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Rare gases in Pacific Ocean water
Deep-Sea Research, 1964, Vo]. 11, pp. 929 to 932. Pergamon Pr¢~ Ltd. Printed in Great Britain.
SHORTER
COMMUNICATION
Rare gases in Pacific Ocean Water E. MAzon, G. J. WAssEnntmo and H. CRAIG California Institute of Technology, Pasadena; Scripps Institution of Oceanography, La Jolla
(Received4 August 1964) Abstract--Concentrations of helium, neon, argon, krypton, and xenon have been measured in some S. Pacific waters. For the latter four gases the observed concentrations are generally consistent to about 4- 10~o with concentrations expected for solubility equilibrium with the atmosphere at the observed water temperatures. ONE important way to approach the problem of the origin and trajectory of the deep water masses of the sea is through the study of elements in sea water whose concentrations are not constant fractions of salinity. The dissolved gases in the sea, whose concentrations are imposed upon the open sea surface in distribution patterns which differ in different areas where deep water may be formed from surface water, are of special importance in this respect since the varying concentrations should, to first approximation, be controlled by their respective solubilities which can be measured. For example, if the surface waters have reached solubility equilibrium with the atmosphere, then deep water formed in the Antarctic at, say, -- I°C should contain about 10~o more argon and 15~o more xenon than deep water formed in the N. Atlantic at q- 3°C. If very precise measurements can be made, the relative inputs of such water masses into the deep waters of the Pacific and Indian Ocean can be studied. Oxygen is of course non-conservative in sea water because o f biological consumption, and PdCHARDS and B~ssos (1961) have shown that nitrogen is probably produced in anaerobic environments in the sea. Helium may be sigoificantly in excess of solubility because of radioactive production in the rocks beneath the sea and leakage of such radiogenic helium into the sea. However, the other rare gases should be conservative within the sea, and should be close to saturation in surface waters. Since the solubility curves of gases in water as a function of temperature show positive curvature, mixing of water masses will produce slight supersaturation o f gases in the mixed waters relative to observed potential temperatures. On the other hand, rapid addition of glacial melt water to surface sea water might result in the sinking of undersaturated waters in high latitudes. Thus mechanisms exist for both positive and negative deviations of rare gas concentrations relative to solubifity equilibrium with the atmosphere, but such deviations should be of the order of a few per cent or so. We have measured the helium, neon, argon, krypton, and xenon contents in four S. Pacific ocean waters. The gas samples were part of the set collected on the Scripps Institution Expedition Monsoon (CRAIO and GORDOn, 1963). Two-litre water samples were collected in plastic Van Dorn hydrographic bottles, and about 1.2 litres of each was processed on the research vessel Argo, using a sea-going, all-glass high vacuum line. The filled sample bottles were suspended on gimbals to prevent agitation, and each sample was processed within 15 minutes after arriving at the sea surface. The sea water was acidified in vacuum with 2 ml of degassed concentrated HsPO4, boiled, stirred, and pumped on with a Toepler pump which collected the gases in a 300 ml sample tube closed by asilicone-greasedstopcockandstoredwith severalcentirneters of mercury above the bore. Laboratory tests established that the procedure collected more than 99.95~ of nitrogen and oxygen, and of CO2, which comes off more slowly because of its chemistry; thus it seems certain that all of the rare gases were collected. Total processing time for each sample was about 1 hour. The volume of the extracted water was measured volumetrically to about 0.2 ~o. 929
930
Shorter C o m m u n i c a t i o n
T h e rare gas a n a l y s e s were d o n e on a 10 per cent aliquot o f the total gases, u s i n g a 6-inch radius, 60 ° Nier type m a s s spectrometer designed for rare gas work at the California Institute o f Technology. A mixed tracer consisting o f Ne 21, Ne 2z, A r as, K r a~ a n d Xe l~a separated isotopes obtained f r o m O a k Ridge was mixed with the s a m p l e s prior to clean-up a n d rare gas concentration over a t i t a n i u m getter, a n d used to o b t a i n the a b s o l u t e concentrations. T h e tracer was calibrated by spiking air s a m p l e s o f k n o w n a m o u n t . Observed h e l i u m c o n c e n t r a t i o n s were uniformly too high by a b o u t a factor o f six because o f h e l i u m diffusion t h r o u g h t h e glass sample t u b e s before the s a m p l e s could be analyzed, a n d these d a t a are n o t tabulated.
Table 1. Rare gas concentrations observed and predicted fi'om solubility data. All concentrations are in cc (STP)/litre. Sample Depth (m) Salinity (~o) t (°C)
Neon × 10 ~ (obs.) Neon eqlb.* Argon × 10 (obs.) Argon eqlb.* Argon eqlb.t Krypton × l 0 s (obs.) Krypton eqlb.* Xenon x 106 (obs.) Xenon eqlb.*
M--40
M-37
M-39
M-26
Air:~
10 35"46 28"21
3345 34.68 1-60
5010 34"71 1-33
5329 34-71 1.08
-----
1-84 1"50
-1"74
1-81 1.74
1.83 1-74
182 --
2"27 (2"30) 2"44
-3.64 4"05
3.37 3.66 4-07
2.93 3-68 4.10
93.2 ---
4"97 4"63
-8.08
7-97 8.12
7.08 8.17
114 -
6"5 6"0
-11"4
12"0 11"5
10. I 11.6
86 ---
*Expected c o n c e n t r a t i o n for equilibrium with a t m o s p h e r e at temperature o f s a m p l e , according to solubility d a t a o f KoNIo (1963). T h e a r g o n value at 28°C is very a p p r o x i m a t e , as K o n i g ' s argon d a t a scatter so badly t h a t t h e e x t r a p o l a t i o n to this t e m p e r a t u r e is n o t good. i'According to the a r g o n solubility d a t a o f DOtJOLAS (1964b). ~ A t m o s p h e r i c c o n c e n t r a t i o n s f r o m t h e literature. T h e m e a s u r e d c o n c e n t r a t i o n s are s h o w n in Table 1 together with th~ k n o w n concentrations in air. S a m p l e s M-40 a n d M-39 are f r o m 5 ° 4 2 ' S , 1 4 9 ° 4 3 ' W ; M-37 is f r o m 24°41'S, 1 5 4 ° 4 5 ' W ; M-26 is f r o m 36 ° 29'S, 163 ° 0 9 ' W . N o absolute c o n c e n t r a t i o n d a t a were o b t a i n e d for M-37 due to a calibration error which affected all gases equally, so t h a t the ratios n o r m a l i z e d to a r g o n were n o t affected. T h e ratios o f n e o n , k r y p t o n , a n d x e n o n , to a r g o n in the f o u r s a m p l e s are given in Table 2. T h e solubility d a t a given in these two tables are t h o s e for the in situ s a m p l e t e m p e r a t u r e s ; use o f potential t e m p e r a t u r e s w o u l d increase t h e expected equilibrium c o n c e n t r a t i o n s by a b o u t 1 p e r cent for the deep samples.
Table 2. Rare gas concentrations normalized to argon. Observed ratios compared with solubility data of KONIG (1963). Sample
M-40
M-37
M-39
M-26
t (°C)
28-21
1.60
1"33
1.08
--
8"11 6"52
4"98 4"78
5'37 4.75
6-25 4'73
-19.53
2.19 2"01
2.17 2'22
2.36 2.22
2'42 2-22
-1.22
0.29 0"26
0"31 0.31
0'36 0'31
0"34 0"31
-0.092
104 (Ne/Ar) (obs.)
Eqlb. ratio 104 ( K r / A r ) (obs.) Eqlb. ratio 104 (Xe/Ar) (obs.) Eqlb. ratio
Air
W i t h i n t h e level o f precision o f the preliminary d a t a reported here, one sees that the d a t a on the two deep samples, a n d the c o m p a r i s o n o f observed a n d solubility d a t a on all samples, are grossly c o n s i s t e n t to a b o u t 4- 10~o. T h e m e a n deviation for each gas f r o m the solubility d a t a in Table 1 is a b o u t 1 0 ~ or less, a l t h o u g h the neon deviation for M-40 a n d the argon deviation for M-26 are
Shorter Communication
931
about 20~o. Similarly the ratio data in Table 2 agree with the solubility ratios expected for ecluilibrium with the atmosphere, at the observed temperatures, to about 10~o except for the Ne/Ar ratios in M-40 and M-26 which reflect the neon and argon discrepancies just mentioned. Thus both the absolute a n d relative abundances o f these gases are consistent, within the limit of about 10%, with the solubility data. The solubility data for all four gases in sea water are given in Table 1 as measured recently by KONIG (1963). There is a good deal of uncertainty in these data. The data plotted in Konig's Fig. 3 for argon, krypton, and xenon, in sea water do not agree with his tabulated measurements in his Table 2. We have assumed his figure is in error, and have taken the values for the temperatures of our samples from smooth curves redrawn from his tabulated sea water data. Argon solubility in sea water has recently been remeasured by DOUGLAS (1964b) by the method used previously by him to measure gas solubilities in fresh water (DOUGLAS, 1963a). These data for the temperatures of our samples are also shown in Table 1 for argon; the values obtained by Douglas are about 11 ~o higher than those of Konig. This discrepancy exists also in the fresh water data measured by these authors (the fresh water data tabulated by DOUGLAS (1963a) for argon solubilities actually list Konig's seawater data, rather than his fresh water data as stated, so that the discrepancy is not as large as shown by Douglas). The argon solubility data o f ILXKESTRAW and EMMEL (1938) for sea water agree best with those of Konig, but the two solubility curves cross so that at temperatures below 4°C, they agree better with those of Douglas. We do not wish to discuss the solubility data on salt or fresh water in detail. The scatter of the sea water argon data of KONIG (1963) iS such that no good extrapolation can be made to temperatures greater than 20°C and the uncertainty in his data in this range must be about -t- 10~o. However, our data agree better with his solubility data than with those o f Douglas. On the other hand the fresh water data of Douglas for argon agree with recent measurements by KLOTS and BENSON (1963). Konig's neon solubility data for fresh water are systematically about 6~o lower than those given by MORPJSON and JOHNSTONE (1954). Until the solubilities of all the rare gases in sea water are known with confidence, we conclude that the rare gas data are better treated as intrinsic variables characteristic o f given water masses, rather than as reflecting exact agreement or disagreement with solubility models. Comparison o f the observed rare gas ratios with the ratios in air (Table 2) shows that addition of 10~o o f atmospheric rare gases to the extracted rare gases should increase the observed Ne/Ar ratio by about 30 %, but decrease the Kr/Ar and Xe/Ar ratios by 5 ~ a n d 7 ~o. All o f our ratios relative to argon tend to be systematically a little high, so that there is no evidence o f any air contamination during the sampling and extraction procedure. KONIG et al. (1964) have recently measured neon and argon in the north Pacific at one station. Our neon data at depth agree exactly with their values, and our surface argon value agrees with theirs; they find about 10Yo more argon at depth than do we. This is within the precision o f the present data. The present data, the first available on krypton and xenon in the sea, show that these gases, as well as neon and argon, are present in sea water concentrations given by surface equilibrium values corresponding to water temperatures, within the limits o f the present precision and the knowledge of the solubilities in sea water. It should be noted, however, that these preliminary data do not preclude deviations of the order of 10yo, and more precise solubility data in sea water are needed in order to see the fine structure of the deviations which may exist. There is no doubt that the uncertainties in the analyses a n d in the solubility data can he decreased by an order o f magnitude, so that rare gas measurements should become a valuable tool for the study of oceanic mixing and water mass formation. Acknowledgements--This work was supported b y grants from the National Science Foundation and the Oflk~ of Naval Research. We arc greatly indebted to N o r m a n Anderson for his help in the hydrographic work at sea and to Louis G o r d o n for general assistance. The pmTicipation o f the senior author was made possible by the tenure of a Ford Foundation Fellowship during the work. REFERENCES
C x ~ o H. and Gom~oN L. I. (1963) Nitrous oxide in the ocean and the m a ~ e atmosphe~. Geochim. el Co3mochlm. Acta, 27, 949-955.
932
Shorter Communication
DOUGLAS E. (1964a) Solubilities of oxygen, argon, and nitrogen in distilled water. J. Ph3s. Chem. 68, 169-174. DOUGLAS E. (1964b) J. Phys. Chem. (in press). KLo'rs C. E. and B~sor~ B. B. (1963) Solubilities of nitrogen, oxygen, and argon in distilled water. J. Mar. Res. 21, 48-57. Koha~3 H. (1963) Uber die loslichkeit der edelgase in meerwasser. Zeits. Natu~fors. 18, 363-367. KO~G H., WAt~rd~ H., Bran G. S., RAKESTRAW, N. W. and SOESS H. E. (1964) Helium and neon in the oceans. Deep-Sea Res. 11,243-247. MogglsoN T. J. a n d Jorn~STOt,~ N. B. (1954) Solubilities of the inert gases in water. J. Chem. Soc. 3441-3446. RAgES'mAW N. W. and EMM~L V. M. (1938) The solubility of nitrogen and argon in sea water. J. Phys. Chem. 42, 1211-1215. RlcnAgas F. A. and B~Nsor~ B. B. (1961) Nitrogen[argon and nitrogcn isotope ratios in anaerobic environments. Deep-Sea Res. 7, 254-264.
SHORTER
COMMUNICATION
Rare gases in Pacific Ocean Water E. MAzon, G. J. WAssEnntmo and H. CRAIG California Institute of Technology, Pasadena; Scripps Institution of Oceanography, La Jolla
(Received4 August 1964) Abstract--Concentrations of helium, neon, argon, krypton, and xenon have been measured in some S. Pacific waters. For the latter four gases the observed concentrations are generally consistent to about 4- 10~o with concentrations expected for solubility equilibrium with the atmosphere at the observed water temperatures. ONE important way to approach the problem of the origin and trajectory of the deep water masses of the sea is through the study of elements in sea water whose concentrations are not constant fractions of salinity. The dissolved gases in the sea, whose concentrations are imposed upon the open sea surface in distribution patterns which differ in different areas where deep water may be formed from surface water, are of special importance in this respect since the varying concentrations should, to first approximation, be controlled by their respective solubilities which can be measured. For example, if the surface waters have reached solubility equilibrium with the atmosphere, then deep water formed in the Antarctic at, say, -- I°C should contain about 10~o more argon and 15~o more xenon than deep water formed in the N. Atlantic at q- 3°C. If very precise measurements can be made, the relative inputs of such water masses into the deep waters of the Pacific and Indian Ocean can be studied. Oxygen is of course non-conservative in sea water because o f biological consumption, and PdCHARDS and B~ssos (1961) have shown that nitrogen is probably produced in anaerobic environments in the sea. Helium may be sigoificantly in excess of solubility because of radioactive production in the rocks beneath the sea and leakage of such radiogenic helium into the sea. However, the other rare gases should be conservative within the sea, and should be close to saturation in surface waters. Since the solubility curves of gases in water as a function of temperature show positive curvature, mixing of water masses will produce slight supersaturation o f gases in the mixed waters relative to observed potential temperatures. On the other hand, rapid addition of glacial melt water to surface sea water might result in the sinking of undersaturated waters in high latitudes. Thus mechanisms exist for both positive and negative deviations of rare gas concentrations relative to solubifity equilibrium with the atmosphere, but such deviations should be of the order of a few per cent or so. We have measured the helium, neon, argon, krypton, and xenon contents in four S. Pacific ocean waters. The gas samples were part of the set collected on the Scripps Institution Expedition Monsoon (CRAIO and GORDOn, 1963). Two-litre water samples were collected in plastic Van Dorn hydrographic bottles, and about 1.2 litres of each was processed on the research vessel Argo, using a sea-going, all-glass high vacuum line. The filled sample bottles were suspended on gimbals to prevent agitation, and each sample was processed within 15 minutes after arriving at the sea surface. The sea water was acidified in vacuum with 2 ml of degassed concentrated HsPO4, boiled, stirred, and pumped on with a Toepler pump which collected the gases in a 300 ml sample tube closed by asilicone-greasedstopcockandstoredwith severalcentirneters of mercury above the bore. Laboratory tests established that the procedure collected more than 99.95~ of nitrogen and oxygen, and of CO2, which comes off more slowly because of its chemistry; thus it seems certain that all of the rare gases were collected. Total processing time for each sample was about 1 hour. The volume of the extracted water was measured volumetrically to about 0.2 ~o. 929
930
Shorter C o m m u n i c a t i o n
T h e rare gas a n a l y s e s were d o n e on a 10 per cent aliquot o f the total gases, u s i n g a 6-inch radius, 60 ° Nier type m a s s spectrometer designed for rare gas work at the California Institute o f Technology. A mixed tracer consisting o f Ne 21, Ne 2z, A r as, K r a~ a n d Xe l~a separated isotopes obtained f r o m O a k Ridge was mixed with the s a m p l e s prior to clean-up a n d rare gas concentration over a t i t a n i u m getter, a n d used to o b t a i n the a b s o l u t e concentrations. T h e tracer was calibrated by spiking air s a m p l e s o f k n o w n a m o u n t . Observed h e l i u m c o n c e n t r a t i o n s were uniformly too high by a b o u t a factor o f six because o f h e l i u m diffusion t h r o u g h t h e glass sample t u b e s before the s a m p l e s could be analyzed, a n d these d a t a are n o t tabulated.
Table 1. Rare gas concentrations observed and predicted fi'om solubility data. All concentrations are in cc (STP)/litre. Sample Depth (m) Salinity (~o) t (°C)
Neon × 10 ~ (obs.) Neon eqlb.* Argon × 10 (obs.) Argon eqlb.* Argon eqlb.t Krypton × l 0 s (obs.) Krypton eqlb.* Xenon x 106 (obs.) Xenon eqlb.*
M--40
M-37
M-39
M-26
Air:~
10 35"46 28"21
3345 34.68 1-60
5010 34"71 1-33
5329 34-71 1.08
-----
1-84 1"50
-1"74
1-81 1.74
1.83 1-74
182 --
2"27 (2"30) 2"44
-3.64 4"05
3.37 3.66 4-07
2.93 3-68 4.10
93.2 ---
4"97 4"63
-8.08
7-97 8.12
7.08 8.17
114 -
6"5 6"0
-11"4
12"0 11"5
10. I 11.6
86 ---
*Expected c o n c e n t r a t i o n for equilibrium with a t m o s p h e r e at temperature o f s a m p l e , according to solubility d a t a o f KoNIo (1963). T h e a r g o n value at 28°C is very a p p r o x i m a t e , as K o n i g ' s argon d a t a scatter so badly t h a t t h e e x t r a p o l a t i o n to this t e m p e r a t u r e is n o t good. i'According to the a r g o n solubility d a t a o f DOtJOLAS (1964b). ~ A t m o s p h e r i c c o n c e n t r a t i o n s f r o m t h e literature. T h e m e a s u r e d c o n c e n t r a t i o n s are s h o w n in Table 1 together with th~ k n o w n concentrations in air. S a m p l e s M-40 a n d M-39 are f r o m 5 ° 4 2 ' S , 1 4 9 ° 4 3 ' W ; M-37 is f r o m 24°41'S, 1 5 4 ° 4 5 ' W ; M-26 is f r o m 36 ° 29'S, 163 ° 0 9 ' W . N o absolute c o n c e n t r a t i o n d a t a were o b t a i n e d for M-37 due to a calibration error which affected all gases equally, so t h a t the ratios n o r m a l i z e d to a r g o n were n o t affected. T h e ratios o f n e o n , k r y p t o n , a n d x e n o n , to a r g o n in the f o u r s a m p l e s are given in Table 2. T h e solubility d a t a given in these two tables are t h o s e for the in situ s a m p l e t e m p e r a t u r e s ; use o f potential t e m p e r a t u r e s w o u l d increase t h e expected equilibrium c o n c e n t r a t i o n s by a b o u t 1 p e r cent for the deep samples.
Table 2. Rare gas concentrations normalized to argon. Observed ratios compared with solubility data of KONIG (1963). Sample
M-40
M-37
M-39
M-26
t (°C)
28-21
1.60
1"33
1.08
--
8"11 6"52
4"98 4"78
5'37 4.75
6-25 4'73
-19.53
2.19 2"01
2.17 2'22
2.36 2.22
2'42 2-22
-1.22
0.29 0"26
0"31 0.31
0'36 0'31
0"34 0"31
-0.092
104 (Ne/Ar) (obs.)
Eqlb. ratio 104 ( K r / A r ) (obs.) Eqlb. ratio 104 (Xe/Ar) (obs.) Eqlb. ratio
Air
W i t h i n t h e level o f precision o f the preliminary d a t a reported here, one sees that the d a t a on the two deep samples, a n d the c o m p a r i s o n o f observed a n d solubility d a t a on all samples, are grossly c o n s i s t e n t to a b o u t 4- 10~o. T h e m e a n deviation for each gas f r o m the solubility d a t a in Table 1 is a b o u t 1 0 ~ or less, a l t h o u g h the neon deviation for M-40 a n d the argon deviation for M-26 are
Shorter Communication
931
about 20~o. Similarly the ratio data in Table 2 agree with the solubility ratios expected for ecluilibrium with the atmosphere, at the observed temperatures, to about 10~o except for the Ne/Ar ratios in M-40 and M-26 which reflect the neon and argon discrepancies just mentioned. Thus both the absolute a n d relative abundances o f these gases are consistent, within the limit of about 10%, with the solubility data. The solubility data for all four gases in sea water are given in Table 1 as measured recently by KONIG (1963). There is a good deal of uncertainty in these data. The data plotted in Konig's Fig. 3 for argon, krypton, and xenon, in sea water do not agree with his tabulated measurements in his Table 2. We have assumed his figure is in error, and have taken the values for the temperatures of our samples from smooth curves redrawn from his tabulated sea water data. Argon solubility in sea water has recently been remeasured by DOUGLAS (1964b) by the method used previously by him to measure gas solubilities in fresh water (DOUGLAS, 1963a). These data for the temperatures of our samples are also shown in Table 1 for argon; the values obtained by Douglas are about 11 ~o higher than those of Konig. This discrepancy exists also in the fresh water data measured by these authors (the fresh water data tabulated by DOUGLAS (1963a) for argon solubilities actually list Konig's seawater data, rather than his fresh water data as stated, so that the discrepancy is not as large as shown by Douglas). The argon solubility data o f ILXKESTRAW and EMMEL (1938) for sea water agree best with those of Konig, but the two solubility curves cross so that at temperatures below 4°C, they agree better with those of Douglas. We do not wish to discuss the solubility data on salt or fresh water in detail. The scatter of the sea water argon data of KONIG (1963) iS such that no good extrapolation can be made to temperatures greater than 20°C and the uncertainty in his data in this range must be about -t- 10~o. However, our data agree better with his solubility data than with those o f Douglas. On the other hand the fresh water data of Douglas for argon agree with recent measurements by KLOTS and BENSON (1963). Konig's neon solubility data for fresh water are systematically about 6~o lower than those given by MORPJSON and JOHNSTONE (1954). Until the solubilities of all the rare gases in sea water are known with confidence, we conclude that the rare gas data are better treated as intrinsic variables characteristic o f given water masses, rather than as reflecting exact agreement or disagreement with solubility models. Comparison o f the observed rare gas ratios with the ratios in air (Table 2) shows that addition of 10~o o f atmospheric rare gases to the extracted rare gases should increase the observed Ne/Ar ratio by about 30 %, but decrease the Kr/Ar and Xe/Ar ratios by 5 ~ a n d 7 ~o. All o f our ratios relative to argon tend to be systematically a little high, so that there is no evidence o f any air contamination during the sampling and extraction procedure. KONIG et al. (1964) have recently measured neon and argon in the north Pacific at one station. Our neon data at depth agree exactly with their values, and our surface argon value agrees with theirs; they find about 10Yo more argon at depth than do we. This is within the precision o f the present data. The present data, the first available on krypton and xenon in the sea, show that these gases, as well as neon and argon, are present in sea water concentrations given by surface equilibrium values corresponding to water temperatures, within the limits o f the present precision and the knowledge of the solubilities in sea water. It should be noted, however, that these preliminary data do not preclude deviations of the order of 10yo, and more precise solubility data in sea water are needed in order to see the fine structure of the deviations which may exist. There is no doubt that the uncertainties in the analyses a n d in the solubility data can he decreased by an order o f magnitude, so that rare gas measurements should become a valuable tool for the study of oceanic mixing and water mass formation. Acknowledgements--This work was supported b y grants from the National Science Foundation and the Oflk~ of Naval Research. We arc greatly indebted to N o r m a n Anderson for his help in the hydrographic work at sea and to Louis G o r d o n for general assistance. The pmTicipation o f the senior author was made possible by the tenure of a Ford Foundation Fellowship during the work. REFERENCES
C x ~ o H. and Gom~oN L. I. (1963) Nitrous oxide in the ocean and the m a ~ e atmosphe~. Geochim. el Co3mochlm. Acta, 27, 949-955.
932
Shorter Communication
DOUGLAS E. (1964a) Solubilities of oxygen, argon, and nitrogen in distilled water. J. Ph3s. Chem. 68, 169-174. DOUGLAS E. (1964b) J. Phys. Chem. (in press). KLo'rs C. E. and B~sor~ B. B. (1963) Solubilities of nitrogen, oxygen, and argon in distilled water. J. Mar. Res. 21, 48-57. Koha~3 H. (1963) Uber die loslichkeit der edelgase in meerwasser. Zeits. Natu~fors. 18, 363-367. KO~G H., WAt~rd~ H., Bran G. S., RAKESTRAW, N. W. and SOESS H. E. (1964) Helium and neon in the oceans. Deep-Sea Res. 11,243-247. MogglsoN T. J. a n d Jorn~STOt,~ N. B. (1954) Solubilities of the inert gases in water. J. Chem. Soc. 3441-3446. RAgES'mAW N. W. and EMM~L V. M. (1938) The solubility of nitrogen and argon in sea water. J. Phys. Chem. 42, 1211-1215. RlcnAgas F. A. and B~Nsor~ B. B. (1961) Nitrogen[argon and nitrogcn isotope ratios in anaerobic environments. Deep-Sea Res. 7, 254-264.