Air medical service (medical division)

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AIR SERVICE INFORMATION CIRCULAR
Vol. I,
CH EAVI ER-TH AN-Al R)
PUBLISHED BY THE DIRECTOR OF AIR SERVICE, WASHINGTON, D. C.
March 15, 1920
AIR MEDICAL SERVICE
Compiled by The Medical Division of
the Air Service
No. 3
Ralph Brown Draughon
WASHINGTON
GOVERNMENT PRINTING OFFlCE
1920
LIBRARY
MAR 26 2013
Non·Oepoitory
Auburn University
TABLE OF CONTENTS.
Page.
1. "THE AVIATOR'S HEART. ROENTGEN RAY STUDIES UNDER CONDITIONS SIMULATING HIGH ALTITUDE."
By L. T. Le Wald, major, Medical Corps, and G. H. Turrell, major, Medical Corps.. . . . . . . . . . . . . . . . . . . . 3
2. "RECENT WoRK IN PERSONALITY STUDY" (revised paper). By Wm. MacLake, major, Medical .Corps...... 34
3. "THE EFFECTS OF SMOKING ON VISUAL AcuITY." By H. L. Underwood, captain, Medical Corps, and
Prentice Reeves, first lieutenant, Sanitary Corps. . . . . . .. . . . . . . . . .. . . . . . .. . .. . .. .. . .. .. . .. .. .. . . . .. .. 39
4. "A DEVICE ADAPTING THE BARANY CHAIR TO THE REBREATHING TESTS." By Max M. Ellis, first lieutenant,
Sanitary Corps .. . ............................ , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
5. "PSYCHOPATHOLOGY UNDER Low OXYGEN TENSION." By English Bagby, first lieutenant, Sanitary
Corps ............... , .. .. . .. .. . . .. . . .. . . .. . . . .. .. .. .. . . .. . .. .. .. . . . .. . . . . . .. .. . . .. .. . . . . . . . . . . . .. .. 46
6. "A NoTE ON OXYGEN SUPPLY FOR AVIATORS." By G. B. Obear, captain, Sanitary Corps........... ... ... 51
7. "A CoMPARISO.N OF Two METHODS OF APPLYING PRISM TESTS TO THE EYEs." By Jas. N. Buchanan, first
lieutenant, Medical Corps................... . ............................. .. ... .. ..... .. ........... 65
8. "THE SPEED OF AccoMMODATION " (revised copy}. By E. B. Goodall, first lieutenant, Medical Corps...... 70
9. "ABSTRACTS OF THE LITERATURE ON THE ANATOMY AND PHYSIOLOGY OF THE SEMICIRCULAR CANALS." By
Jas. J. King, captain, Medical Corps .. ..... .............. ... ........... ·.. ........................... 76
10. "CULTIVATING THE BALANCE SENSE." By RobertJ. Hunter, major, Medical Corps .. . ..... .. .......... . 85
11. "THE CHANGES IN THE CONTENT OF THE H.EMOGLOBIN AND THE ERYTHROCYTES OF THE BLOOD IN MAN
DURING SHORT EXPOSURES TO Low OXYGEN." By E. C. Schneider, major, Sanitary Corps, B. R. Lutz,
first lieutenant, Sanitary Corps, and H. W. Gregg, second lieutenant, Sanitary Corps . . . . . . . . . . . . . . . . . . . 87
12. "CIRCULATORY RESPONSES TO Low OXYGEN TENSION." By E. C. Schneider, major, Sanitary Corps, and
B. R. Lutz, first lieutenant, Sanitary Corps...................................... ........... . . . . .. .. . 92
13. "A TEST FOR THE JUDGMENT OF DISTANCE." By H. J. Howard, captain, Medical Corps..... . ............ 105
(2)
PART I.
THE AVIATOR'S HEART-ROENTGEN RAY STUDIES UNDER CONDITIONS
SIMULA TING HIGH ALTITUDES.
By LEON T. LE WALD, M. D., Major, Medical Corps, United States Army, Roentgenologist, and G= H. TuRRELL,
M. D., Major, Medical Corps, United States Army, Chief of the Cardiovascular Department, Medical Research
Laboratory, Air Service, Mineola, Long Island, N. Y.
During the examination of aviators under reduced at­mospheric
pressure in the low-pressure chamber at the
Medical Research Laboratory at Mineola, N. Y., Maj.
James L. Whitney, Medical Corps,1 and his coworkers had
observed at pressures corresponding to altitudes of 18,000
or 20,000 feet an increase in the area of cardiac dullness
in the case of certain aviators. Later, a similar increase
in the cardiac dullness was occasionally observed during
the course of the low-oxygen test, conducted at the labora­tory
for the purpose of classifying aviat@rs according to
their ability to withstand the effecta of high altitudes.
The enlargement as observed by Whitney was principally
to the left (fig. 1), but occasionally right-sides enlarge­ment
was encountered in addition (fig. 2). Whitney as­cribed
the increased area of dullness in these cases to
dilatation of the heart, and thought that it was due partly
FIGURE I.
The present studies were undertaken to determine
whether cardiac enlargement actually does occur under
thefie circumstances; and if it does, what is its amount;
whether its onset is sudden or gradual; what is its relation
FIGURE 2.
Dilatation of the heart under deficiency of oxygen beyond the indi­vidual's
power of compensation: Solid line, percussion outline or heart
before and after experiment; broken line, outline at 19,800 feet eleva­tion
in low-pressure chamber.
to the blood pressure and to the psychomotor react10ns of
the aviator; and whether it is a conservative process de­signed
to increase the output of blood by the heart, or
whether it is a true dilatation due to fatigue or exhaustion
of the heart muscle.
Dilatation of tbe heart at 18,000 feet when man was in poor ~ondL 'l'wo series of studies were planned; one with the Hen-tion;
when feeling well, this man could go 5,000 feet higher without.any derson re breather and the other in the low-pressure
ill effects; solid line, outline of heart before and after experiment; chamber. The rebreathing experiments were undertaken
broken line, heart outline to percussion at elevation of 18,000 feet. :first, because any changes observed would almost surely
to fatigue, such as occurs after excessive exertion, as in be due to diminished oxygen alone, whereaa in the low­Marathon
runners, and partly to lowered tonus of the l pressure chamber they might be influenced by the change
heart muscle arising from the lessened oxygen content of in pressure or by thP expansion of abdominal gases causing
the inspired air and of the blood. an upward displacement of the diaphragm.
•"Medical Studies in Aviation," J. A. M.A., Oct. 26, 1918.
(3)
/
The Henderson rebreather (figs .. 3 and 4) consists of an 1 Serial radiograms were made at a 75-centimeter distance
iron tank of from 60 to 100 liters capacity, provided at I in both expirat,ion and inspiration, and in certain illf!tances
the top with a water-sealed spirom,!)ter and connected double exposures on one plate were made to show both
through tubing with a mouthpiece through which the inspiration and expiration. The lesser distance was
subject breathes. The nose is claniped with a spring
"clothespin," so as to tightly close the nostrils. An ar­rangement
of two mica check valves causes the inspired
air to flow through one tube and the expired air to flow
through the other back into the tank. The expiratory
tube :haa inserted in its course a cartridge containing
"shell" potassium hydroxide to absorb the exhaled car­bon
dioxide. As the subject of the experiment breathes
the air in this tank over and over he gradually uses up
the oxygen until finally he may come to a point where
he is breathing an oxygen-nitrogen mixture containing
only 8, 6, or even 5 per cent of oxygen instead of the
usual 21 per cent in normal air. Since the nitrogen is
bland and .neutral (simply a vehicle, as it. were, for the
administration of oxygen), the effect of diminishing the
percentage of oxyg,en in the rebreather has the same
physiological effect as rarefying the air in a low-pressure
chamber, or ascending to a high altitude. 1n either ca.se,
the actual amount of oxygen available for the blood in a
given 4 liters of lung capacity be~mes progressively less '
as the experiment proceeds or as higher altitudes are
reached.
In our iirst series of observations, roentgenograms were
made of aviators every 5 min;ites while they were on the
rebreathing apparatus. The length of the run on the
rebreather varied from 15 to 38 minutes. With the con­trols
taken before and after the run, there were obtained
from 6 to ·13 roentgenograms of each h~t.
The greatest care was taken in the alignment of the tube,
th~ patient, and the plate, so as to make the radiographs
properly comparable one with another, not only those of
the same·but also those of different subjects. The sitting
posture offered the moat advantages, as not interfering
with the rebreathing apparatus, and also enabling the
subjects to maintain a fixed position for the required length
of time. In order to make sure that the alignment was
maintained throughout the· experiment, a special chair
was built having a straight back containing a large trans­parent
celluloid panel. Down the center of the back a
perpendicular line was drawn and divided off into inches
to indicate the distance above the floor, so that the target of
the X-ray tube could readily be adjusted to any required
height to correspond with the point selected on the back
of the subject. As a means of detecting change of pOl!i.tion
and of recording it on the plate, if it occurred, a distinctive
metal marker was placed on a given posterior spinoua
process, and another upon the sternum. After several
trials, a small lead washer of about a half-inch diameter,
fixed by adhesive plaster over the spinous process of the
seventh dorsal, and a straight lead rod, 2 or 3 inches long,
down :the center of the sternum, were found to be very
satisfactory. The displacement of their shadows laterally,
or upward or downward, served to indicate the slightest
change in the alignment and in the posture of the subject.
In a few studies of the movements of the diaphragm
the nipples were marked with a small lead circle and the
apex · by a cr.O!!B. ·
Teleroentgenograms were made at a 2-meter distance
and were taken during both inspiration and expiration.
A
1
E
T
--- - ·--.~--- _-::::::;- -
FIGURE 3.
The re breathing apparatus e!l\ployed ln all routine tests of the a via­tors'
ability to withstand low oxygen. Itconsfsts of a tank, T,of about
120 liters capacity. The volume of air is determined by the amount of
water that is run into it. The man under examination continually
rebreathes the air of the tank (a clip is placed on bis nose) through the
I lnspiratory and expiratory valves, Vi and Ve. The oxygen is thus
consumed and reduced. ·rhe exhaled carbon dioxid is taken up by
' sodium hydroxid in the absorber, A. 'l'he movements of respiration
are recorded by the spirometer, S, connected to a smoked drum, K.
As the oxygen is consumed, and the air volume Is thus reduced, the
spirometer falls and· the graphic record on the smoked drum rises. At
the end or the test a sample of air is drawn from the tank and analyzed
as a conflrmat~on of the oxygen consumption and or the oxygen per­.
centages (that is, altitudes) indicated by the graphic record.
adopted for convenience, as being the shortest possible for
working through the aluminum window of the low pressure
chamber. In view of the danger of implosion, this window
was made of pure aluminum 15 mm. in thickn~.
•
5
Figure 4.- Henderson Rebreather, Radiographic Chair with· Plate Holder and Timer.
The exposures varied from one-twentieth to three­twentieths
of a second at the 75-centimeter distance, and
from one-tenth to three-fifths of a second at the 2-meter
distance. In the series on the rebreather the double ex­posures
were most successfully obtained with that in
expiration given three-twentieths of a second and that in
inspiration given one-fifteenth of a second. Short and
practically instantaneous exposures were necessary during
the rebreathing tests, because it is impracticable to have
the subject hold his breath at the lower oxygen per­centages.
Holding the breath under these circumstances is
liable to produce dizziness and fainting, or other symptoms
of oxygen want in the brain.
In tbe low-pressure chamber exposures were made
through tbe aluminum window at the 75-centimeter dis­tance
in three-twentieths of a second. Single rapid inten­sifying
screens were used in all exposures. 'l'he exposures
were made on X-ray plates of standard makes issued by
tbe Army. The plates were developed by the tank
method, witb Eastman X-ray developer. The transformer
was one of tbe base hospital types issued by the Army.
The exposures were timed by a special timer, depending
upon the principle of falling weights, its correctness having
been checked by stop watch and metronome. Because of
tbe shortness of the exposures, it was thought necessary to
time tbem for a definite period of tbe cardiac cycle, in
order to avoicl possible variations in size due to systole and
diastole. The timer was, therefore, actuated by a special
mechanism Eet off ·by the pulse wave (fig. 4). This was
m.erely an adaptation of the wrist piece and tambour of the
Mackenzie polygraph, with the writing arm, equipped with
a platinum end tha.t dipped into a mercury cup to close the
electric circuit which actuated the timer. The timer
could be set to make the exposure with l.he pulse beat, or
at definite fractions of a second after the .pulse (Pl. II).
In our s'erial plates with the rebreatber, the exposures were
timed to be synchronous with the diastolic phase of the
heart cycle.
A record of the respiratory phase of the exposure was
made by means of a, perforation of the ky;mograph tracing
by a high-tension spark. This spark was obtained by
shunting off through resistance a small amount of current
from the primary terminals of the X-ray transformer, and
then stepping it up to a tension and passing it through a
small Leyden jar as a condenser.
The pulse rate, systolic, and diastolic blood pressures,
were taken every otber minute till the fifteenth minute,
after which time they were taken every minute. A record
of the volume of air inspired per minute was also kept.
All of our subjects were healthy aviators, ranging in age
between 20 and 42 years.
In the very beginning of our work it became evident that
different silhouettes of tbe same heart varied greatly in
form and in measurement of the transverse diameter
6
(Pl. III). As the tube distance, position of the subject, I piration the sterno-phrenic sulcus is rendered so sharp
and the alignment remained the same, it was evident that and thin by the rounding up of the diaphragm that the
the cause was some change taking place in the subject heart is squeezed upward. Conversely, the apex of the
himself. After a series of radiographs it appeared that the thorax and of the mediastinal space is lowered with the
preliminary controls taken during forced held inspiration fall of the ribs and sternum in expiration, and raised
showed a · narrower heart than any of those taken during in inspiration.
the course of the rebreathing tests. We then took an The resulting approximation of the apex and base of
extra plate during forced held expiration, and found that the mediastinal space during expiration thus tends to
these gave a broader shadow than those taken during the squeeze the contained organs outward and to broaden
course of the rebreathing. their shadows. The lengthening of the thoracic cavity
By superimposing a silhouette taken in expiration upop during inspiration tends to stretch out the contained
one from the same subject taken in inspiration (Pl. IV), organs and to narrow their shadows. That this is no mere
so that the shadows of the metallic markers upon fae backs theory but does actually occm is shown by the increase
coincided, and the shadows of the vertical rods on the during expiration of the transverse meaBurements of the
sternum were parallel, the changes taking place in the mediastinal silhouette at all levels. As in the case of
shape and po~ition of .the heart during deep respiration the heart, it is also shown by making two exposures of
could be readily seen. It should be borne in mind tha1 the thorax on the same plate, one dming expiration and
every exposure in each series was made during the same one during inspiration. The apparent broadening of the
phase of the cardiac cycle. This was usually qne-fifth of aortic arch, especiaUy its displacement to the left, is
a second after the pulse wave arrived at the wrist, but very noticeable in such plates. Two radiographs, such
some were set off at the moment of the pulse beat. In as those shown in Plate VII, figures 3, 4, and Plate VIII,
either case it is presumed that the heart outline is that of figures 1 and 2, if taken several months or years apart
diastole. might easily lead to a serious mistake in diagnosi&.
By this method of superimposing plates the excursion Out of a series of piatea of 89 men, the largest difference
of the diaphragm upward in expiration was readily dem-, between the transverse diameters in forced inspiration and
onstrated, and the simultaneous lowering of the apex forced expiration in atmospheric air was 3.3 centimeters
of the thoracic cavity was indicated by the lower position at 75 centimeters distance. The average vmiation was
of the clavicles and of the sternal marker. This was only 1.37 centimeters. One heart showed no change in the
a <lifferent way of demonstrating facts already well known; transverse diameter-a case of valvular diseaae, measuring
but the changes in the media,;tinal contents were to us 17.5 centimeters at 2-meter distance.
rather surprising. This method was supplemented and During the course of the rebreathing tests of the same 89
the results verified by making two exposures of the same aviators, the greatest variation in the transverse diameter
subject on one plate {Pla. V and VI). in any one man Wllf! 3.5 centimeters, and the smallest
The lifting of the apex and the broadening of the variation was 0.15 centimeter. The average difference was
transverse diameter of the heart during expiration have 0.47 centimeter at 75-centimeter distance.
been recognized by all workers with the fluoroscope; but While the variations in the transverse diameter of the
the amount of this change does not seem to have been heart during the rebreathing test averaged less than those
fully realized. Furthermore, most authorities speak only caused by forced inspiration and expiration, yet they may
of left-sided displacement and apparent enlargement; occasionally be even greater. The reason for this is that
whereas our results show in many cases decided broaden- the rebreathing test produces forced breathing in certain
ing of the heart shadow toward the right as well as toward aviators. In the early stages there is frequently irregular
the left. The result is a marked increase •in the tra- breathing due to excitement, but during the latter half of
verse diameter. In several cases this increase amounted the run the respiration is normally very much deepened .
to over 3 centimeters. If radiographs should happen to It seems possible that this deepening results from an in­be
taken of the- same heart at different times and in dif- crease at both ends of the respiratory movement. Expira­ferent
phases of respiration, such differences in the trans- tion, as well as inspiration, is exaggerated. This would
verse diameter of the shadow might easily be misleading seem to be shown in many of the respiratory kymograph
and be the cause of a mistaken diagnosis of enlargement tracings, where the expiratory curve occasionally goes
of the heart. · below·the average level of the expiratory excursion. The
Our results would seem to show that during normal same changes in the respiratory movement occm in the
quiet respiration the changes in the transverse diameter low-pressure chamber or during an ascent to a high alti­are
comparatively small, notwithstanding a fairly large tude, as in the rebreathing test. There is an increase in ,
excursion of the diaphragm (Pls. V and VIII). We the volume of air breathed per minute, and this increase
.would explain this by the fact that the chief movement in the minute volume results from deep breathing much
of the diaphragm in quiet breathing is in the two domes more than from an accelerated rate.
on each side of the central tendon, while the tendinous Practically we found it extremely difficult, or even
portion under the heart itself remains comparatively impossible in many cases, to time our exposures with any
<1uiescent. Moreover, the slant of the portion of the desired phase of respiration. Watching the kymograph
diaphragm beneath the heart downward and forward is drum one frequently would snap the switch at what one
little changed in ordinary breathing. But in forced thought was the height of inspiration, and the next pulse
breathing the sulcus formed between the diaphragm and beat would set off the exposure; but the subject would go
lhe anterior chest wall, which is partly filled by the on taking a Iong breath, and we would really have a radio­lower
border of the heart, is obliterated during inspiration graph taken in midphase respiration; or sometimes the
by the flattening of the whole diaphragm. During ex- electric connection would not be made in the mercury cud
7
Figure 5.-Cas" 110 Respiratory ']'~acing.
until the expiratory movement had begun, or even been
completed. Such irregularities in the depth of respiration
are indicated in the kymograph tracings of cases 153, 110,
142, 116, shown in figure 5. The-clinician in palpating and
percussing the pnecordium will detect the upward and
outward position of the left border during expiration, and
will probably .fail to notice its return downward and
inward during inApiration. A diagnosis of cardiac enlarge­ment
would be obvious and natural under such circum­stances.
It seemed to ns that this might be the explana­tion
of Whitney's findings (figs. 1 and 2). The similarity
of his drawings of the he3.!t outlines, as obtained by per­cussion,
and those obtained by us by two exposures on the
same plate is very striking (PL IV, fig. 2). It therefore
seemed essential that the respiratory phase should be taken
into account in our study of heart measurements.
Turning again to the heart shadows of the 89 aviators
we can readily divide them into three classes. The first
class includes 67 subjects and comprises those in which no
enlargement of the heart occurred under 1owered oxygen
pressure. While marked variations in the transverse diam­eter
in the different plates occurred in a considerable pros
portion of these men, the changes were distributed so
irregularly throughout the run that they could not be
attributed to oxygen want or to the progress of the test.
In no case was the enlargement at the end of the run.
The second class includes 9 cases which showed a more
or less consistent increase in the transverse diameter
toward the end of the test. The greatest increase was 1.4
centimeters and the least 0.2 centimeter. The average
change was 0.75 centimeter. Careful study of the posi­tion
of the diaphragm and of the respiratory phase at which
Figure 6.-Case 153 Respiratory Tracing.
the plate WaB expOBed showed at once that in 6 of these
CaBeB the enlargement WaB merely expiratory displace­ment.
For example, in case 152 the increase of the trans­verse
diameter of the heart silhouette WaB 1.25 centimeters.
At the time of this increase the shadow of the diaphragm
had moved. upward a distance of 4.5 centimeters from its
position in the preceding plates. That is, it had moved
from 7 centimeters below the left nipple and 5 centimeters
below the right nipple (its position in inspiration) to 2.5
and 1.5 centimeters from the respective nipples.
Again, in case 37, the 1 centimeter increaBe occurred at
the twenty-fifth minute of the run, at the time of psycho­motor
inefficiency when the subject waB sitting rigiJ in the
chair. The radiograph shows the diaphragm in the _posi­tion
of expiration. The blood pressures were practically
unchanged. The systolic ranged between 110 and 120,
with the terminal at 112. The diaBtolic varied between
64 and 72, the :final reading being 64. The pulse rate was
not unduly accelerated. In short, there were no evidences
of heart strain. We do not believe the diagnosis of dilata­tion
justified in these two cases. Similarly, the enlarge­ment
of the transverse diameter in caBes 21, 32 (see Pl. X),
40, 77, is explab:iable by variations in the respiratory phase
at the moment the exposures were made.
In the other 3 cases the increase was 0.4 centimeter or
under, and is not explained by the expiratory position of
the diaphragm. In cases 90 and 125 the increase is only
0.2 centimeter and was regular and progressive from start
to finish. Case 125 is illustrated in· Plate XI. The sy.s·
tolic pressure in this subject increased during the re·
breathing test from about 130 to 144 millimeters, while the
diastolic dropped from 70 to 40 millimeters. The pulse
pressure ranged from 60 in the begi:nning to 104 at the end.
The pulse rate increased from 90 to 112. The subject at
the end was still conscious but showed muscular twitching
and motor inefficiency.
Case 90 shows a slight increase in pulse pressure at the
end of the run (from 35 to 49 millimeters Hg). The pulse
rate accelerated from90in the beginning to 117 at the end.
8
It is possible that the increased transverse diameters in
these two cases represent actual enlargement of the heart.
If such is the case, it could possibly be explained by the
diminished tonus of .the cardiac muscle brought about by
oxygen want. This would perhaps account for the greatly
increased pulse pressure, which was produced partly by
increased output of blood at each cardiac systole and
partly by the increase in the rate of the beat. The final
result would be a greatly increased output of blood per
minute. Since the increased pulse pressure in both cases
is due to lowering of the diastolic pressure together with a
slight increase in the systolic pressure without any other
sign of heart strain, we are inclined to consider such an en­largement
of the heart, if it occurs, a conser:vativ:e proceBB
designed to compensate by increased circulation for the
lessened oxygen content in the blood.
In the third subject, case 110 (see fig. 5), the facrew,e in
the transverse diameter was 0.4 centimeters. It is accom­panied
by a slightly higher position of the diaphragm.
This case is noteworthy because the increase in the trans­verse
diameter was accompanied by a rice o.f the respira­tory
volume from 65 deciliters per minute in the begin­ning
to over 200 deciliters per minute at the end. The
respiration was principally deepened. There was little
increase in the rate. We wil1 mention -later another clll'e
in which this respiratory phenomenon was the noticeable
feature, but in which the final transverse diameter in the
run became smaller. It scarcely seems poSBible that car­bon
dioxide retention or elimination can explain th&e two
opposite reactions.
The third class of cases includes those in which there was
a decrease in the transverse diameter. In some subjects
the decrease was gradual and progressive during the test;
in others it was a sudden diminution at the end. Analyz­ing
them according to their probable causation, we may
divide these also into three varieties or groups.
The first group includes those in which the changes a.re
evidently due to varying phase of respiration at the m.o­ment
of exposure. CaEes 51, 82, 114, 121, 139, and. 151
are explainable in this way. All of these subjects really
belong to the class of caEes in which there was no signifi­cant
change in the transverse diameter, or rather the class
in which the change in the tranBverse diameter repr&ents
a displacement rather than a true enlargement of the
heart.
The second variety of cases showing diminution of the
transverse diameter, includes five subjects (Table 1), all
of whom showed symptoms of circul.atary failure at the end
of the rebreathing test.
Case 53 (Pl. XII and fig. 7) went to 9.5 per cent of
oxygen in 27 minutes and 50 seconds. His systolic blood
pressure remained constant at about 120 millimeters of
mercury until the twenty-sixth minute, when it fell sud­denly
to 80 millimeters at the twenty-seventh minute.
The diastolic began at about 78 millimeters, and rose some.
what irregularly to 88 at the twenty'-fifth minute. During
the next two minutes it fell to 42 millimeters of mercury.
9
Figure 7, Case 53.
200 ·+ _ .M lt02
!DO 2
1eo 3
170 •
160 5
150 6
1.(0 . 7
130 8
120 9
110 10
100 11
90 12
80 13
, 70 a
60 15
50 lG
C
40 1· 1.~ 17
30 IS
20 . 19
20
" " ... 0 1 .2 3 4 5 6 7 8 9 10 ·11 12
21
TIME lN MINUTES
Case 53 (L. F. G.). Filing No. 6550. Mar. 25, 1919.
Type of test: X-ray and rebreather, Duration: 27 0 2 per cent start 21; finish 9.
minutes 50 seconds,
Physical condition at time of test: Good,
Legend: 0 2 per cent. O 1 11 1 o 1111 O pulse
Exact condition at close of test: Almost fainted; very
pale.
Recovery: Moderately prompt.
_ - _ Respiration in decil. per minute.
e • • • • • e Syst. B. P. • - •-• Diast. B. P.
O• ••• o pulse pressure.
10
Figure 8, Case 122.
Case 122 (R. A.-McC.). Filing No. 6589. Apr. 23, 1919.
Type of test: X-ray and rebreather. Duration: 36
minutes 26 secon<ls.
Physical condition at time of test: Good.
Exact condition at close of test: Cyanosed; conscious.
Recovery: Prompt.
0 2 per cent start 21; finish 5.2 per cent.
Legend : 0 2 per c~nt. 0 1111 0 1111111 0 pubc.
______ respiration in decil. per minute.
e • • • e • • e Syst. B. P . • - • --• Diast. B. P.
o •••. o pulse pressure.
11
Figure 9, Case 144. 200.
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180
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130
120
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100
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70
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TIME TN MINUTES
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20
''l
8 0 10 11 12 13 14 15 lG 17 18 19 20 21 2·i 23· ~l 2::, 2'3 27 28 20 30 81 32 36 37 J8 JS
Case 144 (G. M. W.). Filing No. 6755. May 2, 1919.
Type of test: X-ra,y and rebreathing. Duration: 32 j
minutes 21 seconds.
Physical condition at time of test: Good.
Exact condition at close of test: Cyanotic; inefficient
and barely conscious.
Recovery: Prompt.
0 2 per cent start 21; finish 6.5 per cent.
Legend: 0 2 per cent. 01111110111110 pulse.
______ respiration in decil. per minute.
• • • • e • • • e Syst. B. P. •-•-• Diast. B. P.
o •.•. o pulse pressure.
900
190
180
110
1r,o
150
liO
130
120
110
100
90
80
.o
GO
50
40
30
20
10
0
' +
~ +,....,-
12
Figure 10, Case 142.
f- qr- : . jj
::t . b.}i,,
t, · . a tiJtl:!'= ~i- ll ;
lil:' f.rr-ss i: ~ t >, .. :, -.
El :i.~t ~ -! . · . , _m
~:J·~W·"i7}._fu "P I 1u ·
.. ~ qi t, •
.i± \1 :p:r -+,, _:, r
±
:-.t.... . -1- • . ,• -1,, $':F+i ;~ . .
. ~;1. 1:+t ~: .=:t'. :
' ,: ;. fg F.tti#TI if#± ~ @ ::~., · ~~= ~J-:.i9- ®= f3-t . ~ ~
11:g .:.~ l=l;"~ {tD ~'i ;;~r%.!:~
~.: ~ ~-~ :sJffi ~ .trr ~ r~.
.....,_ • _,t-+'
. :'·,tt1.'
. +;
. . -.
ti~· ..p.: r+,
+•• ~.
.:\
~ . ::...U ~--, tr, , ~ ~-t_"; .. t :tt
. ~ ~f·. ~~ ri-f .HiJ ·rt ·: ·- ~(I.,.
· ·+ •• ~:fi- ~~-,.~,:;.~~,;;.r~,t; ;1:: ;,1
" " n O 1 2 3 4 5 G 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 2• 26 26 27 .;!8 W 30 31
Case 142. May 1, 1919.
0 2 per cent start 21; finish 7 per cent.
a
4
8
9
20
32 33
21
Type of test: X-ray and rebreathing. Duration: 31
minutes 10 seconds. Legend: 0 2 per cent. O 11111 O 11111 o pulse.
Physical condition at time of test: Good.
Exact condition at close of test: Pale, unconscious,
rigid; convulsive jerking of head.
Recovery: Somewhat delayed.
_ .,- ___ respiration in deciL per minute.
e • • • e • • • e Syst. B. P. •-•-• Diast. B. P.
• • • • • • • pulse preBBUrP.
~
I
13
TABLE 1.-CLASS III, GROUP 2: Tran8Verse diameters and areas of the heart silhouette made at 75 centimeters.
Case 53. Case 122. Case 144. Ca.~e 142. Case&'l.
E>..,osure.
Transverse
diameter. Area. Transverse
diameter. Area. Transverse
diameter.
Transverse
Area. . diameter. Area.
Transverse
diameter. Area.
Om. Sq. cm. Om. Sq.cm. Cm. Sq.cm. Cm. . Sq. cm. Cm. Sq.cm.
1. . .. . .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . 15.4 175 14.7 13.4 150
2 . . ··· · ·· · ·· •· · ······ · . ... •.. .....• . 14. 5 161
3 .•.................... : .. ... .... . . . 14.6 165
4 .•••.•••• •..•.••.. ... ••···• ··•• •••· 14. 5 165
5 ••••• ••• •• ••• •.•• •••••.•.•••.••.••.• ·•· ·•• ••· •• •• • •• ···• ·
6 ••• ••.•... •. ... • . •.•..... .... •. . . .. ·· • ·· •••··· · ·•···•···
Average in run .... .. ·... . .... .. 14. 7 166
15. 5
14.5
14.9
1.5. 2
14. 1
14.9
l====l====l=====I=
End or run •• •. ... ..•..... .. . ·.. . . . . . 11. 9 135 13.8
Preliminary inspiration . . . . • . . . . . . . .13. 5 149
Post (Inspiration) . . • ... . . . . . .. . . . . . . 13. 5 160
(')
14.4
142 11.8 136
142 12.0 139
136 12.5 138
137 12. 4 144
142 12.0 127
135 ....... . . . . .. . ...... .
139 12.1 137
119 11.3 116
(') 11.9 138
(') 11.4 129
16.0 162
1-5. 7 156 12. 75 145
15.5 160 13.0 · 144
15. 8 150 12.8 143
14. 4 161 13.1 149
. ....... .. . --- ·---- -· ..... ...... . ! .-- - -/· · ·
15. 3 157 12.85 146
14.4 142 12.0 132
13.5 152 12.5 144
13.8 150 13.0 148
• Double exposures. .
NOTE.-The numbered axpdsures are those made during the rebreathing test. They were made approximatelv five minutes apart, except
~hat at the "end of run," which was made as nearly as possible at the moment of the termination of the test. Estimation of the area is usually
uncertain in double exposures. The figures are not entered in such cases. _
The pulse pressure remained fairly constant a.round 35
millimeters during the run; but aft.er the subject was re­moved
from the rebreathing ma.chine it. went do:wn to 20
millimeters at the thirty-second minute. The pulse rate
remained between 70 and 75 for 10 minutes, and then rose
gradually to 108 at the end of the test. At the twenty­seventh
minute the subject lost consciousness in a typical
vasomotor faint. As is shown in Ta.hie 1, the transverse
diameter remained at about 14.5 centimeters to the twenty­fifth
minute. At the twenty-seventh minute, at the mo­ment
of the faint, it was 11.9 centimeters. · We believe
tha.t this sudden diminution of the transverse diameter
wa.e caused by dilatation of the splanchnic vessels, so that
the arterial pressure was not sufficient to fill the heart
during its diastolic relazation. The roentgenogram shown
at the moment of the faint is therefore that of an empty
heart.
Case 122 (see chart, fig. 8) ran 36! minutes, at which
time he was breathing air containing only 5.2 per cent
oxygen. He was then cyanotic and unconscious, but not
relaxed. There were moderate convulsive twitchings of
the hands, face, and head. The systolic blood pressure
rose from 130 millimeters at the beginning to 150 milli­meters
at the thirty-third minute. The diastolic gradu­ally
fell from about 80 to 46 during the same period.
The pulse pressure increased steadily from 50 to 104
millimeters at the thirty-third minute. Surely here, if
ever, we would expect to find evidences of heart strain
and dilatation. Plates exposed at the twenty-fifth and
thirtieth minutes, at the heigb.t of inspiration showed
transverse diameters of 14.9 and 15.2. centimeters. The
34-minute plate, taken also at the tip of inspiration, shows
a transverse diameter of 14.1 centimeters. · At this point
both systolic and diastolic pressures were falling. The
36}-minute plate was taken in full expiration. It showed
a transverse diameter of only 13.8 centimeters. The
kymograph tracing showed a marked increase in the depth
of the respiratory movement during the last 10 minutes of
the run. We believe the first decrease in the transverse
diameter to be attributable to this cause. The respiratory­minute-
volume remained below 70 deciliters till the
twenty-fifth minute, but increased rapidly thereafter to
165 deciliters. The second decrease in the transverse
diameter from 14.1 centimeters in inspiration to 13.8
centimeters in expirati-On seems fairly attributable to vaso-motor
collapse similar to that of the preceding case. The
36!-minute exposure was made after the blood pressure
teadings were taken. Had it been possible to take another
reading before the subject was removed from the rebreath­ing
apparatus, we. believe that a further fall of the systolic
and diastolic blood pressures would have been found.
In case 144 (see chart, fig. 9) the transverse diameters
decreased from a range of 12 to 12.5 centimeters during
the first 30 minutes of the run, to 11.3 centimeters at the
thirty-second minute. At this point the test was termi­nated,
the subject being completely inefficient and barely
conscious. The final OJcygen percentage was 6.5 per cent.
During the las't two minutes of the run the systolic blood
pressure fell 20 millimeters. The pulse pressure was then
34 millimeters Hg. Two minutes later the pulse pressure
was 25 millimeters Hg. The decrease in the transverse
diameter in this case also seems to have been due to the
lowered blood pressure not completely distending the
heart during diastole.
Case 142 is shown in Plate XIII and figure 10. The
transverse diameter during the first 25 minutes of the
test varied from 15.5 to 16 centimeters. It was 14.4 at 30
minutes and the same at 31 minutes and 10 seconds when
the test was terminated. At this point the subject was
· breathing 7 per cent of oxygen. He was pale, uncon­scious,
with rigid muscles and fixed jaws. There were
slight irregular jerking movements of the head. The pulse
was barely perceptible and the respiratory movements
were absent. The cessation of breathing was noted
clinically and is also shown on the kymograph tracing.
The subject presented the picture of oxygen want so fre­quently
observed in approaching dissolution accompanied
by circulatory failure. When he was removed from the
machine and allowed to breathe pure air (after slapping
his chest), his recovery was fairly rapid but not immediate,
as iR usually the case after the runs on the rebreather. The
chart shows that the systolic blood pressure fell 15 milli­meters
during the thirtieth minute and the diastolic fell
20 millimeters during the twenty-ninth and thirtieth
minutes, just before the first exposure showing contrac­tion.
It may be noted in passing that the diastolic blood
pressure is always the first to break. At 31 minutes, when
the last plate of the run was taken, both blood pressures
were still falling. The last plate was taken during the
period of apnea and was obtained during midphMe respi-
14
ration or even expiration, as is shown by the kymo­graph
record. The preceding plate with the same trans­verse
diameter was obtained in inspiration. It seems
reasonable to think that the measurement would have
been smaller had this last exposure been obtained in full
inspiration like the others.
Case 83, the fifth of this group, was of the vasomotor
fainting type. He fainted during the preliminary exami­nation
before he ever saw the re breather; a faint caused the
termination of the run; and he had to have his head be­tween
his knees after the control plate following the run.
The transverse diameter at the time of his second faint was
1 centimeter smaller than at any time during the run, and
a half centimeter smaller than that in the preliminary plate
taken in forced held inspiration. The roentgenogram
made during the faint was also in the expiratory phase, and
the systolic blood pressure was 32 millimeters Hg.
The three remaining cases in which there was a decrease
in the transverse diameter form the third group, and one
which is not easily explained. There was no evidence of
circulatory failure during the run, and varying phases of
respiration are not discernable in the plates or in the res­piratory
tracings.
TABLE 2.-CASE 28: Heart measurements during rebreath­ing
test (target distance, 75 centimeters).
Exposure.
5 minutes ...... ... ..... . . ..... ..... ............ .
13 minutes .......... . .. .. ......... . ............ .
15 minutes ...... . •..... .. •........... . .. ... .....
20 minutes ..................... . ......... . . . ... .
25 minutes ........................... . ......... .
F.nd ......... ......... ..... . .......... . ........ .
Post (inspiration) . . ........................... .
Tra.nsverse
diameter.
Cm.
J.4. 75
14. 75
14. 75
14. 75
14. 75
14.00
14. 50
Area.
Sq.cm.
136
140
145
149
151
134
147
In case 100 (Table 3) the diaphragm is also slightly
higher in the final plate of the run than in the preceding
ones. The kymograph tracing likewise shows all ex­posures
to have been made in full inspiration except the
one with the small transverse diameter, which is shown to
have been exposed a little below the apex of the curve.
The decrease in the diameter is 1.4 centimeters.
Case 30, which shows a decrease from an average of 16.5
centimeters during the run to 15.6 centimeters at the end,
muat also be included in this group of unexplained cases of
apparently real decrease in the size of the heart.
These three cases are all excellent examples of a large
class of healthy subjects, who become what the psycholo­gists
somewhat technically term "ineffi.cientm' under the
conditions of low-oxygen pressure. Such men frequently
show little or no effect of their oxygen want in their circu­latory
mechanism. Apparently their psychomoter nerve
centers are more sensitive to oxygen reduction than are
their circulatory centers. It seems possible that in certain
persons oxygen reduction acts like moderate exercise to re­duce
the size of the heart. It is also possible that moderate
oxygen reduction in the circulating blood acts in all cases
like moderate exercise to cauae decrease in the size of the
heart. Under such circumstances the decrease would
uaually occur during the early part of the run, but excep­tionally
it might not appear until later, as in cases 28, 30,
and 100. It would be small in amount and in most cases
overshadowed by the changes due to the varying position
of the diaphragm. The fact that in our series the trans­verse
diameter during forced inspiration after the re­breathing
run is almost always smaller than it is before the
run gives support to this assumption of normal cardiac
contraction during the rebreathing test. More accurate
determination and control of the respiratory'1)hase at which
In case 28 (Table 2) five plates taken during the first 27 the radiographic exposure is made may in the future
minutes of the run each gave a transverse diameter of 14. 75 enable us to definitely decide this point.
centimeters. The next plate made at 30 minutes shows Juat what relation, if any, the enormous increase in the
transverse diameter of 14 centimeters. The subject was respiratory minute volume bears to the reduced diameter
then unconscious, sitting rigidly in his chair, slightly of case 28 and to the increased transverse diameter of
cyanotic, but the circulation well maintained. The case 110 is difficult to determine. In case 28 we might
systolic and diastolic pressures were unchanged. Pulse suspect that the greatly increased minute volume of res­rate
had increased from 66 at the start to 105; it was of good piration so freed the blood from carbon dioxide ,that its
quality. The respiratory volume was high throughout. effect in diminishing the tonus of the heart muscle was
To':ard the end it _fell fro~ 173 deciliters per minu~e / lost, and the oxygen, even though reduced, had an exag­durmg
the twenty-eighth mmute to only 20 and 30 deci- gerated stimulating effect upon the muscle tenus. The
li~ers per m~ute for the tw? minutes following. 1:he small
I
sudden fall in the minute volume of the respiration during
diameter picture was obtamed after these two nunutes of tlie final two minutes of the run would seem to point to a
remarkably small minute-volume respiration. The radio- diminution of the carbon dioxide content of the blood
graphs show the diaphragm to be slightly higher in the 14- below the threshold at which this respiratory center is
centimeter plate than in those with the larger transverse stimulated by CO2 and to indicate that oxygen want
diameter. alone was not a sufficient stimulation. On the other hand,
TABLE 3.-CAsE 100: Heart measurements during rebreath- we might suppose that in case 110, showing enlargement,
ing test (target distance, 75 centimeters). the carbon dioxide was not pumped out of the blood fast
enough to reduce the blood content below the threshold
ITd~iaanmsveetersre. J Area · 1 of respi.r atory str. mu la tw. n, and tha t i. t was sti ll present m.
· sufficient quantity to more than counteract the stimulus
5 minutes....... . . ........ .. ........... 1:7;· Sq. cm. to muscle tonus by the reduced oxygen supply. This,
~g ~~~:~: :::::: ::: :::::::::: :: :: :::: :: : : : ::::: ft~ m however, is only speculation. Unless these discrepancies
Exposure.
~o~J}~-~~~~/;(;;((((;((;;;(((((((:((((((((:(1 ~t! m ~a: ~:e!:::~e::
0
~:e!ef:::1::e:e~;~it:; ~U:J~:
---------------~-(-')_~--- knowledge of the physiological effects of oxygen reduction
1 Plate broken. • Double exposures. in the blood.
l 15
TABLE 4.-Transverse diameters and areas of the heart contours corrected for target distance. True measurements in relation
to weight groups.
Controls. Rebreathing test.
Weight group. Averme Transverse I Area Transverse diameter. Area.
weigh. diameter. ·
Inspira- E,cp!ra- Inspim- Expira- Maxi- Mini- Maxi- Mini-tion.
tion. tion.
- --- -----
Pmnd. Cm. Cm. Sq.cm.
120 to 129 pounds .......... . ... 125.0 11. 9 12. 4 107. 5
130 to 139 pounds .. . ........... 134.8 12. 2 12. 8 118.1
140 to 149 pounds .............. 143.0 11. 8 13.3 111.1
150 to 159 pounds .............. 152. 6 12.3 13. 7 120.4
160 to 169 pounds ........... . .. 162. 8 12. 9 14.1 119. 7
170 to 179 pounds .... . . .... . ... FLO 13.1 14.6 116.8
186pounds ........... . ........ 14. 4 15.1 I 134.0
In order to help determine whether the changes in the
transverse diameters which we have described represent
a true contraction or enlargement of the heart, the areas
of the heart shadows were obtained with a planimeter.
To do this, we outlined the heart on the glass side of the
plate and followed the outlines thus obtained with the
needle of the planimeter with the aid of light transmitted
through a window in a table top. The method of outlining
advocated by Shattuck 1 and by Bardeen 2 was used.
That is, the right and left borders of the heart were drawn
as far as they were clear and distinct, and then these two
lines were joined by a smooth curve continuous with them
at either end (Pl. XIV, figs. 4, 5, and 6). This method
unquestionably cuts off a portion of the left auricle and
includes a portion of the great vessels at the base. .How­ever,
we have found it to give more uniform results when
repeated on the same pictures at subsequent sittings than
are obtained by trying to draw the true outline of the
auricle and the anatomically indefinite junction of the
great vessels with the heart. By administering to the­subject
tartaric acid and soda bicarbonate separately in
half seidlitz-powder doses, the resulting gas in the stomach
aids in giving a fairly complete outline of the lower border.
Practice with the well-outlined shadows enables one to
draw those in which the outline is masked by other shad­ows
with a fair degree of uniformity and accuracy.
Our studies along these lines have caused us to draw the
lower border with a slightly more rounded outline than
does Bardeen. He draws it rather flattened, with sharp
curves at its junction with the right and left borders.
Our reasons for drawing a more rounded outline (Pl. XIV)
are some rather extensive outlines we have obtained in
the living subject by means of the gas bubble in the
tomach and the fact that by so doing we have obtained
more uniform results in the different plates from the same
subject. While in a few of our cases with ·extensively
shown heart outlines the lower border has been flattened,
we believe that it is more often rounded, especially during
inspiration, the time at which most roentgenograms are
obtained. The shape of the heart as well as its position
in the cadaver is th1Jot of relaxation and is not that uf the
functioning organ. We also believe that the rather thin
and sharp lower border of the heart is transparent to the
Roentgen rays and that frequently the shadow, which in
the silliouette is thought to be the lower border, is really the
lowermost portion of the blood-filled ventricular cavity.
Occasionally in forced inspiration we have obtained ex-
1 Shattuck, Bost. Med. & Burg. Jour., Mar., 1916.
tion. mum. mum. Average. mum. mum. Average.
--- --- - - - - - - ---- --- - -
Sq.cm. Cm. Cm. Cm. Sq. cm. Sq.cm. Sq. cm.
103. 7 13. 6 11. 8 12. 2 121 93 104. 8
117. 7 13. 9 10. 3 12.3 136 104 116. 5
116.3 15.3 9. 6 12. 4 141 82 112. 8
120. 2 15.0 11. 7 12. 8 145 86 119.0
126. 9 14.4 13. 4 13. 6 145 107 122.8
121. 5 15. 6 12. 5 13. 5 138 106 112.3
135.0 14. 2 13. 5 13. 9 133 124 128.0
posures showing an apparently complete separation be­tween
the heart and the diaphragm. We believe that this
seeming space is really occupied by the comparatively
transparent thin muscular tissue of the lower border.
Comparing the areas obtained in this way with the trans­verse
diameters during the rebreathing run, we found that
in case 30, where there was apparent contraction at the
end of the run, the areas did not show any decrease in size.
Case 28 (Table 2) shows a difference of 17 square centi­meters
between the largest and smallest area of the sil­houette,
but the 5-minute shadow and that at the end of
the run shows only 2 square centimeters difference.
Case 100 gives the measur.ements shown in Table 3.
There is a difference of 38 square centimeters between the
largest and the smalleat areas, and of 28 square centi­meters
between the smallest area and the average area for
the rest of the run. This is the greatest variation of the
area in our series, and seems to us to indicate the possibility
that a real contraction of the heart has occurred in this case.
On the other hand, in case 28 the area,s at the beginning
and at the end are so nearly the same that we can not
postulate any real change in the size of the heart.
The areas in the 5 cases showing symptoms of circulatory
failure are shown in Table 4, together with the transverse
diameters. On the whole, the decrease in the areas cor­responding
to the decreased transve.rse diameters is very
consistent and tends to support the theory of an actual
dinlinution of the size of the heart in these cases.
Our cases are as yet so few in number that we have not
attempted to decide what are the limits of error in the
estimation of the size of the heart from the area of its
radiographic silliouette. Case 28 shows a variation of over
10 per cent. Where a seri~s of exposures are made of the
same subject and an average area obtained, such an error
might be admissible, but when it is desired to obtain an
accurate knowledge of the size of the heart from one or
two plates, 10 per cent of possible error is too great. We
recognize that the error in the estimation of the silhouette
area arises partly from varying phases of respiration and
the varying degrees of masking of the lower border by the
diaphragm, but after all the difficulty of outlining the
upper and lower borders is inherent in the method what­ever
the respiratory phase. This difficulty iB especially
noticeable in the broad, flat hearts of stocky individuals
having a tendency to overweigq.t, '
While theoretically the area of the radiographic silhou~
ette should give a more correct indication of the size of the
• Bardeen, Am. Jour. Anat., Mar., 1918.
16
TABLE 5.-Variation of the transverae diameter and of the area of the heart contour during expiration. and impiration and
during the rebreathing test (meaaurementlt at i! meters and at 75 centimeters corrected for parallel rays).
Controls.
Case No. Weight. Height.
Transverse di- smeter. Area. Expos-ures
Expi- Expi-during
lnapi- Inspi- test.
ration. ration. ration. ration.
------- - - ------------
Pounds. Inches. Om. Cm. Sq. cm. Sq.cm.
5 ....... . .. ... . . ..... 100 71.0 12.6 116.0 ·-·------ 7
21. ........•. . . . ······ 153 69.5 13.9 ··· ··· ··· 119.2 ----·---· 6
22 •...•... . . .. . •. ... ... 158 70.5 14.4 -··-····· 138.0 ·····---- 5
23 . •. : ... . .. . ... .... . . 150 69.5 12.1 ······- -· 134.4 ···ii1:s· 5
26 • •••••• ••• · •.• .•••.•. 151 71.0 12.6 12.6 122. l 6
28 .... ... .. •..... ..... 142 70.0 13.0 -········ 118.0 ·· ····--· ! 5
30 ........... . .. . ... . . 150 67.0 13.6 -----· ··· 117.8 4
32 ..... .... . . . . ....... . 144 68. 75 10.6 12.3 86.4 84.0
34 .......... . . .. ..... . . 140 70.0 11.5 ···ia:o·· 102.3 . ........ 7
37 •.... . . .. .•. ........ 150 67.0 10.4 80.0 82. 3 5
38 ............. . .. .. .. . 120 65.0 11.2 ... i-t.T 01. 7 . .... . ... 9
39 .................... . 165 69.0 14.0 117.0 110.0 4
40 ......... ... ... . .... . 145 69.5 11. 6 . .. ii:{. 94.0 104. 0 5
41. ........•... . . . ..... 143 71.5 10.4 95. 8 95.8 7
44 .......... ... , . .. .. .. 170 70.0 13.2 ------·-- 128.8 . .. ...... 5
45 ..................... 148 68.5 12.1 ......... 109;6 -- ······· 5
47 ... .... . ..... . ....... 145 68.5 12.5 ········· 111.0 . ..... ... 6
48: ... .. . .... ...... .... 172 69.5 13. 7 ......... 110.4 ········· 5
51. ..... : ... . ... ...•.. . 123 67.5 - 12.1 -·- ---- -- 116. 8 . . ....... 5
52 .... . ... ..... . ... . ... 170 69.0 13. 9 --------- ····--· ·· ----- ---· 6'
53 . . . . .... ..... .. ...... 165 70.5 12.1 '"'ii:91· 119.2 ------ --- 5
55 • . . . ......... . .... .. . 124 67.0 11. 46 105.0 91. 0 5
58 .... . ..... . ... ..... .. 125 67: 0 11.0 11. 52 98.0 91. 0 5
61. ..... .. .. ..•..... . . . 165 71. 0 13.5 --------- 109. 0 125.0 4
62 ..................... 140 71. 0 12.6 14.4 123.0 135.0 5
71. ..... .............. . 134 69.0 ('l (ll ('l ('l 5
73 ... . .......•.... . ... . 170 61.0 13.0 14.4 1!6. 0 117.0 3
74.'. .. ..... . .... ...... ,. 129 67.0 ]2.6 13.0 124. 8 113.0 6
76 •. . .................. 138 66.5 12.5 13.8 118.0 123.0 5
77 •.......... . . ······ · · 140 66.0 12.5 13.0 118. 0 123.0 7
82 ••.•.•.•.• . •.•.••• . . . 165 72.0 12.9 13.9 121.2 117.0 4
83 •••.. : •••••. ·•••···•· 137 68.0 11.3 12.2 115.2 116.8 6
84 ........ ... ......... , 130 70.0 12.6 13.2 123.6 12i. 9, 7
86 .. · .... . .. ... ......... . 140 70. 0 13.1 13.9 123.0 117.0 5
87 •.................... 166 71.0 14. 4 15.1 133. 7 135.4 5
88 .. .. . .. .. . ... .. .... .. 152 69.5 13. 0 14.1 133.6 129.2 5
89 .................... . 132 68.0 13.9 11. 7 132.4 114.2 6
90 .. ... .......... .... .. 140 61.0 11.9 12. 6 109.8 110.4 6
91. .................... . 140 66.0 13.1 13.6 119.4 ·118.8 6
92 .. . ...... . . . .. .... .. . 138 64.0 10.3 12.1 93.0 107.5 6
93 ... . .... ...... . ..... . 127 66.0 13.2 13.3 114.5 116.0 5
94 ... ... ......... ... . . . 135 68.0 12. 2 12.2 108.8 109.6 5
96 •......... . .. ..... . .. 148 70.5 10.! 11.9 --- --- --· ···iuX 6.
97 •.... . .... .... . . .... . 150 70.0 12.6 13.9 126.4 6
98 . ..... .• . ... . ...... .. 172 70.0 ('l (ll (ll ('l 4
99 ... ....... .... : .... . . 165 72.0 12.2 13.0 126.4 139.8 5
100 .. .' .... .............. 134 69. 75 '12. 7. 13.1 136.0 123.2 6
102 •.......... ... .•.... . 141 69.5 9.5 12.3 88.8 ········· 6
103 •.. .. .. •..... . ....... 158 73.0 10. 7 ········· 106.4 ......... 2
l<K ... .. .... .... ........ 154 69.0 11.8 14.4 142.4 116.8 3
105 .............. . ...... 170 70.0 12.4 ... ff .. 112.0 · · ·c;i ·· · 4
106 .. .. ······ ........ . .. 153 69.0 ('l ('l 5
107 •......•............. 128 66.5 12.0 ·-·-· · ··· 105.6 ----- ---· 2
108 ... . . ..... . .......... 135 71.0 ('l (ll
fl (') 3
109 .... . ................ 152 71.5 12.3 14.3 'l ('l 5
110 ..................... 141 71.3 11.3 13.5 ('l ('l 5
112 . ... . ... .. . . .... . . .. . 140 70.0 10.3 13.0 fl ('l 5
114 ..................... 152 71.5 ('l ('l ll (' 5
115 •... . ................ 150 68.0 13.1 14.5 121.5 129.6 5
116 . ... . ................ 160 68.0 12.4 12.6 101.6 126.0 5
118 . ......... . ...•.. ···· 175 73.0 '('l (1) (') ('l 3
119 ..... .•. . ... . . . ...... 135 69.0 (1) 14. 7 (1) (') 5
120 .. . ·· · ······· · ··•···· 170 69.0 13.0 14.8 (') ['> 4'
121. ....•. . ...•.•....... 155 68.5 12.8 14.5 (') 'l 3
t::::::::::::::::::::::I 140 67.0 13.5 14.4 (') (') 7
154 71. 75 12.2 13.0 117.2 106.4 4
125 . ......... . .. ...... .. 145 68.5 11.8 13.5 112.0 111. 7 5
126 . ...... . ............. 160 69.0 13.5 14.4 119.0 111.0 5
131. .... .. ....•......... 155 67.0 12.9 13.0 -----·--· ··· · ····· 5
132 •. . . . ...•....•... . ... 152 71.0 12.1 13.8 120.0 119.0 5
133 .. . .. ... . ............ 162 67.0 13.3 15.2 131.2 136.0 6
134 ..... . . . . . ··········• 145 68.0 11.4 14.4 103.0 125.3 7,
135 .... . .... . . . .•....... 146 71.0 12.0 13. 0 125.0 115.0 5
136 •.... .• .. . .. . . ....... 150 66.0 12.6 14.1 109.6 109.0 5
137 ..... ...... .. . ... .... 145 70.0 11.9 13.9 125.6 108.0 6
138 ......... . ..... . ..... 159 69.0 11. 7 14. 5 119.2 138.4 5
139 ........... .. ••...... 170 72.0 12. 'l 14.6 116:8 125.6 5
140 • .. .. .... . . ....... . .. 11. 7 12.9 98.4 105.6 3
141. .. . . ....... ........ . 150 70.5 11.5 13.5 119.0 129.0 2
142 ........ ..... : ... . ... 143 68.0 12. 2 14 .. 4 117.0 124.8 6
143 ... . ..... ... ... . . . ... 145 71.0 12.1 13.1 -·-· · -··· 121. 6 5
144 ... . .............. . .. 146 71.0 10.3 13.1 lOi.O 120.8 6
146 . ... . .. ... ··········· 145 68.5 12. 5 15.2 131.2 14'1. 0 !
147 • ... . ...... .. ...... .. 161 70.0 12.9 14.9 124.8 140.0 5
H9 •. • .• •• .•...•...••.•. 164 68.0 14.0 14. 2 -------- - 120.9 6
151. ....... ... .• ...... . . 150 68.0 12.3 14.1 108.0 119.0 5
1 Double exposure.
Rebreathing test.
Transverse diameter.
Maxi- Mini- Aver- Maxi-mum.
mum. age. mum.
------------
Cm. Om. Cm. Sg!cm.
13.9 13. 5 13.6 132.1
13.6 12.2 12. 7 122.4
13.2 13.0 13.1 128.8
12.6 12. 2 12.4 129. 7
12. 5 11.7 12.1 110.6
13.2 12.6 13. 1 121.1
15.0 13.5 14.4 124.0
12.1 11.0 11.3 92.8
12.6 11.2 12.2 126.4
12. 7 11.8 12.0 104.0
12.4 11.2 11.6 108.6
14.13 13. 86 13. 95 118.0
12:6 12.1 12.3 107. 2
10.8 9.6 10.2 97.0
13.0 12.6 12. 7 126. 7
13.2 11.9 12. 8 123. 8
15.3 13. 9 14.5 125.6
15.6 13. 7 13.3 119.2
12.6 12.1 12.4 120.0
15.3 14.5 14.8 ·· ······· 13. 8 12.1 13. 6 140.0
12.6 11. 9 12.2 102. 0
11.8 12.3 12.2 103. 2
14.4 13. 9 14.2 112.8
14.0 13.6 13. 7 140.0
12. 0 10.8 11. 7 ,136.0
13.5 12.6 13.3 125.0
12. 7 12.2 12.5 li5. 6
13. 7 13.5 13. 6 121.0
13.5 12. 7 13.6 121.6
13.5 12.1 12. 9 128.2
12.0 10.8 11.6 124.0
12.9 12.4 12. 7 120.6
13.4 12.5 13.0 128.8
14. 2 13.5 13. 9 132. 9
14.3 13.4 14.0 143. 7
12.5 11.5 12.1 122.4
11.9 11.3 11.8 113.3
13.6 12.9 13.3 117.6
12.1 10.3 11.5 112.8
13.8 ·12. 7 13.1 120.9
12.8 12.4 12.5 112. 7
12.2 10. S 11.4 104.8
13.6 13.0 13.4 132.9
12.6 12.5 12.58 122.8
14.1 13.2 13.8 144.9
12.1 11.8 12.0 136.0
11.2 10.3 10.6 108.3
12.4 12.0 12.2 117.8
13.1 12.4 12. 7 125.6
13.9 13. 5 13. 7 128. 7
13. 7 13.1 13.3 126.5
12.0 li.3 11. 7 102.0
12.1 11. 7 11.9 112.0
12.3 12.1 12.1 128.9
12.3 11. 7 12.1 120.4
12.6 12.1 12.3 132.4
12.8 12.4 12.6 113.0
13. 7 13.3 ·13, 5. 136.0
14.4 13.9 14.0 140.1
14.4
I
13.5 13.6 138.2
13.9 13.3 13.5 127.0
15.4 13. 9 14.3 129.6
14.4 13.5 13.8 129.6
13.9 12.4 13.2 113.9
12. 8 12.2 12.5 115.2
12.9 12. 7 12.8 110.7
14.0' 13.6 13.9 117.6
13.0 12.8 12.9 109.0
12.8 12.3 12.5 132.0
13. 7 13. 5 13.6 144.0
13. 7 12.4 13.1 109.5
12.2 11.5 11.8 119.0
13.5 13. 1 13.3 116.0
12.6 11.9 12.3 121:6
13.9 13. 7 13.8 144.0
14.0 13.5 13.8 124.8
12.1 12.1 12.1 112.0
12.1 11. 7 11.9 112.0
14.! 13.0 13.8 129.9
13.5, 11. 8 12. 6 133.6
11.2 10.1 10.8 115.0
14.4
I
14.2 14.1 I
145.6
13.4 12.6 13.1 121.0
14.0 13.0 13.5 124.0
13.5 12. 7 13.1 I 119.0
Area.
Mini-mum.
---
Sq. cm.
122.0
106.4
119.5
119.3
101. 7
107.4
117.4
81. 8
98.9
85.8
92.9
111. 0
101. 6
81. 8
122.6
107.0
109.6
109.6
109.6
.. · i2S: s"
94.0
96.8
109.2
129.6
104.8
106.0
103.0
116. 8
116.8
107.9
106.0
110.6
107.2
123.6
125.0
108.8
107.9
112.9
100.8
109. 7
108.0
95.4
117.0
112.0
128.2
124.8
95.3
112.'8
112.8
116. 7
116.0
100.0
98.8
118.5
110.0
121. 9
107.8
125.1
124.0
136. 7
119.0
120.0
119.0
95.6
104.8
101.5
107.2
104.0
115.0
122.0
102.0
107.0
110.4
105.6
130.4
115.0
108.0
108.0
114.2
108.0
92.8
136.8
109.6
115.0
100.0
Aver-age.
---
Sq.cm.
128. 1
115. 2
125.6
122.0
105. 9
117.0
119.3
87.3
113.9
108.1
94.
115.
104.
94.
6
0
0
6
124.1
114. 7
116.0
114.6
114. 7
······-·· 132.
99.
100.
110.
132.
123.
116.
110.
118.
8
0
0
0
8
7
6
0
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118. 0
117.9
116.9
114. 7
125.9
128.4
.134.1
116. 6
110.
115.
107.
114.
110.
99.
121.
116.
14-0.
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7
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6
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5
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1
4
5
9
7
6
0
0
6
0
4
0
0
0
0
5
6
0
8
0
0
0
98.
114.
119.
123.
122.
101.
105.
124.
114.
126.
109.
130.
128.
137.
122.
124.
123.
109.
110.
102.
113.
107.
123.
127.
106.
114.
113.
114.
136.
121.
110.
110.
123.
117.
109.
140.
113.
120.
108.
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Plate II.
17
TABLE 5.-Variation of the tran3'Verse diameter and of the area of the heart contour during expiration and inspiration and
during the rebreathing test (measurements at 2 meters and at 75 centimeters corrected for parallel rays)--Continued.
Controls. Rebreathing test.
Transverse di- Case No. Weight. Height. ameter. Are'&. Expos- Transverse diaI,neter. Area. ures
Inspi- / Expi- Inspl- Expi- during Maxi- Mini- Aver- Maxi- Mini- Aver-ration.
ration. ration. ration. test. mum. mum. age. mum. mum. age.
----------------- ---------------
Pounds. Inches. Om. Om. Sq. cm.
152 •.. . . .. ..•..... . ..... 155 71.0 12.6 14.8 1130.0
153 . .. . •.. •. •........•. • 155 70.5 12.0 12. 9 1124.0
154 ..•..... : •..•. .• . . ... 152 71.0 11. 7 13.0 1031. 0
156 . .•. ....• • .... .•• .... 160 69.0 12.1 15.0
heart than the transverse diameter, we believe that prac­tically
the transveme diameter iB a very useful measure­ment.
ThiB iB especially true if care be taken to adopt
a · standard phase of respiration in which to make the
exposure. As our studies indicate, the changes in the ·
transverse diameter are less marked in ordinary breathing'
than in forced breathing. On the other hand, the heart
iB seen in ·better outline during inspiration. Therefore
the exposure made in moderate inspiration, as iB cus­tomary
among RoentgenologiBts, iB the rational one,
whether we are looking for the silhouette area or the trans­verse
diameter. However, certain precautions are neces­sary
as to the time of the exposure. The subject may be
able to hold hiB breath for a considerable period, but hiB
diaphragm will very soon begin to creep either upward or
downward. We have taken roentgenogmms of subjects
holding their. breadth (Pl. XV) while the nostrils were
closed with a spring clamp, such as that used with the
rebreather or in the older form of gas mask. Notwith­standing
the apparent impossibility for air to escape from
the lungs, the diaphragm gradually changed its position.
Even when holding the breath for a brief period, unless
the subject is thoroughly trained, involuntary efforts to
breathe will produce changes in the relative positions of
the chest wall and diaphragm, which ;move backward and
forward, and upward and downward in reciprocal action
and reaction. Care should therefore be taken to make
the exposure the moment the respiration reaches the
desired phase, or at the beginning of the held breath.
Cases 135 and 137 illustrated in Plates XIV and XV, i1lus­trate
the changes in the position of the diaphragm when
the nose iB clamped and the breath held for as long as
possible. Incidentally, we- may note that the changes
in the heart silhouette apparently are not all due to dia­phragmatic
change of position.
In determining the phase of respiration, a aimple
respirometer iB very helpful, exposure being made when
the counterweight reaches the proper elevation. We hope
to make further observations on the size of the heart in
aviators from silhouettes taken when the exposure iB
aut.omatically set off at a standard phase of respiration.
The position for the drum at the time of the exposure
can readily be determined from a; knowledge of the volume
of tidal air when the subject iB breathing quietly. ThiB
point. being decided, all we have to do is to cause a counter:
weight to close an electric circuit, which in turn actuates
the X-ray switch.
. Ail will be seen from Table 4, which shows the summary
of the true measurements of the heart as calculated from
the 75-centimeter silhouette, the hearts of aviators are
slightly larger than the standard measurements usually
60683 0 - 31-- 2
Sq. cm. Cm. Cm. Cm. Sq. cm. Sq. cm. Sq. cm.
152.0 3 14.2 13.0 13.3 140.8 130.0 135.6
123.0 5 13.1 11. 7 12. 7 122.0 116.0 119.0
107.0 5 12.6 12.2 12.4 123.0 106.0 114.8
143.0 4 13. 7 13.5 13.6 142.0 129.0 136.8
given for young subjects. We believe, however, that
these measurements are unusually accurate in that they
represent averages of from three to nine silltouettes for
each heart. It iB possible that they represent an enlarge­ment
due to flying at high altitudes, as iB claimed for
French aviators by Etienne and Lamy. We are inclined
to think, however, that our measurements ·represent rather
the heart of the soldier in general, or perhaps the un­damaged
heart of the athlete, from which class a large
proportion of our aviators iB drawn.
NoTE.-In Tables 4 and 5 the measurements given are
the true diameters and the true areas of the contour of
the heart as calculated mathematically. For thiB pur­pose
the plane of the contour of the heart which gives the
silhouette iB assumed to be parallel to the plate, and it
distance from the plate 8 centimeters. It iB admitted
that the plane of the contour may not be absolutely parallel
t.o the plate in many or even in all cases. The silhouettes
will evidently be distorted in proportion to the departure
of the plane of the contour from paralleliBm with that of
the plate. An effort was made in our work to reducfl this
diBtortion to a minimum by having the back of the chair
tilted slightly forward so as to bring the gladiolus of the
sternum parallel to the plate as recommended by Bardeen.
The distance of 8 centimeters from the plate for the con­tour
iB larger· than usual because we were compelled to
allow for the movements of the chest· during the deep
breathing which our subjects indulged in during the
progress of the test-. The sternum was not always in
contact with the plate. As our work was undertaken
primarily to compare the heart measurements obtained
during the course of the .rebreathing test in "the same
subject, and not those of one subject with another, we
believe that the possible distortion resulting from these
departures from the standard method are negligible.
In order that our measurements may be compared wlth
those of other observers, we have endeavored to convert
them as accurately as possible into the true measurements
oi the heart contour. We have done thiB on the formulre
that the true diameter and the silhouette diameter are
directly proportional to their distances from the target;
and that the two areas are directly proportional to the
squares of their distances from the target. Assuming the
heart contour to be 8 centimeters from the plate, these
formulre give the following relations:
With heart 8 centimeters from the plate-­Target
2 millimeters distance--
True T. D. =96 per cent t. d. of silhouette.
True area=92 per cent area of silhouette.
Target 75 centimeters distance--
True T. D.=89.6 per cent t. d. of silhouette.
True area=79.6 per cent area of silhouette.
T--· -~
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19
Plate IV.
IIISPIRAJJON . -;13. 9 .,,
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FI G.2
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Plate V .
M-· -E 0008l£ EXPOSURE TO DEMONSTRATE
100-2 O\APHRAGM EXCURSION CAUSING CARDIAC
DISPLACEMENT l Yr, SEC. AFT ER PULS[ f :P.= rn SEC.
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DIAPHRAGM EXCURSION EXP. ·---Yto IEC.
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21
Plate VI.
DOUBLE EXPOSURE DEMONSTRATING OUTWARD MOYEIEll ~
Of RIGHT & LEFT BORDER Of HEART
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25
U. 13.2 CM.
INSP. ·-'START-T.
o. 12./iCM.
Plate XV.
30 IN.
3/20·S£C .
PART 2.
RECENT WORK IN PERSONALITY S11JDY.
MEDICAL RESEARCH LABORATORY, HAZELHURST FIELD, MINEOLA, LONG ISLAND, N. Y.
WrLLIAM MAcLAKE, Major, Medical Corps, Department of Neurology and Psychiatry.
The work of the Department of Neurology and Psychia- I
try of the Medical Research Laboratory, Hazelhurst Field,
has been largely along the line of pei:sonality study. The
development of an accurate comprehensive examination
blank which in the course of the examination would lead
the examiner through channels which would indicate and
finally determine the type ol pers~nality of the aviator has
consumed much time and effort. Further that the exam­ination
might bring out clearly all the points in the his­tory
which might have an inimical effect on the fitness of
the aviator as well as all points favorable to his efficiency,
many additions have been made as experience has been
gained by the increasing number of men examined.
·Selecting th95e points noted in the accompanying ex­amination
blank which may be considered entirely favor­able
and conducive to efficiency we may note:
(a) Youth, 20 to 24 years.
(b) Single.
(c) Good family history.
(d) Few and only minor diseases-especially those ·
with few complications and sequelre.
(e) No operations or serioliB injuries.
(.f) High-school arid college education-with g:>od
scholarship throughout.
(g) Unusual ability in athletics.
(h) Evidence of manual dexterity-as good in bil­liards,
tennis, sailing, violin, horseback riding
( i) Active, successful civil life.
(j) Liking for . normal amusements-no evidence of
exceBBes and diBB;pations.
(k) Extreme moderation in use or complete abstinence
from tobacco.
(Z) No alcohol or drugs.
(m) Good appetite and digestion.
(n) Normal sleep and absence of dreaIIlB.
(o) Good, active, sympathetic co-operation of family
in all that pertains to flying.
(p) Thorough preliminary training in ground school
and primary flying with high average of schol­arship-
natural bent for flyi~g.
(q) Extended experience in flying-without acci­dents,
crashes, or demerits (benched or set on
ground) .
(r) Experience in actual combat without injury-or
the production of staleneBB.
·(s) Normal reactions throughout physical examina­tion.
(t) Personality showing-
(a) Temperament.-Cheerful, stable, self-reliant,
aggresive, modest, frank, fond of people,
satisfied, punctilious, serious, good co-opera­tion
in work and in examination, good
sportsmanship, moderate tension, enthusi­astic.
(b) Volitional.-Energetic, quick, deliberate, or
moderately impulsive controlled, good te_
nacity of purpose. '
(c) Intelligence, precise, penetrating, sharp, alert,
deliberate, resourceful.
Those points which may and in a majority of cases do
lead to inefficiency:
(a) Increased age.
( b) Marriage.
(c) Poor family history (tuberculosis), nervous and
mental diseases, etc.
(d) Severe diseases of childhood- espfcially nervous.
diseases and defects. Severe infections in
adult life an.d nervous or· mental breakdowns.
(e) Operations-which may have left permanent
impairment.
(/) Inadequate education with poor scholarship
(g) Slight or ·no athletic training and no evidences
of manual dexterity.
(h) Sedentary civil occupation with poor or moderate
success.
( i) No desire for healthy amusement.
(j) ExceBBes in tobacco, alcohol, and sexual life.
(k) Poor appetite and digestion.
(l) Insomnia and frequent unpleasant or terrifying
dreams, especially of an occupation type.
(m) Anxiety or active opposition to flying on part of
family, especially mother and wife.
(n) Poor record in ground school (frequent repeats)
and in primary flying.
(o) Few hours of flying with apprehension or poor
judgment in solo work.
(p) Numerous accidents and crashes.
(q) Numerous demerits.
(r) Shot down or prisoner.
(s) Poor reactions under two or more headings on
physical examination.
(t) Personality study-
(a) Temperament.-Depressed, unstable, sub­missive,
pacific, vain, withholding or
secretive, loquacious, likes to seclude
hiIIlBelf, hypercritical of conditions, care­leBB,
frivolous, poor co-operation, irritable,
poor sportsmanship, exceedingly high
tension, lost enthusiasm.
(b) Volitional.-Sluggish, slow, recklessly im­pulsive,
restless, poor tenacity of pur­pose.
(c) Intelligence.-Vague, superficial,.dull, hesi­tant,
without initiation, untrained.
It is not exp,ected that any one aviator will exhibit all
the best qualities to the exclusion of all the poor ones, but
the preponderance towards a favorable or an unfavorable,
satisfactory or an unsatisfactory, efficient or inefficient type
(26)
will lead to an accurate estimation of the efficiency and true
personality of the aviator.
The complete blanks for personality study and typical
histories are appended .
MEDICAL RESEARCH LABORATORY.
DEPARTMENT OF NEUROLOGY AND PSYCHIATRY.
HAZELHURST FIELD,
Mineola, L. I., N. Y, - --, --.
27
Name, ---; age, --; S. M. -W .. , ---; organiza­tion,---.
Residence : --- ---. Nationality (fatb,er and
mother-grandparents) : ---.
I. Family history.-
II. Personal history.-Diseases (childhood and adult life),
childhood fears, stammering, nervous breakdown;
injuries, operations. Education : School and col­lege,
any difficulties, any failures, reasons for stop­ping.
Athletic training: in school and after, in­door
and outdoor. (Have athletic tendencies.been
continued after school life?) Evidences of manual
dexterity, as in billiards, tennis, etc. Occupation
in civil life (sedentary or active) success. Your
favorite amusement, your relaxation. Tobacco­alcohol
(has there been any special desire for stimu­lants
since flying?) Eating; sleep; dreams (type,
frequency, influence on conduct). Attitude of
family (if married has it affected his flying) .
III. Aviation history. - Enlistment: Date, place sworn in,
assigned to (branch of service). Active service,
entrance or transfer to Air Service. Aviation school
work. Repeats. Aviation, active service·; date of
commission, dates and places of training. Hours of
flying; maximum altitude. Duration. Accidents,
crashes. Cause and effect. Reasons for selecting
aviation. Relative interest in flying and in me­chanics.
What was your reaction towards your
first, second, and third solo flights? Benched or set
on the ground? Reason. Hours over lines. Com­bats,
credits, shot down, prisoner.
IV. Physical examination.-Height, weight (gain or loss).
General build. Personal appearance. Pupils :
Character, reactions, character of sP-condary dilata­tion.
Knee jerks. Psychomotor .tension (normal
or increased). Tic, tremor (hands and tongue).
Draw parallel lines and write slowly. Dermo­graphia:
Before and after rebreathing; describe
fully the phenomena, including tha time reactions.
Condition of peripheral. circulation: Moist, cold
hands, pale face , soft and flabby muscles.
V. Personality stud,11:
A. Temperament: Cheerful or depressed, sta­ble
or unstable, self reliant or submissive,
aggressive or pacific, modest or vain,
frank or withholding, tendency to un­bll!
den, loquacity, fond of people or likes
to be alone. Satisfied with or hypercrit­ical
of conditions, punctilious or careless,
serious or frivoloW! , cooperation, sports­manship,
high tension, does he find pleas­ure
in his work, has he grown irritable.
V. Personality study-Continued.
B. Volitional: Energetic,or sluggish, quick or
slow, impulsive or deliberate, controlled
or restless, tenacity of purpose.
C. Intelligence: Precise or vague, penetrating
or superficial , sharp or dull, alert, hesitant
or deliberate, resourceful or without ini­tiative,
trained or untrained.
Remarks:
Rating:
PERSONALITY RATING.
A. Safe, nervously and mentally, to fly.
B. Safe with limitations.
C. Further investigation and special attention need ed to
determine and to preserve effici ency and morale.
D. Questionable, no definite conclusion reached. Should
be kept under close observation.
E. Nervously and mentally unfit to fly .
F. Not rated.
PERSONALITY R:t<;CORD.
[Hazelhurst Field, Mineola, Long Island, N. Y.]
Name, - -- ---; age, 31; first lieutenant. Ger­m'l.
n. A. S. A.
I. Family history.-Negative.
II. Personal history.-Was invalid until 20 years old.
Had all childhood aiseases, glandular trouble, cer­vical
glands; better late years. Turbinates re­moved.
High school graduate and 2 years post
graduate, West Virginia University. Athletic
training: Tennis and horseback, track. Occupa­tion:
Assistant to president Faultless Rubber Co.
Amusements: Theater, dancing, motonng. To­bacco:
No. Alcohol: No. Eating: Good appetite.
Sleep: Good. Dreams: Pleasant. Family attitude
unfavorable.
III. Aviation record.-Enlisted, Elkins, W. Va., Septem­ber
16, 1917. Ground school: Kelly Field Offi­cers'
Training School, September 20 to November
10. Repeats: No. Training: French Aerial Gun­nery
School, Cazeau, 7th A. I. C., September 15,
1918,. to November 20, 1918; 60 hours; maximum
altitude, 16,000; duration, one-half -hour. Reasons
for aviation: Just desired to enter Army; had tried
all others and been repulsed. Reaction to 1-2-3
so'.o: Bomber, no reaction. Accidente:: One heat
cut. Crashes: One, smashed machine; he and pilot
not hurt. Benched or set: No. Hours overseas:
60. Combats: No. Credits: No. Shot down:
No. Prisoner: No.
IV. Physical examination.-Height, 68; weight, 125. Ap­pearance,
slight. Pupils, normal. Knee jerks,
normal; tic, no. Tremor, fingers. Psychomotor
tension, excellent, relaxes completely. Dermo­graphia,
good, begins to fade in 100 seconds. Pe­ripheral
circulation, good.
V. Personality study.-Cheerfu1, rather submissive, pa­cific,
loquacious, likes flying.
Rating .-Personality, "C."
28
PERSONALITY RECORD.
[Hazelhurst Fi~d, Mineola, Long Island, N. Y.J
Na.me, ------; age, 25; :first lieutenant. Ameri­can.
A. S. A.
I. Family history.-Negative.
II. Personal history.-Always strong; diseases, childhood. _
Broken ann when small. Education: A. B.,
Princeton. Athletic training: Swimming and
wrestling. Evidences of manual dexterity: Ten­nis.
Occupation civil life: Student. Amuse­ments:
Camping and hunting. Tobacco: Yes.
Alcohol: Slight. Eating: Good. Sleeping: Good.
Dreams: No. Attitude of family: Unfavorable.
III. Aviation record.-Enliated April 26, 1917, Princeton,
Officers' Training Camp, New JerEey,_ August 15.
Transferred to A. S. A. Gnound school, Ithaca,
N. Y., August· 10 to Octpber 13. :Repeats: No.
Training: Avord, Chatteroux, France, December 26
to Aprjl 10, 1918. Total flying hours: 500. Maxi­mum
altitude, 21,000; duration, 15 minutes.
Reasons for aviation : Always wanted to fly. Re­action
to 1-2-3-sol-o: Was nervous before first solo.
Accidents: Smashed several machines; don't re-.
D;J.ember how many; never hurt himself. Crashes:
Never kept track. Benched or set: No. Overseas
flying: 500. Combats, noi credits, no; shot down,
no; prisoners, no.
IV. Phy1ncal examination.-B;eight, 70; weight, 150. Ap­pearance,
_gootl. Pupils, normat Secondary dila­tations,
n-one. Knee jerks, norinal. Tic, none.
Tremor, none. Psychomotor tension, normal, re­laxes
well. Dermographla, begin1;1 to fade in 60
seconds. Condition peripheral circulation-, good.
V. Personality study.-UI1Btable, vain, careleBB, restless,
.i.lert, rattlebrain.
Rating.-" E."
PERSONALITY RECORD.
[Hazelhurst Field, Mineola, Long Island, N. Y.J
Name, ---; age, 23 ; single; second lieutenant.
English-American. A. S. A.
I. Family history.-Two infant brothers dead.
II. Personal histpry.-Alwaya strong. Disease: Diph­theria,
typhoid. Injun"es, -operations: fracture of
astragalus. Education: B. S. and engineering de­grees.
Athletic training: Footbal-1. Evidences of
manual dexterity: Tennis. Occupation civil life:
Electrical engineer. SucceBB: Yes. Favorite
amusement: Boa.ting and tennis. Tobacco: Yes.
Alcohol: No. ~a.ting: Good. Sleep: Good.
Dreams: No. Attitude of family: Favorable at
:first, unfavorable now.
III. Aviation record.-Enlisted September 8, 1917, Roan­oke,
V.a. Ground school: -Georgia Technical,
October 1 to November 24, 1917. Repeats: No.
Training: Call Field, November 27 to March 17,
1918. Total hours of flying : 200. Maximum alti­tude
19,500 feet; duration, 10 minutes. Rea.sons
for aviation: To get away from military discipline
and to use his engineering skill. Reactions to
1-2-3-solo: No reactions. Accidents: Three; hurt
foot in last one. Crashes: Three, motor· stopping
and forced landings. Benched or set: No. Hours
flying overseas: 160. Combats: 2. Credits: None.
Shot down: 2. Prisoner: No.
IV. Physical exa?7\ination.-Height, 68; weight, 155. Ap­pearance,
stout. Pupils, normal. Second:μy di­latations,
none. Knee jerks, normal. Tic, none.
Tremor, fingers. Psychomotor tension, relaxes
perfectly. Dermographia, begins clearing 70 sec­onds;
excellent. Condition peripheral circula­tion,
good.
V. Personality study.- Somewhatnervousand excitable;
speaks -quick, impulsive, high tension.
Remarks.----Good type of officer. Better in mechani­cal
end than in flying.
Rating.-Personality " B " minus.
PERSONALITY RECORD.
[Hazelhurst Field, Mineola, Long Island, N. Y.J
Name, ---; age, 23; second lieutenant. English­American.
A. S. A.
I. Family history.-Mother died of pneumonia.
II. Personal history.-Has had hernia an\l appendicitis.
Disease: Mumps, cholera infantum. Injuries,oper­ations,
two, hernia and appendectomy. Education:
High school and 2 years college. Athletic train­ing:
Swii:Jjming and coll~ge athletics. Evidence
di manual dexterity: Pool, billiards., and tennis.
Occupation civil life: Student: Success: Yes.
Favorite amusement: Swimming. Tobacco: Yes.
Alcohol: Slight. Eating: Fair. Sleeps good.
Dreams: No. Attitude of family: Unfavorable .
III. Aviation record.-Enlisted: Philadelphi:;t, May, 1917,
.Infantry. Transferred to aviation September,
1917. Ground school: Cornefi, September to
Novemher, 1917. R epeats: None. Training: R.
F. C. in Texas, December to March, 1918. Total
hours of flying: 250. Maximum altitude: 16,000
feet; duration, 11 hours. Rea.sons for aviation:
Novelty and sporting element. Reactions to
1-2-3-solo: No reaction. Accidents: Six; last one
shot under eye. Crashes: Five, shot down once.
Benched or set: ·No. Hours of flying overseas, 35.
Combats: No. Credits: Not any. Shot down:
1. Prisoner: No.
IV. Physical examination.-Height, 71; weight, 150.
Appearance, slender. Pupils, normal. Second­ary
dilatations, none. Knee jerks, normal. Tic,
none. Tremor, fingers slight. Psychomotor ten­sion,
excellent, -relaxes perfectly. Dermograhpia,
blotching at 90 seconds; begins clearing at 2 min­utes.
Condition peripheral circulation, good.
V. Personality -study.-Cool headed, quiet, resourceful,
even temper-ed, only fear :is of burning up in air.
Remarks.-Excellent type of aviator as to mental con­dition
but should be watched for physical break.
Rating.-Personality, "B." ·
PERSONALITY RECORD.
[Hazelhurst Field, Mineola;Long Island, N. Y.J
29
Name, ---; age, 27; second lieutenant. Nordic.
A. S.A.
I. Family hi.~tory.-Negative.
II. Personal history.-Al,ways strong. Disease: All child­hood.
Injuries, opera.tions: Head, left hip and
right wrist injured; operated on wrist. Education:
Grammar school. .i\thletic training: Football and
all others. Evidences of manual dexterity:
Tennis, pool, billiards, golf. Occupation, civil
life: Auto engineer. Success: Yes. Favorite
amusement: Canoe. Tobacco: Yes. Alcohol·
Slight. Eating: Good appetite. Sleep: Good.
Dreams: Slight. Attitude of family: Unfavorable.
III. Aviation record,-Enlisted Octpber 22, 1917. Ground
school: None except French Army. Training:
Tours, Issoudun, Cazaux. Total hours of flying,
150. Mapmum altitude: 12,000 feet; duration, lf
hours. Reasons for aviation: Sportiest and fastest
branch. ~eaction to 1-2-3- solo: No reaction.
Accidents: Two; engine froze and wing collapsed;
Crashes: One. Benched or set on Ground : No,
Hours of overseas flying: ·150. Combats: 8.
Credits: No. Shot down: No·. Prisoner: No.
IV. Physical examination.-Height, 69!; weight, 150.
Appearance, slender. Pupils, normal. Second­ary
dilatations, none. Knee jerks, normal.
Tic, no. Tremor, no. Paychomotor tension,
relaxes perfectly. Dermographia, clears at 90
seconds, good . Condition peripheral circulation,
good.
V. Personality study. -Cheerful, frank, ·self-confident,
quiet, serious, excellent sport.
Re'l'.Q,arks.-Excellent type, stale now.
Rating.-Personality, "A" (E temporary).
PERSONALITY RECORD.
[liazelhurst Field, Mineola, Long Island, N. Y.J
Name, - - -· -; age, 23; second lieutenant. English.
A. S. A.
I. Family history.-Negative.
II. Personal history.-Strong always. ·Diseases: All child­hood.
Injuries, operations: Varico~ele. Educa­tion:
;lli.gh school. Athletic training: All there
is. Evidence of ip.anual dexterity: Tennis. Oc­cupation
civil life: Carpenter. Favorite .a.mUse­ment:
Basket ·ball. Tobacco: Y~. Alcohol: No.
Eating: Fair. Sleep: Fair. Dreams: No. Atti­tude
of family: Unfavorable.
III. Aviation record.-Enlisted October 29, 1917. Ground
school: Cornell, December 15, 1917, to February
2·!, 1918. Re:peats: No. Training: Park Field,
May 18 to July 6, 1918. Total hours of flying: 80.
Maximum altitude: 15,000 feet; duration, 45 min­utes.
Reasons for aviation: Just wanted to fly.
Reactions to 1-2-3-solo: No reaction. Acddents:
2. Ora.shes: 2, one himself and one with instructor;
bumped nose. Benched or set on ground: No.
Hours of overseas flying: 13. Combats: No.
Credits: No. Shot down: No. Prisoner: No,
IV. Physical examination.-Height, 70; weight, 180.
Appearance, robust; pupils, normal. Secondary
dilatations, none. Knee jerks, normal. Tic, no.
Tremor, fingers. Psychomotor tension, increased ,
cannot relax. Dermographia, good, begins to clear
in 40 seconds. Condition peripheral circulation,
good. .
V. Personality study.-Good physical type; somewhat
nervous; slow; tendency to be a li.ttle sullen.
-Remarks.-A verage type, should be watched for ner­vous
break if under heavy strain.
Rating.-"C."
PERSONALITY RECORD,
[Hazelhurst Ficld, Mineola, Long Island, N. Y.J
Name, ---; age, 24; single; first lieutenant. French­English.
A. S. A.
I. Family history.-Negative.
II. Personal history.-Always strong, except lately has
not felt well. Disease: Childhood . Injuries, op­erations:
Wounded in hand and l~g, slight. Edu­cation:
Graduate of university, A. B. degree.
Athletic training: Basket and base ball. Dex­terity:
Pool, billiards, tennis. Occupation civil
life: Journalist. Favorite amusement: Motor car.
Tobacco: Yes. Alcohol: No. Eating: Poor.
Sleeping: Poor. Dreams: Wild, terrifying, aerial
combats, etc. Attitude of family: Mother does not
like flying.
i:II. Aviation record.-Enlisted May 10, )917, at Fort
Riley; Infantry. Transferred to aviation. Ground
school: Toronto, July to November. Repeats:
None. Training: Toronto and Fort Worth. Total
flying hours, 400. Maximum altitude, 22,000; dura­tion,
10 minutes. Reasons for aviation: Sport.
Reaction to 1-2- 3-solo: Had forced landings first
three solos, but landed safely and since then no
fears at all. Accidents: 4; Slight cuts and bruises.
Four crashes. Benched or set on ground: No.
Hours of flying overseas: 200. Combats: 20.
Credits: 2. Shot down: Yes. Prisoner: No.
IV. Physical examination.-Height; 69 inches; weight,
136. Appearance, slender. Pupils, normal. Sec­ondary
dilatation, none. Knee jerks, normal. Tic,
none. ,Tremor, slight, fingers. Psychomotor ten­sion,
normal. Dermographia, good, · fades at 120
seconds. Condition peripheral circulation, good.
V. Personality study.~Excellent type, but very stale,
frank and self confident, ~eady, serious.
Remarks.~This man is very stale. Good control,but
manifest visible effort, needs long rest.
Rating.-" B" (E temporary).
.PERSONALITY RECORD.
[Hazelhurst Field, Mineola, Long Island, N. Y.]
Nam~,---; age, 33; single, Second Lieutenant.
American. A. S. A.
I. Family history.~Mother died of lung trouble.
II. Perscmal history.-Always strong. Diseases: Measles,
smallpox, mumps, chickenpox, malaria. Injuries,
operations: Varicocele. Education: High school
30
None; never nervous. Accidents: None. Crashes:
None. Benched or set on ground: None. Hours
of flying overseas: None. Combats: None. Cred­its:
None. Shot down: No. Prisoner: No.
and one year college. Athletic training: Gym ·
work, one year in Army. Evidence of manual
dexterity: Pool, tennis, billiards. Occupation in
civil life: Construction engineer. Success: Yes.
Favorite amusement: Gymnasium and swimming.
Alcohol: No. Tobacco: No. Eating: Good.
Sleep: Good. Dreams: Yes, pleasant. Attitude
of family: Favorable.
lV. Physical examination.-Height, 69inches, weight 142.
CII. Aviation record.-Enlisted October 6, 1917. Fort
Sam Houston, A. S. A. Ground school: Austin,
December 29 to March 9, 1918. Repeats:No.
Training: Ellington Field, April 1 to September 6.
Commissioned, August 26. Total flying hours: 70.
Maximum altitude, 12,000 feet; duration, 5 minutes
Reason for aviation: Sport; reaction to 1- 2-3-solo:
Appearance, slender. Pupils, normal. Secondary
dilatations, none. Knee joints, diminished. Tic,
no. Tremor, slight, tongue. Psychomoter ten­sion,
excl')llent, no tension. Dermographia, good,
fades in 105 seconds. Condition peripheral circu­lation,
good.
V. Personal study.-Steady, self-possessed, serious, well­balanced,
intelligent, deliberate, excellent type.
Rating .-"A."
,PART 3.
THE EFFECTS OF SMOKING ON VISUAL ACUITY.
MEDICAL RESEARCH LABORATORY, MINEOLA, LONG ISLAND, N. Y.
H. L. UNDERWOOD, Captain, Medical Corps, and PRENTICE REEVE!' , First Lieutenant, Sanitary Corps.
In a preliminary experimental study of the general
effects of smoking ,on circnlation, retinal sensitivity, ac­commodation,
convergence and visual acuity Underwood 1
obtained some results that tended to show a measurable
effect on visual acuity. 1n his experiment Snellen test
type was found to be unsatisfactory and the Ives visual
acuity test object was used. The test object was operated
by the experimenter at a distance of 20 feet from the
observer, and readings were taken at the instant the
observer first perceived striation as the spacing of the lines
was increased. After a short practice series visual acuity
was recorded at two minute intervals and the observer then
started smoking, during which readings were taken at four
minute intervals. In some cases a control experiment,
i.e., without smoking, was also given at a different time to
compare with the smoking experiment. It was found that
two cigarettes when inhaled produced about the same
result as one cigar, except that the cigarettes acted much
faster. Underwood found that in the vast amount of Ii tera­ture
on tobacco, i:,o references could be found to experi­mental
work on the influence ofsmoking on visual acuity.
.As the visual acuity test was only a part of Underwood's
investigation and some changes in the method of its appli­cation
were found to be advisable, it was decided to con­tinue
the work with exclusive attention to visual acuity.
The same type of test object was t..sed except that the one
later used had a scale with finer gradations. This was
desirable a.s many of Underwood's results showed the neces­sity
of greater accuracy in reading. When the experi­menter
controlled the distance between the lines of the
test object it was necessary for-the observer to perceive the
lines and call out, and then for the experimenter to etop
and read the scale. As the visual threshold is unstable and
not to be accurately determined by any one reading, it was
thought expedient to allow the observer, in the later work,
to manipulate the test object himself. To do this the
distance was decreased to 2 meters and the observer oper­ated
the gratings by means of a small hand wheel belted
to the movement of the test object. A. headrest was used
to fix the distance between observer and test object. To
exclude all light not used in the experiment the ap­paratus
was set up -and used in a dark room. The test
object was viewed through an opening in a white screen
illuminated to a brightness approximately that of the
stimulus, i,o as to condition the adaptation of the observ­er's
retina. Binocular vision was used by all observei:B
during the tests.
The observers were tested by the Snellen test type and
those whose vision was below normal, and who were not
wearing glasses, were corrected from the trial case ; and
these few who,wore glasses used their correction during the
experiment.
The observer waa seated at the apparatus, the headrest
adjusted and the mechanism for changing the lines ex­plained.
A preliminary series was given .to familiarize
him with the experiment and to instruct him in the cri­terion.
The experimenter set the gratings so the lines
were not visible at 2 meters and the observer then increased
the distance between lines until he just perceived them.
The experimenter recorded the scale reading, set the grat­ings
so the lines were plainly visible and the observer de­creased
the distance until the lines just disappeared. This
reading was recorded and the average of the two readings
constituted one result,. After a little practice six such
results were taken at 2-minute intervals. This period of
the experiment will be here called the foreperiod. The
observer then began smoking and results were taken at 3-
minute intervals in the smoking period. The average
smoker consumed a cigar or two cigarettes in about half an
hour .in the test so a standard smoking period was adopted.
This consisted of 10 results taken while smoking. A series
of six resultB was also taken after smoking and recorded as
the afterperiod. With most observers a control test was
given in which the observer did not smoke at all, but in
which readings were taken at the same intervals, with the
fore, smoking, and after periods. Thi!! control experiment
was given to most observers at practically the same time of
day and under the same conditions as far as possible. The
observers were members of the laboratory staff, flying offi­cers,
and convalescent patients from the hospital in
Mitchel Field. As the first group were mostly trained in
laboratory methods it was considered essentir.J to separate
the groups. The results where one medium-strong cigar
was smoked are recorded as follows: Table I, members of
the staff (with controls); Table II, patien~ (witli con­trols);
Table_ IIIA, two staff members and eight flying offi­cers
without controls and IIIB patients without controls.
The resultB from smoking two cigarettes are shown in Table
IV. The observers are divided into heavy, moderate, and
light smokers. The tables show the averages, mean-varia­tions,
and per cent variations for the fore, smoking, and
a.fter periods for the smoking and control experiments. In
Tables I and II the first result is the smoking experi­ment
and the second the control.
If we compare the averages for the three periods in the
smoking experiment and the three in the control we are
able to see the variations within each experiment. This
variation in the smoking test will include any effect that
1 Underwood, Capt. H. L. Visual and General Effects of Tobacco (a preliminary study). An unpublished report from the Medical Research
Laboratory.
(31)
32
TABLE I.
Fore period. Smoking period. After period.
Mean Percent Mean Per cent Mean Percent
Average. varla- mrla- Average. varla- varla- Average. varla- varla-tlon.
tlon. tion. t lon. t lon. tlon.
------- --------------- - -
1. Moderate smoker •. .. . . ... ... . . . .. . . . .. . . .. . .. ... 344 13.0 3.8 377 24.0 6.5 36& 9. 7 2.7 ----------- 425 28.9 6.8
2. Heavy smoker . . .... ... . .. .... ... .. . . . . . . . . .. .... 410 6. 7 1.6 373 :ll.7 5.5 414 12.2 2.9
405 2. 7 . 7 410 8.0 1.9 408 6.8 1.6
3. Moderate smoker ... . . . .. . ........... .. . .. ... .. . . 422 10.7 2.5 413 9.9 2.4
490 10.0 2.0 496 16.0 3.2 - ---
506 16.5 3.3 539 ~.8 3.7 544 11.6 2.1
592 9.9 1.8 586 2.3 .4 588 2.7 . 4
4. Heavy smoker .. •••. . . .. .... •. . ... . . . . ... .. ... ... 404 2.4 .6 386 10.4 2.7 387 7.9 2.0
410 4.7 1.1 410 5.2 1.3 403 5.0 1.2
5. Light smoker .. ... . . . .. . . . ... ... ... . ... . ......... 1455 13.8 3.0 457 8.6 1.9 470 6.6 1.4
405 7.3 1.8 418 2.8 .7 424 4. 7 1.8
6. Heavy smoker . ••.• . .......•• .. .. . ... . . . .... . . ... 386 7.0 1.8 371 12.3 3.3 379 9. 7· 2.6
394 7.8 2.0 383 7.6 2.0 385 9.1 2.4
374 7.2 1.9 389 7.9 2.0 400 3.6 .9
398 6.6 1. 7 400 6. 2 1.5 397 6.0 1.5
442 8.3 1.9 448 12.8 2.9 445 6.2 1. 4
435 5. 7 1.4 439 8.3 1.9 421 9.0 2.1
7. Heavy smoker .... ..• .• ..• .. . . . . . . .. . .• .. • . . . . .. • 418 10.2 2.4 418 11.9 2.8 409 5.0 1.2
409 8.2 2.0 425 5.4 1.3 430 5.0 1.1
1500 28.3 5.7 487 9.8 2.0 460 9.8 2. 1
517 13.3 2.0 519 7.1 1.4
8. Heavy smoker . ... . . .. .. .. .... . ..... . ...... . .. .. . 422 14.3 3.4 412 17. 4 4.2 401 5.2 1.3
468 6.8 1.5 462 7.8 1. 7 476 3. 7 .8
9. Heavysmoker . . .. . •. ...... .. . .. . .. . .. . ..•. .. .. . 389 8.2 2.1 412 15.1 3.7 385 6. 2 1.6
450 8.0 1. 7 461 13.1 2.8 449 4.0 .8
10. Heavy smoker .. ... . ... ... . .. .. . .. ... ... . ... . .. . 373 3.0 .8 4~ 21.3 5.1 424 11. 7 2.8
438 10.3 2.4 466 16.5 3. 5 453 14. 7 3.2
11. Light smoker .••... . . ... . . .. .. .. . .. . .. ... ... .. .. 407 4.8 1.2 410 13.l 3.2 402 15.9 4.0
421 10.0 2.3 424 9.0 2.1 40.. 12.0 2.9
12. Heavy smoker .. ... .. .... . .. ... . ... . .. . . ..... . . . 396 8.3 2.1 429 26.0 6.1 413 15.3 3. 7
498 33.0 6.0 !'iYl 59.0 11.6 551 31. 4 5. 7
13. Moderate smoker . . .. ... .... . ....... ... ...... .. . 484 5.0 1.0 518 18.3 3.5 533 8.7 1.6
622 7.7 1.2 638 4.7 .7 631 4.3 .7
1609 3.0 .5 606 10.2 1. 7 616 6.5 1.1
535 13.8 2.6 560 8.9 1.6
14. Heavy smoker . .... . .... . . . . .... . . . .. ... ... . .. .. 389 15.6 4.0 390 16.9 4.3 392 10.0 2.5
421 7.5 1. 7 427 10.2 2.3 422 9.7 2.0
1 The control was given fust In these cases.
NoTE .. -The reading of the scale on the ·test object divided by 268 gives Snellen units, and 258 divided by the scale reading represents
minutes of visual angle.
33
TABLE II.
Fore period. Smoking period. After period.
Mean Per cent I Mean Per cent Mean Per cent
Average. varla- varia- Average. varia- varia- Average. varia- varia-tion.
tlon. · tion. tlon. tion. tion.
- -------------- --- ---------- --- --------------
1. Light smoker ............ . ...................... 468 8.3 1.8 451 13. 4· 2.9 446 8.3 1. 9
417 1. 7 · .4 425 7.6 1. 7 423 ------
2. Light smoker- ..... . . . . ... . ........ . .. .. .... -- - - 295 3. 7 1. 2 312 12. 2 4.0 281 3.0 1. 1
311 3.6 1.0 410 6. 2 1:5 381 7.0 1.8
? Heavy smoker .. ... _ .... . . . __ ...... . . . . ...... ... 471 18.6 4.0 429 15. 7 3. 7 410 13. 2 3. 2
401 9.3 2.0 479 9.1 1. 9 472 13. 5 92.8
4. Light smoker . . ... · . ........ ...... . ..... ... ... ... 364 10.0 2.8 344 17.7 2.0 310 4.8 1.5
410 6.8 1. 7 430 10.8 2.5 4:itl 12.3 2.9
5. Moderate smoker ... .. _ . .......... . _._ . .. .... . . ·1 367 I 7.4 2.0 381 9.5 2.5 355 4.8 1.4
344 9.0 2.5 373 13.6 3. 7 364 9.6 2. 7
6. Moderate smoker . . ..... .. _ ... _ . . . . .... .......... 386 14.5 3.8 408 13.6 3.3 397 14. 7 3. 7
420 30.0 7.1 420 11.3 2. 7 408 1. 0 .2
7. Light smoker ........ . . . .. .. ·.· .................. 383 13. 7 3.6 402 . 21.3 5.0 373 5.6 1.5
427 5.0 1.2 434 8. 4 1.9 425 11. 2 2, 6
8. Light smoker . . ... , .... . ................. ...... . 423 5.8 1.3 434 11.0 2.5 431 8. 7 2.0
418 4.2 1. 0 412 11.0 2.6 411 5.0 1.2
9. Moderate smoker. ...... _ . . . . .. _ . . . _ . . . __ ._ . .. .. 439 11.0 2.5 473 31. 1 6.6 457 7.8 1. 7
425 -7.5 1. 7 478 21. 9 4. 463 14.5 a.1
10. Moderate smoker .... .. . . ·--·-··············· · ·· 403 8.2 2.0 413 4. 7 1. 1 403 5. 4 1. 4
397 12.5 3. 1 429 5. 7 1.4 123 5. 2 1. 2
11. Heavy smoker . . ......... . ···· • · ····· ·· 337 4.2 1. 2 351 8.5 2.4 348 3.3 1.0
365 1. 3 '4 388' 10. 2 2.6 407 6. 8 1. 7
12. Heavy smoker .... .. . . __ . . ... . . . . . . _ . .. . . . . .... 397 9.5 2.4 402 ·10.2 2.5 397 6.3 1. n
413 8.3 2.0 417 5. 7 1.1 414 3.0 • 7
13. Moderate smoker . . _ ............ .. . , . . .. . . .. .... 362 9.8 2. 7 400 4.6 1.1 402 1. i . 4
426 6.8 1. 4 417 7.6 1.8 423 7. 7 1.8
14. Moderate smoker . ... .... .. . ................... 409 9.2 2. 2 417 3.5 .8 365 5.5 1.5
382 5. 7 1. 5 397 3. 7 .9 396 1.0 .2
15. Moderate smoker. . .. . . . . ... __ .... . .. ..... ... .. . 375 7. 0 1.9 378 3.6 .9 377 3. 7 1.0
383 4. 7 l. 2 385 4.5 1.1 392 3.8 1.0
16. HP.avy smoker . ..... .. ..... ....... .. . .. 398 4.0 1.0 376 8.4 2.2 387 8.0 2.1
423 5.3 1.3 415 7.0 1.7
402 l 8.6 2.1
17. Moderate smoker: . .•...... . . . . . . . .. ... 406 4.0 1. 0 415 6.5 1.6 422 5.6 1.3
424 9.8 2.3 423 4.1 1.0 422 1.6 .4
606830-31--3
34
TABLE III-A.
Fore period. Smoking period. · After period.
Mean
varia ..
tion.
Percent Mean
varia­tion.
Per cent Mean
varia­tion.
Per cent
varia­tion.
Average. varia- A verago.
tion.
varia- Average.
tion.
- - ------- ---------·!---- ------------ ---- ---- ------------
1. Heavy smoker ............ . . .... . . .. .... ...... .
2. Heavy smoker .. . ........ •. ...... • . ........ ....
3. Heavy smoker ... ............. . ............... .
4. Moderate smoker ...... .. ............... . ..... . .
5. Heavy smoker . ........ . •......................
6. Moderate smoker ..... . .. •.. . .. .. . . . . ...•..... . .
7. Heavy smoker . ...... . ... .. . .. . .. ............. .
8. Heavy smoker •............................ ....
9. Heavy smoker .•.. . •. ............. . ............
10. Moderate smoker ........ ... ..• .... ...... ....•..
508
406
404
445
450
402
289
335
322
378
9.2
6.2
8. 7
14.4
5.0
8. 7
13. 5
2.8
29.5
4.2
1.8
1.5
2.1
3.2
1.1
2.1
4. 7
.8
9.2
1.1
516 14.4
402 10.4
394 8.5
460 16.8
444 14.4
387 ,., I 276 20.6
321 7.1
294 13. 5
386 8.9
2.1 518 9.3 1.8
2.6 403 4.0 I. 0
2.2 397 14. 2 3. 6
3. 6 460 5.0 1.1
3.2 439 3.4 .8
4.2 390 4.3 1.1
7.4 267 3. 0 1.1
2.2 335 3.9 1.2
4.6 292 13. 8 4.6
2.3 350 17.4 5.6
TABLE III-B.
Fore period. Smoking period. After period.
Mean Percent I Mean
Per cent Mean Per cent
varia- varia- Average. varia- varia- Average. varia- varia-tion.
tion. tion. tion. tion. tion.
Average.
--------------- ---------
1. Light smoker ............. . . • ..... .• ............
2. Moderate smoker ....................... ... .. ... .
3. Moderate smoker •....... .. ......................
4. Heavy smoker • .•. . .... .. .......... . ........... .
5. Heavy smoker .. .........•....... . . ... .. ........
6. Moderate smoker . ... ................. .. ........ .
7. Heavy smoker .......... . .. .. ... ... .. ...... ... . .
425
261
368
454
421
394
461
19. 9
3.0
7.0
9.5
10. 7
7. 8
3.0
4.5 443
1.1 261
I. 9 379
2.1 496
2.5 454
2.0 408
.6 475 ·
1. 9 .4 442 .5 0.1
.7 .3 262 1.0 .4
12.0 I 3.2 372 7.0 I. 9
16.0 3.2 492 U.6 2.6
7.9 I. 7 464 5.8 1.3
.5.5 1.3 423 2. 21 .5
5.1 I 1. 1 483 1.8 .4
TABLE IV.
Fore period.
Average.
Mean
varia­tion.
Smoking period. After period.
Per cent Mean
vana- Average. varia­tion.
tion.
Percent M~,an
varia- Average. varia­tion:
tion.
Percent
variar
tion.
------------------ ,,------------------------------------
1. Lignt smoker ............. . ..................... .
2. Moderate smoker ....... ... ................. .... .
3. Heavy smoker ......... ... ..........•.... . .•....
4. Moderate smoker ..... ... ............ . ... .. ... .. .
5. Moderate smoker ......... .. ...... . ............. .
6. Light smoker ..................... , ............. .
7. Light smoker .......•......•............. .• ..... .
8. Heavy smoker . . ................. . . .. ....... . .. .
9. Heavy smoker ......... ... .. .... .. . . .. ... ... .. .. .
426
408
310
309
355
410
409
430
382
410
359
9. 7
14.5
8. 7
8. 7
14.0
13.2
6.5
14.0
1.0
13.3
10.0
may be due to smoking. The variations in the control test
are free from the effect of smoking and the comparison of
the two ,variations will enable us to at least partially de­termine
what effect the smoking may have.
In Table I a continued rise is shown in 6 cases smoking
and in 3 controls; 5 cases smoking and 11 controls show a
rise in the smoking period and a fall .in the afterperiod;
5 smoking and 3 controls show a fall in the smoking period
and 2 smoking cases show a continued decrease. In 5
cases the average during the foreperiod is greater in the
smoking test than in the control, but in 2 of these cases the
controls were given first. In 13 cases the control averages
are greater, the controls being given first in 3 cases and last
in the others. If we exclude those observers whose records
are not complete and take the final averages of the three
periods for both experiments we find that, on the whole,
higher values were obtained in the control experiment.
If, however, we look for differences between fore and
smoking periods and between smoking and after periods
we see that these correspond almost to the point of identity
for both experiments. The final averages for the smoking
experiment are: foreperiod, 417; smoking period, 425; and
afterperiod, 426. These averages for the control are: fore-
2.3
3.5
2.8
2.8
3.9
3.2
1.6
3.2
.3
3.2
.2.8
390
405
350
319
362
383
394
450
40\l
401
358
14.0
8. 3
6.9
4.4
17.3
17.5
9.1
11. 0
10.3
10. 2
9. 7
3.6
2.0
2.0
1.4
4. 7
4. 5
2.3
2.4
2.5
2.5
2. 7
407 9. 0 2. 2
415 ~- 7 1. o
347 --·----
335 3. 2 1.-0
363 8. 5 2. 3
397 4. 2 1.1
392 ----1----
450 ------
401 5. 0 1. 2
393 6.0 1.5
350 4.0 1.1
period, 451; smoking period, 457; and afterperiod, 456.
If we examine the differences between the averages in the
three periods for both experiments we find the difference
is 5.2 times the probable error in the foreperiod, 6.9 in the
smoking, and 5.3 in the afterperiod.1
In the smoking test the mean variation rises during the
smoking period then falls again during the afterperiod in
15 cases, remains the same in 1 case, continues to rise in 1,
continues to fall in 1, and falls then rises in another. In
the control test the mean variation rises then falls in 7
cases, rises then remains sa;me in 2, continues to rise in 1,
falls and remains same in 4, falls then rises in 2, continues
to fall in 1, and remains same then rises in 1.
In Table II a continued rise is shown in 2 cases control;
3 cases in each show,a continued decrease; 12 cases smok­ing
and 10 cases control show a rise then fall; 1 case each
fall then rise; and 1 case control remain same then falls.
The difference between the foreperiod averages in the two
experiments shows smoking greater in 7 and less in 10
cases and the smoking test was given first to all observers.
These differences were 3.8 times the probable error in the
foreperiod, 7.2 in the smoking period, and 8.4 in the after­period.
The mean variation rises during the smoking
'It is customary in treating such data to consider a difference which is 5 or more times the probable error as not being due to chance, and
hence dependent on some factor within the test. (See page 14, C. B. Davenport, Statistical Methods (3rd rev. ed.) New York, John Wiley & Sons.)
35
period .and then falls in the afterperiod in 10 caBes smoking
and 4 control, 3 smoking and 6 control continue falls, 4
smoking and 1 control falls then rises, 4 control cases con­tinue
rising, 1 case rises then remains the same, and 1 case
falls then remains the same. The final averages for the
smoking experiment are: Foreperiod, 388; smoking period,
396; and afterperiod, 382. For the three periods in the
control experiment the averages are 405, 419, and 414,
respectively.
Table III-A, in 1 case the average continues to increase
from fore to smoking to after period, 3 cases continue de­crease,
1 rise then fall, 4 fall then rise, and 1 case rises then
remains the same. In 7 cases the mean variation rises in
the smoking and falls again in the afterperiod, 2 cases con­tinue
to rise and 1 falls then remains the same. The final
averages for the fore, smoking, and after periods are 394,
388, and 385.
Table III~B, 3 cases continue increase, 3 cases rise then
fall, and 1 case remain8 the same then a slight rise. In the
· mean variations 3 caBes rise then fall, 3 cases continue to
fall, and 1 case falls then remain8 about the same. The
final averages are: foreperiod, 398; smoking period, 417;
and afterperiod, 420.
Table IV, 2 cases continue increase, 3 cases continue
decrease, 2 cases rise then fall, and 2 caBes fall then rise.
In 4 cases the mean variation rises then falls, 3 cases con­tinue
to fall, and in the other cases the afterperiod was not
recorded. The final averages are: foreperiod, 379; smok­ing
period, 375; and afterperiod, 378.
In interpreting the results from such an experiment one
should advance only with caution, as so many uncontrol­lable
factors enter all visual threshold determinations.
When the average of the smoking period is greater than the
foreperiod and the afterperiod shows a fall from the smok­ing
period we might say smoking caused a rise in visual
acuitiy which disappeared after the completion of the cigar.
The same changes, however, could also be explained by
practice and fatigue and we do find the same changes
occurring in the control tests. A fall in the smoking
period might be interpreted as a depression due to smoking,
but could also be fatigue. Continued rise is typical of
practice and continued decrease typical of fatigue. The
magnitude of some of the changes found is small enough to
come well within the range of chance variation and we
find approximately the same range in both the smoking
and control tests. If all results of all observers in each
period are averaged we find ve:ry slight differences be­tween
the separate periods. The differences between the
foreperiods of the smoking and control tests are due to
factors outside of any influence of smoking and may be
accounted for by the observers becoming familiar with the
apparatus or changing their criterion of visibility. As
almost all of the observers show an increased acuity in the
test give.n second we may assume _a practice effect, but
that practice is not the only factor is shown by comparing
the results of observers 3, 6, 7, and 13 in Table 1.
One of the greatest difficulties encountered in this work
is that most of the observers are habitual smokers and are
never free from any such effects as smoking may have.
This makes a control test, in the strict sense of the word,
almost impossible. Another objection to the experiments
as conducted is the chance of fatigue entering even during
the separate observatim;is when the observer manipulates
the gratings. Untrained observers are apt suddenly to
change their criterion of judgment as to visibility and in­visibility
and th.is makes their records uncertain and often
ambiguous. A further question arises, and this inde­pendently
of the results shown in these experiments. The
question in regard to the effect of tobacco, as it practically
relates to the military aviator, is not adequately answered
when it is shown how vision is modified in the course of an
hour during and after a single smoke. Such clinical dis­turbances,
both of vision and of other bodily functions,,,as
have been ascribed by medical men to the use of tobacco
have been held to be the result of long-continued use of the
drug. Apart from these graver functional and anatomical
disturbances there is a possibility that functional depres­sion,
short of anything that might be held to threaten per­manent
disability, could result from the continued smok­ing
and become fatal to the flier by reason of the exacting
requirements of his work. Such effects could not, obvi­ously,
be shown by a course of testing that extends only
over the course of one or two hours' time.
Owing to the fact that this work was begun in war time
and completed in the unsettled period of transition imme­diately
following, it was not possible to retain subjects
under a course of testing long enough to elicit and measure
such possible long-time effect,a. In order to obtain the
most satisfactory results one should have observers for a
long period of time and a large number of tests should be
given over the entire range of time. Nonsmokers should
be tested thoroughly and then started smoking so as to be
tested after becoming smokers. Regular smokers shonld
be tested before and after abstaining from smoking. Both
groups should be practiced in preliminary tests until that
effect could be neglected and special precautions should
be taken against fatigue. The method of instantaneous
exposure would probably be satisfactory, although the
time required would be considerable. To eliminate the
accommodative fll,ctor the observer should be 6 meters
from the test object. The precautions as to retinal adapta­tion
as used in this work are probably sufficient. All light
sources should be controlled by means of a rheostat and a
voltmeter or ammeter.
From the results 9f this work it is seen that the light
smokers (some of whom were really nonsmokers) show no
greater effects from the amount of smoking given than the
moderate or heavy smokers. (The small nll.lLber of light
smokers does not justify a numerical summation of those
results.) Only a few of the total number of cases show any
marked effect on their visual acuity that might be attrib­uted
to smoking, and the liability of practice and fatigue as
factors makes any definite statement very difficult to give.
The mean variation does rise in most cases with smoking
and this indicates less stability with smoking than with­out.
It is not probable that more observers in this test
would throw more light on the problem, but it is believed
to be worth while to repeat the work under the controlled
conditions as mentioned above.
The writers wish to acknowledge the valuable assistance
of Capt. P. W. Cobb and Capt. H. M. Johnson and to thank
the observers for serving during the e,i:periments.
PART4.
A DEVICE ADAPTINC THE BARANY CHAIR TO REBREA THER TESTS.
MEDICAL RESEARCH LABORATORY, AIR SERVICE, MINEOLA., "LONG ISLAND, N. Y.
MA.x M. ELLIS, First Lieutenant, Sanitary Corps, and CARL N. LARSEN, First Lieutenant, Medical Corps.
With a view to making the Barany chair available for
tests while the subject breathed air of low ·oxygen tension
equivalent to that of the air at high altitudes at -which
aeroplanes are frequently flown, a brass delivery head was
devised.
When ready for use, enough heavy oil (a mixture of two
parts Russian mineral oil and one part castor oil was found
satisfactory) is poured into the lower casting to cover the
bottom to a depth of three-quarters of 9;n inch. The two
brass tubea opening into the chamber of the lower casting
This brass delivery head consists essentially of two
shallow, cylindrical, telescoping castings, one of which is
fastened to the stationary base of the Barany chair and
the other to the underneath side of the chair bottom with
which the' casting revolves. Both castings are concentric
to the turning axis of the Barany chair, around which ~xis
they are mounted. The lower casting has one concentric
chamber, into which the upper casting telescopes. The
upper casting, which has a slightly smaller diameter than
the lower, is divided into two .concentric chambers by a
concentric partition. When the two castings are tele­scoped,
the upper casting revolves inside of the lower and
the inclosed air space of the delivery head as a whole is
_ are still one-quarter of an inch above the oil level. The
upper casting, which swings clear of the bottom of the
lower casting by a quarter of an inch, revolves in an oil
B!lal inclosing the air of the delivery head.
divided into two concentric chambers. ·
Projecting upward inside of the chamber of the lower
casting are two three-quarter-inch brass tubes, each 1 inch ,
high. One of these tubes is plac!ld three-quarters of an
inch from the outer margin of the chamber of the lower
casting, and the other tube, diametrically opposite the
first, three-quartel's of_ an inch inside of the inside -margin
of the chamber. By this arrangement one of the tubes
opens into the inner chamber of the upper casting and the
other tube into the outer chamber, when the two castings
are· telescoped.
Rubber tubes leading from the two brass tubes on the
underneath side of the lower casting connect the delivery
head with a rebreather or an oxygen spirometei. Two
gas-mask tubes leading from the t:wo tubes in the · top· of
the upper casting connect the delivery -head with · tli.e.
mouthpiece used by the subject.
At the beginning of an experiment the subject is seated
as usual in the Barany chair. On placing the mouthpiece
in his mouth and a nose clip on his nose he. is forced to
breathe air through the delivery head. His expired air
passes down the right tube through the outer chamber of
the delivery head int,o the right side of the rebreather.
Air returp.s to the subject through the left side of the
rebreather, the inner ,chamber of the delivery head, and
the left gas-mask tube. This circulation of air is main­tained
by the flutter valves of the rebreather, which pre­vent
a back flow of the air inside of the rebreather-delivei:y
head system. · _
During the whirling tests on the Barany chair the re• ·
volving chair bottom carries the subject, mouthpiece, g~­mask
tubes, and upper casting of the delivery -head,
while the lower casting of the delivery head remains sta­tionary
on the chair base. As the cubic contents of the
outer and inner chambers of the delivery head are not
altered by the revolution of the upper casting, because of
the concentric nature of the chambers and the heavy oil
seal protecting them from contamination with outside air
the respirations of the subject continue uninte~ptedl;
through the rebreather-delivery head system.
Two brass tubes three-quarters of an inch in diameter
perforate the upper casting, one opening into the inner
chamber and the other into the outer chamber of that
casting. These two tubes, however, do not project be­yond
the casting and into the chamber space as do those
of the lower casting. The closed delivery head is connected
with the outside when the two castings are telescoped by
four tubes, therefore,. two in the bottom casting and two
in the upper casting, one pair for the inner chamber and
one pair for the outer chamber.
This device has been used successfully in rebreather
tests and during exposure to air of low oxygen tension.
(36)
A-
----E
--F
--G
---A
------.D
Figure 1.-Diagrams of upper and lower castings of the delivery head, inside view. Left-hand drawing, upper casting; right-hand 'drawing, lower casting.
A-Inlet tube.
A'-Outlot tube.
B -Axle of Bara.ny chair.
B'-Bearlng o!axle.
C -Leg ofBarany chair.
D -Underside of bottom of chair.
E -Outerchamberofuppercast-
!ng.
F -Concentric partition of upper
casting.
G -Inner chsmber of upper cast­ing.
H -Chamber of lower casting.
I -Gas-mask tube from the mouth·
piece.
I'-Gas-mask tube to the mouth•
piece.
J -Tube to the re breather.
J'-Tube from the rebreather.
K-Oillevol.
L-Supports of upper casting.
~ e ~
I t I I I'---- ----1 I I
I II L;----- ---·L
A--- ... --Ii,.
F--- ---E
K--- ---G i:;;.,
--H 00
I t
I I I
AI AI t ---A'
'· J'----
_. _...,
.;v,: W. If, •11~1.,,-r #u.
Figure 2.-Side views of the delivery head. Left-hand drawing, sectional diagram; right-hand drawing, delivery head in place on the Barany chair.
PART 5.
PSYCHOPATHOLOGY UNDER LOW OXYGEN TENSION.
ENGLISH BAGBY, Ph. D., First Lieutenant, Sanitary Corps, Medical Research Laboratory.
No feature of the flight surgeon's work is more important
than the prompt detection of psychopathic traits as they
develop in the flyers under his care. An unstable mental
condition adds v.ery materially to the danger of flying in
tending to produce a state of confusion and helplessness
in moments of crisis in the air. Further than this, "ner­vous"
tendencies are usually regarded as symptomatic of
"staleness," a serious condition to which the streE;S of
aviation is especially liable to give·rise. Unfortunately,
the mental features of staleness are rather obscure and
not · readily observed, and the flight surgeon must avail
himself of special assistance in their detection.
The psychologists of classification units are in a position
to give especially effective aid in this connection, since
they observe the behavior of the flyer under conditions
which, in certain essential respects, are not unlike those
of flying. Evidence of emo_tional instability is frequently
discovered, and the flight surgeon's attention may be
directed to such cases as require a thorough medical exam­ination.
In order that the flight surgeon may make most
effective use of the unit psychologist, it is necessary that
he know not only the nature of the phenomena which the
psychologist observes, but he must also have a clear con­ception
of the psychological attitμde- toward mental
disease. This attitude is not clinical, and the psycho­logical
method of recording the data of observation is
therefore not familiar to the average physician. Since the
matter is one of such great practical importance, an ex­position
of the psychological view is not out of place.
This exposition will be given in rather greater detail than
the present necessity requires in the hope that the view
will be of some general value to those of psychiatric inter­est.
A preliminary discussion of normal mental activity
is of necessity included.
THE PRESENT STATUS OF PSYCHOLOGY.
At the present time there is considerable difference of
opinion among psychologists regarding the most furida­men
tal features of their science. This lack of agreement
extends even to the question of the proper material of
psychological study. One group forming the "Struc­tural"
school (1),1 takes as its problem the analysis and
description of mental states as such, without reference to
behavior. Another group (2), investigates the problem of
mental development through the application of menta!
tests. A third gro