A CHARACTERISTIC PROPERTY OF WHALE OILSCONCERNING THE ABSORPTION OF GASES II.
ON THE ABSORPTION OF NITROGEN
BY WHALE OILSYASUTARO ISHIKAWA*
In a previous paper (Ishikawa, 1956), we have reported on the absorption of carbon dioxide by the oily substances, including whale oils, inwhich it has been established that the kinds of whale oils, especially thesperm oil from spermaceti, far exceed the vegetable oils, in the absorption velocity of carbon dioxide.
In this paper, tests were made with the absorption of nitrogen by
several kinds of oily substances, not only on its solubility but also on
the absorption velocity.
In connection with the present subject, reference may be made to a
profound investigation pertaining to deep sea diving and aviation, in
which Albert R. Behnke, JR. (1941-42) had found the solubility ofvarious gases, including nitrogen, in olive oil and in water, at ordinarypressures and at 38°C. So that he had determined the oil-water solubility ratio of various gases. However, in his investigation, emphasis
is laid upon the solubility of various gases, in a kind of oil. On thecontrary, our present subject .is to study the property of various kindsof oils, as to the absorption of nitrogen.
As a result of the present experiments, it was proved that the solubility of nitrogen in various materials, was rather small, compared tothat of carbon dioxide. As for the absorption velocity, it has beensuggested in the earlier report (Ishikawa, 1956) that a equation, L1V0 =A(l-e-"'i), will hold for the processes of this kind, if the process were
subjected to constant pressure. In the case of carbon dioxide, however,
the measurements were carried out not at constant pressure, but atconstant volume. Furthermore the change of pressures caused by absorption was so great, owing to the great solubility of carbon dioxide,that the processes could not in any way, be regarded as such. Whereas,in the present experiments, they can be approximately regarded as atconstant pressure, because of the small solubility of nitrogen. Consequently it seems fully probable that this equation may be valid forthe processes, though they were carried out at constant volume, as wellas in the previous work.

* Hiroshima University309

Y. ISHIKAWA

310

Indeed, as a result, it was ascertained that this equation was valid,
within the limits of experimental error, for any of the processes included.
Details of analysis will be described later.
EXPERIMENTAL

Materials.-Three kinds of whale oils*, sperm oil from spermaceti,
sperm wh~le body oil and blue whale oil were chosen. The first two
are marked by containing of a large amount of wax. The other is one
from a blue whale and the majority of it, is constituted from glycerides,
as is clear from table 1. On the other hand, three kinds of vegetableoils, olive-, camellia- and castor oil were tested for the sake of comparison.
TABLE 1.

PHYSICAL AND CHEMICAL PROPERTIES OF THE MATERIALS

Materials

Specific
Gravity

Water
Sperm Oil
Sperm Body Oil
Blue Whale Oil
Olive Oil
Camellia Oil
Castor Oil
Liquid Paraffin

0.994
0.858
0.865
0.907
0.913
0.903
0.967
0.874

ns5
4

Index ofRefraction
nn

Acid
Value

1.4530 (35°)
1.4612 (35°)
1.4736 (35°)
1.4631 (30°)
1.4692 (30°)
1.4747 (25°)

0.65
1.23
0.52
2.46
2.30
2.16

Saponification Value

IodineValue

Unsaponified
Matter
%

147.8
138.5
195.7
196.3
192.3
188.7

54.9
72.8
101.8
88.4
81.3
87.4

34.2
31.8
0.36
0.43
o.86
0.46

Distilled water and liquid paraffin were also added as materials. The
water which is the most important physiological matter, seems reasonable
to be tested in comparison with oily substances. Liquid paraffin waschosen from another interest, for it is expected as a matter of poor
absorption.
Physical and chemical properties of the materials used, were given intable 1.
Apparatus and Procedure.-Apparatus and procedure employed, havebeen fully described in the previous paper (Ishikawa, 1956), and only abrief description on essentials is given below.
In every measurement, 100 g. of a material was taken. With eachmaterial, the measurements were carried out under five pressure-lebels,
i.e. under the pressure, near but a little higher than 1, 2 and 3 atmos.
pressures respectively, and under every intermediate lebel.
Deaeration of the materials to be tested, was performed in the verysame way as described in the earlier report (Ishikawa, 1956): Deaeration in boiling water bath, was followed by the deaeration in thermostat* Kindly supplied by the Taiyo Fisheries Co., Ltd.

A CHARACTERISTIC PROPERTY

311

of 35°C, until the temperature of the contents became constant. Nitrogen gas was then introduced from the gas-reservoir into the pressurevessel, up to the desired pressures, for which operation 30 to 40 sec.
elapsed.
30

JO_.,_._ ..._.___..-..---·-·-&-·-·_.._
50

250

150

JOO

Pf (cm. Ha)
Sperm Oilff[;,'; fnf v Oil
Blue
Whale Oil
Liquid Paraffin

Camellia Oil
Castor Oil
Water

--+.

+---

- --- -----{>--------- - --- ---- ----@---------·-fr--·-·-·-·-· -·ll-· - · - · ------o··----·---·-··--0··-··----------0----------------------0--------_______,.__ _____________ __., ____ _Fig. 1. Relation between probable solubility and pressure
in various materials

The measurements were made at 35± 0.05°C. The temperature was
required to be closely constant, because the decrease in pressures causedby the absorption was relatively small, owing to the small solubility ofnitrogen. On the other hand, with our apparatus, the temperaturegradient of pressure is 7 .35 mmHg°C. This value is equivalent to about
5 cc/°C of the volume change. The fluctuation of the temperatures
seems to be the largest error source.
Cooling effect which will occur on passing of the gas through thethrottling cock, must be also a matter of consideration, on the sameaccount. No preliminary test in this connection, has been done. But,
granted that the process were entirely adiabatic, this effect can be esti273)'dP, where dT is the decrease in
mated by the formula, dT=r(.T
temperatures which will occur when the difference of pressures between
both sides, is dP, r, a empirical constant, characteristic of the gas ; itamounts to 0.3°C atmos. for nitrogen.

312

Y. ISHIKAWA

According to this, we have 0.2 to 0.4°C, for the decrease in temperatures, with our operations. However, considering that our processes
are not adiabatic, but will occur rather isothermally, the net decreasein temperatures must be far smaller than the adiabatic one. Indeed ourmeasurements were scarcely interfered by this effect, except that a slightirregularity of the decrease in pressures was recognized at the very
earliest interval of the measurements (within 1 min. from outset).
4

30

20

40

Time (min)Fig. 2.

Absorption curves for water under various pressure lebels.

30

30
25

0

10

20

30

40

Time (min}Fig. 3. Absorption curves for sperm
oil under various pressure lebels.

0

10

2

30

40

50

Time (min)Fig. 4. Absorption curves for sperm
body oil under various pressure lebels.

Mercury manometer employed, is of an open type, 2.2 m in height,
graduated in mm interval, with a reading glass.
The mechanical conditions of the constant movement of the pressurevessel and the other procedures were almost alike as those in theprevious work (Ishikawa, 1956).
Obtaining of L1V0 from LIP.-In the present work, as well as in theprevious one, (Ishikawa, 1956) LIP, the decrease in pressures caused by

A CHARACTERISTIC PROPERTY

313

absorption, was punctually measured at constant volume. But, if supposedthat the pressure were kept at initial constant value during the wholeprocess, the decrease in volume will occur at this constant pressure andthis decrease in volume at a initial definite P, must have been absorbedby the material, during the process.
This decrease in volume was obtained from LlP, by the very same way
as described in the earlier report (Ishikawa, 1956). The formula used,is
L1V0 =1'o__!_ V • LlP
T

Po

( 1)

where L1V0 is a decrease in volume (in cc) of a gas, reduced to standard
state, T 0 =273°K, T=308°K, P 0 =760 mmHg, and Vis the volume (684cc) of the pressure-vessel less the volume of the material used. The
formula (1) was deduced from the well known relation, PV=const., fora given amount of a gas.
Thus, in the formula (1), ~__!_ is a common constant disregarding the
T P0materials, and Vis a constant regarding the capacity of the vessel andthe amount of the material taken into the vessel. So we obtain L1V0
from LlP, by multiplying LlP with this constant factor, l'o__!_ V for a
T P0 '
fixed amount of a material.

RESULTS
Solubility** of Nitrogen in Various Materials.-In figure 1, each curve
gives the values of A's for each material, plotted against the final press
sure, P1 • Symbol A, essentially represents the solubility of the gas ina material. It was obtained by some mathematical means, on the basisof L1Vomm the maximal volume of the gas absorbed. Upon the method,by which, A was obtained, we will describe in the next chapter. At
any rate, there exists no great difference between A and LlVomau forour experiments, where the measurements were made so long till thesaturation was practically reached.
In figure 1, it is corollary that every curve must pass the origin, andtherefore it takes a form reading** The solubility is expressed in terms of the volume (in cc.) of the gas per 100 g. ofa material, when the latter has absorbed the former to a possible maximal extent. It
must be also mentioned that the volume was measured indirectly from dP. So it may bequite possible that this volume differs from that of the real solubility, by the amount of
the gas taken into the material, in some labile state, say, in the form of visible or invisible
bubbles suspending. Though it is again questionable that the bubbles in a liquid, caneffect a decrease in pressures, to what extent.

Y. ISHIKAWA

314

A=cP
The coefficient c may be a characteristic of the material. But there
exists no remarkable difference between the values of c's for the various
oily materials. So it seems impossible that they can be characterized
by the magnitude of c. Although the closer examination of the figure

20

5

40

50

60

Time (min)Fig. 5. Absorption curves for blue whale oil undervarious pressure lebels.

25

20---x-·-·--·-·-·-x--·-·-·- ·-·---«

c;-x·.--·_.-·x-·-·- -·--·§ 15,,,..,,,.,,,......

--<>-·-··-··-··-··-O--··---··-··-·-·O--··-··-··-··--o

/

/"

IO

20

----4·--··

30

40

50

60

70

80

90

JOO

Time (min)Fig. 6.

Absorption curves for olive oil under various pressure lebels.

l, reveals that the value of c is greater for the wax-oils than for theglyceride-oils and the minimum for castor oil, which possesses hydroxyacids in its molecules: The value of c is 0.12 cc/cmHg, for sperm oil
and it is near but a little less than that for sperm body oil. For blue
whale oil, is 0.098 and those for camellia oil and liquid paraffin standA CHARACTERISTIC PROPERTY

315

very close by that. For castor oil, c is 0.073.
On the other hand, it differs greatly therefrom and amounts to 0.016
cc/cmHg, for the water. Hence the coefficients for the oily materials
25

20________ ... ---_______ .A------------------1:!.

_/:r ______ _;,,---

c;;

---

§ 15

____________ x-·-·-·-··-----X_.----_.x-.-· --x-.,----$>~--------·--------------.()---·-··-··--·-··-<>____ x

"'10

40

50

60

120

130

140

Time (min)Fig. 7.

Absorption curves for camellia oil under various pressure lebels.

20p------------------1:!.

..................
cr, 158--<>-· - ·- -··-· -<>~ 10-----5

60

160

170

180

Time (min)Fig. 8.

Absorption curves for liquid paraffin under various pressure lebels.

(with the exception of caster oil}, are 6 to 7.5 times as great as thatfor the water. In other words, the oily substances can absorb 6 to 7.5
times as much nitrogen as the water, at every pressure value. Evencastor oil can absorb 4.5 times as much as the water.
In the case of carbon dioxide, it has been determined in the earlier
paper, that c is 1.78 cc/cmHg, for sperm oil, and the values for the otheroily substances, are of the magnitude close but less than that and theY. ISHIKAWA

316

c for water is 0.78 cc/cmHg. When compared within the oily materials,
they can absorb nitrogen 1/10 or less, as much as carbon dioxide, at
any pressure, and in the case of water, it can absorb nitrogen some
1/50 as much as carbon dioxide.
Absorption Curves.-In figure 2 to figure 9, each diagram shows absorption curves for each material respectively. Any of the diagrams consistsof five curves, corresponding to five pressure lebels. Every curve wasdrawn based upon two or three times parallel experiments. In most of
the cases, the discrepancy between the corresponding values of .dV0 's,
is less than 5 %.

15
Ci

§10

>
"<;J

5

0
Time (min)Fig. 9.

Absorption curves for castor oil under various pressure le~els.

When comparing these 8 figures, there seems to exist a great difference in the absorption velocity of nitrogen, between the individualmaterials. But any quantitative evaluation about the velocity, can not
be made without the analysis of the curves.
ANALYSIS

As noted in the foregoing chapter, it seems very probable that theequation( 2)

will be valid for any of the curves included. If it were true, log (A-.dV0 )must become linear against the time, t. Indeed, as illustrated in figure
10, it proved that in all of the cases, log (A-.dV0) showed the strong
linear regression to the time t. In equation (2), .dV0 is a decrease involume caused by absorption, A, the solubility of the gas, and a, avelocity constant, as seen in its differentiated formd-(.d V0 ) = a(A-.d Vo)

dt

( 3)

317

A CHARACTERISTIC PROPERTY

Figure 10 was chosen altogether at random from 8 :figures obtained forthe 8 materials. Another 7 figures were given up to save space.
TABLE 2.
Materials

Water

Sperm Oil

Sperm Body Oil

Blue Whale Oil

Olive Oil

Camellia Oil

Liquid Paraffin

Caster Oil

THE VALUES OF A'S AND a FOR EACH MATERIAL
Pressure Lebels(mm. Hg)a
PeriodA(min- 1 )(min.)
(cc.)
pi
P1
~-~'~

931.8*
1,238.7
1,651.0
2,060.0
2,364.0929.0
1,241.0
1,652.2
2,061.3
2,365.0926.7
1,238.2
1,651.0
2,060.5
2,361.0930.0
1,241.5
1,649.7
2,063.3
2,364.6929.8
1,240.2
1,649.0
2,059.0
2,360.2
930.7
1,240.3
1,650.0
2,061.0
2,365.3
931.7
1,241.0
1,649.7
2,060.4
2,365.6930.4
1,240.0
1,649.7
2,060.5
2,361.5

929.5*
1,235.7
1,647.0
2,055.0
2,358.5
912.7
1,219.0
1,623.0
2,025.0
2,322.0
909.6
1,216.7
1,623.0
2,025.3
2,321.0
916.7
1,224.0
1,625.6
2,035.0
2,330.6
916.2
1,221.5
1,623.2
2,027.3
2,326.7919.0
1,225.0
1,627.8
2,033.0
2,331.3
919.5
1,224.3
1,626.3
2,031.0
2,331.6920.8
1,226.7
1,633.7
2,040.7
2,338.6

40

"
"
"
"

40

"

"
"
"

50

"

"
"

"

60

"

"
"
"

80
100

"
"
II

140

"
"
"

"

180

"
"
"
"

330

"
"

"
"

1.5
2.0'
2.7
3.4
3.8
10.8
14.65
19.4
24.5
28.3
11.3°
14.3
18.7
23.45
26.8
8.8
11.85
15.85

r

0.155

20.0

0.154

20.0

0.114

15.0

0.081

10.5

0.056

7.5

0.035

4.5

0.021

3.0

0.0076

1.0

20.2

22.9
9.2
12.6
17.3
22.6
25.3
8.1
10.7
15.2
18.8
22.8
8.45
11.35
15.9
19.8
23.0

7.0
9.7
11.5
14.1
17.0

* These values in water, were obtained by substracting 42mm. Hg, the saturated
vapor pressure of dist. water at 35°C, from the total pressure.
Determination of A.-It may be essentially possible to determine two
unknown factors, A and a, respectively, when the values of L1V0's andt's, more than two sets are given. However it is very difficult to solve
such simultaneous equations as involving the exponential functions.
To avoid such difficulties, a graphical method is adopted: The firstestimated value of A, is obtained from the L1Vo-t diagram, by extra-

318

Y. ISHIKAWA

polating the curve to the infinite value of t. Then, using this value ofA, the values of log (A-.dV0 )'s are plotted against t. Thus, if theequation is valid, it will be sure that the log (A-.dVo) becomes rather
linear against t, in the interval, where t is relatively small. But,
with increase of t, the curve will show a tendency to bend upwards or
downwards, according as the estimated value of A is too great or too
small. If the curve is bending downwards, some value is to be added
to the first estimated value of A, to get a straight line. Then we havea second estimated value of A, and so forth, when log (A-.dVo) becomesreally linear against t, over the whole interval, the then value of A must
be the value to be found.
Of course, individual points may fall rather scattering, up and downon the line, we must pay attention to the tendency. In the case of thematerials with slow absorption, as castor oil and liquid paraffin, difference
between A and .dVomax becomes somewhat considerable, and in those with
rapid absorption, as sperm oils and other whale oils, the difference isalmost negligible.
Determination of a.-a was obtained by the method of averages, using
the formula derived from the equation (2)nn ·log A- L, log (A-.dV0 )a=2.3026

1

L." t
1

Thus we have five different values of a, for each material. However,in all of the cases, the values of a's obtained within a given material,
were found to be almost much the same, disregarding the pressure lebels.
At least, we could not find any orderly relationship between the magnitude of a and pressure lebels. It seems likely that within such narrow
range of pressures, a becomes approximately constant, though it is nota theoretical consequence. For this reason, by averaging the five values,
a single value of a was given for each material, without regard to thepressure lebels.
As seen from table 2, the value of a is great in the decreasing orderof water, sperm oil, sperm body oil, blue whale oil, olive oil, camellia
oil, liquid paraffin and castor oil. This order proves to be consistent
with that of the absorption velocity of carbon dioxide (cf. previous
paper). Here again, the value of a is outstandingly greater for thewhale oils than for the vegetable oils, and the greatest two are thosefor sperm oil and sperm body oil, both containing a large amount of wax.
In the table 2, the other descriptions were also given; in the second
and third column, the pressure lebels, under which the measurements
were carried out, in the fourth, the lapse of time, during which each

319

A CHARACTERISTIC PROPERTY

measurement was made, in the fifth, the values of A, for each material,
under various pressure lebels, and the last column headed by r, gives
the ratio of a for each material to that for castor oil.
We shall now compare the absorption velocity of nitrogen with thatof carbon dioxide, in various materials. Unfortunately, however, a generalcomparison is not possible, since another formulae are used in bothcases: In the case of carbon dioxide, we have been obliged to use aexperimental formula as~(LIV.)=a'b• tb-r0(4)

dt
and in the present work, we can do with the equation (3). Therefore
the absorption velocity of the both gases must be compared in a fixed
condition, i.e. urrder a definite pressure lebel and at a definite time.

"'

~05
J!_

-05

Time (min)Fig. 10. Relation between log(A-.dV0) and t.
blue whale oil, as an illustration.)(In the case of

Nevertheless, in the equation (4), a'b shows the velocity at 1 sec
after outset, that is approximately regarded as the initial velocity,whereas aA represents the initial velocity itself, in the equation (3).
Thus we can make a rough comparison of the initial velocity of theboth gases, by comparing a'b with aA. For instance, in the caseof sperm oil, the value of a'b was 1.68 cc/sec (cf. p. 204 of the earlier
paper), i.e. 100.8 cc/min, under the pressure lebel, whose initial pressure
was 2,364 mmHg. While aA is 4.36 cc/min, under the pressure lebel,
initial pressure of which is 2,365 mmHg. So, in the case of sperm oil,the initial absorption velocity of carbon dioxide, is some 23 times as great
as that of nitrogen, at the same pressure.

320

Y. ISHIKAWA

Such ratio, a'b/aA, at the same pressure, remains almost constant,within any of the materials used, disregarding the pressure lebels, butvaries with the kind of material. It ranges from 20 to 30, in the oilymaterials, except castor oil, in which it comes to about 70. On the other
hand, it amounts to some 200, in the case of the water.
SUMMARY

1. Asborption of nitrogen was studied with 8 kinds of substances,i.e. distilled water, sperm oil from spermaceti, sperm body oil, blue
whale oil, olive oil, camellia oil, liquid paraffin and castor oil.
2. Decrease in pressures, LIP, caused by absorption, was punctually
measured with each material, at constant temperature (35 ± 0.05°C) andat constant volume, under five different pressure lebels, i.e. under thepressure, near but a little higher than 1, 2 and 3 atmos. pressures respectively and under every intermediate lebel.
3. Decrease in volume, corresponding to LIP, was reduced to standard
state, and designated by L1V0 , this volume of nitrogen must have beenabsorbed by a given material, during the process.
4. From the results obtained, following conclusions were drawn:
a. The value of A was found to be approximately proportional to thepressure, with each material, where A stood for the solubility of nitrogenin a material. Therefore the relation, A=cP, was postulated.
b. Within the oils and oily substances tested, the value of c does notdiffer so greatly from each other. So, we consider, they can not becharacterized by this magnitude. On the contrary, there existed a great
difference between c for water and those for oily substances, the lattersare 6 to 7.5 times as great as the former.
c. As compared to the solubility of carbon dioxide, the solubility ofnitrogen is of the magnitude about one-tenth of the former in the oilymaterials, and some 1/50, in the water.
d. The results of the analysis indicated that the equation (2) was valid
in good approximation, for all the curves included.
e. The absorption velocity constant, a, was prominently characteristicof the material, its value was far greater for the oils from whale kinds,
especially for the oils from sperm whale, which contain a large amountof wax, than for the vegetable oils.
f. The value of a was great in the order, named in section 1. of thissummary.
g. In the order of magnitude, the absorption velocity of nitrogen isconsistent with that of carbon dioxide, within the materials, used incommon to both the works.

A CHARACTERISTIC PROPERTY321

ACKNOWLEDGEMENT

The author takes this opportunity to express his deep gratitude toProf. Dr. T. Mori of the Tokyo University for his kind guidance andencouragement throughout the course of this work.
REFERENCESISHIKAWA, Y. (1956). A characteristic property of whale oils concerning the absorption ofgases. I. On the absorption of carbon dioxide by whale oils. Sci. Rep. Whales,
Res. Inst. no. 11 191-213, 1956.
BEHNKE, A. R. JR. (1941-42). Physiologic studies pertaining to deep sea diving andaviation especially in relation to the fat content and composition of the ·body. The
Harvey Lectures, Ser, 37, 198-226.