Relationship of Hydrocarbons with Six to Nine Carbon Atoms HAROLD M. SMITH AND H. T. RALL Petroleum Experiment Station, Bureau of Mines, Bartlesville, Okla.
I
1
e
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I
N 1944 Forziati and coworkers ( 1 ) working a t the National
brief, the method consisted of separating the aromatics from the naphthenes and paraffins by silica gel adsorption and subjecting Bureau of Standards, under the auspices of API Research each of the two portions to efficient fractionation, determining Project 6 directed by F. D. Rossini, studying the components of straight-run naphthas from seven crude oils, observed that the density and refractive index on each fraction, and from the combined data estimating individual hydrocarbon contents. ratios of the percentage of certain individual hydrocarbons and clasFes of hydrocarbons present in these naphthas showed surThe accumulated Bureau of Mines data are tabulated in Tables prising constancy. The present report presents data on naphthas I11 and IV, and a portion of these data is plotted in Figures 1to 8. from 21 domestic and 11 foreign crude oils that substantiate this These data give the volume per cent of hydrocarbons, or groups of hydrocarbons, contained in the crude oil. I n the figures these observation. The authors' data for the naphthas reported here are derived volume per cents are plotted as a function of the volume per cent of another hydrocarbon or group of hydrocarbons. This method from analyses ( 5 )made during and after World War 11. Although these analyses were made primarily for another purpose, they of presentation not only shows the variation of the percentage of provide an excellent opportunity to study the quantitative relasome specific hydrocarbon from crude oil to crude oil, but also tionships between hydrocarbons, individually and collectively, indicates the degree to which the ratio of two hydrocarbons or as they exist in the straight-run gasoline fractions of widely difhydrocarbon groups remains constant. The conclusions to which ferent types and from widespread geographical and geological the data apparently point are open to the objection that no two samples of crude oil, even from the same well, will be exactly formations. Table I lists the crude oil sources of the naphthas investigated, giving the country, state, and county (or other alike. Thus, for example, the extent of loss of light material may political subdivision), the field, and the geological series, so far as this was determinable, from vvhich the crude oil originated. TABLE I. CRUDEOIL SOURCE OF NAPHTHAS STUDIED Table I also indicates the reNaphtha Produoed finery or laboratory that procItem Field Name of Geologic System from Crude Oil Prow State or County or No. Crude Oil Source Country Other Unit or Series essed by: essed the original crude oil to obtain the naphtha. InFpecCalifornia Fresno Plio-Mio. tion data for the naphthas, Texas Montgomery Eocene Texas U. Cretaceous Gmg where these were available, are Park Pennsylvanian Wyoming Standard Oil C Laf ourche Louisiana U. Miocene Texas Co. given in Table 11. Oligocene Brasoria Texas Crown Central Pet. Co. The analytical methods emWichita Pennsylvanian Bureau of Mines Texas U. Miocene Gulf o i l C o r n Louisiana Aoadia ployed by the Bureau of Mines Wichita Texas Bureau of Mines Ordovician Lea New Mexico Permian Gulf Oil Cor for analyzing these naphthas Oklahoma Oklahoma Ordovician Deep Rock &I Corp. are fully described by Thorne Brazoria Texas Oligocene Texas Co. San Patricio Texas Southwestern Oil & Oligocene et al. (6) and Gooding et al. ( 2 ) . 14 Saxet Texas Nueces Oligocene Essentially the procedure conCorp. sisted of using efficient fracEocene 15 Segno Texas Polk Gulf Oil Corp. Permian 16 Slaughter Texas Hockley Motor Fuels Corp. tionation to produce narrow 17 Tom O'Connor 8Z%, boiling-range fractions containHeyaer 9% Plymouth 6 % , Melon ing relatively few individual Creek Greta Deep, Refugio 3% Texas Ref ugio Humble Oil & Refg. Oligocene hydrocarbons. Densities and co. Oligocene Southwestern Oil & 18 Wade City Texas Jim Wells refractive indices for the merRefg. Co. cury 9 line and the sodium D 19 Wasson Texas Yoakum-Gaines Permian Bureau of Mines 20 West Edmond Oklahoma Oklohama Devonian Bureau of Mines line were determined for each 21 Yates 73 6% Taylorfraction a t 20" C., from which Link i5.861, Natl. Shell Oil Co. Texas Pecos Permian Gasoline 0.6% specific dispersions and refracForeign tivity intercepts were calcuBureau of Mines 22 Santa Barbara Venezuela lated. Aromatic hydrocarbons Bureau of Mines 23 Abqaiq Saudi Arabia Nejd Sultanate Limestone Bureau of Mines 24 Abu Hadriya Saudi Arabia Cretaceous were determined from specific 25 Aeha Jari Iran Khuzistan U. Oligocene-L. Miocene dispersion, and naphthenes and Bureau of Mines paraffins by the use of a series Bureau of Mines Limestone 26 Bahrein Bahrein Bahrein 27 Haft Kel68%, MasjLd, of modified Kurtz and Head. - ____ -- ,", Lali 5 % , M d t Safid ington (@refractivity-intercept Iran Khuzistan U. Oligocene-L. Mio5% charts. cene Bureau of Mines Bureau of Mines Limestone Nejd Sultanate Saudi Arabia Dammam 28 The analytical methods used Bureau of Mines Khuzistan Limestone Iran 29 Gach Saran Bureau of Mines Iraq Kirkuk 30 by the National Bureau of Limestone Bureau of Mines Nejd Sultanate Saudi Arabia 31 Qatif C Standards are fully described Limestone Bureau of Mines, Nejd Sultanate Saudi Arabia 32 Qatif D by Forziati et al. (I). In I
1491
Vol. 45, No. 7
INDUSTRIAL AND ENGINEERING CHEMISTRY
1492
TABLE 11. INSPECTION DATA ON NAPHTHAS STUDIED, AND THEIR QUANTITATIVERELATIOXSHIP TO CRUDE OILS~URCF. Coalinpa, Calif. 25.0
tjouroe Crude oil % ASTM D’ 86 distillation
F.D., F. 5 7 evap.,
10%evap., 507’ evap., 90% evap.,
E.P..
93 105 129 262 395 425 1.1 3.9 54.7 9.1
F. F. F. F.
O
0 O
0
F.
Residue, % Loss 7% Gravit;, API Vapor pressure, lb.
Loaa %
Gravit;
API
Vapor Gressure, lb.
souree Crude oil, % Gravity, O A P I
East
Elk
Golden Meadow, La. 9.0 104 139 165 227 277 305 0.7 1.8 60.4 7.0
Basin,
Texas, Tex. 25.8 89 123 154 249 342 370 0.9 2.3 68.3 8.5
WYO. 27.85 100 128 147 254 356 416 1.0 2.0 60.3 6.3
Hastings, Tex. 7.8 100 132 160 219 267 299 0.6 2.4 68.4 7.2
Hull-SilkSikes, Tex. 35.2 107 144 162 241 322 406 1.2 1.0 61 . O 5.2
Jennings, La. 20.4 127 177 205 289 380 426 1.o 0.7 51.9 3.2
KMA, Tex. 36.0 106 149 167 242 320 342 0.9 1.1 59.8 4.8
Monument, N. M. 32.2 115 155 176 280 380 426 1.4 0.6 55.6 4.0
City, Okla.
Ocean, Old
Plymouth,
Saxet,
Segno
Edmond, West
Yates,
Okla. 12.0
Tex. 26.8
Tex. 33.8
Tex. 5.0
Tex.’ 30.5
Tex. 33.0
Tex. 31.0
Tex. 28.5
Tex. 34.3
Okla. 33.1
Tex. 25.2
114 195 253 282 0.5 5.5 69.9 12.5
...
104 138 156 226 281 300 0.8 1.2 61.6 7.1
117 172 193 283 387 420 1.3 0.7 51.7 3.9
170 209 219 276 346 404 1.3 0.6 48. 1 1.7
109 147 172 270 376 420 1.3 0.9 54.2 4.9
88 104 137 233 342 390 1.1 3.3 57.9 10.1
110 155 179 265 358 398 1.2 0.9 54.5 4.6
162 203 219 300 3 76 404 1.0 0.6 46.9 2.2
102 126 148 245 341 368 1 .o 2.0 56.7 5.0
96 128 149 257 346 376 1.3 2.2 61.1 8.3
105 144 175 286 380 420 1.0 1.0 55.0 4.9
Santa Barbara, Venezuela 22.1 58.4
Abqaiq, Saudi Arabia 22.76 66.7
Agha Jari, Iran 22.02 65.0
Bahrein Bahreii 20.94 64.7
Central Area, Saudi Arabia 20.89 60.7
Dammam, Saudi Arabia 20.16 62.9
Gach Saran, Iran 19.25 62.1
Qatif D, Saudi Arabia 23.77 68.1
Qatif C, Saudi Arabia 12.69 63.4
Source Crude oil % ASTM 6 86 distill8ition F.D F. 5%’evap., 0 F. 107’ evap., O F. 6 0 9 evap., 0 F. evap., 0 F. E.P., 0 F. Residue, 7%
sod
Conroe, Tex. 18.3 104 142 163 2 15 259 284 0.9 1.7 56.0 7.0
87
Abu Hadnya,
Saudi
Arabia 14.51 62.3
be a contributing factor to errors when the data are presented on a crude oil basis. Another source of error in this specific investigation, and this would also apply to the National Bureau of Standards data, is that certain naphthas were furnished by refiners, and the percentage of crude oil that the naphtha represents would be difficult to ascertain in their full scale operation and may not be correct. However, an incorrect value for the naphtha content of a crude oil would not invalidate the data as regards relative ratios between hydrocarbons or groups of hydrocarbons, provided these hydrocarbons are not themselves involved in any distillation loss. Along these lines, Forziati has pointed out that commercial fractionation should not be expected to yield distillates containing the total amount of any given hydrocarbon
Slaughter,
O’Connor, Tom
City, Wade
Wasson.
Iiirkuk, Iraq 25.39 67.2
normally present in the crude oil within a given boiling range, especially for those compounds whose boiling points are near either end of the boiling range of the distillate. I n Figure 1 the volume per cent of n-heptane is shown as a function of volume per cent n-hexane. Some scattiring is evident, but it appears unnlistakable that there is a linear relationship between the data representing the quantities of these hydrocarbons present in the crude oils used in this study. The Bureau of Mines data in all the graphs are shown by circles, and those from the Bureau of Standards are indicated by triangles. Although both sets of data indicate a linear relationship, there is some disagreement as to the slope of the line. The data from the National Bureau of Standards were obtained by an analytical method that should provide more accurate results than the method used by the Bureau of Mines. There is also the possiblility that the samples from both laboratories were deficient in varying amounts in the total quantity of n-hexane originally associated with the crude oil,
c 18
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1.2 1.6 2 . 0 2.4 2.8 3.2 M E T H Y L C Y C L OH E X A N E , P E R C E N T
0.4
0.8
3.6
4.0
Figure 6. Methylcyclohexane and Cyclohexanes in Crude Oils 16
0.06
14
12
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m 4
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04
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Figure 7.
06
o a I O 12 14 T O L U E N E , PERCENT
0:03 0.03 0.01 0.04 0.01 0.01 0.02 0.09
1.8
36
DATA F R O M PRESENT REPORT BUREAU OF STANDARDS
34
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20
Toluene and Benzene in Crude Oils
32
$
2 8
0
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16
. A
28
0
E 24
24
u- 2 0 z
$20 4
2W
16 W
:12
16
4
12
5 I
8 4
0
0.18 0.98 0.15 0.97 0.45 1.42 0.15 0.26 0.41 3.14
1.57 1.58 0.36 0.94 0.27 1.21 0.12 0.26 0.38 5.10
0.06
0.36 0.15 0.48 0.26 0.74 0.04 0.19 0.23 1.54
0.03 0.23 0.15 0.43 0.24 0.67 0.08 0.21 0.29 1.37
0.80 1.52 0.35 1.04 0.41 1.45 0.16 0.33 0.49 4.61
0.06 0.36 0.14 0.34 0.16
0.50
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..
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.. 0:05 0.05 0.01 0.06 0.03 0.10 0.13 0.24
oils from widespread geographical and geological locations, this report substantiates an observation reported by Forziati el al. (1) that certain definite relationships appear to exist between the quantities of some hydrocarbons occurring naturally in crude oils. Although this may be of theoretical interest, one of the practical implications of this observation is the possibility of calculating or estimating the hydrocarbon composition of a naphtha from any crude oil source once the amounts of certain “key” hydrocarbons are known. This esti-nate, except for “abnormalities,” should be expected to be correct within 20%.
S 4
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0
0
4
8
12
16
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o 4 TOLUENE,PERCENT
20 2 4
a
1 2 16 20 2 4 2 8 30
Figure 8. Toluene, n-Heptane, and Methylcyclohexane in Crude Oils The extreme scattering of data in attempting to correlate percentages of unrelated hydrocarbons, instead of detracting from the conclusion above, strengthens the belief that the numerous indications of linearity, where found, are surely not happenstance. THERMODYNAMIC CONSIDERATIONS
The excellent data acquired through the work of Rossini and his coworkers ( 4 ) on the thermodynamic properties of hydrocarbons make it possible to calculate equilibrium constants for mixtures of isomers at variouR temperatures. It is interesting to compare the ratios of total isohexanes vs. total n-hexane based on these equi-
INDUSTRIAL AND ENGINEERING CHEMISTRY
1496
VOl. 45, No. 7
TABLE IV. COMPOSITIOX OF NAPHTHAS moir 11 FOREIUN CRUDEOILS Santa Barbara South Amercca Abqaiq ~
Hydrocarbon
Total dimethylbutanes 2-M ethylpentane 3-Methylpentane Total methylpentanes Total isohexanes n-Hexane Total hexanes HEPTANES 2.2-Dimethylpentane, 2,4dimeth Ipentane, 2,3-dimet~ylpentane, 2methylhexane 3-Methylhexane Total isoheptanes n-Heptane Total heptanes OCTANES 2,2-Dimethylhexane P&Dimethylhexane, 2,4dimethylhexane 2,3-Dimethylhexane Total dimethylhexanes Total methylheptanes Total iao-octanes n-Octane Total octanes NONANES Dimethylheptanes Methyloctanes Total isononaneq n-Nonane Total nonanes
CYCLOPENTAXES
Cyclopentane RIethylc yclopentane 1,l-Dimethylcyclopentane 1,3-Dimeth~lcyclopentane 1,2-Dimethylcyclopentane Total dimethylcyclopentanes Ethycyclopentane Total trimethylcyclopentanes Total cyclopentanea CYCLOHEXANES Cyclohexane Methylc yclohexane 1,3-Dimethylcyclohexane, 1,4-Dimethylcyclohexane 1,2-Dimethylcyclohexane Total dimethylcyclohexanes Total ayclohexanes AROMATICS Benzene Toluene Ethylbenaene nz-Xylene, p-xylene o-Xylene Total xylenes Isopropylbenzene n-Propylbenaene Total propylbenzenes Total aromatics
Abu Hadriya
Aeha J&i
Bahrein
Source Asiatic (Middle East) Central Area Dammam
Gach Saran
Kirkuk
Qatif C
Qatif D
0.05 0.32 0.37 0.89 0.90 1.79 2.16 2.17 4.13
0.04 0.12 0.16 0.09 0.19 0.28 0.44 0.86 1.30
0.04 0.25 0.29 0.59 0.61 1.20 1.49 2.39 3.88
0.04 0.14 0.18 0.35 0.42 0.77 0.95 0.72 1.67
0.04 0.26 0.30 0.52 0.55 1.07 1.37 2.12 3.49
0.03 0.06 0.09 0.12 0.23 0.35 0.44 0.73 1.17
0.06 0.25 0.31 0.37 0.45 0.82 1.13 1.77 2.90
0.04 0.15 0.19 0.40 0.42 0.82 1.01 1.92 2.93
0.04 0.17 0.21 0.34 0.37 0.71 0.92 1.55 2.47
0.02 0.22 0.24 0.43 0.28 0.96 1.50 2.45
0.04 0.26 0.30 0.38 0.34 0.72 1.02 1.38 2.40
0.05
0.13
0.08
0.12
0.09
0.08
0.07
0.10
0.18
0.07
0.10
0.60
0.85 0.51 1.49 1.96 3.45
0.68 0.18 0.94 1.37 2.31
0.76 0.38 1.26 1.33 2.59
0.86 0.31 1.26 1.98 3.24
1.10 0.21 1.39 1.48 2.87
0.74 0.24 1.05 1.57 2.62
0.70 0.38 1.18 1.14 2.32
1.43 0.39 1.97 1.72 3.69
0.39 0.36 0.82 1.19 2.01
0.97 0.32 1.39 2.02 3.41
0.19 0.84 0.84 1.68
0.71
0.12
0.19
0.10
0.20
0.22
0.25
0.13
0.13
0.12
0.13
0.24
0.09 0.16 0.37 0.67 1.04 0.92 1.96
0.13 0.36 0.68 1.02 1.70 1.93 3.63
0.07 0.34 0.51 0.83 1.34 1.84 3.18
0.08
0.07 0.71 1.00 0.72 1.72 2.07 3.79
0.09 0.67 1.01 0.65 1.66 1.63 3.29
0.15 0.25 0.53 0.29 0.82 1.70 2.52
0.07 0.25 0.46 0.80 1.25 1.12 2.37
0.18 0.41 0.71
0.08
0.12 0.62 0.98 0.69 1.67 2.04 3.71
0.25 0.42 0.67 0.69 1.26
0.37 0.76 1.13
0.36 0.57 0.93
.. ..
0.34 0.81 1.15 1.65 2.80
0.36
.. ..
0.27 0.84 1.11 1.61 2.72
0.32 0.64 0.96
.. ..
0.25 0.49 0.74 0.91 1.65
0.43 0.98 1.41
0.05 0.30 0.06
0.08 0.31 0.03
0.01 0.12 0.06
0.09 0.52 0.07
0.05 0.26 0.03
0.06
0.08 0.36 0.06
0.08 0.54 0.09
0.52 0.80 0.66 1.46 1.32 2.78
.. ..
..
..
0.41 0.09
1.38 2.09 1.66 3.75
0.37 0.58 0.64 1.22 1.49 2.71
0.33 0.77 1.10
..
0.27 0.63 0.90 1.27 2.17
0.08 0.36 0.03
0.02 0.15 0.03
0.07 0.32 0.07
..
.. ..
0.24
0.13
0.10
0.33
0.15
0.34
0.18
0.38
0.39
0.06
0.17
0.15
0.07
0.02
0.14
0.04
0.05
0.06
0.24
0.13
0.05
0.04
0.45 0.19
0.23 0.16
0.18 0.12
0.54 0.22
0.22 0.13
0.48 0.25
0.30 0.13
0.71 0.30
0.55 0.29
0.14 0.07
0.28 0.14
0.37 1.36
0.15 0.93
0.10 0.53
0.37 1.74
0.16 0.82
0.37 1.57
0.22 1.07
0.35 1.98
0.24 1.52
0.09 0.47
0.14 0.95
0.26 0.67
0.21 0.45
0.12 0.28
0.30 0.82
0.19 0.48
0.27 0.75
0.27 0.54
0.35 0.78
0.35 0.74
0.08 0.25
0.17 0.45
0.50
0.26
0.21
0.43
0.23
0.40
0.80
0.50
0.53
0.13
0.22
0.26
0.11
0.15
0.31
0.24
0.31
0.17
0.34
0.24
0.11
0.17
0.76 1.69
0.43 1.09
0.36 0.76
0.74 1.86
0.47 1.14
1.71 1.73
0.97 1.78
0.84 1.97
0.77 1.86
0.24 0.57
0.39 1.01
0 22 0.77 0.21 0.68 0.29 0.97
0.12 0.52 0.22 0.52 0.28 0.80
0.03 0.24 0.18 0.31 0.15 0.46 0.07
0.20 0.66 0.25 0.53 0.18 0.71
0.12 0.51 0.27 0.48 0.29 0.77 0.09
0.19 0.78 0.28 0.65
0.26 0.79 0.23 0.71 0.42 1.13
0.16 0.49 0.19 0.44 0.16 0.60 0.07
0.02 0.17 0.16 0.52 0.32 0.84
0.05 0.26 0.20 0.22 0.11 0.33 0.09
0.10 0.53 0.25 0.48 0.33 0.81
.. ..
.. ..
0.06 0.25 0.31 2.48
.... .. ..
.. ..
.. .. ..
..
..
librium constants with the actual values found from this study. Such data are shown in Figure 9, where the total per cent of isohexanes in the crude oil is plotted as a function of the per cent of n-hexane in the crude oil for all the crude oils studied by this laboratory and by the work of API Research Project 6. Also shown by dash-lines are the compositions that would be theoretically expected a t the temperatures indicated at the top of each line. It is at once apparent that the bulk of data fall outside of any range of temperatures considered reasonable in the light of
....
..
.. *.
..
.. ..
.. ..
..
.. ..
.. .. .. ..
.. ..
..
.. .. .. ..
recent theories on the origin of petroleum. Three crude oilsWinkler, Yates, and Monument-exhibit hydrocarbon ratios that correspond to considerably lower temperatures than any of the other crude oils examined. However, even these temperatures are considerably higher than any of the bottom hole temperatures customarily found in that area, which probably are in the vicinity of 100' to 125' F. This would indicate that, with a possible exception of these three crude oils, the composition of crude oils is not one that results from thermodynamic equilibrium.
INDUSTRIAL AND ENGINEERING CHEMISTRY
July 1953
v.14
L
I I
I
0
4
.e
I
I
I
I
I
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1.6
20
24
2 8
acquired the sulfur after an equilibrium situation was reached or that, if sulfur was indigenous to the oil, it never was at an equilibrium temperature as is indicated on the graph, because if it had been all of the elemental sulfur could have long since reacted and none would be present now.
decrease in this ratio as one approaches the older gealogic formations. There are, however, exceptions to these generalizations and a great many more data of an analytical nature as well as better geological information w o u l d b e necessary before any sound conclusions could be reached, In connection with the thermodynamic equilibrium situation it is of interest, although of what significance we cannot say, that the oldest oils and in general those with the lowest ratios of isohexane to n-hexane appear to be those that would had to have an extremely high temperature histow. The three Permian oils p r e v i o u s l y mentioned, how-
LITERATURE CITED
GEOLOGICAL CORRELATIONS
Attempt has also been made to ascertain if any correlation exists between the ratios of hydrocarbons and geological occurrence of the oil. The data shown on Figure 9 are also used for this purpose by means of the legend showing the geologic era and series evidence Of from whence the crude Oil Originated' There is segregation in that all of the Cenozoic Age oils appear to have the higher ratios of isohexanes to n-hexane and, in general, there is a
e
1497
'
(1) Forziati, A. F.,Willingham, C. H., Mair, B. J., and Rossini, F D., J. Research Natl. Bur. Standards. 32. 11 (1944). (2) Gooding, R. &I., Adams, N. G., 'and Rail, H: T., IND.EXG. CHEM., ANAL.ED., 18, 2 (1946). (3) Kurtz, S. S., and Headington, C. E., Ibid., 9,21 (1937). (4) Rossini, F. D., Prosen. J. R., and Pitzer, K. S., J . Research Nut2 Bur. Standards. 27, 529-41 (1941). ( 5 ) Smith, H. M., Kraemer, A. J., and Thorne, H. M., Bur. &lines, Bull 497 (1951). M,, Murphy, w., and Ball, s,, IND. ENQ. Thorn;, ANAL.ED., 17,481 (1945).
J.
RECEIVED for review February 2, 1953. ACCEPTED March 4, 1963. Presented before the XIIth International Congress of Pure and Applied Chemistry, Section 7, Fuel, Gas, and Petroleum Chemistry, New York, N. Y., September 10 to 13, 1951.
Variation in Smoking Tendency AMONG HYDROCARBONS OF LOW MOLECULAR WEIGHT ROSE L. SCHALLA AND GLEN E. McDONALD National Advisory Committee for Aeronautics, Lewis Flight Propulsion Laboratory, Cleveland, Ohio
I
N RECENT years a considerable effort has been made to de-
termine the factors and mechanisms that govern the formation of smoke during the burning of fuels, so that, eventually, methods of controlling smoke formation can be devised (1,8,11). Particular emphasis has been placed on preventing smoke formation during the burning of fuels in combustion chambers. As the type of hydrocarbon present in a fuel is known to affect smoke formation (3,6), an investigation was conducted as part of the
fundamental combustion program a t the NACA Lewis Laboratory to determine the maximum rate at which various pure hydrocarbons could be burned without producing smoke. From this investigation, it was hoped that tbe effects on smoking of such variables as chain length, chain branching, degree of unsaturation, position of unsaturation, and ring size could be evaluated and an explanation found to account for the variations. Previous investigators have determined smoking tendencies by
