Ved nærværende AfhandUng er Bundprøverne væsentlig 

 betragtede fra et kemisk Standpunkt. En grundig 

 mikroskopisk Undersøgelse ai' Slammet med Hensyn til dets 

 forskjellige Bestanddele vikle visselig være af Interesse, men 

 kommer for Øieblikket til at træde .i Baggrunden, da jeg 

 endnu ikke har faaet Anledning til at gjøre det nødvendige 

 Forstudium for dette specielle Emne. Men hvis Leilighed 

 dertil gives, kommer jeg maaske senere til at undersøge 

 Expeditionens righoldige Materiale ogsaa i denne Retning. 

 For der arbeides videre, vil det imidlertid være tjenlig at 

 afvente Resultateime af Bundprøvernes zoologiske Behand- 

 ling ved Hr. Professor Sårs. ligesom man maa være beret- 

 tiget til at formode, at Hr. Prof. Mobns Undersøgelser af 

 Havets fysiske Forhold maa kunne kaste Lys over mangt 

 et Spørgsniaal med Hensyn til Slamarternes Udbredelse. 

 Thi vi ved. at mange forskjellige Kxæfter kan bidrage til 

 Sedimenternes Dannelse og Afleiring, og for at belyse dem 

 paa en alsidig Maade er det nødvendigt at tåge flere af 

 Natur videnskaberne til Hjælp. Det store Materiale af 

 Bundprover fra Expeditionens 375 Stationer frembyder rig 

 Anledning til et fortsat Studium. For den kemiske Under- 

 søgelse har de Sedimenter, der forekommer i den fineste 

 og mest ensartede Tilstand, størst Interesse. Jeg har der- 

 for væsentlig lagt Vægten paa det egentlige Dybvandsslam 

 — Biloculinleret — . der desuden ogsaa er det mest ube- 

 kjendte. Kystbankernes Afleiringer har jeg derimod tåget 

 mindre Hensyn til. da allerede Udseendet viser, at deres 

 kemiske Sammensætning maa være altfor vexlende til. at 

 at det i Almindeligbed skulde være Umagen værd at under- 

 kaste dem en fuldstændig kemisk Analyse. I mineralogisk 

 Retning har de allerede tidligere været Gjenstand for tal- 

 rige Undersøgelser. 



Rhabdammina-Leret frembyder derimod paa (i rund af 

 Forekomststedet og sit særegne Udseende en større Interesse. 



For at udfore en fuldstændig kemisk Analyse af Bund- 

 proveme. er jeg gaaet frem paa følgende Maade: 



Paa forskjellige Punkter af Bundprøven udtoges nogle 

 Stykker, der pulveriseredes og udvadskedes med Vand for 



In this Memoir, the samples of the bottom a re regarded 

 chiefly from a chemical poinfr of view. A mieroscopic 

 examination of the deposit — ooze, mud. or clay — to ascertain 

 the various substances composing it. would unquestionably 

 be attended with interesting results, but cannot, for lack of 

 time and special acquaintance with the subject, be under- 

 takeu here. Meanwhile. I may perhaps on some future 

 occasion so investigate the large amount of material col- 

 lected on the North- Atlantic Expedition. Before proceed- 

 ing further in that direction. it will however be best to 

 await tbe results of Professor Sarss zoological treatment 

 of the samples of the bottom, as there is also good reason 

 to believe that Professor Mohn. in his observations to de- 

 termine the physical conditions of the sea, will throw light 

 on much that is' no w dubious respecting the distfibution of 

 oceanic deposits. We know that divers widely different 

 forces contribute to form thé surface-layers of the bottom, 

 and must. therefore. for a full explanation of the phenomena 

 have recourse to several branches of natural science. The 

 rich collection of material obtained on the Norwegian Ex- 

 pedition. at 375 observing-stations, affords ample means for 

 studying the nature of the substances distributed over the 

 bed of the North-Atlantic. As regards the chemical in- 

 vestigation of the samples, it is the finest and compara- 

 tively homogeneous deposit that, when submitted to analysis, 

 may be expected to give the most interesting rtjsults. Hence, I 

 have laid especial stress upon the necessity of thoroughly investi- 

 gating the deep-sea or Biloculina clay. — which besides is the 

 least known of oceanic deposits. To the surface-layers of the 

 coastal banks, on the other hand, comparatively little at- 

 tention has been paid, their outward aspect being of itself 

 sufficient to show that. as a rule, they will not repay the 

 trouble of a rigorous analysis. by reason of the varying 

 character of their constituents. The mineralogical features 

 of these coastal deposits have been repeatedly determined. 



Rhabdanimina clay has a peculiar and easily recog- 

 nizable appearance. which gives it accordingly so far excep- 

 tional interest. 



When submitting the samples of the bottom to rigor- 

 ous analysis. I went to work as follows: — 



Portions of the sample were picked.out at different 

 points, pulverized. and washed several times in distilled 



