-55 |
— |
|
132 |
— |
64 |
42 |
6 |
47 |
0 |
0 |
I O265 |
19.0 |
10.6 |
I .0266 |
1.0268 |
— |
3-5 > |
— |
|
133 |
— |
64 |
37 |
8 |
0 |
0 |
0 |
1.0265 |
19.0 |
10.8 |
I 02 66 |
1.0267 |
— |
3-5 1 |
— |
|
134 |
— |
64 |
27 |
8 |
36 |
0 |
0 |
I.O253 |
19.2 |
10.5 < |
I 02 545 |
1.0256 |
— |
336 |
. |
|
1 35 |
— 1 |
Mellom Sy «Unn id og HuviUcu. lletwccn Sydtiund mid ltcvilleit. |
0 |
0 |
I .02 20*. |
15.8 |
— |
1.02 17 |
— |
— |
2.86 |
— |
|||
|
136 |
63 |
64' |
41-3 |
9 |
0' |
0 |
0 |
I .0278 |
13-4 |
1 1.6 |
I .0268 |
1.02675 |
— |
3 53 |
■ — |
|
137 |
68 |
64 |
‘ 44.1 |
8 |
9 |
0 |
0 |
1.0277 |
130 |
1 1.6 |
I .0266 |
1 .0266 |
— |
3-5 > |
— |
|
73 |
64 |
46.5 |
7 |
28 * |
0 |
0 |
I 0276 |
13.0 |
>>•3 |
I 02 65 |
1.0265 |
— |
3 50 |
— |
|
|
* 39 |
— |
64 |
48 |
6 |
45 |
0- |
0 |
I.O277 |
13.0 |
1 >-5 |
I .0266 |
1.0266 |
— |
3-5i |
— |
|
140 |
— |
64 |
48 |
6 |
26 |
0 |
0 |
J.O281 |
12.2 |
1 1.6 |
I O2685 |
1.0268 |
— |
3-54 |
— |
|
1 41 |
— |
64 |
33 |
5 |
3i |
0 |
0 |
I.O278 |
14.2 |
11. 8 |
I 0269 |
1.0269 |
— |
3-55 |
— |
|
142 |
— |
64 |
4 |
5 |
35 |
0 |
0 |
I.O277 |
>3-8 |
> >-7. |
I.O2675 |
1.0267 |
- — |
3-53 |
— |
|
M3 |
— |
64 |
i |
5 |
42 |
0 |
0 |
I.O277 |
>3-8 |
12.0 |
I O2675 |
1 .0267 |
— |
3-53 |
— |
|
144 |
89 |
64 |
1 |
6 |
7-5 |
0 |
0 |
I.O277 |
13-8 |
122 |
1.02675 |
1 .0266 |
— |
3-53 |
— |
|
M5 |
— |
64 |
0 |
6 |
42 |
0 |
0 |
1.02 79 |
12.0 |
1 1.4 |
I .0266 |
1 02665 |
— |
3-5i |
— |
|
146 |
— |
63 |
48 |
6 |
4 2 |
0 |
0 |
1.0268 |
12.8 |
12.8 |
I.O257 |
1 .0264 |
— |
3-39 |
— |
|
147 |
— |
63 |
22 |
6 |
47 |
0 |
0 |
1.0259 |
12.8 |
• — |
I.O248 |
— |
— |
3-2 7 |
— |
|
148 |
— |
btadt. |
0 |
0 |
1.0250 |
14.2 |
— |
IO2415 |
— |
— |
3-19 |
— |
|||
|
149 |
94 |
59° |
8.2 |
4 |
38' |
0 |
0 |
I.O259 |
12.0 |
9.8 |
1.0245 |
1 0248 |
— |
3-23 |
— |
|
150 |
94 |
59 |
8.2 |
4 |
38 |
145 |
265 |
I .O263 |
12.0 |
5-o |
1.0249 |
1 .0258 |
— |
3.28 |
— |
|
95 |
60 |
42-5 |
4 |
13-7 |
0 |
0 |
I.O254 |
12.9 |
9-4 |
1 .02 42 |
1.0245 |
3*8 |
-* |
||
|
152 |
95 |
60 |
42-5 |
4 |
13-7 |
175 |
320 |
I.O278 |
11. 9 |
5-8 |
I.O264 |
1 .0272 |
— |
3-48 |
— * |
|
153 |
— |
64 |
47 |
2 |
50 |
0 |
0 |
I.O276 |
12.7 |
9.4 |
I.O263 |
1 0267 |
— |
3-47 |
— |
|
154 |
96 |
66 |
8.5 |
3 |
0 |
0 |
0 |
I.O278 |
13-5 |
8.2 |
1.0266 |
1.0272 |
. |
3-5 1 |
* — |
|
155 |
96 |
66 |
8-5 |
3 |
0 |
805 |
1472 |
1-92 75 |
14.9 |
— 1. 1 |
1.0266 |
1.0280 |
‘ |
3-5'i |
— |
|
156 |
97 |
66 |
2 |
4 |
2 1 |
683 |
1249 |
IO284 |
10.9 |
1 . 1 |
1.0268 |
1.0283 |
— |
3-53 |
— |
|
157 |
98 |
65 |
56 |
5 |
2 1 |
388 |
710 |
I .0278 |
13.0 |
— 1.0 |
I.O2655 |
1.0280 |
3-50 |
— |
|
|
*58 |
99 |
65 |
51-5 |
6 |
25 • |
213 |
390 |
1.0277 |
13-5 |
6. 1 |
1 .0265 |
1.0274 |
3-50 |
— |
|
|
159 |
IOI |
65 |
36 |
8 |
32 |
0 |
0 |
I.O276 |
12.6 |
9.4 |
I.O263 |
1.02665 |
3-47 |
— |
|
|
160 |
IOI |
65 |
36 |
8 |
32 |
223 |
408 |
I.O283 |
10.3 |
6.0 |
1.0266 |
10275 |
3-5 |
||
|
161 |
104 |
65 |
28 |
9 |
56 |
162 |
296 1 |
1 .0282 |
11. 4 |
6-5 |
I.O267 |
10275 |
3-52 |
— |
|
|
162 |
124 |
66 |
41 |
6 |
59 |
0 |
0 |
>02735 |
>4-5 |
8.4 | |
I .0264 |
1 .0269 |
3-48 |
||
|
163 |
125 |
67 |
52.5 |
5 |
12 |
0 |
0 |
1 .0282 |
IO.I |
7.0 |
I.O265 |
1.0272 |
>•957 |
3-50 |
3-54 |
|
164 |
125 |
67 |
525 |
5 |
12 |
700 |
1280 1 |
1.0280 |
10.4 |
— 1. 1 |
I O2635 |
1.0278 |
1 -95 > |
3-48 |
3-53 |
|
165 |
137 |
67 |
24 |
8 |
58 |
0 |
0 |
102745 |
9.9 |
8.2 |
1 0257 |
1-0263 |
— |
3-39 |
— |
|
166 |
137 |
67 |
24 • : |
8 |
58 |
400 |
732 |
1.0281 |
11. 7 |
— 1.0 1 |
1 .0266 |
1.0281 |
— |
3-5 |
— |
|
167 |
143 |
66 |
58 |
IO |
33'. |
0 |
0 |
1.0273 |
10.7 |
8.2 I |
10257 ' |
1.0262 |
>.899 |
3-39 |
3-44 |
|
168 1 |
143 |
66 |
58 |
IO |
33 |
189 |
346 |
1.0279 1 |
12.0 |
6.2 | |
I.O265 |
1.0273 |
1.956 |
3-50 |
3-54 |
Den norske Nordhnvsexpedition.. Tornne : Clieini.
|
Dybdc*hvorfra Pro- |
Temperatur. |
Egenvægter. |
Saltmrongde. |
||||||||||||
|
ven hentet. |
(Amount of Salt |
||||||||||||||
|
Nordlig Bredde. 1 Nor tli I. ali ludc.) |
Længde fra |
[Depth from which the Sam- ple* were collected.) |
Aflrestc Egen- vægter. (Specific Gravity |
(Temperature.) |
(Specific Gravity.) |
Chlor- |
mecuitred.) |
||||||||
|
No. |
Stat. No. |
Green- wich. [Longitude |
Engelske Favne. |
Meter. |
Under ’ Aflresnin- |
I Havet. |
Ved i7.° r> nTTT |
Ved tn 4°. |
mængde. (Amount of Chlorine.) |
Efter Aræo- meter. |
Efter Chlor- mængde. |
||||
|
from Greenwich.) |
[Knglith Fathom*.) |
[Metre*.) |
read.) |
( When read.) |
(In Situ) t° |
. At J7o 3 17 0 3 |
.11 • To |
(By the Areometer.) |
(Dy the Amount of Chlorine.) |
||||||
|
169 170 |
1 52 |
67 |
Hnpou veil Dodo. (Ilopon near Uodn.) ■18' 12 0 46' E. |
0 0 |
0 0 |
I .0091* 1.0266 |
ii. 7 14-3 |
8.2 |
I.OO83 I.O256 |
1.0261 |
— |
1.09 3-38 |
1 |
||
|
171 |
67 |
l8 |
12 |
46 |
70 |
128 |
I.O27O |
>3-5 |
4.1 |
I 02585 |
1.0269 |
— |
3-4 1 |
||
|
1 7 2 |
152 |
67 |
l8 |
12 |
46 |
>25 |
229 |
> 0274 |
1 3-5 |
4.1 |
1.0262 |
10273 |
— |
346 |
— |
|
1 73 |
162 |
68 |
2 3 |
IO |
20 |
795 |
>454 |
I.O27O |
17.2 |
— 1.2 |
1.0266 |
1.0280 |
>•943 |
3-5 > |
. 3-5 1 |
|
1 7 4 |
— |
hirilnhct fil IlatnolQord. {Kntmiioo to die Hawol l'Jor'l,) |
0 |
0 |
I.O269 |
14-5 |
8.8 |
I 0259 |
1.0264 |
— |
3-4 |
— |
|||
|
>75 |
171 |
69 |
18' |
14 0 |
29' |
0 |
0 |
1.0272 |
1 1-9 |
9.0 |
1.0258 |
1 .0262 |
3-40 |
||
|
176 |
171 |
69 |
18 |
1 4 |
29 |
642 |
1 >74 |
1.0282 |
9.9 |
— 1.0 |
1.0265 |
1.0279 |
— , |
3-50 |
|
|
1 77 |
176 |
69 |
18 |
>4 |
32-7 |
0 |
0 |
I.O27O |
1 3-3 |
8.0 |
1.0258 |
1 .0264 |
340 |
— |
|
|
178 |
179 |
69 |
32 |
1 1 |
10 |
0 |
0 |
1.0280 |
10.9 |
8.8 |
I.6264 |
1.0269 |
1-945 |
3-48 |
3-52 |
|
179 |
1 79 |
69 |
32 |
1 1 |
IO |
1607 |
2939 |
1.0282 |
97 |
— 1.2 |
1.0264 |
1 .0279 |
1-935 |
3-48 |
3-50 |
|
180 |
183 |
69 |
59-5 |
6 |
15 |
0 |
0 |
1.0279 |
13-3 |
8.6 |
1.0267 |
1.0272 |
>•952 |
3-52 |
3-53 |
|
181 |
184 |
70 |
4 |
'9 |
50 |
0 |
0 |
1.0280 |
12.6 |
7.6 |
1.0267 |
1.0273 |
1-943 |
3-52 |
3 5 |
|
182 |
184 |
70 |
4 |
9 |
50 |
660 |
1097 |
1.0279 |
12.8 |
0.0 |
I .0266 |
1 .0280 |
1.928 |
3-5 1 |
3-49 |
|
183 |
184 |
70 |
4 |
9 |
50 |
1547 |
2829 |
I.O2765 |
>3-4 |
— 1-3 |
I.O265 |
1.0279 |
1-935 |
3-50 |
3-50 |
|
184 |
187 |
69 |
5 1 -5 |
1 4 |
41 |
>335 |
2441 |
IO276 |
>5-2 |
— 1.1 |
IO2675 |
1.0282 |
1-933 |
3-53 |
3-50 |
|
>85 |
188 |
69 |
43 |
1 5 |
29 |
0 |
0 |
I.O278 |
>3-2 |
9.0 |
1.0266 |
1 .0270 |
1-939 |
3 5> |
3 5 |
|
186 |
189 |
69 |
4> |
>5 |
42 |
0 |
0 |
1-027$ |
13.2 |
9.6 |
1.0263 |
1.0266 |
1.923 |
3-47 |
3-48 |
|
187 |
189 |
69 |
4> |
>5 |
42 |
860 |
>573 |
1.0279 |
12.9 |
— 1. 1 |
1.0266 |
1.0281 |
>•93 > |
3-5 |
3-49 |
|
188 |
200 |
7 1 |
25 |
>5 |
40.5 |
0 |
0 |
1.0282 |
9.9 |
7.8 |
1.0265 |
1.027 1 |
— |
3-50 |
— |
|
189 |
200 |
7> |
25 |
>5 |
40-5 |
620 |
1 134 |
1.0285 |
9-4 |
— 1,0 |
1.0267 |
1 .0281 |
1.949 |
3-52 |
3-53 |
|
190 |
206 |
70 |
45 |
14 |
36 |
0 |
• 0 |
1.0282 |
9 5 |
8.2 |
1.0264 |
1.0270 |
1-945 |
348 |
3-52 |
|
191 |
206 |
70 |
45 |
>4 |
36 |
700 |
1280 |
1.0285 |
• 8.7 |
—0-7 |
1.0266 |
1 .0280 |
1-945 |
3-5 |
3-52 |
|
192 |
206 |
70 |
45 |
14 |
.36 |
1248 |
2282 |
1.0283 |
9.2 |
— 1. 1 |
1.0265 |
1.0279 |
1-945 |
3-50 |
3-52 |
|
>93 |
— |
' Indlnhct III Malaugenfjord. (Entrance 10 the Malangen Fjord. |
0 |
0 |
— |
-e ■ |
— |
— |
— |
1.744 |
— |
3->5 |
|||
|
194 |
212 |
7° |
12.5 |
1 7 0 |
41' |
0 |
0 |
1-0255 |
21.7 |
7-2 |
1.026 I |
1.0I2675 |
1.895 |
3-44 |
3-43 |
|
>95 |
2 1 2 |
70 |
12.5 |
>7 |
41 |
142 |
260 |
1 .0272 |
17.6 |
5-8 |
1.02685 |
1.02775 |
1.940 |
3-54 |
3-5i |
|
196 |
213 |
70 |
23 |
2 |
30 |
0 |
0 |
1.0277 |
14.2 |
8.2 |
1.0267 |
1 .0272 |
1.956 |
3-52 |
3-54 |
|
197 ' |
213 |
70 |
23 |
2 |
30 |
1760 |
3219 |
1.0274 |
>5-5 |
— 1.2 |
I.O266 |
1.02805 |
1 -95 1 |
3-5 |
3-53 |
|
198 |
215 |
70 |
53- |
2 |
0 w. |
0 |
0 |
1.0276 |
14.9 |
8.0 |
I O267 |
2.0273 |
>■945 |
3-52 |
3-52 |
|
199 |
215 |
70 |
53 |
2 |
0 |
200 |
366 |
1-02755 |
>5-2 |
2.8 |
1.0267 |
1.0279 |
1-945 |
3-52 |
3-52 |
|
200 |
215 |
70 |
53 |
2 |
0 |
700 |
1280 |
1.0276 |
>4-3 |
—0.6 |
1.0266 |
1.0280 |
>•935 |
3-51 |
3-50 |
|
201 |
215 |
70 |
53 |
2 |
0 |
1665 |
3045 |
1.027,5 |
14-5 |
— 1.2 |
1.0265 |
1.02795 |
>•939 |
3-50 |
3 5 |
|
202 |
217 |
7 1 |
0 |
5 |
8-5 |
0 |
0 |
1.0283 |
6-5 |
4.6 |
1.0262 |
1.0272 |
— |
3-46 |
— |
|
203 |
— |
llilji; nten af Jan Mayen. (Kaclcrn Extremity of Jnu Mayen.) |
0 |
0 |
1 .0280 |
4-o |
3-o |
I.O2565 |
1.0268 |
— |
3-38 |
• — |
|||
|
204 |
225 |
70 |
58' |
8 |
4' |
0 |
0 |
1.0278 |
9.2 |
3-4 |
1.0260 |
i. 027 1 |
— |
3-43 |
— |
|
205 |
226 |
70 |
59 |
7 |
54 |
0 |
• 0 |
1.0277 |
10.5 |
3-o |
1.0261 |
1.0272 |
1.893 |
3-44 |
3-42 |
|
206 |
226 |
70 |
59 |
7 |
5> |
340 |
622 |
1.0282 |
-9-1 |
— 0.6 |
1.02635 |
1 .0278 |
1.936 |
348 |
3-50 |
|
207 |
— |
69 |
20 |
1 1 |
18 |
0 |
0 |
1.0276 |
12.8 |
4-3 |
1.0263 |
1.02745 |
>•925 |
3-47 |
3-48 |
|
208 |
— |
68 |
33 |
7 |
25 |
0 |
0 |
— |
— |
6.0 |
— |
— |
1.936 |
— |
3-50 |
|
209 |
2 43 |
68 |
32-5 |
6 |
26 |
0 |
0 |
1.0280 |
12.8 |
7.8 |
I .0267 |
1.0273 |
>■945 |
3-52 |
3-52 |
|
210 |
243 |
68 |
32.5 |
6 |
26 |
600 |
1097 |
1-02715 |
16.7 |
— 0.8 |
1.0266 |
1.0280 |
>.927 |
3-5 1 |
3-49 |
|
2 1 1 |
2 43 |
68 |
32.5 |
6 |
26 |
1385 |
2533 |
1 .0286 |
5-7- |
— i-3 |
I 0264 |
1.0278 |
1.940 |
3-48 |
3-5i |
|
212 |
2 45 |
.68 |
2 1 |
2 |
5 |
0 |
0 |
1.0280 |
13-4 |
9.0 |
I .0268 |
1.02725 |
. . — . |
4-53 |
— |
|
2>3 |
247 |
68 |
5-5 |
2 |
24 E. |
0 |
0 |
1.0278 |
13.8 |
9-4 |
I O267 |
1.027 1 |
>•954 |
3-52 |
3-53 |
|
214 |
247 |
68 |
5-5 |
2 |
24 |
500 |
9>4 |
1 .0278 |
>3-> |
— 0.4 |
1.0266 |
1.0280 |
>.927 |
3-5 1 |
3-49 |
|
215 |
247 |
68 |
5-5 |
2 |
24 |
1 120 |
2048 |
>0275 |
>4-5 |
— 1.2 |
I.O265 |
1.02795 |
1.929 |
3 50 |
3-49 |
|
216 |
249 |
68 |
12 |
6 |
35 |
1063 |
1944 |
1.0274 |
>5.-4 |
— >•3 |
I .0266 |
1.0280 |
>•937 |
3-5 |
3 50 |
|
217 218 |
251 252 |
68 |
6.5 1 9 44 Bendenfor Mkraavcn. (Mouth of Mkraavcn.) |
0 0 |
0 0 |
1 .0276 1.0254 |
>3-9 19.2 |
>3-2 14.0? |
I .0265 1.02 54 |
1.0262 1.0249 |
1.927 1.820 |
3-50 3-35 |
3-49 3-2 9 |
||
|
219 |
253 |
Slcjærstadijord. |
0 |
0 |
1.0178* |
>4.4 |
130 |
I.OI73 |
1 .0168 |
1.261 |
2.28 |
2.28 |
|||
|
220 |
253 |
67 |
Do. |
0 25' |
263 |
481 |
>•02755 |
1 1.2 |
3-2 |
I O26O |
>•02715 |
1.887 |
3-43 |
3-4 1 |
|
|
221 |
254 |
27 |
>3 |
0 |
0 |
- 1 .0266 |
12.6 |
10.0 |
1-0253 |
10255 |
1.843 |
3-34 |
3-33 |
||
|
222 |
| 254 |
67 |
27 |
>3 |
25 |
.70 |
128 |
1 .0278 |
1 1.2 |
4-8- |
1 .02625 |
1.0272 |
1.929 |
346 |
3-49 |
|
223 |
1 254 |
67 |
27 |
1 3 |
25 |
140 |
256 |
1 .0281 |
12. 1 |
5-8 |
1 0267 |
1.0276 |
1-93 |
3-52 |
3-49 |
|
224 |
r ronavet. |
0 |
0 |
1 1.0262 |
12.0 |
— |
1.0248 |
— |
1.822 |
3-27 |
3-29 |
63
|
Dybde hvorfra Pro- ven hentet. |
Temperatur. |
Egenvcegtor. |
||||||||||
|
Liengde |
( Depth jrom which the Ham- |
A thus to Egen- |
(Temperature.) |
(Specific Gravity.) |
||||||||
|
Stat. |
Nordlig |
. fra |
pies were |
collected.) |
||||||||
|
No. |
tn-een- |
Vod |
Vcd |
|||||||||
|
No. |
\vich. |
viegter. |
Under Afliesnin- gen. |
|||||||||
|
(North Latitude.) |
(Longitude Jrnm |
Engelske Favne. |
Meter. |
(Specific Gravity read.) |
1 Havet. |
1 7." 5 17." 6 |
t° 4" |
|||||
|
Greenwich.) |
(English Fathoms.) |
(Metres.) |
[When read.) |
(In Situ) t" |
At 17» 3 17»~3 |
At «■> i » |
||||||
|
225 |
255 |
68° |
12- '3 |
!5 |
40' E. |
O |
O |
[.0262 |
14-3 |
10.7 |
1.0252 |
10253 |
|
226 |
255 |
68 |
12.3 |
15 |
40 |
300 |
549. |
I .0280 |
12.9 |
6-5 |
I.O267 |
1.0275 |
|
227 |
256 |
70 |
8-5 |
23 |
4 |
O |
0 |
— |
. — |
— |
— |
|
|
228 |
256 |
70 |
8-5 |
23 |
4 |
225 |
41 1 |
I(.02 8o |
10.9 |
4.0 |
I.O264 |
1.0275 |
|
2 2 Q |
258 |
70 |
1 2.6 |
2 3 |
2-5 |
O |
0 |
1.0276 |
8-3 |
1 1 .6 |
1.0257 |
1.0256 |
|
230 |
258 |
70 |
r 2 .6 |
23 |
2-5 |
230 |
421 |
1.0282 |
6.9 |
4.0 |
I 026l |
I.0272 |
|
231 |
259 |
70 |
48.9 |
25 |
59 |
80 |
146 |
1.0286 |
6.7 |
4-i |
I.O2645 |
1.0275 |
|
232 |
261 |
70 |
47-5 |
28 |
30 |
O |
0 |
1.0248 |
11 -9 |
7-4 |
I.O234 |
I.0240 |
|
233 |
261 |
70 |
47-5 |
28 |
30 |
127 |
232 |
1.0280 |
10.9 |
2.8 |
I.O264 |
1.0276 |
|
234 |
262 |
70 |
36 |
32 |
35 |
0 |
0 |
1.0282 |
8-5 |
5-6 |
I.O263 |
1.0272 |
|
2 35 |
262 |
70 |
36 |
32 |
35 |
I48 |
•271 |
1.0284 |
8.9 |
1.9 |
I.O265 |
1.0278 |
|
236 |
263 |
70 |
44-5 |
34 |
14 |
12 I |
221 |
1 . 1286 |
6.9 |
1. g |
I.O265 |
1.02775 |
|
2 37 |
264 |
70 |
56 |
35 |
37 |
0 |
0 |
1.0279 |
1 1.3 |
5-2 |
I.O264 |
1.0273 |
|
238 |
264 |
70 |
56 |
35 |
37 |
- 86 |
«57 |
1. 0281 |
II- 4 |
1.9 |
1.0266 |
1.02785 |
|
230 |
2 68 |
7i |
36-5- |
36 |
18 |
0 |
0 |
1.0284 |
8-7 |
4.4 |
I.O265 |
102755 |
|
240 |
268 |
7i |
3^-5 |
36 |
18 |
130 |
238 |
1.0285 |
8.9 |
— 1.0 |
1.02 66 |
1.0281 |
|
241 |
270 |
72 |
27-5 |
35 |
1 |
0 |
0 |
1.0284 |
9.0 |
3-6 |
1.02655 |
1.0277 |
|
242 |
270 |
72 |
27-5 |
35 |
1 |
136 |
249 |
1 .0286 |
8.9 |
0 0 |
I .0267 |
1.0281 |
|
243 |
272 |
73 |
10.8 |
33 |
3 |
1 13 |
207 |
1.0285 |
89 |
i-5 |
1.0266 |
1.0279 |
|
244 |
• 273 |
73 |
25 |
3i |
30 |
0 |
0 |
1.0285 |
8.7 |
4.9 |
1.0266 |
1.0276 |
|
245 |
273 |
73 |
25 |
3i |
30 |
197 |
360 |
1.0285 |
8,5 |
2.2 |
1.0266 |
1.0278 |
|
246 |
275 |
74 |
8 |
3i |
12 |
0 |
0 |
1.0287 |
5-9 |
2.9 |
I.O265 |
1.0277 |
|
2 47 |
275 |
74 |
8 |
3i |
12 |
147 |
269 |
1.0289 |
5-5 |
—0.4 |
I.O2665 |
1 .02805 |
|
248 |
278 |
74 |
i-5 |
22 |
27 |
0 |
0 |
1.0286 |
5-9 |
4.2 |
I .0264 |
1. 02.7 45 |
|
249 |
278 |
74 |
i-5 |
22 |
27 |
230 |
421 |
1.0287 |
5-3 |
0.9 |
I O264 |
1.0278 |
|
2 50 |
280 |
74 |
10.5 |
18 |
5i |
0 |
0 |
1.0282 |
9-3 |
1.2 |
I.O264 |
1.0277 |
|
251 |
280 |
74’ |
10.5 |
18 |
51 |
35 |
64 |
1.0283 |
9-4 |
I. I |
I O265 |
1.0278 |
|
252 2 53 |
281 |
74 |
3 |
17 |
18 |
0 |
0 |
1.0285 |
8.9 |
4.6 |
I .0266 |
1.02765 |
|
281 |
74 |
3 |
17 |
18 |
* 15 |
210 |
1.0287 |
8.8 |
2.2 |
1.0268 |
1.0281 |
|
|
254 |
283 |
73 |
47-5 |
14 |
2 1 |
0 |
0 |
1.0282 |
1 1-3 |
7-2 |
I .0267 |
1.0274 |
|
255 |
284 |
73 |
1 |
12 |
58 |
0 |
0 |
1.0283 |
. 1 1 .2 |
6.8 |
I.O2675 |
1.0275 |
|
2 56 |
286 |
72 |
57 |
1 4 |
32 |
447 |
817 |
1.0284 |
9-5 |
—0.8 |
1.0266 |
1 .02805 |
|
25 7 |
289 |
72 |
4i-5 |
20 |
18 |
0 |
0 |
1.0282 |
1 1. 1 |
7.6 |
I .02665 |
1.0273 |
|
258 |
289 |
72 |
4 1 -5 |
20 |
18 |
219 |
400 |
1.0282 |
1 1. 1 |
2.0 |
I.O2665 |
1.0279 |
|
2 59 |
291 ' |
71 |
54 |
2 1 |
57 |
0 |
0 |
1.0280 |
12.0 |
7-4 |
I .0266 |
1.02725 |
|
260 |
291 |
7i |
54 |
2 1 |
57 |
194 |
355 |
1.0284 |
10.5 |
3-0 |
I 02675 |
1.02795 |
|
261 |
293 |
7i |
7 |
2 1 |
1 1 |
0 |
6 |
1.0272 |
5-o |
— |
1.02495 |
■ |
|
262 |
293 |
7 1 |
7 |
2 1 |
1 1 |
95 |
174 |
1 .0276 |
5-3 |
— |
1.0254 |
-r— |
|
263 |
294 |
7 1 |
35 |
15 |
1 1 |
0 |
0 |
1 .0272 |
4 9 |
— |
102495 |
|
|
264 |
294 |
7 i . |
35 |
15 1 1 |
1 1 |
637 |
1165 |
1 .0284 |
7-i |
— 1.2 |
1.0263 |
1.02775 |
|
265 |
295 |
7 1 |
59 |
40 |
0 |
0 |
1 .0278 |
13-5 |
7.0 |
1 .O2665 |
'■02735 |
|
|
266 |
295 |
7 1 |
1 1 |
3° |
100 |
183 |
1.0283 |
10. 1 |
3-2 |
1 .0266 |
1 .0278 |
|
|
267 |
295 |
7 1 ' |
55 |
1 1 |
3° |
600 |
1097 |
1 .0281 |
10.7 |
—0.8 |
I.O265 |
1.0279 |
|
268 |
295 |
7 1 |
59 |
1 1 |
40 |
1 1 10 |
2030 |
1 .0278 |
13-3 |
— i-3 |
1.0266 |
1 .02805 |
|
269 |
2 96 |
72 |
1 5-5 |
8 |
9 |
100 |
183 |
1 .0286 |
7-i |
3-1 |
I.O265 |
1 0277 |
|
270 |
296 |
72 |
15 5 |
8 |
9 |
600 |
1097 ' |
1.0287 |
7-i |
—0-5 |
1.0266 |
1 .0280 |
|
271 |
297 |
72 |
36.5 |
5 |
12 |
0 |
0 |
1 .0284 |
5-9 |
4.8 |
I .0262 |
1 .0272 |
|
272 |
297 |
72 |
36.5 |
5 |
12 |
1280 |
2341 |
1 .0286 |
5-o |
— i-4 |
I .0263 |
1.02775 |
|
2 7.3 |
298 |
72 |
52 |
1 |
50.5 |
0 |
0 |
1 .0272 |
1 5- 1 |
4.0 |
I.O263 |
1.0274 |
|
274 |
298 |
72 |
52 |
1 |
5" 5 |
1500 |
2 743 |
1.027 I |
16.8 |
-1-5 |
I .0266 |
1 .0280 |
|
275 |
299 |
73 |
10 |
2’ |
14 w. |
0 |
0 |
1.0269 |
13-7 |
3-6 |
1.0258 |
1 .0269 |
|
276 |
3°° |
73 |
10 |
3 |
22 |
0 |
0 |
1.0255 |
15.2 |
. 17 |
4.0247 |
1.0259 |
|
277 |
301 |
74 |
1 |
1 |
20 • |
0 |
0 |
1.0263 |
14 3 |
2.2 |
1-0253 |
1.0265 |
|
278 279 280 |
30 2 |
75 75 75 |
16 |
0 |
0 |
0 |
1.0285 |
7-9 |
3 0 |
1.0265 |
1.0277 |
|
|
303 303 |
12 12 |
3 3 |
2 E. 2 |
a» O O |
0 274 |
1.0283 1 .0288' |
6-5 4.4 |
3-3 — 11 |
1.02615 1.02645 |
1.0273 1 1.0279 |
|
Saltmrengdo. |
||
|
(.Im-xinl |
Of Salt |
|
|
mtasu red.) |
||
|
(’ldor- |
||
|
nuengdo. |
Eftor |
Eftor |
|
f.lniotini 0/ |
||
|
Chlorine,) |
meter. |
mrengde. |
|
(lly the |
||
|
Areometer.) |
.Inioniit 0/ Chlorine.) |
|
|
3-32 |
— |
|
|
' — |
3-52 |
|
|
1 . 1 1 8 |
— |
2.02 |
|
1-930 |
3-48 |
3-49 |
|
1.865 , |
. 3-39 |
3-37 |
|
1-907 |
3-44 |
3-45 |
|
1.942 |
3-49 |
3-5i |
|
I-7I3 |
309 |
3-io |
|
1.920 |
3-48 |
3-47 |
|
1.92 1 |
3-47 |
3-47 ■ |
|
1.932 |
3-50 |
3-49 |
|
1.927 |
3-50 |
3-49 |
|
1.929 |
3.48 |
3-49 |
|
1-934 |
3-5 1 |
3-50 |
|
1-925 |
3-50 |
2.48 |
|
1.938, |
3-31 |
1 -5 1 |
|
1-937 |
3 -'50 |
1.50 |
|
1-937 |
3-52 |
3-50 |
|
1-937 |
3-5i |
3-50 |
|
1.938 |
3-5i |
3-5i |
|
1-943 |
3-5i |
3-5i |
|
1-935 |
3-50 |
■3-5° |
|
1.936 |
3-52 |
3 50 |
|
— |
3-48 |
— |
|
3-48 |
||
|
— |
3-48 |
|
|
— |
3-50 |
— |
|
1.967 |
3-5i |
3-56 |
|
1-939 |
3-53 |
3-5» |
|
1.938 |
3-52 |
3-5i |
|
I.940 |
3 53 |
3 5 |
|
— |
3-5 1 |
— |
|
— |
3-52 |
\ — |
|
— |
3-52 |
— |
|
1.936 |
3-5i |
3-50 |
|
1.944 |
3-53 |
3-52 |
|
1.909 ? |
3 -2 9 |
3-45 |
|
1-943 |
3-35 |
3-51 |
|
1.918 |
3-29 |
; 3-47 |
|
1-934 |
3-47 |
1 3-50 |
|
1.942 |
3-52 |
! 3-5 |
|
1.942 |
3-5i |
3-5i |
|
1.936 |
3-50 |
3-50 |
|
1-934 |
3-5 1 |
3 50 |
|
1.944 |
3-50 |
3-52 |
|
1-939 |
1 3 51 |
3-51 |
|
1.928 |
3.46 |
3 49 |
|
1.926 |
| .3-47 |
; 3-48 |
|
1.917 |
! 3-47 |
3-47 |
|
1.9 15 ? |
3-5 * |
— |
|
1.888 |
3-40 |
3-42 |
|
1. 810 |
3.26 |
3-27 |
|
i-837 |
, 3-34 |
3-32 |
|
1.920 |
3-50 |
3-47 |
|
! I-9I4 |
3-45 |
3-46 |
|
! 1-929 |
1 3-49 |
3-49 |
Dybde hvorfra Prø- ven hentet-
L æilgde (Depth f mi which the Sam-
|
Nordlig Bredde. i North Latitude,) |
frn |
I pies wer |
collected.) |
||||
|
No. |
Stat. No. |
tn-een- wich. (Longitude, frpm Greenwich.) |
Engelske Favne. ( English Fathoms-) |
Meter. (Metres.) |
|||
|
281 |
' 304 |
75 |
° 3‘ |
4 |
" 5i' E |
300 |
549’ |
|
282 |
304 |
75 |
3 |
4 |
5-i |
1735 |
3173 |
|
283 |
305 |
| 75 |
i-5 |
7 |
56 |
O |
O |
|
284 |
306 |
75 |
0 |
10 |
27 |
0 |
O |
|
285 |
306 |
75 |
0 |
10 |
27 |
1334 |
2440 |
|
286 |
310 |
74 |
56 |
13 |
50 |
0 |
0 |
|
287 |
310 |
74 |
56 |
•3 |
50 |
1006 |
1840 |
|
288 |
316 |
74 |
56 |
16 |
29 |
0 |
0 |
|
289 |
316 |
74 |
56 |
16 |
29 |
129 |
236 |
|
290 |
321 |
74 |
56.5 |
19 |
30 |
25 |
46 |
|
291 |
323 |
72 |
53-5 |
2 1 |
51 |
0 |
0 |
|
2 92 |
323 |
72 |
53-5 |
2 1 |
5 1 |
223 |
408 |
|
293 |
326 |
75 |
3i-5 |
17 |
50 |
0 |
0 |
|
294 |
326 |
75 |
3i-5 |
17 |
50 |
123 |
225 |
|
295 |
328 |
75 |
42 |
15 |
39 |
0 |
0 |
|
296 |
328 |
75 |
42 |
15 |
39 |
200 |
366 |
|
297 |
331 |
75 |
5i |
13 |
5 |
O |
0 |
|
298 : |
332 |
75 |
56 |
1 1 |
36 |
1149 |
2 IOI |
|
2 99 |
334 |
76 |
12.5 |
H |
0 |
O |
O |
|
300 |
334 |
76 |
12.5 |
14 |
0 |
403 |
737 |
|
301 j |
335 |
76 |
16.5 |
14 |
39 |
O |
0 |
|
302 |
335 |
76 |
16.5 |
H |
39 |
179 |
327 |
|
303 | |
•339 |
76 |
30 |
15 |
39 |
O |
0 |
|
3°4 ( |
339 |
76 |
30 |
15 |
39 |
37 |
68 |
|
305 |
342 |
7*> |
33 |
13 |
18 |
0 |
0 |
|
306 |
342 |
76 |
33 |
13 |
18 |
523 |
956 |
|
307 |
344 |
76 |
42 |
1 1 |
16 |
0 |
0 |
|
308 |
347 |
76 |
49-5 |
7 |
47 |
0 |
0 |
|
309 |
347 |
76 |
40-5 |
7 |
47 |
1429 |
2613 |
|
3 10 |
349 |
76 |
30 |
2 |
57 |
0 |
0 |
|
3 1 1 |
349 |
76 |
30 |
2 |
57 |
1487 |
2719 |
|
312 |
350 |
76 |
26 |
0 |
29 W. |
0 |
0 |
|
3>3 |
35° |
76 |
26 |
0 |
29 |
300 |
549 |
|
3H |
350 |
76 |
26 |
0 |
29 |
1686 |
3083 |
|
345 1 |
352 |
77 |
56 |
3 |
29 E. |
0 |
0 |
|
316 , |
352 |
77 |
56* |
3 |
29 |
300 |
549 |
|
3 1 7 ' |
355 |
78 |
0 |
8 |
32 |
0 |
0 |
|
318. |
355 |
78 |
0 |
8 |
32 |
948 |
1734 |
|
319 |
357 |
78 |
3 |
1 1 |
18 |
0 |
0 |
|
320 |
359 |
78 |
2 |
9 |
25 |
0 |
0 |
|
321 |
359 |
78 |
2 |
9 |
25 |
416 |
761 |
|
322 |
361 |
79 |
8.5 |
5 |
28 |
0 |
0 |
|
323 |
361 |
79 |
8-5 |
5- |
28 |
9°5 |
1655 |
|
324 |
362 |
79 |
59 |
5 |
40 |
0 |
0 |
|
325 |
36 2 |
79 |
59 |
5 |
40 |
459 |
839 |
|
326 |
363 |
80 |
0 |
8 |
15 |
0 |
0 |
|
327 |
3^3 |
80 |
0 |
8 |
15 |
260 |
475 |
|
328 |
— |
Veil KoraknvriH'. (TU* Kortk I «landa t |
0 |
0 |
|||
|
329 |
— |
Magdalenebay. |
0 |
0 |
|||
|
330 |
368 |
78 |
43' |
8 |
20' |
0 |
0 |
|
331 |
368 |
78 |
43 |
8 |
20 |
3 1 5 |
576 |
|
332 |
— |
78 |
34 |
9 |
22 |
0 |
0 |
|
333 |
372 |
78 |
9 |
14 |
12 |
0 |
0 |
|
334 |
373 |
78 |
10 |
14 |
26 |
0 |
0 |
|
335 |
Mumtlnicon of Advciittinv. (Knlrnncc to Advimt liny.) |
0 |
0 |
Aflæste
Egen-
vægter.
(Specific
Gravity
read.)
1.0273
1.0273
1.0272 1-0275.
1.0272
1.0274
1.0275 I .026q
1.0275
1.0275
1.0283
1.0284
1.0276
I.O284
1.027Q
1.0282
IO286
1.0275
1.0277 1.0270
1.0276
1.0267
1.0273 I O277
1.0277
1.0283
1.0277
1.0278
1.0274
1.0277 1.0270
1.0279 1.0276 1.0272
1.0274
1.0275
1.0280
1.0261
I.O280
1.0276
1.0278 1.0272
1.0274
1.0275
1.0276
1.0284 1.0283
1.0268 I .0266 1 .0286
1.0262 I O258 1.0250 1.0250
|
Temperatur. (Temperature.) |
Egenvfegter. (Specific Gravity.) |
Saltmængde. (Amount of Salt measured.) |
||||
|
Under Afla*snin- gen. ( IF hen read. |
I H avet. (In Situ.) t° |
Ved 1 7.° r> 17.° 5 At 17.0 6 17.0 6 |
Ved t.° 4° At t° 40 |
Ynængde. (Amount of Chlorine.) |
Efter Arceo- meter. (By the Areometer.) |
Efter Chlor- mængde. (By the Amount of Chlorine.) |
|
14-9 |
—0.8 - |
I .O264 |
I.O278 |
1.929 |
3-48 |
3-49 |
|
14-5 |
— i-5 |
I .0263 |
1.02775 |
1.940 |
3-47 |
3-5i |
|
■t8 |
5-3 |
1.0263 |
1.0272 |
1.947 |
3-47 |
3-52 |
|
. I4I |
5-4 |
1.02645 |
1.0274 |
1.929 |
3-49 |
3-49 |
|
14.9 |
— i-3 |
1.0263 |
1.0277 |
i.920 |
3-47 |
3-47 |
|
I4.7 |
5-5 |
1.02645 |
1.0274 |
1.936 |
3-49 |
3-50 |
|
13-8 |
— 1.4 |
I .0264 |
I.O278 |
1-932 |
3-48 |
3-49 |
|
. *4-7 |
3-6 |
1.02 595 |
1.02705 |
1.903 |
3-42 |
3-44 |
|
14.6 |
1.9 |
1.02655 |
I .O278 |
1.930 |
3-50 |
3-49 |
|
9-7 |
0.2 |
I-O2575 |
1.027 I |
— |
3-40 |
' — |
|
9-7 |
7.8 |
I.O2655 |
I .0272 |
1.947 |
3-5° |
3-52 |
|
8.9 |
i-5 |
I O265 |
1.0278 |
1-933 |
3-50 |
3-50 |
|
8.9 |
4.8 |
I *02 575 |
I.O267 |
1.904 |
3-40 |
3-44 |
|
8.7 |
1.6 |
1.0265 |
I.O278 |
1.930 |
3-50 |
3-49 |
|
. 9-9 |
4-7 |
1.0262 |
I .0272 |
1.908 |
3-46 |
3-45 |
|
9.8 |
—i-3 |
I.O2645 |
1.0279 |
1.942 |
3-49 |
3-5i |
|
— |
— |
— |
— |
1-935 |
— |
3 50 |
|
6-3 |
— i-5 |
I.O264 |
1.0279 |
— |
3-48 |
— |
|
13-7 |
6.0 |
I.O264 |
1.0272 |
1.923 |
3-48 |
3-48 |
|
!3-7 |
1.0 |
I .0266 |
1.0279 |
1-935 |
3 5 |
3-50 |
|
!5-5 |
5-4 |
I .0262 |
1.027 I |
I-9I4 |
3-46 |
346 |
|
13-4 |
1.0 |
1.0264 |
1.0277 |
1.940 |
3-48 |
3-51 |
|
12.7 |
2.6 |
I 0254 |
1.0266 |
1.867 |
3-35 |
3-38 |
|
13.6 |
0.9 |
1.02615 |
1.0275 |
1.924 |
3-45 |
3-48 |
|
12 4 |
6.2 |
1.02635 |
1.0272 |
1.936 |
3-48 |
3-50 |
|
I 2.2 |
— 1 .0 |
I.O263 |
1.0277 |
1-933 |
3-47 |
3-50 |
|
6.2 |
5-2 |
I.026l |
1.027 I |
— |
3-44 |
— |
|
II -3 |
4-4 |
1.0262 |
1.0272 |
1.924 |
3-46 |
3-48 . |
|
1 1 .6 |
— i-3 |
I.O263 |
1.02775 |
1-935 |
3-47 |
3-50 |
|
1 1 .2 |
3-8 |
I 02585 |
I.O269 |
1.898 |
3-4i |
3-43 |
|
1 1-3 |
— i-5 |
1.0262 |
I.O276 |
1.946 |
3-46 |
3-52 |
|
10.9 |
3-o |
1.0254 |
I .0266 |
1.872 |
3-35 • |
3-39 |
|
10.9 |
— 1. 1 |
I .0263 |
1.02775 |
1.922 |
3-47 |
3-48 |
|
10.8 |
— i-5 |
I .0260 |
1.0274 |
1.916 |
3-43 |
3-47 |
|
12.8 |
3-9 |
1.0259 |
1.0270 |
1.908 |
3-4i ‘ |
3-45 |
|
14.0 |
— 0.8 |
I.O263 |
1.02775 |
1.928 |
3-47 |
3 49 |
|
10.3 |
4.9 |
1.0258 |
1.0268 |
1.890 |
3-40 |
3-42 |
|
9.9 |
— i-3 |
I.O263 |
1.0277 |
1.927 |
3 47 |
3-49 |
|
10 9 |
5-o |
1-02455 |
I.O2545 |
1.797 |
3-24 |
3-25 |
|
5-3 |
4-3 |
1-02575 |
1.0268 |
— |
3-40 |
|
|
137 |
0.8 |
1.0265 |
I.O278 |
1.925 |
3-50 |
3-48 |
|
1 1-5 |
4.2 |
1.0263 |
I.O2735 |
1.906 |
3-47 |
3-45 |
|
12.9 |
— i 7 |
102595 |
1.02705 |
1.928 |
3-42 |
3-49 |
|
13.0 |
5-2 |
1.02615 |
1.027 I |
I-9I7 |
3-45 |
3-47 |
|
12.8 |
— 1 .0 |
1.0262 |
I.O276 |
1.922 |
3-46 |
3-48 |
|
10.9 |
4.6 |
1.0260 |
1.0270 |
• — |
3 43 |
|
|
7-7 |
1 . 1 |
1.0264 |
1.0277 |
i-945 |
3-48 |
3-52 |
|
4.1 |
2.7 |
1 02595 |
1.02 7 I |
— |
3-42 |
|
|
12.3 |
2.2 |
102545 |
1.0266 |
— |
3-36 |
|
|
1 3-0 |
4.6 |
1.0254 |
1.02 635 |
’ — |
3-35 |
|
|
8-5 |
1.6 |
1.0267 |
1.0280 |
1.936 |
3-52 |
3-50 |
|
1 1.9 |
4-5 |
1.0248 |
I.O258 |
— |
3 27 |
|
|
5-o |
4.1 |
1.0236 |
I .O246 |
— |
3-i 1 |
|
|
12 5 |
4.0 |
1.0237 |
1.0247 |
’ — |
3-43 |
|
|
5-3 |
4-7 |
1.02285 |
1.0237 |
— |
3-oi |
— |
Af denne Tabel freragåax det, at Differentserne mel- lem de ved Hjælp af Egenvægt og Chlormængde beregnede Saltmængder i Regelen ere meget smaa, kuu de 3 samtidig udførte Bestemmelser i Vandprøverne No. 261, 262 og 263 danne i saa Henseende en Undtagelse. I)e store her optrædende Differentser skyldes udeu Tvivl en Feil ved Aflæsningen af Egeuvægterne, som for disse Vandprø- vers Vedkommende ere fundne altfor lave, til at de kunne bringes i Harmoni med andre paa Steder i Nærhe- den udførte Observationer. Det er saaledes i høi Grad paafaldende for Vandprøven No. 262, optagen fra et Dyb af 95 Favne (174 Meter) i ca. 8 Miles Afstand fra Land. at tinde Egenvægten 1.0254. medens man i de iudenfor liggende Fjorde, hvor Saltgehalten ellers overalt er mindre end paa Havet, i lignende Dyb tinder en meget større Egenvægt. Selv i den indelukkede Skjærstadfjord, hvor Overfladevandet er særdeles fattig© paa Salte, .er dog Egen- vægten paa Bunden funden at være 1.026, kort sagt, Egen- vægter som de i de omtalte Tilfælde observerede staa paa dette Strøg af Kysten fuldstændig uden Sidestykke. Natur- ligst lade disse Urimeligheder sig forklare ved at antage Egeuvægterne atlæste med 0.001 for lavt. da de ved denne Antagelse paa det Nærmeste kan bringes i Overensstem- melse saavel med de i de samme Vaudprøver udførte Chlor- bestcmmelser som med de andre Observationer fra nærlig- gende Puncter.
Bortser man fra disse 3 nævnte Observationer og af de øvrige beregner den gjennemsnitlige halve Differents mellem to paa samme Vandprøve ved Hjælp af Chlortitrering og Aræometer udførte Saltbestemmelser, resulterer som Udtryk for denne 0.00904, eller man erholder under For- udsætning af, at Feilene i lige høi Grad skyldes Chlor- som Egenvægtsbestemmelserne, for den gjennemsnitlige Feil al en Egenvægtsbestemmelse Værdien 0.000069 og al en Chlor- bestemmelse 0.005. Differentserne falde, som man ser, snart til den ene snart til den anden Side, idet det dog maa bemærkes, at Chlormængden gjennemsnitlig giver lidt over 0.008 °/p høiere Saltgehalt end Egenvægterue, hvad der næsten udelukkende skyldes de nordentor den 75de Breddegrad udførte Observationer.
Førend jeg nu gaar over til at give en Oversigt over de Resultater, som af disse Observationer lader sig udlede, vil det være nødvendigt parenthetisk at indslcyde nogle Be- mærkninger om Dybde- og Temperaturforholdene i det norske Hav i sine groveste Træk. Hvad der til den Ende her meddeles, er hovedsagelig hentet fra en af Prolessor Dr. Mohn forfattet Athaudling, som findes trykt i C. F. * Schiibelers -‘Væxtlivet i Norge.”
Dybden i det af den norske Expedition undersøgte Hav, forsaavidt det ligger vestenfor en Linie fra Spitsber- gen til det nordlige Norge, er i større Afstand Ira Land overalt over 1000 Favne (1829 Meter) og gaar i Regelen op til mellem 1500 og 2000 Favne (2743 og 3658 Meter) eller endog derover. Paa Strøget mellem Beeren Eiland og Jan Mayen hæver sig en Ryg, hvor Dybden ikke naar 1500 Favne. (2743 Meter), medens der saavel søndenfor
Don norske Nordlmvsexpeditiou. Tornne: Chemi.
This Table shows the differences in the amount of salt computed from specific gravity and the proportion of chlorine to be. as a rule, exceedingly small, the 3 determ- inations performed successively with samples Nos. 261, 262, and 263 constituting the sole exception. The great dif- ferences observed here must unquestionably arise from er- roneous readings of the specific gravity, which, as found for these samples, is much too low when compared with that determined for others obtained from adjacent localities. Thus, for instance, the specific gravity of sample No. 262, drawn ’ at a depth of 95 fathoms (174 metres), about 8
geographical miles from land, is stated to be 1.0254,
whereas that determined for the water of the neighbouring fjords, in which the amount of salt at equal depths is invariably less than in the open sea, was much greater. Even for a frith locked in as is the Skjærstadfjord.
where the surface-water is remarkably deficient in salts, the specific gravity of bottom-samples was found to be 1.0260; in short, such exceptional specific gravities
are without a parallel on this line of coast. The most natural explanation of these incongruities, is afforded by assuming the specific gravity in each case to have been read 0.001 too low; the results could then be made to agree pretty closely both with the chlorine-determinations performed with the same samples of water and with observations taken in adjacent localities.
Now, if we disregard the 3 exceptional observations, and for the others compute the average half-difference be- tween two salt- determinations performed with the same sample of water by means of the areometer and titrating with chlorine, this will be expressed by 0.00904; or, as- suming the errors to lie equally in the chlorine and the specific gravity determinations, the mean error ol a spec- ific gravity determination is 0.000069, and ot a chlorine- determination 0.005. As will be seen, the differences be- tween the 2 right-hand columns of the Table are sometimes positive, sometimes negative; but the amount of salt ind- icated by the proportion of chlorine exceeds on an average that denoted by the specific gravity by a trifle over 0.008 per cent, which must be referred almost exclusively to the observations taken north ol the 75th parallel ol latitude.
Before proceeding to review the results deducible from these observations, it will be necessary to interpolate a few general remarks on the depth and temperature of the Norwegian Sea. To this end, I shall merely recapit- ulate what Professor Mohn has stated on the subject in a Memoir printed in C. K. Schiibelers "\æxtlivet i Norge."
The depth of the Sea investigated by the Norwegian North- Atlantic Expedition was found to be as follows: Throughout the tract extending west of an imaginary line drawn from Spitsbergen to the northern extremity of Nor- way, it is never less than 1Q00 fathoms (1829 metres) some considerable distance irom land, and generally ranges from 1500 to 2000 fathoms (2743—3658 metres); nay. in some places it is even greater. Between Beeren Ei-
10
som nordenfor findes betydelig større Dyb paa indtil over 2000 Favne (3658 Meter). Østliavet, det vil sige Havet østenfor en Linie fra Spitsbergen til det nordlige Norge, er overalt meget grundt. da Dybden der paa faa Steder overskrider 200 Favne (366 Meter).
De talrige udførte Temperaturobservationer vise. at Våndet i den af Expeditionen undersogte Del af Østliavet med 1 ndtagelse af den østligste og nordligste Strækning bolder Varmegrader ligefra Overfladen til Bunden, saaledes som dette ogsaa er Tilfælde med Våndet paa de norske Banker, som paa enkelte Steder strækker sig ml til en ikke ubetydelig Afstand fra Kysten. Helt anderledes er Forholdet i det vestenfor liggende dybere Hav, som med Hensyn paa Temperaturforholdene naturlig kan inddeles i 2 Hovedstrøg, den i den østlige Del nordover gaaende saa- kaldte Golfstrøm og den i den vestlige Del sydover gaaende østgrønlandske Polarstrøm. Grændsen mel lem disse gaar nordenom Island op til Jan Mayen, bøier i en Bue sønden- om og østenom denne og overskrider paa omkring 3° vestlig Længde med nordostlig Betning den 71de Breddegrad. Herfra gam* den mod Øst til lienimod 7 "østlig Længde og fortsætter derfra i nordlig og lidt vestlig Betning til nor- denom den 80de Breddegrad.
I den. østenfor denne Grændse beliggende Del af Havet besidder Overfladevandet en forholdsvis hoi Tempe- ratur. der endog overskrider Luftens midt om Sommeren, hvorhos ogsaa Våndet i de nærmest under Overfladen be- liggende Lag holder Varmegrader, saaledes at 0" først fore- findes i et Dyb af omkring 500 Favne (914 Meter), hvor- fra Temperaturen jevnt og langsomt synker til omkring — 1.°3 ved Havbunden.
I den østgrønlandske Koldvandsstrom er derimod Tem- peraturen i selve Overfladen meget lav men om Sommeren i isfri t Vand dog overalt over 0U, medens den allerede fra faa Favnes Dyb og nedover lige til Bunden holder sig under 0°.
Med Hensyn paa Saltgehalten i Overfladevandet hen- vises til Kartet No. I, hvori Andes indtegnet en større Del af do Tal. der fremgaa som Middel af de efter Chlor- og Egenvægtsbestemmelserne beregnede Værdier for Salt- mængden. Efter disse Observationer findes ogsaa optruk- ket Grændserne for 3.55, 3.50, 3.45 og 3.40 "/« Salt, saar ledes som deres Form maa antages at være i Sommermaar nederne. Kartet viser, at den i Syd ind i det norske Hav strømmende Varmvandsstrøm fører Vand af temmelig stor Saltgehalt, som* i de sydligste Egne paa begge Sider af Færøerne gaar op til 3.55 % eller endog derover. Herfra gaar Strømmen videre i nordostlig Retning med noget lavere Saltgehalt (omkring 3.525 °/0) indtil lienimod Be eren Eiland, hvor den deler sig og sender en Arm mod Øst ind i Østliavet og en anden i nordlig og noget vestlig Betning
land and Jan Mayen there is a vast ridge, and here the depth does not reach 1500 fathoms (2743 metres); but south and north of that ridge it is much greater, in some localities more than 2000 fathoms (3658 metres). Barents' Sea, or. the tract of ocean stretching between Novaja Zemlja and an imaginary line drawn from Spitsbergen to the northern extremity of Norway, is everywhere exceed- ingly shallow, the depth in but few places reaching above 200 fathoms (366 metres).
The extensive series of observations shows that the temperature of the water throughout the part of Barents' Sea investigated by the Expedition, saving the most easterly and northerly tracts, exhibits everywhere a. temperature above zero, from the surface to the bottom, as is also the case with the water on- the great Norwegian banks, which, in certain localities, extend to a considerable distance from the coast. A very different relation rules in the deep western section, which, as regards temperature, may be divided into two principal tracts, an eastern, with the Gulf Stream, as it is called, flowing north, and a western, with the Arctic current, -flowing south, along the shores of East Greenland. The boundary -line between these two currents extends north of Iceland to the island of Jan Mayen, where it makes a bend southward and eastward, crossing, in long- itude about 3°W., with a north-easterly direction, the 71st parallel of latitude. From thence it runs east, and, when in longitude about 7° E.. takes a northerly and somewhat westerly direction, continuing on past the 80th parallel of latitude.
In the tract of ocean stretching to the east of this boundary, the temperature of the surface-water is compara- tively high, exceeding even that of the atmosphere in the middle of summer; the water, too. some distance below the surface exhibits a temperature above zero, the depth at which 0° is reached being about 500 fathoms (914 metres), from which the. temperature sinks slowly and gradually to about — 1.°3, at the bottom.
In the cold East Greenland current, the temperature at the surface is on the other hand exceedingly low. though in summer above zero where the water is free from ice; 0° however is reached at the depth of a few fathoms.
As regards the amount of salt in the surface-water, the reader is referred to Plate I, in which will be found most ol the figures representing the mean values, deduced from the chlorine and specific gravity-determinations, for the proportion ol salt. In Pl. I. too, are laid down curves constructed lrom these results, to show the limits of dis- tribution lor the following percentages of salt: 3.55, 3.50, 3.45, and 3.40, ås they may be assumed to extend in the summer months. The warm current, flowing from the south into the Norwegian Sea, brings with it, as shown by the Plate, an indraught of water containing a comparatively large amount ol salt, the maximum percentage, upwards of 3.55. being reached in the most southerly tracts, along the eastern and western shores ol the Feroe Islands. From thence, with a slightly reduced amount of salt (about 3.525), the
forbi Spitsbergen Vestkyst. I den mod Øst gaaende Gren synker Saltgehalten meget langsomt og jevnt, indtil den ved Grændsen af det af Expeditionen .undersøgte Eelt har naaet 3.50 °/„. medens den i den nordover flydende Arm meget kurtigt synker til endog under 3.45 °/0 for atter ved Spitsbergens Nord vestkyst at liæve sig til lidt over 3.45 "/0.
Denne i Vest for Spitsbergen forefundne ringe Salt- holdighed i Overdåden er dog sandsynligvis kun eiendom- melig for den varmere Aarstid. da der fra Spitsbergens mægtige Is- og Snebræér fly der store Mængder Fersk vand ned i det tilstødende Hav.
Indflydelsen af saadant fra Kysterne udgaaende Fersk- vand indskrænker sig dog liovedsagelig kun til meget smaa Dyb. da det saavel af disse som tidligere publicerede Un- dersøgelser af samme Art fremgaar, at et over saltere Vand flydende ferskere Overfladelag besidder en mærkelig Evne til meget længe at holde sig forholdsvis ublandet, saaledes at den fra Kysterne liidrørende Fortynding i Overfladen ofte kan spores 30 til 40 Mile tilkavs, medens man ved Hunden i Nærheden af Land ja endog i Fjordene kan finde meget saltkoldigt Vand. Denne Eiendommelighed træder meget skarpt frem i •Observ^tionsrækken No. 1 til 8.1 da Saltgehalten her fra Overfladen til 1 Favus (2 Meters) Dyb tiltager med over 1 °/o, medens den siden temmelig jevnt voxer med kun 0.06 °/0 for hver Favns Tilvæxt af Dybden. De paa Spitsbergens Banker tagne Observationer viser da ogsaa ganske rigtigt. at Våndet der paa Bunden i nogen Afstand fra Land besidder en Saltstyrke. som paa sine Steder endog gaar op til over 3.50 °/o-
Paa begge Sider af den midt efter det norske Hav flydende salte Overfladestrøm synker Saltgehalten paa den ene Side mod den norske Kyst og paa den anden Side mod den østgrønlandske Polarstrøm. en Synkning. som paa Grund a f de herskende Strømforholde hverken er jevn eller regelmæssig. Saaledes fly der der fra Nordsøen langs Norges Vestkyst i nordlig Retning en lidet saltkoldig Over- fladestrøm, som ved den 62de Breddegrad, hvor Kysten hoier nordostover, forlader denne, og fortsætter fremdeles i nord- lig Retning, indtil dens Virkningcf i omtrent 40 Miles Afstand ifra «Land efterkaanden taker sig. En mindre ud- præget lignende Kyststrom gaar fra ^ esttjordeu udover i sydvestlig Retning og naar ligeledes temmelig langt tilkavs. førend dens Indflydelse paa Saltgehalten i Overfladevandet fuldstændig forsvinder. Mellem disse Kyststrømme kaster der sig en smal Arm af det saltere Atlanterhavs vand for- holdsvis nær ind under Land, hvor den meget skarpt
1 Disse Observationer kunne desuden ogsna tjene som Bevis for Fortrinlighedeu af den af Ekman angivne Vanilhenter. som ved denne Leilighed benyttedes.
current flows in a north-easterly direction, as far north almost as Beeren Eiland. where it divides into two arms, one running east into Barents' Sea, and the other in a north-westerly direction past the west coast of Spitzbergen, In the branch flowing east, the amount of salt diminishes very slowly .and gradually down to 3.50 per cent, at the limit of the region explored by the Expedition, whereas in that running north it rapidly sinks even below 3.45 per cent, rising, however, on the north-western coast of Spitz- bergen a little above 3.45 per cent.
This low percentage of saft in the surface-water west of Spitzbergen is. however, in all probability the result of summer heat, vast quantities of freshwater pouring down to the sea at that season of the year from the immense glaciers and snow-flelds of that group of islands.
The effect of such an influx of fresh water from the coast is. however, mostly confined to a very trifling depth, the result of the observations taken on the Expedition, and of others in connexion with the same subject previously •published, being to show, inter alia, that freshwater possesses the remarkable property of floating on salt water for some considerable time in a comparatively unmixed state, so that its influence may be frequently traced at a distance of from 30 to 40 geographical miles off shore, whereas the bottom-water .close in shore, nay that of friths and estu- aries even, often contains a very large proportion of salt. This peculiar feature was strikingly instanced in the series of observations from No. I to 8. 1 the amount of salt at the depth of 1 fathom (2 metres) exceeding that at the surface by 1 per cent, whereas the subsequent increase with the depth did not amount to more than 0.06 per cent for every fathom. The observations taken on the banks of Spitzbergen show that the maximum percentage of salt in the bottom-water some distance from land, in certain localities, reaches 3.50.
On either side of the salt surface-current flowing through the medial portion of the Norwegian Sea, the amount of salt diminishes, eastward in the direction of the Norwegian coast and westward in the direction of the Arctic current oft East Greenland; but tliis diminution, owing to the effect of ocean currents, is however anything but regular and gradual. Thus, for instance, a surface-current, with a low percentage of salt, flows from the North Sea in a north- erly direction along the west coast of Norway, from which it diverges near the 62nd parallel ol latitude, continuing on. still in a northerly direction, till, about 46 geograph- ical miles from land, its influence gradually ceases to be felt. Another coastal current, more limited in extent, flows from the Vestfjord in a south-westerly direction, its influence on the amount of salt in the surtace- water being likewise perceptible comparatively far out at sea. Between these coastal currents runs a narrow arm
1 These observations likewise attest the excellence of Ekman s apparatus for collecting sea-water, which was used on this occasion.
10
afgrændser sig mod det indenfor flydcnde meget ferskere Vand. Forøvrigt holder Grændsen for det saltere Over- riadevand sig meget langt tilhavs med Undtagelse al, at den ved den 70de Breddegrad paa en ganske kort Stræk- ning kaster sig tæt ind under Kysten.
Denne Fortynding af OverHadevandet, som overalt ytrer sig- ved den norske Kyst. er intetsteds ledsaget af nogen væsentlig Forrykkelse af Overfladetemperatureu. Salt- gehaltens Formindskelse skyldes her aabenbart detfraKys- terne udstrommende Flodvand, der om Sommeren besidder en ikke ringe Varmegrad, saaledes at man i den mest fremtredende Kyststrøm langs Norges Vestkyst endog lin- der en noget høiere Overlladetemperatur end paa nærlig- gende Puncter. Ganske anderledes stiller Sagen sig paa den mod den østgrønlanskc Polarstrøm vendende Side, hvor OverHadevandet fortyndes ikke ved Flodvand men ved det ved Havisens Smeltning dannede, stærkt afkjølede Ferskvand, og det viser sig derfor, at en Synken i Saltge- halten her bestandig er ledsaget af en tilsvarende Formind- skelse af Overfladetemperaturen. Grændsen for det saltere Vand i Overfladen følger derfor paa denne Side ofte Po- larstrømméns Grændse, # og selv der. hvor den forlader denne, optræder der dog samtidig med Overgangen fra saltere til ferskere Vand altid meget tydelige Variationer i Temperaturen, der gaa i samme Retning som Saltgehal- tens. At Overfladetemperaturen synker, naar man enten nærmer sig eller overskrider Grændsen for 3.50 °/„ Salt, vise Observationerne No. 115 til 120 og No. 207 til 209.
I selve Polarstrømmen er Saltgehalten i Overfladen i nogen Afstand fra Grændsen oftest fundet meget lav, kun paa et Sted optræder i saa Henseende en Undtagelse fra den almindelige Regel, idet der omtrent paa den 75de Breddegrad skvder sig en smal Tunge med Vand af høiere Saltstyrke ind over Polarstømmen, uden at der dog derved bevirkes nogen væsentlig Forhøielse af Overfladetempera- turen. En Mærkelighedj som fortjener at omtales, er den, at Professor Dr. G. O. Sars, som paa Expeditionens Tog- ter jevnlig undersøgte Dyrelivet i Overfladen, netop paa dette Punct langt inde i Polarstrømmen har gjenfundet de for det varmere Atlanterhavsvand eiendommelige Dy refor- mer. der forresten intetsteds ellers ere fundne i den øst- gi’onlandske Koldvandsstrøm.
Med Hensyn paa Saltmængderne i de større Dyb henvises til Kartet No. 11. hvori paa samme Maade som ovenfor Andes indtegnet Saltgehalten ved Havbunden samt i de intermediate Dyb, forsaavidt Observationerne refererer sig til Puncter saa dybt under Overfladen, at Temperatu- ren der ligger under 0°. Hvor en Observation hidrører fra et intermediært Dyb, er Tallet i Kartet understrøget.
Naar man bortser fra enkelte i Nærheden af Kys- tenie og paa grundt Vand optagne Vandprøver, varierer Saltgehalten paa de store Dyb mellem 3.59 og 3.45 %,
of the salt ocean-water of the Atlantic, distant but a lew miles from land, its boundary being distinctly marked by the limits of the brackish water flowing along the shore. Except in this region, and a locality bordering the 70th parallel of latitude, where, tor a short distance, it runs close to the coast, the boundary of the salt surface-water lies far out at sea.
This dilution of the surface-water on all parts of the Norwegian coast is not anywhere found to exert a material influence on the surface-temperature. The decrease in the amount of salt must be obviously ascribed to the influx ol river-water, the temperature of which during the summer months is relatively high, — so high indeed, that the principal coastal current, flowing along the western shores ol' Norway, has a, somewhat higher surface-temperature than that observed in its immediate vicinity. • Phenomena the reverse of these prevail in the tract of ocean exposed , to the influence of the Arctic, or East Greenland, current. There, the surface-water is not diluted by an influx of river- water, but with freshwater of a low temperature, produced by the melting of drift-ice; and hence a decrease in the percentage of salt is invariably attended with a correspond- ing reduction of the surface-temperature. The salt surface- water borders, therefore, not infrequently the Arctic current; and even where its boundary diverges from it. the transi- tion from salt to comparatively fresh water is always ac- companied by a • very considerable variation in temperature, proportionate to the variation in the amount of salt. That the surface -temperature becomes gradually lower on- ap- proaching the limits of the section in which the proportion of salt is 3.50 per cent, will be seen from the series of observations Nos. 115 — 120 and Nos. 207 — 209.
In the Arctic current, some distance from its extreme boundary, the proportion of salt at the surface was found to he very small, except in one locality, near the 75th parallel of latitude, where a narrow strip of salter water flows into the current, without, however, causing an appreci- able rise in the surface-temperature. It is a remarkable fact, which must not be passed by unnoticed, that Profes- sor G. 0. Sars, naturalist to the Expedition, found here in the surface-water, which lie examined from day to day, forms of animal life peculiar to the warm area of the Atlantic water, which be never met with in any other part of the cold East Greenland current.
As regards the amount of salt observed at great depths, the reader is referred to Pl. II, in which, as in Pl. 1. will be found the percentage both at the bottom and at intermediate depths, provided the observations were taken with samples of water the temperature of which in situ was below 0". Observations with water from interme- diate depths are denoted by underlining the figures ex- pressing their results.
Disregarding a few samples of water collected .near the coast and in shallow spots, the proportion of salt, where the depth is great, ranges from 3.59 to 3.45 per
og Differentserne ere saaledes ogsaa lier vel paa viselige' om end mindre end i Overfladen. For tydeligt at kunne mar- kere disse optrædende Differentser paa en let overskuelig Maade, har jeg benyttet forskjellige Farver. Saaledes ere de Strøg, hvor Saltgehalten beløber sig til 3.50 °/o eller derunder, betegnede med blaa Farve, de Strøg, hvor Salt- gehalten ligger mellem 3.50 og 3.55 °/0. med rød F arve, medens de Vandmasser, der ifølge Observationerne besidde en Saltmængde af over 3.55 °/0, ere tegnede med en noget kraftigere rød Farve. I Nærheden af Kysterne er Kartet overalt ufarvet uden Hensyn til. om Våndet der henhører under den ene eller den anden af de tre Hovedgrupper.
Den uregelmæssige .Fordeling af Saltgehalten i de større Dyb, som det saaledes tegnede Kart udviser. maa unegtelig -betegnes som meget paafaldende. At Saltmæng- derne paa Bankerue og i den sydlige Del af Østhavet paa det Nærmeste tindes at svare til den, som det i Overfladen svømmende varme Atlanterhavsvand besidder, kan ikke synes overraskende. Havet er her meget grundt, og det deri fiydende Vand besidder overalt en Temperatur af over 0" og maa saaledes nærmest henføres til den nordover fly- dende Atlanterhavsstrøm, med hvilken det da ogsaa helt naturligt har Saltgehalt tilfælles. Ligeoverfor de store Dyb maatte man derimod paa Forhaand vente et andet Resul- tat. Temperaturen ligger her uden Uudtagelse under 0” ja paa de fleste Steder endog under — 1", og det kunde derfor synes rimeligst at tilskrive det der fiydende \ and polar Oprindelse. Det fremgaar imidlertid med Bestemt- hed af alle mig bekjendte Undersøgelser over Saltmæng- derne i de forskjellige Have, at de fra arktiske Egne ud- gaaende Strømme uden Uudtagelse fører ^ and at lavere Saltgehalt end de fra de mere tempereredé Himmelstrøg udgaaende Varmvandsstrømme, og man skulde derfor i de dybere og koldere Lag af det her undersøgte Hav vente at finde en Vand masse med adskilligt lavere Saltgehalt end den, der er funden i det i Overfladen og nærmest under den fiydende Vand. som aabenbart skriver sig fra varmere Egne. Hvad der virkelig finder Sted er desuagtet dette, at det i de dybere liggende Lag fiydende, iskolde Vand paa store Strækninger viser sig at have en Saltgehalt, der temmelig nøie svarer til den, der er funden i den atlan- tiske Overtladestrøm.
Saavel af denne Grand som ogsaa af andre Grunde, som jeg senere skal fremføre, tinder jeg det nmeligt at gjøre del Antagelse, at Våndet paa de større Dyb paa de Steder, som i Kartet tindes aflagte med rød Farve, enten udelukkeude skriver sig fra varmere Egne eller under en- hver Omstændighed er saa opblandet med saadant \and. at det Hele derved antager en tydelig atlantisk Karakter, medens Våndet i de med blaa Farve betegnede Stræknin- ger mere eller mindre skarpt udpræger sig som hidrørende fra polar Oprindelse. •
Hvor det gjælder at besvare Spørgsmaalet om. hvor- ledes de øvre Lag finder Vei ned til Bunden. da synes dette ikke at kunne besvares paa anden Maade, end at det atlantiske Vand under stadig Afkjøling maa synke gjen- nem det iskolde og fordrive dette, under enhver Omstæn-
cent: and there tod, accordingly, the differences are appre- ciable, though smaller than at the surface. For the better apprehension of these differences, the sections in which
I they occur have been differently coloured in the Plato: blue indicates a percentage of 3.50, and under; red, a per- centage ranging from 3.50 to 3.55; and a somewhat deeper
!red, a higher percentage than 3.55. Along the coasts, the Plate is left uncoloured, no matter to which of the three principal groups the water there belongs.
This irregular distribution of the amount of salt at great depths, as shown in the Plate, is certainly a most remarkable phenomenon. That the proportion of salt on the banks and in the southern portion of Barents' Sea should agree pretty closely with that contained in the warm surface-water of the Atlantic, is not indeed surprising: the depth is in both localities comparatively trifling, and the water, having everywhere a temperature above 0°, must be referred to the warm Atlantic current; its percentage of salt is therefore naturally the same as that of the Gulf Stream. For the great depths, on the other hand, there was reason to expect a very different result. Here, the temperature is without exception below 0°, nay inmost places below —1°; and hence,, as regards the origin of such water, there seems much to urge in favour ot an in- draught from the Polar Sea. Of the observations undertaken to determine the amount ot salt in sea-water, all with which l am acquainted furnish incontestible proof that the water of the currents flowing from the Arctic Ocean has a lower percentage of salt than that of the warm currents flowing from more temperate regions; and the proportion of salt in the deeper and colder strata of the tract oi ocean explored by the Expedition was expected, therefore, to prove considerably lower than that observed at the sur- face or a short distance beneath it, where the water is ob- viously an influx from warmer climes. But such was not the case, for the amount of salt found in the water of the cold area, where the temperature is below zero, agrees, in some localities, pretty closely with that in the water of the Atlanic surface-current.
This phenomenon, in conjunction with reasons that will afterwards be explained, has led me to assume, that the water met with at great depths in the sections coloured red in the Plato, is either exclusively the result of an in- flux from warmer regions, or is. at least, so mixed with such water as to have distinctly acquired Atlantic charac- teristics: whereas the water in the blue-coloured sections would seem to indicate more or less determinately a Polar origin.
As to the question involved in the descent ot the upper strata to the bottom, the only 'way in which this can take place seems to be by tin* Atlantic- surface-water, as it parts with its excess of heat, gradually sinking through the water of the cold area, and displacing it: at all events,
70
digked synes det sikkert, at man for det afgrændsede østen- for Jan Mayen beliggende Strøg ikke kan antage nogen anden Vei. Men at den varmere Vandmasse saaledes skulde synke gjennem den koldere. kunde jo ved første Øiekast synes stridende mod vel kjendte Naturlove, da man nærmest maatte tro. at det i Nærheden af Overdåden fly- dende atlantiske Vand paa Grand af sin høiere Tempera- tur skulde være specifisk lettere end det ifølge sin lave Temperatur stærkt fortættede Bundvand. Nærmest for at fjerne enhver Tvivl i saa Henseende, er del* i den forken gjengivne Takel opført en Rubrik for Vandprøvernes Egen- vægter ved den i Havet observerede Temperatur i Forhold til rent Vand af 4 '. Ved Hjælp af de der beregnede Tal kan man med Lethed studere den specidske Vægts Varia- tion med Dybden, saaledes som den finder Sted i Havet, bortseet fra den ved Vandets Sannnentrykkeligked foraar- sagede Fortætning i de større Dyb.
Den Region, som i denne Henseende mest interesse- rer os. er den. hvori der i Overfladen og nærmest under den findes en bestemt udpræget atlantisk Varmvandsstrøm. en Region, som paa det Nærmeste falder sammen med den søndenfor en Linie fra Island til Beeren Eiland liggende Del af Havet, dog saaledes at det nærmest Norge liggende Parti paa Grund af den fra Ivysterne udgaaeude Fortyn- ding maa bortskjæres. Grupperer man de i denne Egn tagne Observationer over Saltgehalt og den specifiske Vægt reduceret til Havets Temperatur og en Atmosphæres Tryk efter Dybden, fremgaar som Resultat heraf Følgende.
|
Dvbdeinterval. |
Midlere Dybde. |
Midlere Saltgehalt |
Midlere Egenviugt ved |
||
|
Engelske Favne. |
Meter. |
Engelske Favne. |
Meter. |
Havets Tempe- ratur. |
|
|
O |
0 |
0 |
0 |
3-526 |
1 .02688 |
|
0—300 |
0—549 |
167 |
305 |
3514 |
1.02782 |
|
300 — 600 |
549-1097 |
502 |
918 |
3-521 |
1.02812 |
|
600 — 1000 |
1097—1829 |
681 |
1245 |
3-5I3 |
1.02802 |
|
IOOO 1500 |
1829-2743 |
1203 |
2200 |
3-506 |
1 .02800 |
|
under 1 5 00 |
under 2743 |
1688 |
3087 |
' 3-507 |
1.02800 |
Det i denne Tabel erholdte Tal for Saltgehalten paa Strøget mellem 0 og 300 Favnes (0 og 540 Meters) Dyb er imidlertid uden Tvivl for lavt. da en uforholdsnuessig stor Del af Observationerne i dette Dyb hidrøre fra Øst- havet. hvor Saltgehalten overalt er mindre end i de cen- trale og sydlige Dele af Feltet. De Observationer. som skrive sig fra dette Dyb i større Afstand fra Kysten, tyde hen paa. at Saltgehalten der meget nær svarer til den. der er lunden i Overfladen paa de samme Steder. Denne Mis- lighed ved den geografiske Fordeling af Observationerne fra de mindre Dyb faar derimod ingen væsentlig Indflvdelse paa det som Middel a f de specifiske Vægter erholdte Tal. da den i de nordligere Egne ved Saltgehaltens Synkning ioraarsagede Formindskelse af Egenvægterne paa det Nær-
it is certain that no other plausible explanation can be given of the phenomenon for the region east of Jan Mayen. But, that water of a higher temperature should sink in this manner through water of a lower, appears at first sight to be at variance with well-known physical laws; for the water from the Atlantic current having a higher temperature, one would imagine it to be specifically lighter than the cold and dense bottom-water. With the object of dispelling every doubt that might arise in connexion with this sub- ject. a column has been added to the Table given above for the specific gravity of the samples of water at their temperature in situ . as compared with that of pure water of 4°. By means of the figures set down in the column, the variation of the specific gravity with the depth, as it occurs in the sea irrespective of increased density from the compressibility of water at great depths, may be readily investigated.
The tract of ocean which in this respect it will be most desirable to investigate, is that through which flows, on or near the surface, a warm current, setting from the Atlantic, — a tract which nearly coincides with the region stretching south of an imaginary line drawn from Iceland to Beeren Eiland, but from which, owing to the influx of freshwater, must be cut off the section extending along the Norwegian coast. Now, if we group together the ob- servations taken in this part of the North- Atlantic to determine the percentage of salt and the specific gravity reduced to the temperature of the sea and a pressure of one atmosphere, the result will be as follows: —
|
Intervals of Depth. |
Mean Depth. |
Mean Amount of Salt per cent. |
Mean Sp. (t r. at the Temp, of the Sea. |
||
|
English Fathoms. |
Metres. |
English Fathom's. |
Metres. |
||
|
O |
0 |
0 |
0 |
3-526 |
1.02688 |
|
0—300 |
0—549 |
167 |
305 |
3-514 |
1 .02782 |
|
300—600 |
549-1097 |
502 |
918 |
3-521 |
1.02812 |
|
600-1000 |
1097—1829 |
681 |
1245 |
3-513 |
1.02802 |
|
1000—1500 |
1829-2743 |
1203 |
2200 |
3-506 |
1.02800 |
|
below 1500 |
below 2743 |
1688 |
3087 |
3-507 |
1.02800 |
The figures in this Table expressing the amount of salt at depths ranging from 0 to 300 fathoms (0—549 metres) are, however, unquestionably too low. . seeing that a disproportionate number of the observations at this depth were taken in Barents Sea, where the amount of salt is everywhere smaller than in the central and southern sections ol the tract investigated. The observations refer- ring to this depth at a considerable distance from land, show that the percentage of salt is very nearly the same aS that at the surface. The said defect in the geographical disti ibution oi the observations taken at a comparatively trifling depth, does not however materially affect the cor- rectness ot the figures expressing the mean specific gravity ; tor the tall in specific gravity occasioned in northern regions
71
meste opveies af don Forøgelse af samme, der skyldes de der herskende lavere Temperaturer.
Det fremgaar altsaa, at Differentserne mellem Salt- gehalten i de atlantiske Overfladelag og de paa Hunden hvilende iskolde Yandmasser gjennemsnitlig kun ere meget smaa, om de end paa de Puncter, hvor Våndet i de dybere Lag besidder en overveiende polar Karakter, turde være adskilligt mere fremtrædende. Disse Differentser af hen- imod 0.02 °/p ere dog mere end tilstrækkelig store til i de nederste mere alkjølede Lag af det atlantiske Vand at fremkalde et, som det vil sees af Tabellen, meget tydeligt om end svagt Maximum af den specifiske Vægt, livad der nærmest bevirkes derved, at Søvandet ved Afkjøling under 0° nærmer sig sit Tæthedsmaxinium og derfor i Nærheden af dette for mindre Temperatur variationer kun forandrer sit Volum med næsteh umærkelig smaa' Værdier, saaledes at en selv meget ringe Forøgelse af Saltgehalten under disse Omstændigheder faat en overveiende IudHydelse lige- overfor en Grads Forandring af Temperaturen.
Det er saaledes saa langt fra Tilfælde, at der i de specitiske Vægter af de forskjellige Vandlag ligger nogen Hindring for Antagelsen af, at det atlantiske Vand skulde synke .gjenuem det koldere Polarvand, at man tvertom af , disse maa, slutte, at .saa maa være Tilfælde, dersom ikke andre i Havet herskende Strømme virke hemmende paa en saadan Bevægelse. Man tænke sig f. Ex. ved Siden af hinanden i Havet to Vamdsøiler af 2000 Favnes (3658 Meters) Dybde, hvori Temperaturens Variation med Dybden for Simpelheds Skyld kan antages at være den samme, hvorimod Saltgehalten i den Iste helt igjemiem sættes til 3.52 °/0f medens den i den 2den paa Strøget fra Overdåden til 500 Favnes (014 Meters) Dyb gives Værdien 3.52 °/0 og fra 5U0 til 2000 (914 til 3658) Værdien 3.50 °/0, saa- ledes som Forholdet ifølge Observationerne virkelig synes at stille sig paa enkelte Steder i det undersøgte Hav. Det er da umiddelbart indlysende, at en saadan Fordeling af Saltgehalten vil have en Synkning i den Iste Søile til Følge, saaledes at Våndet i denne vil søge at udbrede sig langs Hunden og fordrive det omliggende specifisk lettere Vand. Den Hastighed, hvormed en saadan Bevægelse foregaar, vil naturligvis rette sig efter Differentsen mellem Trykkene i samme Niveau i begge Søiler, en Differents. som ved Bunden i 200U Favnes (3658 Meters) Dyb efter Beregning beløber sig til henimod 32 mm Kviksølvsøile.
For nærmere at begimnde den forhen iremsatte Hvpo- these, om at det paa Bunden hvilende iskolde \ and paa de i Kartet med rød Farve betegnede Steder skulde have atlantisk Oprindelse, vil jeg benytte mig af de i en tidligere Afhandling1 beskrevne Observationer over de i Søvandet iudeholdte Kvælstofnuengder, hvis Anvendelse i saadaut Øiemed allerede paa det Sted løselig er ble ven antydet.
Som bekjendt herskede der i ældre Tider den An- skuelse. at de i Søvandet i de større Dyb indeholdte Luft- mængder paa Grtind af det der herskende Tryk maatte
by a decrease in the amount of salt, is almost compensated by the rise resulting from the low temperatures prevailing there.
It appears, therefore, that the differences between the amount of salt in the warm upper strata and that in the cold water at the bottom, are, on an average, exceedingly small, though more striking perhaps in localities where the water of the deeper strata to a very great extent is Polar in origin. These differences — about 0.02 per cent — are, however, as will be seen from the Table, more than suffi- cient in the deepest and coldest strata of Atlantic water to occasion an appreciable, though a low. maximum of specific gravity, which is explained by the fact, that sea- water below 0" has very nearly reached its maximum of density, and the increase in volume then resulting from trifling variations in temperature, is a well nigh inappreci- able magnitude: hence, under such circumstances, the in- fluence of a very slight addition to the amount of salt with but one degree’s difference in temperature will be ex- ceedingly great.
Such being the case, there is nothing in the specific gravities observed in the different strata of water to dis- favour the assumption that the comparatively warm At- lantic water should sink through the cold water of Polar origin; nay, from these specific gravities we may infer its correctness, provided only that such descending motion be not counteracted by the effect of ocean currents. To give an illustration. Let us imagine two columns of water, 2000 fathoms (3658 metres) deep, in both of which, for convenience' sake, the variation in temperature with the depth is assumed to be equal ; the amount of salt on the other hand, being put at 3.52 per cent throughout the whole of the first, but in the second, at 3.7)2 per cent from the surface to a depth of 500 fathoms (914 metres), at 3.50 per cent from 500 to 2000 fathoms (914—3658 metres). — a ratio of distribution actually observed in some localities. This given, it is obvious that such a distribution must cause the water in the first column to sink, and spread itself over the bottom, displacing as it does so the speci- fically lighter. The rapidity of this downward motion will of course be proportionate with the difference in pressure at the same level in the two columns, a difference which, at the depth of 2000 fathoms (3658 metres), has been computed equal to that of a column of mercury 32 wm in •height.
With a view to furnish additional confirmation of the hypothesis brought forward above, which assumes the cold bottom -water in the red-coloured sections of the Plate to be of Atlantic origin, 1 shall have recourse to my observations on the amount of nitrogen in sea-water, published in a former paper,1 where their application to such a purpose was briefly alluded to.
The opinion formerly entertained, that the quantity of air contained in sea-water at great depths must be ex- ceedingly great, by reason of the immense pressure pre-
’ "Om Luften i Søvarittet/’
1 “On the Air in Sea-Water."
72
være uforholdsmessig store, en Anskuelse, som ved de senere Undersøgelser fuldstæudig er bleven modbevist. Rig- tignok er det paa den engelske Cliallengerexpedition iagt- taget, at de i den hede Zone fra Havbunden optagne A and- prøver ved at henstaa nogen Tid vise Overmætningsphæno- mener. men dette vil jo ikke være vanskeligt at forklare, naar man erindrer, at Våndet i de store Dyb selv iÆqta- toregnene er meget nær iskoldt. Det følger nemlig at sig selv. at de til en saa lav Temperatur svarende Luftmæng- der ikke kunne holdes opløste, naar Vandprøverue ved læn- gere Tids Henstand antager de tropiske Egnes liøie Luft- temperatur. Stærkest taler de paa den norske Expedition udførte Luftbestemmelser for. at Tryktilvæxten med Dyb- den ikke kan have nogen Indflydelse paa Mængden af den i Sovandet opløste Luft. Tager man nemlig Middelet af Dybder. Temperaturer og Kvælstofmængder for .alle de fra Puncter under Overfladen stammende Våndprøver, hvori der paa denne Expedition er foretaget Luftbestemmelser. erholder man til et Middeldyb 693 Favne (1267 Meter) en Middeltemperatur — 0."05 og en midlere Kvælstofgehalt 13.99 CC. per Litre, det vil sige. Våndet i Dybet indeliol- der gjeunemsnitlig næsten 0.5 CO. Kvælstof mindre, end det ved sin Temperatur vikle kunne holde opløst under eli Atmosphæres Tryk.
Naar man erindrer, at Trykket i Havdybene ikke dreier sig om Atmosphærer men om Hundreder af Atmo- sphærer. saa maatte man dog vente, at dets Indflydelse (om det havde nogen) vikle give sig tilkjende ved Uregel- mæssigheder a f pa a viselig Størrelse, og man er, da dette ikke i mindste Maade er Tilfæklet, berettiget til den Slut- ning, at Trykket ikke besidder nogen Evne til i mærkbar. (i rad at opkobe Luftmængderne i de store Dyb. Paa den anden Side maa det fomuftigvis antages, at Våndet i de dybere liggende Lag ikke kan afgive rioget af sin Luft. da det jo paa Grund af det der herskende Tryk vil kunne holde opløst overveiende større Mængder end de, der nogen- sinde ere forefundne.
Den rimeligste Slutning af de senere Tiders Obser- vationer over disse Gjenstande vil saaledes være den, at en Yandprøve, saahenge den befinder sig under Overfladen. uforandret vil beholde den samme Luftmængde eller rig- tigere Kvælstofmængde1, som den havde absorberet. da den sidste Gang befandt sig i Overfladen udsat for Luftens frie Indvirkning.
Nu er den Luftmængde. som Sovandet absorberer af Atmosphæren, hovedsagelig afhængig af Vaudets Temperatur, idet Barometerstandens Variationer ligeoverfor støi-re Tem- peraturdiffcrentser kun har en underordnet Betydning. Heraf følger, at de Vandmasser, der have absorberet sin Luft- mængde under varmere Himmelstrøg. maa være forholdsvis
1 Den absorberede Surstofmængde er nemlig i nogen Grad af- luvugig af Dyrelivet «g andre Tilfældigheder, saaledes at det her lige- Kom i den tidligere Afhandling vil viere det Rigtigste at anvende Kvælstofmængden som Maal for den samlede Luftmængde.
vailing there, has been wholly refuted by the results of later observations. True, the samples of water obtained at great depths within the tropics on the “Challenger Expedition were found to exhibit the phenomena of super- saturation when allowed to stand over some time; this, however, is easily explained, il we call to mind that the water at great depths, even in equatorial regions, lias a temperature but little above zero. Hence it naturally fol- lows. that the quantity of air corresponding to so low a temperature cannot be retained on the samples ol water having stood over sufficiently long to acquire the high tem- perature of the atmosphere in tropical climates. The air- determinations performed on the Norwegian Expedition afford the strongest proof ol' the fact, that the increase of pressure with the depth does not exert any appreciable influence on the proportion of air in sea-water. Now. it we compute the mean depth, temperature, and amount of nitrogen for all the samples of water from below the sur- face examined for air-rdetermiuations, the result will be as follows: mean depth 693 fathoms (1267 metres); mean temperature — 0.° 05 ; mean amount of nitrogen 13.99 cc per litre, which shows that in the depths of the ocean the proportion of nitrogen averages 0.5 cc less than could be absorbed by sea-water ol the temperature prevailing there with the pressure of one atmosphere.
If we call to mind that the pressure in the depths of the sea is not computed even by tens, hut by hundreds of atmospheres, its influence, if any. must surely, one would imagine, occasion irregularities of appreciable magnitude; and we may therefore safely conclude, since no such disturbance can be detected, that pressure does not perceptibly increase the amount of air at great depths. On the other hand, there is every reason to infer, that the water in the lower strata, owing to the immense pressure, cannot part with any of its air. the quantity actually absorbed never being even approximately so great as such a pressure would enable it to retain.
From the latest observations throwing light on this question, we may therefore reasonably infer, that all sea- water below the surface retains undiminished the quantity of air. or rather of nitrogen.1 which it absorbed when last at the surface, in direct contact with the atmosphere.
Now. the quantity of air absorbed by sea-water is mainly dependent on the temperature of the latter, tile rise or fall of the barometer, as compared with consider- able differences in temperature, being in this case of hut little moment. Hence it follows, that the proportion of air absorbed by sea-water in warm climates is small compared
1 The amount of oxygen absorbed by sea-water depending to a certain extent on the presence of animal life and other accidental causes, the amount of nitrogen may. with greater precision, be as- sumed to represent the total amount of air — a standard' of measure- ment adopted in the proceeding Memoir.
73
lidet luftholdige, medens de, der have absorberet sin Luft- mængde i de arktiske Egne, maa indeholde meget større Mængder, og man vil derfor netop i de paa Expeditionen udførte Gasanalyser have et fortrinligt Middel til at con- trollere den forhen opstillede Hypothese, ifølge hvilken en- kelte Regioner af det iskolde Dyb skulde være opfyldt af Vandmasser, der ialfald delvis havde. atlantisk Oprindelse.
Forat vise Udfaldet af en saadan Control har jeg teg- net Kartet No. III. hvorpaa efter samme Princip. som det ved Tegning af Kartet No. II befulgte Andes afsat de i Dybet fundne Kvælstofmængder udtrykte i CC. pr. Litre reducerede til 0° og 760wm Tryk. ligesom der ogsaa ved Si- den af disse Tal Andes opført den Temperatur, hvorved Søvandet absorberer denne Ivvælstofmængde. beregnet til nærmeste hel Grad efter den af de tidligere bskrevne For- søg udledede Formel
N= 14.4;— 0.23|
Det siger sig selv, at disse Temperaturer ikke kunne gjøre Fordring paa nogen stor Grad af Nøiagtighed. da en forholdsvis liden Feil i Kvælstofbestemmelsen bevirker en meget stor Feil i den deraf beregnede Temperatur. Der Andes saa ledes flere Observationer, der give Temperaturen
— 4", en Temperatur, der mig bekjendt. ikke er observeret i Havet. Dette vil dog ikke forekomme saa urimeligt, naar man tåger Hensyn til. at Søvand ai — 2° ved <8pmm Barometerstand’ absorberer en Kvælstofmængde. der paa det Nærmeste gaar op til. hvad der i Ydertiliældene er fundet.
Farvelægningen er her foretagen saaledes, at*deStrøg, hvor Kvælstofmængden er funden at være 14.4 CC. eller derover, ere betegnede med blaa Farve, de Strøg, hvor Kvælstofmængden ligger mellem 14.4 og 12.5 CC.. med en svag rød Farve, medens et mindre Parti, hvor Kvælstot- mængden er funden at ligge under 12.5 CC., er betegnet med en noget kraftigere rød Farve. Betydningen at disse Farver bliyer ligesom i Kartet No. IT den, at de røde Far- ver* bedække de Strækninger, hvor Yandet i mere eller mindre Grad besidder atlantisk Karakter, medens den blaa Farve tilhører de Yandmasser, der have absorberet sin Kvælstofmængde. ved en Temperatur af under 0°, og som altsaa nærmest synes at hidrøre fra de arktiske Egne.
Ved at sammenligne Kartene No. II og III vil man strax se. at Farvelægningen i disse i alt \ æsentligt \isei en særdeles stor Overensstemmelse, som paa mange Puucter
endog nærmer sig til Congruents,* om man end 'ed næi- niere Betragtning vil Ande. at disse Ligheder ikke gaa igjen i alle Detailler, hvad man heller ikke paa nogen Maade kunde vente. Grændserne bliver nemlig paa Kartet No.* III paa Grund af Observationernes Faatallighed meget vanskelige at bestemme, ja der Andes endog her paa om- kring den 65de Breddegrad et større Strøg, hvorom man intet med Bestemthed kan slutte, da der under Analysen tabtes en mindre Del af de Luftprøver, der vare bestemte til at udfylde dette Hul. saaledes at den samlede Lult- mængde désværre ikke kunde maules. Desuden ere ogsaa Observationsfeilene baade for Salt- og Kvælstofbestemmel-
Den norsko Nordlinvscxpedition. Tornoe: Cliemi.
with that absorbed in the Arctic regions, wherefore the analyses of gas performed on the Expedition furnish an excellent means of testing the value of the hypothesis ac- cording to which certain sections of the cold area are assumed to be made. up of water part of which at least would seem to be of Atlantic origin.
To show the result of such a test, I have annexed a third Plate (drawn on the same principle as Pl. II), in which are given the different amounts of nitrogen present in deep water, expressed in c.centim. per litre, reduced to 0° and a pressure of760™m. Along with these Agures will be found, too, the temperature at which sea-water absorbs such an amount of nitrogen, computed, in whole degrees, by means of the formula deduced from the observations pre- viously described, viz : —
14.4 — 0.23C
These temperatures cannot of course pretend to any high degree of accuracy, a comparatively small error in a nitrogen-determination involving a very considerable error in the temperature. Thus, for instance, several of the ob- •servations indicate — 4". a temperature which, so far as I am aware, was not anywhere observed in the sea. rI his. however, will not appear so strange, if regard be had to the fact, that sea-water of — 2°, at a pressure correspond- ing to 780™m, absorbs an amount of nitrogen which agrees very closely with the highest found on the Expedition.
The sections in this Plate are coloured as follows: those in* which the amount of nitrogen was found to equal or to exceed 14.4% blue; those in which it ranged from 14.4 to 12.5% light red; a somewhat deeper red serves to indi- cate a small tract in which the amount of nitrogen did not reach 12.5. Moreover, as in Plate II. the red coloui indicates water more or less distinguished by Atlantic characteristics; the blue, -water in which the nitrogen was absorbed at a temperature below 0°, and which, therefore, would seem to have derived its origin' from some part of the Polar Seas.
A comparison of Plates II and III will at once show considerable agreement in the distribution oi colour, many of the sections almost coinciding; though, on closer inspection this approach to congrulty is not found to char- acterise all details, which indeed there was no reason to expect. In PI. III. the limits proved exceedingly difficult to define, owing to the limited number of observations; nay, respecting an extensive tract near the 65th parallel of latitude nothing definite can be inferred, part of several samples of air. the analysis of which would have served to All up the blank, having been unfortunately lost, and the total amount of air could not, therefore, be measured. Besides, the errors of observation both in the salt and the nitrogen determinations, are so considerable, when com- pared with the minute differences in amount, that, in some
n
semes Vedkommende af saadan Størrelse, at de i Sammen- ligning med de sraaa Differentser, som det her gjældev at paavise, lettelig paa sine Steder kunne gjøre sig gjældende og frembringe Uoverensstemmelser, hvor de i I ilfælde at absolut nøiagtige Observationer ikke vilde tindes.
Hvilke'n Vægt man nu end vil tillægge disse faaFor- skjelligheder mellem de to Karter, saa meget er dog sikkert, at de kun optræde som Undtagelser, medens den langt stæi- kere fremtrædende Regel er Overensstemmelser ai saadan Art, at de ikke uden videre kunne tilskrives Tilfældiglieder. Der existerer uimodsigeligt en paa mange Puncter næsten til Proportionalitet grændsende lovmæssig Forbindelse mel- lem Saltgehalten og lvvælstofmængderne. som muligens ikke turde lade sig forklare paa anden Maade end netop gjen- nem den for omtalte Hypothese. som saaledes maa ansees for at indebolde ialfald en stor Del Sandhed, idet den samtidig bestyrkes af to af hinanden fuldstændig uafhængige, uensartede Observationsrækker, der i alt Væsentligt give det samme Resultat.
Den, som det synes, største Vanskelighed ved denne Hypothese bestaar i at forklare, hvorledes det i de store Dyb flydende atlantiske Vand skulde have antaget en saa lav Temperatur, som det ifølge Observationerne viser sig at besidde. Dette turde dog inaaske ikke synes saa urime- ligt, uaar man betænker, at den varme, søndentra kommende Atlanterhavsstrøm ved at flyde henover det underliggende meget kolde Vand paa de nærmest til dette grændsende Lag maa blive udsat for en meget stærk Al kjøling neden- - fra, og at det først gjennem • en saadan Afkjøling til om- kring 0° opnaar den hoie specifiske Vægt, der er den nød- vendige Betingelse for. at det skal kunne synke tilbunds. Det atlantiske Vand har altsaa, allerede førend det begyn- der at synke, antaget en meget lav Temperatur og vil desforudén- under selve Synkningen, idet det da kanske i et meget langt Tidsrum belinder sig paa alle Sider omgivet af polart Vand, end yderligere blive Gjenstand for Afkjø- ling, førend det naar Bunden. Det fremgaar forøvrigt ogsga af de endnu ikke offentliggjorte Temperaturobserva- tioner. som jeg desuagtet ved Velvillie af Professor Molin har faaet Anledning, til at gjøre mig bekjendt med, at Temperaturen i de store Dyb paa de med rød Farve be- tegnede Partier er no'get høiere end der, hvor Kartet er farvet blaat, saaledes at i Virkeligheden ogsaa Temperatur- forholdene tale for den opstillcde Hypothese.
Det vilde dog være paa urette Sted paa dette Sta- dium at. forsøge * udredet alle Vanskeligheder, saalænge de paa Expeditionen udførte talrige Temperaturbestemmelser endnu ikke ere forelagte Offentligheden, da man alene ved at tage tilbørligt Hensyn til det hele foreliggende Materiale af Observationer vil kunne vente at faa det bedst mulige Indblik i de mere indviklede Spørgsmaal om Strømforhol- dene. Det er dog meget sandsynligt, at man senereheu ved at combinere alle Data vil kunne kaste Lys over me- get, som nu maa synes dunkelt.
Uheldigvis var det ved Expeditionens Udreise* ikke muligt at forudse. at de chemiske Observationer skulde kunne føre. til Slutninger af saadan Art som de lier paa-
of the computations, they might easily affect the result, and give rise to discrepancies which, with perfectly accurate observations, there would be no fear of.
Whatever weight may be attached to these differences, they must unquestionably be regarded as exceptional; the rule is agreement, and of a character precluding the possi- bility of ascribing it to chance. Many ot the observations prove incontestibly the existence of a definite, well nigh proportional connexion between the amount ot salt and that of nitrogen, “a connexion difficult, perhaps, to explain without having recourse to the aforesaid hypothesis, which cannot but come near the truth, confirmed as it is by two widely different series of observations, leading, each independently of the other, in all essential points, to the same result.
The greatest apparent difficulty involved in this hypo- thesis consists in explaining the low temperature of the Atlantic water in the deeper strata. We must, however, bear in mind that the warm Atlantic current, in flowing over the cold ‘water of the lower strata, is necessarily made to part with a very considerable amount of heat; and that the high specific gravity, without which it could not sink to the bottom, involves a temperature of about 0°. Hence, the Atlantic water will have acquired a very low temperature before beginning to sink, and moreover, being surrounded during its downward passage, possibly for a considerable period, by Polar water, give off a further amount of heat ere it reaches the bottom. For the rest, it appears from the independent series of temperature observations, not yet in print, with which Professor Mohn has kindly made me acquainted, that the temperature at great depths in the sections coloured red in the Plate, is somewhat higher than in those coloured blue ; and hence the hypothesis adopted here derives additional support from the variation in temperature.
Meanwhile, it would be premature to attempt dis- posing of all difficulties, till the numerous temperature determinations performed on the Expedition shall have been made public, since to elucidate fully the more intri- cate questions connected with ocean currents, the whole stock of materials must be dealt with. We may however venture to hope, that, at a later stage of this interesting inquiry, a general combination of data will throw light upon much that is at present involved in obscurity.
Unfortunately, it was not possible to foresee on the departure of the Expedition, that such inferences as those here, pointed out would be drawn from the chemical ob
75
pegecle, og det er derfor helt naturligt, naar Undersøgel- serne ikke i Henseende til Studiet af tidligere ukj endte Eiendommeligheder ved Havet kunde føre til saa fyldige Resultater, som ønskeligt kunde være. Men om end disse Undersøgelser paa. Grund lieraf nærmest faa Karakteren af forberedende Arbeider, saa vil det døg, som jeg lumber, indrømmes, at de desuagtet kunne have sine maaske ikke uvigtige Følger, idet de vise, at man gjennem de chemiske Observationer, der tidligere i Sammenligning med Tempe- ratur- og Dybdebestemmelser har spillet en mindre frem- tredende Rolle ved Studiet af Havets Pliysik, vil kunne skaffe Oplysninger om mærkelige Forholde i Havet, som man ad anden Vei vanskelig skulde falde paa at søge op- klarede. Man vil ved Hjælp af de her erholdte Resultater med Lethed i Fremtiden kunne udkaste en detailleret Plan for en fornyet Undersøgelse af det norske Hav, der i mine Øiue stiller sig som særdeles ønskelig, da man ved at gjøre et hidindtil ukjendt Hav til Gjenstand ' for Bearbeidelse vanskelig turde gjøre Regning paa at træffe et, der i Hen- seende til Studiet af Strømforholdene er saa iustructivt som det norske Hav.
Ved saadanne fremtidige Undersøgelser kunne de paa den norske Expedition benyttede Arbeidsmethoder ikke i alle Retninger blive optagne i uforandret Form. og det vil derfor ikke være ubeføiet til Slutning med faa Ord at paa- pege de Mangler, der klæbe ved disse.
De til Saltbestemmclserne tidligere . benyttede Metho- der, ifølge hvilke alle herken hørende* Observationer an- stilles ombord, bør utvivlsomt ior Fremtiden ikke komme til Anvendelse, da man ad den Vei tiltrods for al anvendt Moie ikke vil kunne opnaa den Nøiagtighed. som tiltrænges for med ønskelig Sikkerhed at kunne paavise de i Havet forekommende ofte meget smaa Differentser. Paa den norske Expedition blev denne Frenlgangsmaade benyttet, fordi man med ældre Iagttageres 1 dtalelser lor Øie maatte befrygte. at Søvand ikke lod sig opbevare i længere Tids- rum uden at undergaa forskjellige Forandringer, en Frygt, der imidlertid efter min Erfaring kun forsaavidt er be- grundet, som man til Opbevaring af Våndet benytter Kar, der ere forsynede med Korkeprop. Jeg har nemlig under- søgt llere- Vaiulprøver, der have været opbevarede paa denne Maude i omkring 2 Aar og fundet, at de alle uden Undtagelse have undergaaet Forandringer al saadan Art, at man turde være berettiget til at anse dem uskikkede til Egenvægtsbesteinmelse, hvorimod jeg hos Vandprøver, der i lignende Tidsrum havde henstaaet paa Flasker lor- synede med isleben Glasprop, ikke kunde opdage nogen- somhelst Eiendommeligheder, der kunde adskille -dem fra friskt øste Vandprøver. Ved denne Opbevaringsraaade risikerer man dog ganske sikkert Fordunstning al en Del af Våndet, og man maa derfor beskytte sig mod denne Feilkilde ved at lijemføre det til Saltbestemmelser be- stemte Vand paa tilsmeltede Glasrør.
I de saaledes conserverede Vandprøver vil man senere- hen efter Hjemkomsten kunne bestemme Egenvægten ved Sprengels Pyknometer og Ohlorgehalten ved fijælp at \ ei- ningsanalyser med saadan Skarphed, som man ved. Arbeide
servations, • and hence the results of the work done, em- bracing as it did the investigation of phenomena unknown before, were naturally less comprehensive than might other- wise have been attained. But, though such labours must to a certain extent, be regarded as preliminary, they will,
1 trust, prove of considerable importance, showing as they do, that chemical observations, which, as compared with determinations of temperature and depth, previously held quite a subordinate rank among the means employed for studying the physical conditions of the ocean* will serve to throw light upon many remarkable phenomena, that without such data would be extremely difficult to explain. On I the basis of the results here set forth, a detailed plan might be easily laid down for the further exploration of the Norwegian Sea, — in my opinion a most desirable un- dertaking, since of ocean tracts as yet unknown, there are probably few that, in regard to the study of ocean cur- rents, would so well repay investigation as that section of the N Orth-Atlantic.
As several of the methods of investigation practised on the Norwegian Expedition, will not admit of being adopted on future occasions in a wholly unmodified form, it will not be out of place in conclusion briefly to point out their defects.
The methods previously devised for determining the amount of salt in sea-water, by which all observations with this object in view were taken on board, should unquestion- ably cease to be adopted, since they will not suffice, with the greasest care even, to attain the high degree of accu- racy requisite for detecting such minute differences as are frequently found to occur. These defective modes of op- eration were, however, adopted on the Norwegian Expedi- tion. there being reason to believe from the statements ol earlier observers, that sea-water could not be preserved for any length of time without undergoing chemical change, a supposition which, so far as my experience goes, is con- tinued only in the event of its being kept in corked vessels. I have examined, for instance, various samples ot sea-water that had been preserved for about 2 years in corked bottles, and found all without exception to have undergone a change sufficient to render them unfit for specific gravity deterin- ■ inations; whereas, on the other hand, sea-water which had . been allowed to stand over for the same space ol time in bottles furnished with ground glass stoppers, was not to be distinguished from freshly drawn samples. There is, how- ever, a risk of loss from evaporation.’ the Stoppers being seldom, if ever, tight-fitting; and to guard against this source of error, the water lor salt-determinations must be brought home in hermetically sealed glass tubes.
With water thus preserved, the specific gravity may be determined bv means of Sprengel s pycnometer, and the ainoifnt of chlorine by weighing, on the return ol the Ex- pedition, far more accurately than would be possible on
n *
r
70
ombord ikke i fjerneste Maude vil kunne gjøre Regning paa at opnaa, hvorhos man tillige vil have den Fordel at kunne benytte directe Saltbestemmelser som Controlmiddel.
Mod de ]>aa Expeditionen udførte Luftbestemnielser vil ikke kunne gjores nogen væsentlig Indvending. med mindre man skulde anke over. at de benyttede A andprøver ere optagne ved Hjælp af Apparater, der ikke vare om- givne med slette A'armeledere, saaledes at de *ved An- komsten til OverHaden vikle have liavt Anledning til at antage en i Forhold til sin Luftmæiigde noget for hoi Temperatur. Denne Feilkilde kan dog ikke antages at have faaet nogen væsentlig Indfiydelse i et Hav som det her undersøgte, hvor kuu et meget tyndt Lag nærmest OverHaden besidder en Temperatur af over 5°, især da Vand. der kun er svagt overmættet med Luft, meget lang- somt giver Slip paa den overskydende Del.
Det ved Udkogningen benyttede, af Jacobsen beskrevne Apparat er i alt Yæsentligt fundet særdeles bekvemt, kun vilde det maaske være hensigtsmæssigt at give Luftopsam- lingsrøret en noget forandret Form. hvorved man lettelig vikle undgaa den Vanskelighed, hvormed det nu er for.- bundet at overfylde Luftmængden i Eudiometret uden Tab.
. Ovenstaaende Afhandlinger ere indsendte til Redac- tionscomiteen for den norske Nordhavsexpeditions General- beretning, No. I og II i April 1879 og No. Ill i Decem- ber samme Aar.
De i disse 3 Afhandlinger beskrevne Observationer ere. forsaavidt de ikke eré udførte ombord, anstillede i Professor AV aages Aldeling af Universitetets chemiske La- boratorium i Christiania.
Sluttelig benytter jeg Anledningen til at udtale min Tak til IVHrr Professoreme AVaage og Mohn for den. Bi- stand. de under 'mit Arbeide med disse Gjenstande paa flere Puncter har ydet mig.
board; moreover, there is the additional advantage of being able to test the results by direct salt-determinations.
i
As regards 'the air-determinations performed on. the Expedition, their general accuracy can hardly be impugned. True, the apparatus with which the samples of water were collected not having been surrounded by a non-conducting medium, they may possibly in their passage to the surface have assumed a temperature somewhat too high as com- pared with the amount of air contained in them: but the error arising from this source cannot have exerted any material influence, since the tract of ocean investigated .has but a thin stratum of water in which the temperature rises above 5° ; besides, water slightly surcharged with air is found to part very slowly with the surplus portion.
The boiling-apparatus devised by Jacobsen proved very convenient; possibly, however, the tube for collecting air might be given a somewhat different form, to obviate the difficulty now experienced in transferring the air to the eudiometer without loss.
These Memoirs were sent in to the Editorial Com- mittee for the Norwegian North- Atlantic Expedition as follows: — Nos. I and II in April 1879 and No. Ill in December.
The observations set forth in the foregoing Memoirs were, when’ not taken on board, instituted in Professor AVaage's department of the Chemical Laboratory of the University of Christiania.
In conclusion. 1 must not omit to thank Professors AVaage and Moliu for the assistance they kindly rendered me, in certain respects, when engaged on the investigation of the subjects treated of in these papers.
Ertata.
Pa<*e 3, line 26, from top of page, for ‘3.\4 to 32.4 — 33.6 per cent, being’ read ‘3r>.4 to 32.4, 33.6 per cent being.’
- 9, line 20, from ’top of page, for the extent to which the results based on that hyppothesis,' etc. read ‘the slight extent to which .Jacobsen’s results.’ etc.
— 28, line 22, from top of page, for Soda was added, and the whole compound' wad ‘carbonate of soda was
added, and the whole mixture.’
— 38, line 3, from foot of page, for ‘soda’ read ‘carbonate of soda.’
— 39, line 13. from foot of page, for ‘soda’ read ’carbonate of soda.' .
Translated into English by John Hazeland.
Norske Noi-dhavs-Expeclition H Tomor. ilawaudets Saltholdiéhcd..
\ I
H a wan det s S alth oldi «1 i e d
Proportion of Salt m the Surface -Water.
SABS
S3t©
>3Å1
Aoizs
Shetland
CrrfrmvTcti
Opnuiith*\f> t«l An/t.Ut KnMmt fn
Norske Nordli avs- Expedition . H.Tomoe. Hawandels Salllioldiglu-d
H awa n d ets S al fh o ldi gh e d i de dybere l.ae'.
Prop onion of Salt in the Deeper Strata
«3 5.505
03,501
O 5. So
^etlitad
Dm /m pair O/iinnafinifS hth .biM.tU Kmltaitii
N" III
Proportion of Nitrogen m the Deeper Strata .
•S}l erland
G
Norske Nurdhavs-tlxpeditiun . H.Touioe. llawandets Kvcdslofholdiéhed
J),H yrif J/S htk.iniUit Krrtttan
AMNH LIBRARY
100086155