THE OFFENSIVE USE OF GAS
WHAT CHEMICAL WARFARE INCLUDES
Chemical Warfare includes all gas, smoke and incendiary materials and
all defensive appliances, of which the mask is the principal item, used
by the Army. Some of the items or materials in both offense and defense
are used by the entire Army, while a few are used only by Chemical
Warfare troops.
THE TERM “GAS”
The term “gas” is now taken to include all materials that are carried
to the enemy by the air, after their liberation from cylinders, bombs
or shell. It is necessary that this broad use of the term “gas” be
thoroughly understood, because some of these materials are solids,
while all others are liquids, until liberated from the containers at
the time of the attack. These containers may be special cylinders for
cloud gas attacks, special bombs for Livens’ projectors and mortars,
or artillery shell, and even aviation bombs. Some of the liquids which
have a very low boiling point volatilize quickly upon exposure to air,
and hence require only enough explosive to open the shell and allow the
liquid to escape. Practically all solids have to be pulverized by a
large amount of high explosive, or driven off as smoke by some heating
mixture.
TECHNICAL NATURE
Chemical warfare, besides being the newest, is the most technical and
most highly specialized Service under the War Department. There is
no class of people in civil life, and no officers or men in the War
Department, who can take up chemical warfare successfully until they
have received training in its use. This applies not only to the use of
materials in attack, but to the use of materials for defense. Ten years
from now perhaps this will not be true. It is certainly hoped that it
will not be. By that time the entire Army should be pretty thoroughly
trained in the general principles and many of the special features
of chemical warfare. If not, chemical warfare cannot be used in the
field with the efficiency and success with which it deserves to be
used. Furthermore, it is believed that within ten years the knowledge
of the gases used in chemical warfare will be so common through the
development of the use of these same materials in civil life, that it
will not be so difficult, as at the present date, to get civilians who
are acquainted with Chemical Warfare Service materials.
EFFECTIVENESS OF GAS
Chemical warfare materials were used during the war by Chemical Warfare
Service troops, by the Artillery and by the Infantry. In the future
the Air Service and Navy will be added to the above list. Chemical
warfare, even under the inelastic methods of the Germans, proved one
of the most powerful means of offense with which the American troops
had to contend. To realize its effectiveness we need only remember
that more than 27 out of every 100 casualties on the field of battle
were from gas alone. Unquestionably many of those who died on the
battlefield from other causes suffered also from gas. No other single
element of war, unless you call powder a basic element, accounted for
so many casualties among the American troops. Indeed, it is believed
that a greater number of casualties was not inflicted by any other arm
of the Service, unless possibly the Infantry, and even in that case it
would be necessary to account for all injured by bullets, the bayonet,
machine guns and hand grenades. This is true, in spite of the fact
that the German was so nearly completely out of gas when the Americans
began their offensive at St. Mihiel and the Argonne, that practically
no gas casualties occurred during the St. Mihiel offensive, and only a
very few until after a week of the Argonne fighting. Furthermore, the
Germans knew that an extensive use of mustard gas against the American
lines on the day the attack was made, and also on the line that marked
the end of the first advance a few days later, would have produced
tremendous casualties. Judging from the results achieved at other times
by an extensive use of mustard gas, it is believed that had the German
possessed this gas and used it as he had used it a few other times,
American casualties in the Argonne would have been doubled. In fact,
the advance might even have been entirely stopped, thus prolonging the
war into the year 1919.
HUMANITY OF GAS
A few words right here about the humanity of gas are not out of
place, notwithstanding the Army and the general public have now so
completely indorsed chemical warfare that it is believed the argument
of inhumanity has no weight whatever. There were three great reasons
why chemical warfare was first widely advertised throughout the world
as inhumane and horrible. These reasons may be summed up as follows:
In the first place, the original gas used at Ypres in 1915 was
chlorine, and chlorine is one of a group of gases known as
suffocants—gases that cause death generally by suffocating the patient
through spasms of the epiglottis and throat. That is the most agonizing
effect produced by any gas.
The second reason was unpreparedness. The English had no masks, no
gas-proof dugouts, nor any of the other paraphernalia that was later
employed to protect against poisonous gas. Consequently, the death rate
in the first gas attack at Ypres was very high, probably 35 per cent.
As a matter of fact, every man who was close to the front line died.
The only ones who escaped were those on the edges of the cloud of gas
or so far to the rear that the concentration had decreased below the
deadly point.
The third great reason was simply propaganda. It was good war
propaganda to impress upon everybody the fact that the German was
capable of using any means that he could develop in order to win a
victory. He had no respect for previous agreements or ideas concerning
warfare. This propaganda kept up the morale and fighting spirit of the
Allies, and was thoroughly justifiable upon that score, even when it
led to wild exaggeration.
The chlorine used in the first attack by the German is the least
poisonous of the gases now used. Those later introduced, such as
phosgene, mustard gas and diphenylchloroarsine are from five to ten
times as effective.
The measure of humanity for any form of warfare is the percentage of
deaths to the total number injured by the particular method of warfare
under consideration.
=American Gas Casualties.= The official list of casualties in battle as
compiled by the Surgeon General’s office covering all cases reported up
to September 1, 1919, is 258,338. Of these 70,752, or 27.4 per cent,
were gas casualties. Also of the above casualties 46,519 resulted in
death, of whom about 1,400 only were due to gas. From these figures it
is readily deduced that while 24.85 per cent of all casualties from
bullets and high explosives resulted in death, only 2 per cent of those
wounded by gas resulted in death. That is, a man wounded on the battle
field with gas had twelve times as many chances of recovery as the man
who was wounded with bullets and high explosives.
FUNDAMENTALS OF CHEMICAL WARFARE
Before taking up in some detail the methods of projecting gas upon the
enemy, it is very desirable to understand the fundamentals of chemical
warfare, in so far as they pertain to poisonous gases. Following the
first use of pure chlorine all the principal nations engaged in the
war began investigations into a wide range of substances in the hope
of finding others more poisonous, more easily produced, and more
readily projected upon the enemy. These investigations led to the use
of a large number of gases which seriously complicated manufacture,
supply, and the actual use of the gases in the field. Gradually a more
rational conception of chemical warfare led both the Allies and the
enemy to restrict the numbers of gases to a comparative few, and still
later to divide all gases into three groups. Thus the German divided
his into three groups known as (1) Green Cross, the highly poisonous
non-persistent gases, (2) Blue Cross, or diphenylchloroarsine,
popularly known as sneezing gas, and (3) Yellow Cross, highly
persistent gases, such as mustard gas. In the American Chemical Warfare
Service we have finally divided all gases into two primary groups.
These groups are known as “Non-persistent” and “Persistent.” The
“Non-persistent” gases are those quickly volatilizing upon exposure
to the air, and hence those that are carried away at once by air
currents, or that in a dead calm will be completely dissipated into
the surrounding air in a few hours. If sufficient high explosive be
used to pulverize solids, they may be used in the same way, and to a
large extent certain highly persistent liquid gases may have their
persistency greatly reduced by using a large amount of high explosive,
which divides the liquid into a fine spray. The “Persistent” group
constitutes those gases that are very slowly volatilized upon exposure
to the atmosphere. The principal ones of these now used or proposed are
mustard gas and bromobenzylcyanide. For purposes of economy, and hence
efficiency, certain gases, both persistent and non-persistent, are
placed in a third group known as the “Irritant Group.” These gases are
effective in extremely low concentrations against the lungs and other
air passages, or the eyes. Diphenylchloroarsine, and some other solids
when divided into minute particles by high explosive or heat, irritate
the nose, throat and lungs to such an extent in a concentration of
one part in ten millions of air as to be unbearable in a few minutes.
The tear gases are equally powerful in their effects on the eyes. The
irritating gases are used to force the wearing of the mask, which in
turn reduces the physical vigor and efficiency of the troops. This
reduction in efficiency, even with the best masks, is probably 25 per
cent for short periods, and much more if prolonged wearing of the mask
is forced.
EFFICIENCY OF IRRITANT GASES
One pound of the irritant gases is equal to 500 to 1,000 pounds of
other gases when forcing the wearing of the mask alone is desired. The
great economy resulting from their use is thus apparent. Due to the
rapid evaporation of the non-persistent gases they are used generally
only in dense clouds, whether those clouds be produced from cylinders
or from bombs. These gases are used only for producing immediate
casualties, as the necessary amount of gas to force the enemy to
constantly wear his mask by the use of non-persistent gases alone could
not possibly be taken to the front.
Mustard gas, which is highly persistent and also attacks the lungs,
eyes and skin of the body, may and will be used to force the wearing
of the mask. It has one disadvantage when it is desired to force
immediately the wearing of the mask, and that is its delayed action
and the fact that it acts so slowly, and is usually encountered in
such slight concentrations that several hours’ exposure are necessary
to produce a severe casualty. For these reasons the enemy may often
take chances in the heat of battle with mustard gas, and while himself
becoming a casualty, inflict quite heavy casualties upon opposing
troops by continuing to operate his guns or rifles without masks. A
powerful tear gas on the other hand forces the immediate wearing of the
mask.
MATERIAL OF CHEMICAL WARFARE USED BY C. W. S. TROOPS
Chemical warfare troops, in making gas attacks, use cylinders for the
cloud or wave attack, and the Livens’ projector and the 4-inch Stokes’
mortar for attacks with heavy concentrations of gas projected by bombs
with ranges up to a mile. This distance will in the future probably
be increased to 1½ or 1¾ miles. The original cylinders used in wave
attacks were heavy, cumbersome and very laborious to install, and
notwithstanding the wave attack was known to be the deadliest form of
gas attack used in the war, fell into disrepute after the use of gas
became general in artillery shells and in special bombs.
=Cloud Gas.= The Americans at once concluded that since cloud gas
attacks were so effective, efforts should be made to make these attacks
of frequent occurrence by decreasing the weight of the cylinders, and
by increasing the portability and methods of discharging the cylinders.
As early as March, 1918, specifications for cylinders weighing not more
than 65 pounds, filled and completely equipped for firing, were cabled
to the United States. They would have been used in large numbers in
the campaign of 1919 had the enemy not quit when he did. Toxic smoke
candles that are filled with solids driven off by heat will probably
be the actual method in the future for putting off cloud attacks. The
toxic smoke candle is perfectly safe under all conditions and can
be made in any size desired. Cloud gas attacks will be common in
the future, and all plans of defense must be made accordingly. They
will usually be made at night, when, due to fatigue and the natural
sleepiness which comes at that time, men are careless, lose their way,
or neglect their masks, and are thus caught unprepared. Experience in
the war proved that a wave attack always produced casualties even, as
several times occurred, when the enemy or the Allied troops knew some
hours beforehand that the attack was coming. The English estimated
these casualties to be 10 or 11 per cent of the troops exposed.
=Livens’ Projectors.= The second most effective weapon for using gas
by gas troops was and will be the Livens’ projector. This projector is
nothing less than the simplest form of mortar, consisting of a straight
drawn steel tube and a steel base plate. As used during the World War
by the Allies it did not even have a firing pin or other mechanism in
the base, the electric wires for firing passing out through the muzzle
and alongside the drum or projectile which was small enough to permit
that method of firing. These were set by the hundreds, very close
behind or even in front of the front line trenches. They were all fired
at the same instant, or as nearly at the same instant as watches could
be synchronized, and firing batteries operated. As discussed on page 18
these mortars were emplaced deep enough in the ground to bring their
muzzles practically level with the surface. It usually took several
days to prepare the attack, and consequently allowed an opportunity
for the enemy to detect the work by aeroplane photographs or by raids,
and destroy the emplacements by artillery fire. It should be added,
however, that notwithstanding this apparent great difficulty, very
few attacks were broken up in that way. Nevertheless, in line with
the general policy of the American troops to get away from anything
that savored of trench warfare, and to make the fighting as nearly
continuous as possible with every means available, the American
Chemical Warfare Service set at work at once to develop an easy method
of making projector attacks.
It was early found, that, if the excavation was made just deep enough
so that the base plate could be set at the proper angle, the drums or
projectiles were fired as accurately as when the projectors or mortars
were set so that the muzzles were level with the surface. The time
required to emplace a given number of mortars in this way was only
about one-fifth of that required for digging them completely in.
Coupled of course with these proposed improvements in methods, studies
were being made and are still being made to produce lighter mortars,
better powder charges, and better gas checks in order to develop the
full force of the powder. Many improvements along this line can be
made, all of which will result in greater mobility, more frequent
attacks, and hence greater efficiency.
=4-Inch Stokes’ Mortar.= The Stokes’ mortar is not different from that
used by the Infantry, except that it is 4-inch, while the Infantry
Stokes’ is 3-inch. The 4-inch was chosen by the British for gas, as
it was the largest caliber that could be fired rapidly and yet be
moderately mobile. Its range of only about 1,100 yards handicapped
it considerably. The poor design of the bomb was partly responsible
for this. The powder charges also were neither well chosen nor well
designed. It is believed that great improvements can be made in the
shape of the bomb and in the powder charge, which will result in much
longer range and high efficiency, while in no way increasing the weight
of the bomb or decreasing the rate of fire. These last two weapons
were used during the World War, and will be very extensively used in
the future for firing high explosive, phosphorus, thermit and similar
materials that non-technical troops might handle.
Since gas has proven without the shadow of a doubt, that it will
produce more casualties for an equal amount of material transported to
the front than any other substance yet devised, all troops using short
range guns or mortars should be trained to fire gas whenever weather
conditions are right. When weather conditions are not right, they
should fire the other substances mentioned. The Livens’ projector with
its 60 pound bomb, of which 30 pounds will be gas or high explosive,
is a wonderful gun up to the limit of its range. The bomb, not being
pointed, does not sink into the ground, and hence upon exploding exerts
the full force of high explosive upon the surroundings, whether bombs,
pill boxes, barbed wire or trenches, to say nothing of personnel.
=High Explosive in Projectors.= When these are burst by the hundreds on
a small area everything movable is blotted out. Thus concrete machine
gun emplacements, lookout stations, bomb-proofs and wire entanglements
are destroyed, trenches filled up, and the personnel annihilated. This
was amply demonstrated on the few occasions when it was actually used
at the front. The American Infantry, wherever they saw it tried out,
were wild to have more of it used. The German was apparently equally
anxious to have the use stopped. It is, however, one of the things
that must be reckoned with in the future. It means practically that No
Man’s Land in the future will be just as wide as the extreme range of
these crude mortars—and here a word of caution. While efforts have been
made to increase the range of these mortars, whether of the Livens’
projector or Stokes’ variety, no further increase will be attempted
when that increase reduces the speed of firing or the efficiency of
the projectile. In other words results depend upon large quantities of
material delivered at the same instant on the point attacked, and if
this cannot be obtained the method is useless. For this reason these
mortars will never be a competitor of the artillery. The artillery will
have all that it can do to cover the field within its range—beyond that
reached by the mortars.
=Phosphorus in 4-Inch Stokes.= Phosphorus will be used largely by gas
troops, but only in the 4-inch or other Stokes’ mortar that may be
finally adopted as best. The Livens’ projector carries too great a
quantity, and being essentially a single shot gun, is not adapted to
keeping up a smoke screen by slow and continued firing, or of being
transported so as to keep up with the Infantry. Phosphorus has also
very great value for attacking personnel itself. Any one who has been
burned with phosphorus or has witnessed the ease with which it burns
when exposed to air, wet or dry, has a most wholesome fear of it. The
result of it in the war showed that the enemy machine gunners or other
troops would not stand up under a bombardment of phosphorus fired from
the 4-inch Stokes’ mortar—each bomb containing about seven pounds.
=Thermit.= Thermit is used in the same way, and while the idea of
molten metal, falling upon men and burning through clothing and even
helmets, is attractive in theory, it proved absolutely worthless for
those purposes on the field of battle. It was found impossible to throw
sufficiently large quantities of molten metal on a given spot to cause
any considerable burn. In other words, the rapid spreading out and
cooling of the metal almost entirely ruined its effectiveness, except
its effect on the morale. This latter, however, was considerable, as
one might judge from seeing the thermit shells burst in air. For this
reason thermit may find a limited use in the future.
THE SPREAD OF GAS
=Height of Gas Cloud.= The height to which gas rises in a gas cloud
is not exactly known, but it is believed to be not much more than
fifty feet, and then only at a considerable distance from the point of
discharge. Moving pictures taken of gas clouds show this to be true. It
is also indicated by the fact that pigeons, which are very susceptible
to poisonous gas, practically always return to their cages safely when
liberated in a gas cloud. This was a good deal of a mystery until it
was realized that the pigeon escaped through his rising so quickly
above the gas. This of course would be expected when it is known that
practically all gases successfully used were two or more times as heavy
as air. Such gases rise only by slow diffusion, or when carried upwards
by rising currents. The absence of these upward currents at night is
one of the reasons why gas attacks are more effective at night than
during the day.
=Horizontal Spread of Gas.= Another important thing to know in regard
to the behavior of the wave of gas is the horizontal spread of a cloud.
If gas be emitted from a cylinder the total spread in both directions
from that point is from 20° to 30° or an average of 25°. This varies,
of course, with the wind. The higher the wind the less the angle,
though the variation due to wind is not as great as might be expected.
This horizontal spread of the gas cloud was measured experimentally,
and the results checked by aeroplane pictures of heavy wave attacks
over the enemy line. In the latter case the path of the gas was very
closely indicated by the dead vegetation. This vegetation was killed
and bleached so that it readily showed up in aeroplane photographs.
The visibility of a gas cloud arises from the fact that when a large
amount of liquid is suddenly evaporated, the air is cooled and moisture
condensed, thereby creating a fog. With gases such as mustard gas
and others of slight volatility, a visible cloud is not formed. For
purposes of identification of points struck by shell, smoke substances
are occasionally added, or a few smoke shell fired with the gas shell.
As future battle fields will be dotted everywhere with smoke clouds, a
point that will be discussed more fully later, the firing of smoke with
gas shell will probably be the rule and not the exception.
REQUIREMENTS OF SUCCESSFUL GAS
If we succeed in getting a poisonous gas that has no odor it will be
highly desirable to fire it so that it will not be visible. In that
case no smoke will be used. Carbon monoxide is such a gas, but there
are several important reasons why it has not been used in war. (See
page 190). These considerations indicate the general requirements
for a successful poisonous gas. If non-persistent it must be quickly
volatilized, or must be capable of being driven off by heat or by other
means, which can be readily and safely produced in the field. It must
be highly poisonous, producing deaths in high concentrations, and more
or less serious injuries when taken into the system in quantities as
small as one-tenth of that necessary to produce death. If it has a
slightly delayed action with no intervening discomfort, it is still
better than one that produces immediate discomfort and more or less
immediate action. It must be readily compressed into a liquid and
remain so at ordinary temperatures, with the pressure not much above 25
or 30 pounds per square inch.
As a persistent gas it must be effective in extremely low
concentrations, in addition to having the other qualities mentioned
above.
These general characteristics concerning gases apply whether used by
Chemical Warfare troops, the Artillery, the Air Service, the Navy,
or the Infantry. In speaking of these substances being used by the
Infantry, it is understood that an ample number of Chemical Warfare
officers will be present to insure that the gases may not be turned
loose when weather conditions are such that the gas might drift back
and become a menace to our own troops. This is absolutely essential
since no troops who have as varied duties to perform as the Infantry,
can be sufficiently trained in the technical side of chemical warfare
to know when to put it off on a large scale with safety and efficiency.
ARTILLERY USE OF GAS
The Artillery of the future will probably fire more gas than any other
one branch of the Army. There are two reasons for this—first, the large
number of guns now accompanying every Army, and second, the long range
of many of these guns. As before indicated, the gases are adaptable to
various uses, and hence to guns differing both in caliber and range.
The gas will be fired by practically all guns—from the 75 mm. to the
very largest in use. It is even possible that if guns smaller than the
75 mm. become generally useful that certain gases will be fired by them.
=Efficiency of Artillery Gas Shell.= It is well to remember in the
beginning that all artillery shell so far designed and used, contain
only about 10 per cent gas, i.e., 10 per cent of the total weight of
shell and gas. It is hoped that gas shell may later be so designed
that a somewhat greater proportion of the total weight of the shell
will be gas than is now true. This is very desirable from the point of
efficiency. As stated above the bombs used by Chemical Warfare troops
contain nearly 50 per cent of their total weight in gas, and hence are
nearly five times as efficient as artillery shell within the limit of
range of these bombs. This fact alone is enough to warrant the use of
gas troops to their full maximum capacity in order that the artillery
may not fire gas at the ranges covered.
GUNS FIRING PERSISTENT AND NON-PERSISTENT GASES
Considering the firing of non-persistent and persistent gases, it may
be said generally that non-persistent gases will be fired only by the
medium caliber guns which are available in large numbers. In fact, the
firing of non-persistent gases will be confined mainly to the 6-inch or
155 mm. Howitzer and gun.
As our Army was organized in France, and as it is organized at present,
the number of 155 mm. guns will be greater than all others put
together, except the 75 mm. In order that a non-persistent gas may be
most effective a high concentration must be built up very quickly. This
necessitates the use of the largest caliber shell that are available
in large numbers. Of course, a certain percentage of the gas shell of
other calibers may consist of non-persistent gases in order to help out
the 155 mm. gun. This is in accordance with the present program for
loading gas shell and applies particularly to the 8-inch and 240 mm.
Howitzer.
=Few Ideally Persistent or Non-Persistent Gases.= Naturally there
will be very few gases that are ideally non-persistent or ideally
persistent. The groups will merge into one another. Those on the border
line will be arbitrarily assigned to one group or the other. It might
be said definitely, however, that a gas which will linger more than six
or possibly eight hours under any conditions, except great cold, will
not be considered non-persistent. For reasons of efficiency and economy
persistent gases will not be chosen unless they will persist under
ordinary conditions for two or three days or more. Accordingly, a gas
which would persist for one day only would have to be extraordinarily
useful to lead to its adoption.
=Firing Non-Persistent Gases.= Of the non-persistent gases phosgene
is the type and the one most used at present. Furthermore, so far as
can now be foreseen, it will continue to be the non-persistent gas
most used. It volatilizes very quickly upon the bursting of the shell.
Accordingly, in order that the shell fired at the beginning of a gas
“shoot,” as they are generally referred to in the field, shall still
be effective when the last shell are fired, it is necessary that the
whole number be fired within two to three minutes. The temperature
and velocity of the wind both affect this. If it be in a dead calm,
the time may be considerably extended; if in a considerable wind, it
must be shortened. Another important consideration requiring the
rapid firing of non-persistent gases is the fact that nearly all
masks thoroughly protect against phosgene and similar gases. It is
accordingly necessary to take the enemy unawares and gas him before he
can adjust his mask; otherwise, practically no harm will result. From
the considerations previously mentioned, these “gas shoots” are usually
made at night when, as before stated, carelessness, sleepiness and the
resulting confusion of battle conditions always insure more casualties
than firing gas in the daytime.
=Firing Persistent Gases.= The persistent gases will be fired by all
caliber guns, but to a less extent by the 155 mm. than by the other
calibers. Persistent gases must be sufficiently effective in low
concentrations to act more or less alone. If it be desirable to fill an
atmosphere over a given area with mustard gas, the firing may extend
for two or three, or even five or six hours and all shell still act
together. The same is true of bromobenzylcyanide. This, then, permits
the minimum number of guns to be used in firing these persistent gases.
Inasmuch as they persist and force the wearing of the mask, they are
available for use in long-range, large-caliber guns for interdiction
firing on cross-roads, in villages, and on woods that afford hiding
places, as well as on other similar concentration points.
=Firing Irritant Gases.= The irritant gases will be fired by the
various caliber guns, in the same manner as the persistent and
non-persistent gases. We will have non-persistent irritant gases and
persistent irritant gases. They are, however, considered as a group
because they are used for harassing purposes, due to their efficiency
in forcing the wearing of the mask.
Before the signing of the Armistice, the General Staff, A. E. F., had
authorized, beginning January 1, 1919, the filling of 25 per cent of
all shell with Chemical Warfare materials. The interpretation there
given to shell was that it included both shrapnel and high explosive.
Of the field guns in use, the 75 mm. will be best, up to the limit of
its range, for persistent gases such as mustard gas, and the tear gas,
bromobenzylcyanide. A considerable number, however, were filled with
non-persistent gases and probably will continue to be so, since, due to
the very large number of 75 mm. guns available, they can be used to add
greatly at times to the amount of non-persistent gas that can be fired
upon a given point.
USE OF GAS BY THE AVIATION SERVICE
No gas was used by aeroplanes in the World War. Many rumors were spread
during the latter part of the war to the effect that the Germans had
dropped gas here or there from aeroplanes. Every such report reaching
the Chemical Warfare Service Headquarters was run down and in every
case was found to be incorrect. However, there was absolutely no
reason for not so using gas, except that the German was afraid. In the
early days of the use of gas he did not have enough gas, nor had he
developed the use of aeroplanes to the point where it would have seemed
advisable. When, however, he had the aeroplanes the war had not only
begun to go against him, but he had become particularly fearful of gas
and of aeroplane bombing.
It does not seem to be generally known, but it is a fact, that after
three or four months’ propaganda he made a direct appeal to the Allies
to stop the use of gas sometime during the month of March, 1918. This
propaganda took the form of an appeal by a Professor of Chemistry who
had access to Switzerland, to prevent the annihilation of the Allied
forces by a German gas that was to make its appearance in 1918. This
German professor claimed that, while favoring the Germans winning the
war, he had too much human sympathy to desire to see the slaughter that
would be caused by the use of the new gas. The Allies in the field felt
that this was simply an expression of fear and that he did not have
such a gas. The Germans were accordingly informed that the Allies would
not give up the use of gas. Later events proved these conclusions to be
absolutely correct. The German evidently felt that the manufacturing
possibilities of the Allies would put them in a more predominant
position with gas than with anything else. In that he was exactly
correct.
The use of gas by aeroplanes will not differ from its use in artillery
or by Chemical Warfare Troops. Non-persistent gases may be dropped
on the field of battle, upon concentration points, in rest areas, or
other troop encampments to produce immediate casualties. Persistent
gases will be dropped particularly around cross-roads, railroad yards,
concentration points and encampments that cannot be reached by the
artillery. The sprinkling of persistent gases will be one of the best
ways for aeroplanes to distribute gas.
It might be said here that the aviation gas bomb will be highly
efficient, inasmuch as it has to be only strong enough to withstand the
low pressure of the gas and ordinary handling, whereas artillery shell
must be strong enough to withstand the shock of discharge in the gun.
INFANTRY AND GAS WARFARE
When one suggests the possibility of the infantry handling gas, it is
at once argued that the infantry is already overloaded. That is true,
but in the future, as in the past, the infantryman will increase or
decrease his load of a given material just as its efficiency warrants.
If he finds that gas will get casualties and help him win victories
more readily than an equal weight of any other material, he will carry
gas material. A study of the articles of equipment abandoned by 10,000
stragglers in the British Army picked up during the great German drive
towards Amiens in March, 1918, illustrates this very clearly. Of the
equipment carried by these stragglers, more than 6,000 had discarded
their rifles. The helmets were thrown away to a somewhat less extent,
but the gas mask had been thrown away by only 800 out of the 10,000.
Now the gas mask is not a particularly easy thing to carry, nor was
the English type comfortable to wear, but the English soldier had
learned that in a gas attack he had no chance whatever of escape if his
gas mask failed him. Accordingly, he hung on to the mask when he had
discarded nearly everything else in his possession. The same thing will
be true of any gas equipment if it proves its worth.
SMOKE AND INCENDIARY MATERIALS
So far nothing has been said in regard to smoke or incendiary
materials. This has been due to the fact that their use is not
dependent upon weather conditions to anything near the extent that
gas is. Second, the smokes, not being poisonous, are not a danger to
our own troops, although they may hamper movements and add to the
difficulty of taking a position, if used improperly. Of the two classes
of materials, smoke and incendiary, smoke materials may be said to be
at least a thousand times as important as the incendiary materials. A
material that will burst into flame when a shell is opened or that will
scatter balls of burning fire appeals to the popular imagination, and
yet actual results achieved by such materials on the field of battle
have been almost nil. About the only results worth while achieved by
incendiary materials have been in occasionally firing ammunition dumps
and more frequently, setting fire to warehouses and other storage
places. This will undoubtedly continue in the future.
FLAME THROWER
Of the incendiary materials the least valuable is the flame thrower. In
the Chemical Warfare Service it has been the habit for a long while not
to mention the flame thrower at all, unless questions were asked about
it. It is mentioned here to forestall the questions. Even the German,
who invented it and who, during the two years of trench warfare, had
full opportunity for developing its use, finally came to using it
largely as a means of executing people that he did not want to shoot
himself. Men falling in that class were equipped with flame throwers
and sent over the top. The German knew, as did the Allies, that each
man with a flame thrower became a target for every rifle and machine
gun nearby. The flame thrower is very quickly exhausted and then the
one equipped with it has no means of offensive action, and in addition,
is saddled with a heavy load, hampering all movements, whether to
escape or to advance.
INFLAMMABLE MATERIALS
There will probably be some use for materials such as metallic sodium,
spontaneously inflammable oils, etc., that will burst into flame and
burn when exposed to the air, though white phosphorus is probably
equal, and in most cases vastly superior to anything else so far
suggested. Phosphorus burns with an unquenchable flame when exposed
to the air, whether wet or dry. It is of great value for screening
purposes, and for use against the enemy’s troops. The German did not
use phosphorus simply because he did not have it, just as he did not
use helium in his observation balloons because he did not have it.
The value of phosphorus was just beginning to be realized slightly when
the Americans entered the war, while its full value was not appreciated
even by the American troops when the war closed.
The work of the First Gas Regiment with phosphorus against machine gun
nests proved how valuable it is against the enemy’s troops. It proved
also its tremendous value as a screen.
The Chemical Warfare Service was prepared to fill a great number of
artillery shell with phosphorus, but due to the failure of our shell
program to mature before the Armistice, phosphorus was not used by
American artillery to any appreciable extent.
SMOKE USED BY EVERYONE
Smoke will be used by every fighting arm of the Service in practically
every battle, both by day and by night. If you have ever tried on
a target range to shoot at a target that was just beginning to be
obscured by a fog, you will recognize the difficulty of hitting
anything by firing through an impenetrable smoke screen. It is simply
a shot in the dark. Future battles will witness smoke formed by smoke
candles that are kept in the trenches or carried by the troops, by
smoke from bursting artillery shell and rifle grenades, by smoke from
aeroplane bombs and possibly even from what is known as the smoke
knapsack. The knapsack produces a very dense white smoke and very
economically, but will probably not be much used. This is because,
notwithstanding its efficiency, the knapsack cannot be projected to a
distance, that is, the smoke screen is generated on the person carrying
the knapsack. On the other hand the great value of phosphorus is that
it can be fired to great distances in rifle grenades or artillery
shell, and dropped from aviation bombs. The smoke screen is thus
established in front of the object it is desired to cut off, whether it
be a battery of artillery, an advancing wave of infantry, or a lookout
station. Thus smoke, for screening purposes alone, will be used to a
tremendous extent. It will also be used in conjunction with gas.
SMOKY APPEARANCE OF GAS CLOUD
Due to the smoky appearance of an ordinary gas cloud and to the coming
use of poisonous smokes, no one on the field of battle in the future
will ever be certain that any given smoke cloud is not also a poisonous
cloud until he has actually tested it. And there lies an opportunity
for the most intense study and for the greatest use of the proverbial
American ingenuity that war has ever furnished.
In the variations that can be played with smoke containing gas, or not
containing gas, with smoke hurled long distances by the artillery or
dropped from aeroplanes, the possibilities indeed are unlimited. Every
officer will need to study the possibilities of smoke, both in its use
against him and in his use of it against the enemy. He can probably
save more casualties among his own troops by the skillful use of smoke
than by any other one thing at his command. On the other hand, the
unskilled use of smoke on the part of one side in a battle may lead to
very great casualties in proportion to those of the enemy should the
latter use his smoke skillfully. This is a subject that deserves deep
and constant study.
PROTECTION BY SMOKE CLOUDS
Smoke in the future will be the greatest protective device available
to the soldier. It shuts out not only the view in daylight, but
the searching of ground at night by searchlights, by star bombs or
other means for illuminating the battlefield. It has already been
used extensively by the Navy and undoubtedly will be used far more
extensively in the future.
SHELL MARKINGS
Modern artillery shell have distinctive colors for high explosive, for
shrapnel, for incendiary materials, and for gases. A grayish color has
been adopted as the general color of the paint on all gas shells, bombs
and cylinders. In addition a system of colored bands has been adopted.
These bands are white to indicate poisonous non-persistent substances,
and red—persistent. Yellow is used to indicate smoke. With any given
combination of red and white and yellow bands, the artillery-man at
the front can tell, at a glance, whether the gas is non-persistent or
whether it is persistent, and also whether or not it contains smoke.
There will be secondary markings on each shell which, to the trained
Chemical Warfare Service officer, will indicate the particular gas or
gases in the shell. These markings however, will be inconspicuous and
no attempt will be made to give the information to the soldier or even
to the average officer firing gas.
These secondary markings are for the purpose of enabling the Chemical
Warfare Service officers in charge to use certain gases for particular
uses in those comparatively rare cases when sufficient gas is on hand
and sufficient time available to enable such a choice to be made.