19 
0 — 7.79 — 0.2 1 -j- 0.005 t i . 
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— 1760 1 
2 56o— 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 * 
