[ 5 8 2 ]
SOME TABLES FOR THE IONIC COMPOSITION
OF SEA WATER
BY H. BARNES
The Marine Station, Millport
{Received n January 1954)
There exists a considerable and increasing interest in the ionic composition of the various tissues and body fluids of a wide variety of animals. During the course of such investigations a knowledge of the ionic composition of the natural environment from which the animals were taken is often required. Routine determinations of salinity are usually made in a Marine Biological Laboratory, but the concept of salinity (or chlorinity), of fundamental importance in oceanography, is somewhat artificial and confusion may be felt by those not familiar with the concept.
The object of this paper is to make available a set of tables dealing with the composition of sea water. The preparation of these tables involves the use of the salinity concept, which is first briefly discussed.
A number of physical properties of water depend upon the two variables, tem-perature and pressure; but in the case of sea water, a third variable, the salt content, has to be considered. It is in its effect upon the physical properties (particularly density) and as an indicator of physical processes (such as evaporation) that the salt content of sea water is of importance in oceanography. The ionic composition is of less interest. Because of its complex composition the total quantity of dissolved solids in any given sample of sea water is difficult to determine by direct analysis. Reproducible results are not obtained by evaporation methods. The difficulties have been avoided by an arbitrary definition of the total salt content, the so-called salinity. Salinity (S%<j) was originally defined as the weight in grams (in vacuo) of the solids that can be obtained from 1 kg. of sea water (likewise measured in vacuo), when all the carbonate has been converted to oxide, the bromine and iodine replaced by chlorine, all organic matter oxidized and the remainder dried at 4800 C. to constant weight (Forch, Knudsen & Sorensen, 1902).
Some tables for the ionic composition of sea water 583
standard is Normal Water (see below), and the titration result be calculated using Knudsen's Hydrographical Tables (1901). The following equation expresses the relation between salinity and chlorinity:
S%o = o-o3 +1-805 XC1&. (1)
This definition of chlorinity introduces a chlorine equivalent which is dependent upon the atomic weights of the elements present in the standard solution. In order that the apparent chlorinity of the oceans shall not vary as revisions of atomic weights affect the appropriate gravimetric factors, it is essential to maintain an international standard for chlorinity which is independent of atomic weight changes. This has been effected in the past by standardization of all solutions against the so-called Normal Water (Eau de mer normale) which has its chlorinity adjusted to about i94%o and which is accurately standardized either directly or indirectly against the 1902 standard. This standard sea water has been prepared and dis-tributed by the Hydrographic Laboratories at Copenhagen. More recently, Jacobsen & Knudsen (1940) have established a permanent standard for chlorinity by standardizing Normal Water against the mass of silver required completely to pre-cipitate the halogens in 1 kg. of such water. On the basis of this work a new definition of salinity may be given; the number giving the chlorinity in grams per kilogram of sea water sample is identical with the number giving the mass in grams of 'atomic weight silver' just necessary to precipitate the halogens in 0-3285233 kg. of sea-water sample. This new definition makes the chlorinity inde-pendent of any atomic weight changes and the empirically established relations between salinity and chlorinity remain valid.
We may now turn to the ionic composition. The best values of the ionic ratios have been selected by Lyman & Fleming (1940) after a critical examination of published work; they are given below, together with the weights per kilogram of sea water for sea water with a chlorinity of i9-oo%,j.
Ion... Cl Br SO4 HCO, Ca Ratio to chlorinity 0-99894 0-00340 0-1394 0-00735 0-02106
Mg K Sr Na H.BO,
0-06695 O-O2OO O-OOO702 0-5556 O-OOI37
Cl Br SO4 HCO, Ca
Grams, per kilogram 18-9799 0-0646 2-6486 0-1397 0-4001 Mg K Sr Na H,BO, 1-2720 0-3800 0-0133 10-5561 0-0260
The total salt content calculated from these values is 34-4816 g./kg.; converting the bromide to chloride and the bicarbonate to oxide, this gives for the salinity as defined above 34-3243 %<, as compared with 34-325 %,, given by Knudsen's equation (1).
Lyman & Fleming (1940) give equations for the relation between chlorinity and these four constituents, as follows:
SO4=o-oo6i+0-1391 Cl, (2)
Ca = o-oi54+o-O2O25Cl, (3) Mg = o-oo2o +006684 Cl, (4)
HCO3 = 0-0493 +0-004755 Cl. (5)
Total salts (as distinguished from salinity)
= 0-073 + I - 8 I I O C 1 . (6)
Using these equations for the four ions indicated and assuming the ratios to chlorinity of all the other components are constant and are given by the values in Table 1 (even if slightly incorrect, this will introduce no significant discrepancy) the composition of sea water equivalent to any chlorinity (determined in the standard way using Knudsen's Hydrographical Tables) can be calculated. Knowing the density of the sea water at the given chlorinity the values can be converted to a volume basis.
The following tables have been prepared:
Table 1. Grams per kilogram of sea water for chlorinity 1-23 %o(S= 1-84-41-55%,,): calculated from the best available ratios of ions to chlorinity (Lyman & Fleming, 1940).
Table 2. Grams per litre (200 C.) of sea water for chlorinity i-23%o(S= 1-84-41 -55 %o): calculated from Table 1 and the densities obtained from Knudsen's Tables.
Table 3. Millimoles (milligram-ions) per kilogram of sea water for chlorinity 1-23%Q (S= 1-84-41-55 %o): calculated from Table 1, and 1940 values for atomic weights.
Table 4. Millimoles (milligram-ions) per litre (200 C.) of sea water (molarity) for chlorinity i-23%o(S = i-84-4i<55%0): calculated from Table 2 and the 1940 values for atomic weights. Note: the milliequivalents per kilogram or per litre (20° C.) are readily obtained from Tables 3 and 4 by multiplying the values by the valency of the particular ion.
Table 5. Grams per kilogram of water for chlorinity r-23 %,, (S= i-%^-^i-^%^): calculated from Table 1 and the values of total salt content from equation (6) (see text).
Table 6. Millimoles (milligram-ions) per kilogram of water (molality) for chlorinity 1-23 %, (S= 1-84-41 -55 %o): calculated from Table 5 and the 1940 values for atomic weights. Note: milliequivalents can be calculated from Table 6 by multiplying the values by the valency of the particular ion.
Some tables for the ionic composition of sea water
Table i. Grams per kilogram of sea water for chlorinity 1-23% (S =1-84-41-55 %,,)
585
ci%. I 2 3 4 5 6 7 8 9 1 0 11 1 2 13 14 15 16 17 18 19 2 0 21 2 2 23 S%o 1-84 3-64 5-45 7-25 9-06 1086 12-67 14-47 16-28 18-08 19-89 21-69 23-50 25-30 27-11 2891 30-72 32-52 34-33 36-13 37-94 39-744 1 - 5 5
Cl 0-9989 1-9979 29968 3-9958 4-9947 5-9936 6-9926 79915 8-9905 9-9894 109883 11-9873 129862 139852 14-9841 15-9830 16-9820 179809 189799 199788 20-9777 21-9767 22-9756 Br 0-0034 00068 0-0102 0-0136 0-0170 0-0204 0-0238 0-0272 0-0306 0-0340 0-0374 0-0408 0-0442 0-0476 0-0510 0-0544 0-0578 0-0612 0-0646 0-0680 0-0714 0 0 7 4 8 0-0782 SO4 0-1452 0-2843 0-4234 0-5625 0-7016 0-8407 0-9708 [•1189 [•2580 i-397i •5362 •6753 [•8144 [-9535 2-0926 2 2 3 1 7 2-3708 2 5 0 9 9 2-6490 27881 2-9272 3-0663 3-2054 HCO, 0-05406 005881 006357 0-06832 0-07308 0-07783 0-08259 0 0 8 7 3 4 0-09210 0-09685 0-1016 0-1064
O - I I I I
0-1159 0-1206 0-1254 0-1301 O-I349 0-1396 0-1444 0-1492 0-1539 0-1587 Ca 003565 O-O559O 0-07615 0-09640 0-1167 0-1369 0 1 5 7 2 0-1774 0 1 9 7 7 02179 0-2382 0-2584 0 2 7 8 7 0-2989 0 3 1 9 2
O-3394 O-3597 O-3799 0-4002 0-4204 0-4407 0-4609 0-4812 M g 0-06884 O-I357 0-2025 0-2694 03362 0-4030 0-4699 05367 0-6036 0-6704 O-7372 08041 08709 09378 1-0046 1-0714 1383 •2051 •2720 •3388 [•4056 [•4725 [-5393 K 0-O2OO 0-0400 0-0600 0-0800 o-iooo O-I2OO 0-1400 0-1600 0-1800 0-2000 0-2200 0-2400 0-2600 0-2800 0-3000 0-3200 0-3400 0-3600 03800 0-4000 0-4200 0-4400 0-4600 Sr 0-000702 0-001404 0-002106 0002808 0-003510 0-004212 0-004914 0-005616 0-006318 0-007020 0-007722 0-008424 0-009126 0009828 0-01053 O-OII23 0-01193 0-01264 0 0 1 3 3 4 0-01404 0-01474 0-01544 0-01615 Na O-5556 1-1112 1-6668 2-2224 2-778O 3-3336 3-8892 4.4448 5-OOO4 55560 6-m6 66672 7-2228 7-7784 8-3340 8-8896 9-4452 10-0008 10-5564
1 1 • 1 1 2 0
11-6676 12-2232 12-7788 H.BO, 0-00137 0-00274 0-00411 0-00548 0-00685 0-00822 000959 0-01096 0-01233 0-01370 0-01507 0-01644 0-01781 0-01918 0-02055 0-02192 0-02329 0-02466 0-02603 0-02740 0-02877 0-03014 0-03151
Table 2. Grams per litre (200 C) of sea water for chlorinity 1-23 %<, (S = 1-84-41-55 %„)
Cl%o I 2 3 4 5 6 7 8 9 1 0 11 12 13 14 15 16 17 18 19 2 0 21 2 2 23 1-84 3-64 5-45 7-25 9-06 io-86 12-67 14-47 16-28 18-08 1989 21-69 2 3 5 0 2 5 3 0 27-11 28-91 30-72 32-52
34-33
3 6 1 3
37-94 39-74 41-55 Cl 0-9986 2-0000 3OO4O 4'OIO8 5-O2O4 60327 7-O476 8-0654 9-0858 IO-IO89 II-I348 12-1034 13-1947 I4-2288 15-2656 16-3051 I7-3476 18-3926 I94404 2O-49II 21-5444 22-6007 23-6597 Br 0003399 0-006807 O-OIO22 0-01365 0-01709 O-O2O53 O O 2 3 9 9 0-02745 0-03092 0-03441 0-03790 0-04140 004491 004843 0-05196 0-05550 0-05904 0-06260 0-06617 0 0 6 9 7 4 007333 0-07692 0-08053
so
4 0-1452 0-2846 0-4244 0-5646 0-7052 0-8462 0-9875 1-1292 1-2713 1-4138 1-5567 1-6999 1-8435 1-9875 2-1319 2-2767 2-4218 2-5674 2-7133 2-8596 30063 3-1534 33008 HCO, 0-05404 0-05887 0-06372 006858 0-07345 0-07834 0-08323 0-08815 0-09307 0-09801 0-1030 0-1079 0-1129 0 1 1 7 9 O-I229 0-1279 0-1329 0-1380 0 1 4 3 0 0-1481 0-1532 0 1 5 8 3 0-1634Ca
0 0 3 5 6 4 005596 007633 0-09676 0-1172 0-1378 0-1584 0 1 7 9 0 0 1 9 9 7 0-2205 0-2413 0-2622 0-2831 0-3041 0-3251 0-3462 0-3674 0-3886 0-4099 0-4312 0-4526 0 4 7 4 0
O-4955 M g 0-06882 0-1358 0-2030 0-2704 O-3379 O-4O57 04736 o-54i7 o-6ioo 0-6784 0-7471 0-8159 08849 09541 •0235 •0930 •1628 [•2327 [•3028 [-3731 I-4436 I-5I43 1-5852 K 0-01999 0-04004 0-06014 0-08030 0-1005 0-1208 0-1411 0-1615 0-1819 0-2024 0-2229 0-2435 0-2642 0-2849 0-3056 0 3 2 6 4
O-3473 0-3682 0-3892 0-4103 O-43I3 O-4525 O-4737 Sr 0-0007018 0-001405 0002111 0-002819 0-003528 0-004239 0-004953 0-005668 0-006385 0-007104 0-007825 0-008548 0-009273 0009999 0-01073 0-01146 0-01219 0-01293 0-01366 0-01440 0-01514 001588 0-01663 Na 0-5554 I-II24 1 6708 2-2308 27923 3-3553 39198 4-4859 5-O534 56225 6-1930 6-7651 7-3388 79139 84906 90687 9-6485 10-2298 10-8126 11-3970 11-9828 12-5703 I3-I593 H,BO, 0-001370 0-002743 0-004120 0-005501 0-006885 0-008274 0-009665 0-01106 0-01246 0-01386 0-01527 0-01668 0-01810 0-01951 0-02094 0-02236 0-02379 0-02522 0-02666 0-02810 0-02955 0-03100 0-03245
[image:4.451.21.433.387.599.2]Table 3. MUHmoles (milligram-ions) per kilogram of sea water for chlorinity Cl%. I 2 3 4 5 6 7 8 9 1 0 1 1 1 2 13 14 15 16 17 18 1 9 2 0 2 1 2 2 23 S%o 1-84 3-64 5-45 7 2 5 9-06 io-86 12-67 14-47 16-28 18-08 19-89 21-69 23-50 25-30 27-11 2891 30-72 32-52 34-33 36-13 37-94 39-74 41-55 Cl 28-17 56-35 84-52 1127 1409 169-0 197-2 225-4 2536 2817 309-9 338-1 3663 394-4 422-6 450-8 478-9 507-1 535-3 563-5 591-6 619-8 648-0 Br 0-04254 0-08509 0-1276 0-1702 O-2I27 O-2553 O-2978 0-3404 0-3829 O-4254 0-4680 O-5IO5 O-553I O-5956 0 6 3 8 2 O-68O7 O-7233 0-7658 0-8083 0-8509 0-8934 0-9360 0-9785 SO, 1-512 2-960 4-408 5-856 7-304 8-752 IO-20 II-65
I 3 - I O
14-54 15-99 17-44 18-89 20-34 2 1 7 8 23-23 2468 26-13 27-58 29-02 3O-47 31-92 33-37 HCO, 08859 0-9638 1-042 I-I2O I-I98 I-276 1-354 I-43I 1-509 1-587 1 6 6 5 1-743 1-821 1 8 9 9 1-977 2-055 2 1 3 3 2-211 2-289 2-367 2-444 2-522 2-600 Ca 08895 1-395 1-900 2-405 2-910 3-416 3921 4-426 4-931 5-437 5-942 6-447 6-952 7-458 7-963 8-468 8-973 9-479 9-984 10-49 10-99 11-50 I2-OO Mg 2-831 5-579 8-327 11-08 1 3 8 2 i6-57 1932 22-07 24-82 27-57 3031 33-o6 35-8i 38-56 4i-3i 44-06 46-80 49-55 52-30 55-O5 57-80 60-55 6 3 2 9
K 0-5116 1-023 •1-535 2-046 2-558 3-069 3-58i 4-O93 4-604 5-116 5-627 6 1 3 9 6-650 7-162 7-673 8-185 8-697 9208 9-720 10-23 10-74 1 1 2 5
n-77 Sr 0-008011 0-01602 0-02403 0-03204 0-04005 0-04807 0-05608 0-06409 0-07210 0-08011 0-08812 0-09613 0-1041 O-II22 O-I2O2 O-I282 0-1362 O-I442 O-I522 0-1602 0-1682 0-1762 0-1843 Na 24-16 4832 72-48 9664 120-8 145-0 169-1 193-3 217-4 241-6 265-8 289-9 314-1 338-2 362-4 386-6 410-7 434-9 459-O 483-2 5°7-4 531-5 555-7 H,BO, 0-02215 004431 0-06646 008861 0-1108 01329 0-1551 0-1772 O-I994 0-2215 0-2437 0-2658 0-2880 0-3101 03323 O-3544 0-3766 0-3987 0-4209 O-443I 0-4652 0-4874 0-5095
Table 4. Millimoles (milligram-ions) per litre (200 C.) of sea water (molarity)
for chlorinity 1-23%,, (S = 1-84-41 -55%,)
Cl%o I 2 3 4 5 6 . 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 16 17 18 1 9 2 0 2 1 2 2 2 3 S%o 1-84 3-64 5-45 7-25 9-06 io-86 12-67 14-47 16-28 1808 1989 21-69 2350 2530 27-11 28-91 30-72 32-52 34-33 3 6 1 3 37-94 39-74 41-55 Cl 2816 56-41 §4-72 113-1 141-6 170-1 1988 2275 256-2 2851 3 I 4 O 343-o 372-1 401-3 43O-5 459-9 489-3 518-7 548-3 577-9 6 0 7 6 637-4 667-3 Br 0-04253 0-08518 0-1279 0-1708 0-2138 0-2569 0-3002 O-3435 0-3870 O-43O5 0-4742 0-5180 0-5620 0-6060 0-6502 0-6944 0-7388 0-7833 0-8280 0-8727 0-9176 0-9626 1 008 SO, 1-511 2-963 4-418 5-878 7-341 8-809 10-28 11-76 1 3 2 3 14-72 16-21 17-70 19-19 20-69 22-19 23-70 25-21 26-73 28-25 29-77 31-30 32-83 34-36 HCO, 08856 0-9648 1-044 1-124 1-204 1-284 1-364 1-445 1-525 1606 1-687 1-769 1-850 1-932 2-014 2-096 2179 2-261 2-344 2-427 2-511 2-594 2-678 Ca 0-8892 1-396 1-905 2-414 2-925 3-438 3-952 4-467 4984 5-502 6-O2I 6-542 7-064 7-588 8-II2 8639 9-167 9-696 10-23 10-76 11-29 11-83 12-36 M g
2 8 3 0 5-5§5 8-347 11-12 13-90 1668 19-47 22-27 25-08 27-90 30-72 33-55 36-39 39-23 4208 44-94 47-8i 50-69 53-57 5 6 4 6 59-36 62-27 6 5 1 8
Some tables for the ionic composition of sea water
587
Table 5. Grams per kilogram of water for chlorinity 1-23 %„
( S = I - 84-4I - 5 5 %0)
C13C 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2 0 21 2 2 23
s%.
I-84 3 64 5-45 7-25 9-06 io-86 12-67 14-47 1628 1808 1989 21-69 23-50 25-30 27-11 28-91 30-72 32-52 34-33 3613 37-94 39-74 41-55 Cl 1-0008 2-0053 3-QI34 4-0252 5-O4O7 6 0 5 9 9 7-0829 8-1096 9-1401 10-1744 11-2125 12-2545 13-3003 I4-35OO I5-4O37 16-4612 17-5227 18-5882 I9-6577 20-7312 21-8087 22-8903 23-9760 Br 0-003406 0-006825 0-01026 0-01370 0-01716 0-02063 0-02411 0-02760 0-03111 0-03463 0-03816 0-04171 0-04527 0-04884 0-05243 0-05603 0-05964 0-06327 0-06691 0-07056 0-07423 0-07791 0-08161 SO4 O-I455 0-1854 O-4257 0-5666 0-7081 0-8500 0 9 9 2 5 I-I354 1-2789 1-4230 I-5675 1-7126 1-8583 2-0045 2-1512 2-2985 2-4463 2-5947 2-7436 28931 3-0432 3-I938 3-345O HCO, 0-05416 005903 0-06392 006882 007375 0-07869 0-08365 008863 0-09363 0-09864 0-1037 0-1087 0-1138 0-1189 0-1240 0-1291 0-1343 O-I394 0-1446 0-1498 0-1551 0-1603 0-1656 Ca 003572 0-05611 0-07657 0-09711 0-1177 0-1384 0 1 5 9 2 0-1800 0-2009 0-2219 0-2430 0-2642 0-2854 03067 0-3281 0-3496 0-3711 0-3927 0-4144 0-4362 0-4581 0-4801 0-5021 M g 0-06897 0-1362 0-2036 0-2713 O-3393 0-4075 0-4759 O-5447 0-6136 0 6 8 2 8 0-75230-8220 0-8920 0-9622 •0327 •I O
35 c-1745 [•2458 •3174 •3892 [-4613 [-5337 [•6063 K 0-02004 0-04015 0-06033 0-08059 0-1009 0-1213 0-1418 0-1624 0-1830 0-2037 0-2245 0-2453 0-2663 02873 0-3084 0-3296 0-3508 0-3722 0-3936 0-4151 0-4366 0-4583 0-4800 Sr 0-0007033 0-001409 0-002118 0-002829 0-003542 0-004259 0-004977 0-005699 0-006423 0-007150 0-007880 0-008612 0 0 0 9 3 4 7 0-01008 0-01082 0-01157 0-01231 0-01306 0-01381 0 0 1 4 5 7 0-01533 0-01609 0-01685 Na 0-5566 11153 1-6760 22388 2-8036 3-37O5 3 9 3 9 4 4-5IO5 50836 5-6589 62363 6 8 1 5 8 7-3975 7-0813 8-5674 9-I556 9-7460 103386 IO-9334 II-53O5 12-1298 12-7314 I3-3352 H.BO, 0001373 0-002750 0-004133 0-005520 0-006913 0-008311 0009714 0-OI1I2 O-OI254 O-OI395 0-01538 0-01681 0-01824 0-01968 0-02113 0-02258 0-02403 002549 0-02696 0-02843 0-02991 0 0 3 1 3 9
003288
Table 6. MiUimoles (milligram-ions) per kilogram of water (molality) for
chlorinity 1-23 %, ( S = I - 84-4I - 5 5 %>)
[image:6.451.26.424.368.601.2]588
Cl%o
IO I I 1 2
13 14 15 16 17 18 19
2O 2 1 2 2
Table 7. Vapour pressure
R
0-02861 0-02869 0-02877 0-02885 0-02893 0-02901 0-02908 0-02916 0-02924 002932 0-02940 0-02948 0-02956
NaCl
02861 0-3156 0-3452 0-3751 0-4050 O-4352 0-4653 0-4957 0-5263 0-5571 0-5880 0-6191 0-6503
KC1
0-2908 0-3211 0 3 5 1 6 0-3825 0-4134 0-4447 0-4760 O-5O77 0-5397 0-5719 0-6043 0-6370 0-6698
CaCl,
0-2039 0-2240 0-2441 0-2642 0-2841 03043 0-3243 O-3445 03645 0-3845 0-4044 O-4243 0-4440
and osmotic equivalence
MgCl,
0-2005 0-2199 0-2393 0-2588 0-2780 0-2975 0-3165 O-3356 0-3546 0-3738 0-3929 0-4122 O-43I3
MgSO4
0-5056 O-5597 06138 0-6675 0-7206 07738 0-8264 08786 0-9300 0-9803 1-028 1-076 1-123
Na.SO.
0-2374 0-2643 0-2918 0-3196 O-3477 03762 0-4051 O-4347 04648 O-4954 0-5264 O-5578 0-5896
of sea water ai
Sucrose
0-5065 05560 06053 0-6546 0-7040 O-7534 0-8025 08516 0-9008 09497 0-9982 1-047 1095
Urea
0-5400 0-5965 06534 0-7112 O-7695 0-8285 o-888o 0-9482
I-OIO
1-071 i-i33 1-197 1-260
' 25° C.
V.P.
lowering
0-00946 0-01042 0-01139 0-01237 0-01334 0-01433 0-0:532 0-01631 0-01732 0-01833 0-01936 0-02039 0-02142
Osmotic pressure (atm.)
1287 I4-I9 I5-5I 16-85 18-19 19-55 20-91 22-28 2 3 6 6 25-06 26-47 27-89 2933
The column headed V.P. lowering gives the relative pressure lowering &plp" = (po—p)lp'', where p is the
vapour pressure of the sea water and p° is the vapour pressure of pure water. p° = 23-756 mm. 250 C. i i = M-NaCl/%0Cl.
The data are not more accurate than warrants five significant figures in the tables, the accuracy varying with the analytical methods involved. In some of the tables more figures are quoted and may be rounded off; in tables of milligram-ions only four significant figures are given.
I wish to thank both Dr L. H. N. Cooper and Dr J. D. Robertson for helpful criticism and for checks on a number of the tables, and the former for drawing attention to Prof. Robinson's work.
REFERENCES
DITTMAR, W. (1884). Report on researches into the composition of ocean water, collected by H.M.S. Challenger. Challenger Rep. Physics and Chemistry, 1, 1.
FORCH, C , KNUDSEN, M. & SORBNSHN, S. P. L. (1902). Berichte iiber die Konstantenbestimmungen zur Aufstellung der hydrographischen Tabellen. K. danske vidensk. Selsk. 6. Raekke, natur-vidensk. og mathem. Afd. XII, 1, 151 pp.
JACOBSEN, J. P. & KNUDSEN, M. (1940). Urnormal 1937 or primary standard sea water 1937.
Publ. set. Ass. Ocianogr. no. 7, 38 pp. Liverpool.
KNUDSEN, M. (1901). Hydrographical Tables. Copenhagen: G. E. C. Gad.
KNUDSEN, M. (1903). Gefrierpunkttabelle fur Meerewasser. Publ. Ore. Cons. Explor. Mer, no. 5, p. 11.
LYMAN, J. & FLEMING, R. H. (1940). Composition of sea water. J. Mar. Res. 3, 134.
ROBINSON, A. R. (1954). The vapour pressure and osmotic pressure equivalence of sea water.
