NGI 
har en Temperatur under 0°, Tornge har vist, at Vandet 
i de dybeste Lag indeholder omtrent den samme Luft- 
mængde som ved Overfladen, og at det er her, at Hav- 
vandet optager sin Luft. Med de nedstigende Strømme, 
som vi have paavist, føres Luften ned til Dybene; Havet 
er saaledes fuldstændig ventileret, og denne Betingelse for 
det organiske Livs Trivsel i alle Dybder og paa Havbun- 
den er tilvejebragt ved Strømningernes Mekanisme. 
Vi have seet, hvorledes Strømningernes Hastighed 
aftager mod Dybet, og at den i de store Dyb rimeligvis er 
temmelig ringe, men dog tilstrækkelig til at bolde Vandets 
Circulation vedlige. De Aflagringer, der findes paa Hav- 
bunden, ere af en mere grovkornet Art ved Kysterne, hvor 
Strømmen er sterkest, og Landjorden, hvorfra Materialet 
tages, er nærmest, medens de finere Partikler findes i de 
store Dybder, hvor Vandet er roligere og Afstanden fra Land 
større. Her dækkes Bunden af Biloculinleret, hvis Hoved- 
bestanddel er Skaller af Foraminiferer, især Globigeriner, 
og som i chemisk Henseende indeholder kulsur Kalk som 
Hovedbestanddel?. Om dette Ler siger J. Murray?: 
“Den kulsure Kalk i det norske Hav bestaar hoved- 
sagelig af Skaller af Globigeriner, der ere sunkne ned tra 
Overfladen, og nogle andre Arter Foraminiferer (mest Bi- 
loculiner), der leve ved Bunden. Paa nogle Steder nærmer 
denne Aflejring sig i sin Charakter til Atlanterhavets Globi- 
verina-Ler eller Mudder, men er meget fattig paa pela- 
giske Skaller i Sammenligning med Aflejringerne under 
lavere Bredder. De pelagiske Foraminiferer og Pteropo- 
der, der ere saa talrige i de tropiske Dele af Golfstrom- 
men, dø og falde tilbunds, idet de føres ind i Nordatlan- 
terhavets koldere Strøg*. 
Efter disse Udtalelser af Mr. Murray er det at vente, 
at de varme nedstigende Strømninger i Nordhavet skulde 
medføre en større Rigdom paa kulsur Kalk paa Havbun- 
den end de kolde opstigende. Et opmerksomt Studium af 
Schmelcks Afhandling og navnlig af hans Kart over 
Mængden af kulsur Kalk i Biloculinleret vil ogsaa 1 det 
hele taget stadfæste dette. Hele det søndre Bækken er rigt 
paa kulsur Kalk, medens det nordre Bækken er yderst 
fattigt, undtagen — og det er meget interessant — langs 
Spidsbergbanken og der, hvor vi under Greenwichs Meri- 
dian i 779 til 78° Bredde have et Trykmaximum, begge 
Steder med nedstigende Bevægelse af oprindelig atlantisk 
Vand. Den hos Schmelek antydede store Mængde af 
kulsur Kalk i Jan Mayen Renden svarer ogsaa til de samme- 
steds ovenfor omtalte nedadgaaende Stromninger.  Imellem 
Island og Norge findes et Par Steder over 40 Procent kulsur 
Kalk, i Station No. 52 (Temperaturmaximum) over 45 Procent. 
Den yderst ringe Kalkmængde i Strøget Nordost for Jan 
1 
Den norske Nordhays-Expedition. Chemi. Af L. Schmelek. 
2 
Encyclopedia Britannica. Norwegian Sea. 
by contact and intermixture with Polar water it has a 
temperature of under 0°. that the 
water in the deepest strata contains about the same 
amount of air as at the surface, and that here it is sea- 
Water absorbs its As we have pointed out, the 
air is carried, with the descending currents, down into the 
deep; thus the sea becomes thoroughly ventilated, and this 
Tornøe has shown 
air. 
condition for the existence of organic life at all depths and 
on the sea-bed, is brought about by the mechanism of 
the currents. i 
We have already seen how the velocity of the currents 
diminishes with depth, and that probably in the great deeps 
but trifling, though amply suffieient to keep up 
the circulation of the The deposits met with on 
the sea-bed are coarsely granulous in character off the 
coasts, where the current is strongest and the detritus- 
it is 
water. 
yielding land nearest, whereas the finer. particles of matter 
occur in the great depths, where the water is calmer and 
the land more distant. Here the bottom is covered with 
Biloculina clay, the chief constituents of which are the 
shells of Foraminifera, more especially Globigerina, and 
which, regarded chemically, contain as their principal con- 
stituent carbonate of lime." Respecting this subject, J. 
Murray states. ? 
“The carbonate of lime (in the Norwegian Sea) con- 
sists chiefly of the shells of Globigerina, which have fallen 
from the surface, and some other species of Foraminifera 
(the most frequent of which is Biloculina) which live on 
the bottom. In some places this deposit approaches in 
character the Globigerina ooze or mud of the Atlantic, but 
is very poor in pelagic shells when compared with the 
deposits in lower latitudes. The pelagic Foraminifera and 
Pteropod shells so abundant in tropical parts of the Gulf 
Stream are killed off and fall to the bottom as they are 
carried into the colder areas of the North Atlantic.” 
From these statements by Mr. Murray, there was reason 
to expect that the warm descending currents in the North 
Ocean would be attended with a greater amount of car- 
bonate of hme on the sea-bed than the cold ascending 
ones. An attentive study of Schmelck’s Memoir, and more 
especially of his map showing the amount of carbonate of 
lime im the Biloculina clay, will also in the main confirm 
this result. The whole rich in 
carbonate of lime, whereas the northern basin is exceedingly 
of the southern basin is 
poor, except — and this fact is very interesting — along 
the Spitzbergen Bank, and where, on the meridian of 
Greenwich, in lat. 77° to 78° N, we have a pressure- 
maximum, in both places with a descending motion of 
originally Atlantic water. The large amount of carbonate 
of lime found by Schmelck, in the Jan-Mayen Channel, 
corresponds to the above-mentioned descending currents in 
the same locality. Between Iceland and Norway, carbon- 
ate of lime, in a proportion of more than 40 per cent, is 
' The Norwegian North-Atlantic 
L. Schmelck. 
2 Encyclopedia Britannica. 
Ixpedition. Chemistry. By 
Norwegian Sea. 
