10 



I A aret 1873 udgik atter fra England en Expedition. 

 Ohallengerexpeditionen, som i et Tidsrum af 3 Aar skulde 

 undersøge baade de æquatoriale og antarktiske Farvande. 

 Med denne Expedition fulgte som Chemiker J. Y. Bu- 

 chanan. som besluttede sig til at anvende de paa Pomerania- 

 expeditionea benyttede Methoder og Apparater saa godt 

 som uden Moditikationer. Kesultaterne af hans Dnder- 

 søgelser ere. saavidt jeg ved. endnu ikke offentliggjorte i 

 sine Enkeltheder, medens der dog er gjort nogle foreløbige 

 Meddelelser, hvoretter man vil kunne danne sig • et Be- 

 greh om de Slutninger, hvortil hans Observationer ville tore. 



Han rinder 1 , at Snrstofmængden i Overtladevandet 

 varierer mellem 33 og 35 "/ u af den samlede Surstof- 

 Kvælstofmængde, saaledes at den største Mængde er fundet 

 (baade relativt og absolut) i Vandprøver oste i Nærheden 

 af den sydlige Polarcirkel og den mindste i Pasatvind- 

 egnene. Hvad angaar de under Overfladen liggende Lag. 

 da har han observeret det mærkelige Factum. at Surstof- 

 procenten aftager nedover indtil et Dyb af 300 Favne, hvor 

 den opnaar et Minimum for atter igjen at stige, saaledes 

 som det fremgaar af følgende Tabel. 



o + N = loo 



0«i 33-7 33-4 32.2 30.2 33.4 11.4 15.5 22.6 23.3 



Om den absolute Mængde af de af hans Vandprøver 

 udkogte Gasarter lindes paa dette Sted Intet, hvorimod 

 der seilere er bleven offentliggjort følgende Tabel-. 



In the year 1873. another Expedition was dispatched, 

 from England, with H. M. S. '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 1 the 'Pomerania' Expedition, almost without moditica- 

 tion. The resnlts of his labours are not vet. I believe, 

 published in detail; preliminary papers have. however, ap- 

 peared, from which we can form some general idea of his 

 results. 



Buchanan fouud 1 the proportion of oxygen in surface- 

 water to vary between 33 and 35 per cent of the total 

 amouut 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 diminshes 

 down to a depth of 300 fathoms. where a minimum is 

 reached. and then begins to increase. as shown by the 

 lollowing Table. 



With respect to the absolute amounts of the gases 

 boiled out of the different samples of water, nothing is 

 stated in the work alluded to. hut the following Table 8 has 

 since appeared. 



dero\ '■' . 



'• 5 



14-37 



15-40 



Hermed er i Korthed gjengivet det Vigtigste af de 

 til Dato fremkomne Bidrag til Løsningen af Spørgsmaalet 

 om Luften i Søvandet. 



I Vaaren 1S7U. da man i Norge var beskjæftiget med 

 1 drustningen al' den Expedition, som vai- besluttet udsendt 

 for i Sommermaanederne al' Aarene L876 — 77 02 7* at 



1 Tin- \ oyage ni' Hu- ■( Jhallengei 

 1 Ber. Berl. chem. Ges. 1 1 — 410. 



'lli- 'Atlantic' 2 



A brief account has now Keen given of what had pre- 

 viously been accomplished as regards the solution of the 

 problem presented by the air in sea-water. 



lu the spring of lS7(i. when titting out the Norwegian 

 Expedition, whicll had for its object the investigation. 

 during the summer months of 1876. 1877, and 1S78. of 



1 Tin- Voyage of tin- 'Challenger.' 

 ' Ber. Berl. chem. Ges. 1 1. p. 1 10. 



The 'Atlantic, 





