GAS WARFARE
Germany first made use of poisonous and asphyxiating gases on the
field of battle. It has become an accepted element in the present war.
Every soldier should, therefore, have a knowledge of the various ways
in which gas is employed in the attack, as well as the measures to be
taken to counteract its effect in the defense.
The two methods of disseminating the gas over the battlefield are by
emanation and grenades charged with it.
EMANATION
This method has for its object to create a poisonous or irritant
atmosphere. This is accomplished by means of the arsenic and
phosphorous gas being forced through tubes in the direction of the
enemy or by means of liquefied chlorine, bromide, phosgene and
sulphuretted hydrogen gas stored in cylinders under high pressure.
To be successful the gas attack must be attended by the following
conditions:
1. The weather must be comparatively calm with a wind blowing in the
direction of the enemy at about 5 miles an hour. If the wind is too
strong the gas will be carried over the enemy's trenches so rapidly
that it will not settle in them. If the wind be too light the gas will
be carried up into the air and disseminate or may even be blown back
into our own trenches, in which case chloride of lime scattered about
freely will disperse them.
2. There must be no rain, for that would quickly disseminate the gas
and negative the effect.
3. The attack must come as a surprise. If the elements of surprise are
missing and the enemy has time to take protective measures, the effect
is lost. If the surprise is complete, the enemy trenches should be
emptied very quickly.
4. The gas used must be heavier than the air, so that it will sift into
the enemy's trenches as it passes them. It is impracticable to decide
upon any definite hour for launching the gas attack. Everything depends
upon the direction and velocity of the wind. If an hour has been
tentatively designated and the wind changes, the attack will have to be
postponed.
When an assault follows the gas attack the men should wear the smoke
helmets for at least 30 minutes after the dissemination has ceased; in
fact they must not be removed until the order to do so is given by the
officer commanding the attack. You will appreciate that the enemy's
machine gunners may have better protection than the men in the bays of
the trenches.
SHELL AND GRENADE METHOD
In this method the gas dissemination is effected by means of shells
or bombs being fired into the enemy's trenches containing the desired
substances which are released and give off irritant fumes on explosion.
The grenades used weigh about 1 pound. They are similar in appearance
to the ordinary tin can grenade. Their effect in a trench will
continue for 20 to 30 minutes. In the attack a large number should be
concentrated in a particular area to produce a large volume of gas.
They are thrown by hand, trench mortar or catapult.
DEFENSE
Surprise must be guarded against in every possible way. The direction
of the wind must be continually watched, and when its velocity and
direction are specially favorable the protective measures must be
kept ready for instant use and special observers posted. Previous to
an attack the enemy may remain comparatively quiet for several days.
Noises like the moving of sheet iron may be heard. Preparations may be
observed along the position. When the attack starts a hissing noise is
heard; this latter is one of the indications that may be evident at
night.
HELMETS
Each man on duty in the trenches is provided with two smoke helmets,
specially devised and constructed so as to absorb the gas and
neutralize its effect, and which if properly cared for and used will
provide complete protection from any substance likely to be used by the
enemy. They are fitted with a valve tube through which to breathe and
with goggles to see through. There are certain rules prescribed for
their care and use.
1. They must not be removed from the protective covering except for
actual use against an attack.
2. When the helmet has been used once it should be replaced by a new
one.
DUMMY HELMETS
Dummy gas helmets will be provided in each organization by which the
men may be practiced in putting them on. The men must be thoroughly
drilled in the methods to be employed.
[Illustration: Plate 40a.--Gas helmet.]
The following directions accompany the helmets issued to the
British Army. When our helmets are issued it is probable that each
will be accompanied by a complete set of rules for its use and full
instructions for the method of getting into it and for its care and
preservation.
DIRECTION FOR USE AND CARE OF TUBE HELMETS
DESCRIPTION
These helmets are the same as the smoke helmet already issued, except
that stronger chemicals are added and a tube valve provided through
which to breathe out. The tube valve makes the helmet cooler and saves
chemicals from being affected by the breath. The wearer cannot breathe
_in_ through the tube valve; this is intended for breathing _out_ only.
DIRECTIONS FOR USE
Remove paper cap from mouthpiece of tube valve. Remove service cap.
Pull helmet over head. Adjust so that goggles are over eyes. Tuck in
skirt of helmet under coat collar and button coat so as to close in
skirt of helmet. Hold the tube lightly in lips or teeth like stem of
pipe, so as to be able to breathe in past it and out through it.
_Breathe in through mouth and nose, using the air inside the helmet.
Breathe out through tube only._
DIRECTIONS FOR CARE OF TUBE HELMET
1. Do not remove the helmet from its waterproof case except to use for
protection against gas.
2. Never use your tube helmet for practice or drill. Special helmets
are kept in each company for instruction only.
Should the goggles become misty during use they can be cleared by
rubbing them gently against the forehead.
When lacrimatory gases are used goggles affording mechanical protection
may be worn, as these gases are not likely to irritate the lungs,
though they sometimes produce sickness.
IMPROVISED METHODS
If a soldier does not possess one of the official pattern respirators,
the following measures will be found useful:
1. Wet and wring out any woolen article, such as a stocking or muffler,
so as to form a thick pad large enough to cover the nose and mouth,
and press firmly over both.
2. Place in a scarf, stocking or handkerchief, a pad of about three
handfuls of earth, preferably damp, and tie it firmly over the mouth
and nose.
3. A wet cloth pulled down over the eyes will be found useful as
additional protection, especially against certain gases other than
chlorine or when the gas is too strong for the ordinary respirator.
4. A stocking, wetted with water and soda solution or tea, folded into
eight folds and firmly held or tied over the nose.
5. A sock folded fourfold similarly wetted and held or tied. If the
sock or comforter has been soaked in soda solution it will still act
efficiently when dry, though if possible, it should be moist. The spare
tapes from puttees may be used for tying on the sock.
6. Any loose fabric, such as a sock, sandbag, woolen scarf or
comforter, soaked in urine, then wrung out to allow of free breathing
and tied tightly over the nose and mouth.
In the absence of any other cloths, the flannel waistbands issued for
winter use could be used for this purpose.
KNAPSACK SPRAYERS
Knapsack sprayers are issued for use to clear gases out of the trenches
after the cloud has blown over. A man with the sprayer on his back (and
wearing his smoke helmet) slowly traverses the trench, working the
spray. If this is not done the heavy poisonous gas may linger in the
trench for days and be a source of great danger.
If supports or reinforcements enter a trench charged with gas, they
should be preceded by a man using a sprayer.
Sprayers are charged with sodium thiosulphate--more commonly known as
"hypo"--6 pounds being dissolved in a bucket of water and a handful of
ordinary washing soda added.
Garden syringes and buckets may be used if sprayers are not available,
but these are not so effective. Sprayers should be charged before they
are taken up to the trenches, and should be kept ready for immediate
use.
Every officer defending a trench against an enemy gas attack should
endeavor to collect information whenever possible, to be sent to
headquarters through the usual channels. Particularly valuable is the
capture of apparatus used by the enemy either for disseminating gas or
for protection against it. If a shell attack is made, unexploded shells
or portions of them should be sent through to headquarters at once. The
time of day, duration of attack, color, taste or smell of gas used,
effect on the eyes, breathing, and all other symptoms should be noted.
New gases may be used at any time, and speedy information greatly
forwards the adoption of preventive measures.