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 m v r 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, J r 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 2.928 m ' ,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‘d mjr 
per litre. Now, the difference, 44 m ^ 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 53 rai,r 
per litre of carbonic acid forming carbonates and only 
about 44 m, J r per litre of carbonic acid forming bicar- 
bonates. 
