PROGRAM OF TRAINING IN 
 GAS DEFENSE 
 
 FOR 
 
 DIVISIONAL ANTI-GAS SCHOOLS 
 
 EDITED AT 
 
 ARMY WAR COLLEGE 
 
 OCTOBER, 1917 
 
 WASHINGTON * 
 GOVERNMENT PRINTING OFFICE 
 
 1917 
 
T Tf 
 
 a 3 
 
 WAR DEPARTMENT. 
 Document No. 686. 
 o/ T/ie Adjutant General. 
 
 
WAR DEPARTMENT. 
 WASHINGTON, October 23, 1917. 
 
 The following pamphlet, " Program of Training in Gas De- 
 fense for Divisional Anti-Gas Schools," is published for the 
 information of all concerned. 
 [062.1, A. G. O.] 
 
 BY OEDER OF THE SECRETARY OF WAR : 
 
 TASKER H. BLISS, 
 
 General, Chief of Staff. 
 OFFICIAL : 
 
 H. P. MCCAIN, 
 
 The Adjutant General. 
 (3) 
 
 664369 
 
PROGRAM OF TRAINING IN GAS DEFENSE FOR 
 DIVISIONAL ANTI-GAS SCHOOLS. 
 
 45 minutes. 
 
 hours. 
 
 SYLLABUS CF TRAINING'. ; ' ', v 
 
 First day : 
 
 Theoretical. Lecture on the general principles of gas war- 
 fare 
 
 (a) History of the use of gas. 
 (&) Gas-cloud attacks. 
 
 (c) Gas-shell attacks. 
 
 (d) Various kinds of gas used. 
 
 (e) The effect of gas. 
 
 (/) Methods of protection. 
 Practical 
 
 (a) The mechanism of the mask. 
 
 (I)) Gas mask drill (individually and in 
 squads). 
 
 (c) Inspection of masks. 
 Second day: 
 
 Theoretical. Lecture on signs of approaching gas 
 
 (a) Three signs of cloud gas. 
 
 (&) Wind observations. 
 
 (c) Precautions to be taken during wind- 
 
 dangerous period. 
 
 (d) Means of giving the alarm (cloud gas). 
 
 (e) Action to be taken in trenches. 
 (/) Signs of gas-shell attack. 
 
 (#) Means of giving the alarm (gas shells). 
 (h) Rules to be observed during any gas 
 
 attack. 
 Practical 
 
 (a) Repeat gas-mask drill one-half hour. 
 (&) Exercise in gas house with lachryma- 
 tory gas. 
 
 (5) 
 
 45 minutes. 
 
 hours. 
 
6 
 
 Third day : 
 
 Theoretical. Lecture on action to be taken after gas at- 
 tack 
 
 (a) Clearing of shelter, trenches, and shell] 
 
 craters (gas fans and fire pots). 
 (&) Cleaning of arms and ammunition. 
 (c) Protection of dug-outs and all arms. 
 Practical 
 
 (a) Repeat gas-mask drill one-fourth hour. 1 
 
 (V>) Exorcise in gsis house with chlorine gas m hours. 
 
 one hour. 
 Fourth day: 
 
 Theoretical. Lecture on the effect of gases and treatment 
 
 of gas cases, 30 minutes. 
 Practical 
 
 (a) Gas-cloud attack. 
 
 (?>) Use of gas fan and fire pot in clearing 
 
 trenches. 
 
 hours. 
 
 (c) Demonstrate protection afforded in dug- 
 outs by means of wet blankets. 
 Fifth day : 
 
 Theoretical. Lecture on organization of gas service in 
 foreign forces 
 
 (a) Anti-gas duties within an Infantry 1 
 
 regiment. 
 
 (6) Standing orders, 
 (c) Collection of gas samples. 
 Practical 
 
 (a) Repeat gas-mask drill. 
 
 (?>) Exercise in gas-shell attacks (lachrymatory gas), 
 
 li hours. (Explosion of grenades.) 
 Sixth day : 
 
 For officers 
 
 Written quiz covering instruction given during the 
 
 week. 
 For enlisted men 
 
 Verbal quiz and general exercises of the course. 
 Upon completion of this training all troops should be given 
 one hour mask drill per week under their platoon commanders. 
 This drill should include the mask drill proper and other drills 
 and exercises while wearing the mask. 
 
r 
 
 LECTURE NO. 1 (first day). 
 
 The use of gas, like many of the other weapons now in com- 
 mon use in the armies of Europe, such as the catapult, flame 
 projector, trench knife, and sling, is an inheritance from the 
 early ages amplified, improved, and made more destructive by 
 the aid of modern science. 
 
 The first recorded effort to overcome the enemy by the genera- 
 tion of poisonous and suffocating gases seems to have been in the 
 wars of the Athenians and Spartans (431 to 404 B. C.), when, 
 in besieging the cities of Platea and Belium, the Spartans satur- 
 ated wood with pitch and sulphur and burnt it under the walls 
 of those cities in the hopes of choking the defenders and render- 
 ing the assault less difficult. They also melted pitch, charcoal, 
 and sulphur together in cauldrons and blew the fumes over the 
 defenders' lines by means of bellows. 
 
 " Greek fire " was used by the Byzantine Greeks under Con- 
 stantine about 673 A. D., to destroy the Saracens, and Saracens 
 in turn used it as a weapon of defense against the Christians 
 during the Crusades. This Greek fire had the double advantage 
 of being not only inflammable but also generating during the 
 process of combustion clouds of dense, blinding smoke and gas 
 of an asphyxiating character. (This gas sulphurous dioxide 
 is one of the gases used to-day.) Its chemical composition was 
 supposed to be a mixture of quicklime, petroleum, sulphur, and 
 such other inflammable substance as pitch, resin, etc. Upon the 
 addition of water the slaking process which the quicklime under- 
 went generated enough heat to ignite the petroleum, which in 
 turn ignited the resin, pitch, and sulphur. This flaming mixture 
 was delivered against the enemy by means of fantastic syringes 
 in the shape of dragons and other monsters with wide jaws. 
 
 The first use of gas in modern warfare was in an attack April 
 22, 1915, by the Germans. at Ypres on a sector of trench where the 
 French and Canadians met. The surprise was complete and the 
 number of casualties enormous. On April 26 gas was liberated 
 against two French battalions which were making an assault, 
 and broke down the assault completely. Repeated gas attacks 
 followed, and it soon became recognized that gas was an ac- 
 cepted weapon in modern warfare. These first gas attacks w T ere 
 of the gas-cloud type, but soon gas shells began to make their 
 appearance and now gas shells are in use in all armies and are 
 one of the most important weapons in modern warfare. 
 
GAS-CLOUD ATTACK. 
 
 The gas-cloud attack is brought about by the liberation of gas 
 from metal containers buried under the parapets of the front-line 
 trenches. Tubes from these containers provided with a stop- 
 cock attachment, are carried up over the parapet and through 
 them the gas is liberated. These containers are usually placed 
 in batteries of three or four at intervals of about 30 yards apart. 
 The gas in them is in a liquid state, but upon being released by 
 turning on the stop cock it volatilizes rapidly and escapes in the 
 form of a dense vapor. This escape of the confined gas is accom- 
 panied by a low whistling sound which is frequently the only 
 warning the opposing side has of the coming attack. The gases 
 used in cloud attacks are heavier than air and when released 
 under proper atmospheric conditions move or, rather, appear to 
 roll along the ground, usually in the form of a dense greenish- 
 yellow cloud, toward the lines of troops to be attacked, and when 
 it reaches the trenches it settles down into all parts of them, 
 penetrating the dugouts and bomb proofs and remaining some- 
 times for several days. 
 
 The success of the " gas cloud " is dependent on the atmos- 
 pheric conditions. A calm night or day, with a gentle wind 
 blowing in the right direction, is essential. A strong wind dis- 
 tributes the gas too quickly and diminishes its concentration, 
 and a variable wind is not to be depended on. Gas attacks have 
 been made with wind velocities varying from 3 to 15 miles per 
 hour, i. e., from 1 to 7 yards per second. A wind between 
 4 and 8 miles is the most favorable. With such a wind gas 
 would reach trenches 100 yards away in 22 seconds. Gentle 
 rain has no effect on the gas but a heavy rain washes it down. 
 Fogs have but little effect and may be taken advantage of to 
 conceal the approach of a gas cloud. 
 
 While the gas cloud form of attack, if successful, can pro- 
 duce a number of casualties, its operjation is uncertain and its 
 approach can be anticipated if proper watchfulness is main- 
 tained. Efficient measures can be taken by trained troops to 
 nullify its effects, and its military value therefore is probably 
 not so great as when it is used in shells, bombs, hand gre- 
 nades, etc. 
 
 GAS-SHELL ATTACK. 
 
 Gas used in shells has a much more definite military value 
 than gas used in clouds. The gas shell has, in fact, become 
 
9 
 
 one of the most important weapons in modern warfare and at 
 present 20 per cent of all shells used on the western front are 
 gas shells. 
 
 They fulfill a double purpose; they are excellent in forming 
 a barrage to prevent the bringing up of supplies and reinforce- 
 ments, and they are most excellent in silencing artillery posi- 
 tions. Their method of employment, as described to me recently 
 by a French officer, was like this : A continued barrage fire was 
 kept up behind a certain artillery position for 24 hours. Then 
 a cloud fire was kept up on the artillery position itself for 12 
 hours. The infantry assault was then made and there was no 
 fire at all from the artillery position. When this was taken, 
 it was found that most, of the men there were dead and those 
 that survived were too weak to work the guns. The protective 
 power of their masks had been exhausted by the long exposure 
 to gas. 
 
 Gas is used in shells of both heavy and light field howitzers. 
 The 5.9 Minemverfer is the shell most used by the Germans. 
 
 These shells hold about 7 liters of a gas-producing liquid. 
 They have a short ogival head and a long cylindrical body of 
 thin steel, about one-fourth of an inch thick ; closely fitted 
 against the inside walls is a cylinder of sheet lead about one- 
 eighth inch thick, which is filled with the gas-producing liquid 
 and then tightly soldered. This load container fills nearly the 
 whole cylindrical portion of the shell ; just above it, but not 
 resting on it, is the explosive, and above this, on the point of 
 the shell, is a combination of time and impact fuze. The effect 
 of the charge upon exploding is to tear open the head of the 
 shell and the top of the lead container so as to allow the liquid 
 to spill out and liberate the gas. 
 
 Hand grenades of various kinds, made of both glass and iron, 
 and containing a quantity of gas-producing liquid, are used in 
 trench warfare, and iron bombs, with a bursting charge of black 
 powder and containing gas liquid, are also used in trench 
 mortars. 
 
 Unlike cloud gas, gas shells can be used in wind blowing in 
 any direction. The strength of the wind, however, has consid- 
 erable influence on the effective use of the shells. A wind of 
 7 miles per hour or less is as high a wind as is practical for 
 their effective use. 
 
 21168 17 2 
 
10 
 
 THE VARIOUS KINDS OF GASES. 
 
 (a) Lachrymatory gases (cause an intense inflammation of 
 the eyes with temporary inability to see). 
 
 (&) Asphyxiating gases (extremely severe in their action, 
 causing either rapid death or lingering death with much suf- 
 fering). 
 
 (c) Suffocating gases (causing death by spasm of the glot- 
 tis; they are usually combined with lachrymatory gases). 
 
 (d!) Paralysant gases (causing instant death when in suffi- 
 cient concentration). 
 
 The three latter classes are known as lethal gases. The 
 asphyxiating gases, because of their weight, are the ones used 
 in cloud-gas attack. The other gases, and the asphyxiating 
 gases, also are used in shells. 
 
 A great variety of acids may be used for the production of 
 gases, and chemists in all armies are constantly experimenting 
 with a view to perfecting new and more potent combinations. 
 The ones most commonly used now, however, for the suffocat- 
 ing and lachrymatory group are combinations of benzol and 
 acetone with chlorine and bromine, such as cloracetone, bro- 
 macetone, and benzyl bromide. The principal acids used for 
 asphyxiating purposes are chlorine, bromine, and phosgene. 
 These acids are abundantly produced in commercial processes of 
 manufacture, are easily obtained, and answer every purpose. 
 They are, however, with the exception of phosgene easily neu- 
 tralized by alkalies. In addition to these commoner acids many 
 other acids have been used; some of them are hydrogene sul- 
 phide, sulphurous anhydride, various nitrous vapors, formol, 
 arsene, and prussic acid. 
 
 THE EFFECT OF GASES. 
 
 Certain gases, such as prussic acid, produce instant death by 
 paralyzing the central nervous system, but the majority of the 
 gases have a special affinity for the mucous membranes, and 
 their systemic effect depends on the amount of damage they do 
 to those tissues. The lachrymatory gases have a special action 
 on the membranes of the eye and upper air passages, and their 
 effects though severe while they last are as a rule temporary. 
 They cause a severe smarting pain and running of the eyes 
 (tearing) and soon the lining of the eyelids become so swollen 
 that vision is impossible. At the same time there is a dryness. 
 
11 
 
 burning, and smarting of the nose and throat, with coughing 
 and sometimes vomiting. In three or four hours those symp- 
 toms begin to disappear^ and gradually the soldier recovers. 
 
 The asphyxiating and suffocating gases are far more severe in 
 their action. Their potency can be realized when it is known 
 that a dilution of 1: +1,000 is fatal with chlorine and bromine, 
 and a 1 : +25,000 is fatal with phosgene. A dilution of 1 : 100,000 
 or more has a marked effect. These gases act to a less degree 
 on the membranes of the eye than the lachrymatory gases, but 
 their action is particularly virulent on the membranes of the 
 respiratory tract, which they cause to swell rapidly and finally 
 destroy. The result is oedema of the lungs, accompanied by 
 persistent coughing and spitting of blood, then great difficulty 
 in breathing, the soldier becoming cyanosed and struggling for 
 breath. Death may be almost instantaneous, or it may be post- 
 poned for several days, the sufferer in the meantime not being 
 able to eat anything and undergoing great agony. Many of the 
 cases in which recovery does take place develop later a chronic 
 disease of the lungs. 
 
 METHOD OF PROTECTION. 
 
 The deadly character of gas attacks can be almost entirely 
 obviated if the proper measures of protection are known and 
 strictly enforced. 
 
 A perfect familiarity with the gas mask and its prompt ap- 
 plication is the only certain means of defense. The development 
 of the gas mask has kept pace with the development of gas as 
 a weapon. From the first the principle of the mask has been 
 to provide a filter through which the inspired air must pass, 
 this filter to be made of chemicals which have a neutralizing 
 effect on the gases. At first the mask was simply a pad of 
 cotton or gauze soaked in a soda solution, and this afforded 
 fairly good protection against chlorine. With the introduction 
 of the lachrymatory and more poisonous gases, however, the sim- 
 ple pad proved inadequate and new types of mask were con- 
 stantly appearing. 
 
 Three types are now in use in the European armies. The box 
 respirator, the tube helmet, and the M. 2 French mask. Of these, 
 "he box respirator is by far the best. While cumbersome in ap- 
 pearance, it is really the most comfortable, and has the longest 
 life against the greatest variety of gases. 
 
12 
 PRACTICAL INSTRUCTION (First Day). 
 
 1. Explain the mechanism of the mask. Point out the way in 
 which the inspired air passes through the bottom of the canister, 
 tlie connecting tube, and the mouthpiece. Dwell on the fact 
 that air reaching the lungs in any other way is poisonous when 
 gas is present. For this reason the nose clip must be worn. 
 Explain how the expired air escapes through the flutter valve. 
 
 Impress upon the soldier that the mask is of the utmost im- 
 portance, and any failure to keep it in good condition and adjust 
 it promptly and properly when the gas alarm is given may cost 
 him his life. 
 
 GAS-MASK DRILL. 
 
 The detachment should be in line with the masks in the carry 
 position. The haversack slung at the right side, sling passing 
 over the right shoulder, flap buttons toward the body. 
 
 Practice "A." Adjustment of the respirator box in the 
 "Alert " position. 
 
 On the command " Gas alert " hang the haversack around the 
 neck with the press buttons next the body. With the right hand 
 seize the satchel by the leather tab, with the left hand seize the 
 sling by the brass button, and clip this into the leather tab. 
 Undo the press buttons closing the flap, tuck in the slack of the 
 sling into the left-hand compartment, so that it lies under the 
 mask. 
 
 The length of w-hipcord will then be withdrawn from the right- 
 hand compartment, passed through the ring on the right of the 
 satchel, and carried around the waist to the ring on the left, 
 where it is fastened. The press button closing the flap will be 
 left undone, but the flap will be put in condition to keep the 
 respirator from wet. 
 
 Practice "B" Drill by numbers to obtain correct adjustment 
 of the mask. 
 
 1. On the command " One " press down both thumbs between 
 the satchel and the body and open the satchel flap. Immediately 
 seize the mask with the right hand, the metal breathing tube just 
 outside the mask being in the palm of the hand, and the thumb 
 and first finger grasping the wire frame of the nose clip. 
 
 2. On the command " Two " bring the mask smartly out of the 
 satchel and hold it in both hands with all the. fingers outside 
 around the binding, and the two thumbs inside, pointing toward 
 
13 
 
 and upward under the elastic. At the same time throw the chin 
 well forward ready to enter the mask opposite the nose clip. 
 
 3. On the command " Three " bring the mask forward, digging 
 the chin into it, and with the same mot : on bring the elastic bands 
 back over the crown of the head to the full extent of the retaining 
 tape, using the thumbs. 
 
 4. On the command " Four " seize the metal breathing tube 
 outside the mask, thumb on the right, fingers on the left all 
 pointing toward the face. Push the rubber mouthpiece well 
 into the mouth and pull it forward until the rim of the mouth- 
 piece lies between the teeth and the lips and the two rubber grips 
 are held by the teeth. 
 
 5. On the command " Five " adjust the nose clip to the nose, 
 using the thumb and first three fingers of the right hand. Come 
 smartly to attention. 
 
 At the completion of this exercise, the instructor inspects each 
 man and corrects any faults of adjustments. It is very impor- 
 tant to see that the mask fits the face properly and that the 
 length of the sling in the alert position is such that the man 
 can move his head about freely without exerting traction on the 
 rubber tube. 
 
 NOTE. (a) If, after wearing for a long time, the pressure of 
 the nose clip becomes unbearable, it may be relieved for a few 
 moments by taking off the pressure without removing clip. 
 
 (.&) Removing masks. It must be seen that when masks are 
 removed this is done without strain on the face piece or elastic. 
 On the command " Take off masks " insert the fingers of the left 
 hand under the mask at the chin, bend the head forward, at the 
 same time removing the mask with an upward motion of the 
 left hand. 
 
 (c) After all drills the mouthpiece must be disinfected, the 
 mask wiped dry, folded correctly, and put away in such a way 
 that the rubber valve is not bent. 
 
 Repeat practices "A" and " B " several times and note progress 
 made. Then start " judging the time." With the mask in the 
 " Gas alert " position the command " Gas " will be given and 
 each man will proceed to adjust his mask in the manner pre- 
 scribed in practice " B." When adjusted he will take one step 
 forward and his time will be recorded. All men must be drilled 
 until they can make a perfect adjustment in six seconds. 
 
 Practice " C." The purpose of practice " C " is to teach the 
 men the procedure to be gone through when a sudden gas-shell 
 attack is made. 
 
On the command " Gas shells " pass the left arm back through 
 the sling, throwing the haversack to the front of the body, under 
 the flap buttons and adjust the mask as in Practice " B," allow- 
 ing the haversack to hang by the rubber tube. While doing this, 
 men must be taught to hold their breath. After the mask is ad- 
 justed, breathing can be resumed and the haversack fastened in 
 the alert position. The complete adjustment should be made in 
 seven seconds. 
 
 At the end of every drill period entry will be made on the 
 record card in the haversack of the approximate time of actual 
 breathing through the respirator. This record must be kept 
 accurately, so that the life of the mask can be ascertained. 
 
 Repeat Practices "A," " B," and " C " a few times. 
 
 Practice " D." Drill to teach cleaning of eyepieces. 
 
 On the command " Clean eyepieces " the right eyepiece will be 
 gripped between the thumb and first finger of the left hand. 
 The first finger of the right hand will then be pushed gently into 
 the flap of the mask behind the right eyepiece, which w r ill be 
 cleaned with a gentle circular motion. 
 
 The left eyepiece will be cleaned in a similar way. 
 
 Practice " E" Drill to teach method of giving orders. 
 
 It is first explained to a squad that the nose clip must not be 
 removed to talk, and that before each sentence is spoken a long 
 breath must be taken and the mouthpiece removed sideways 
 from the mouth by turning the metal tube outside the mask to 
 one side. After speaking the mouthpiece is replaced. 
 
 The squad should then be numbered off, extended to four 
 paces, and orders passed along the line. 
 
 Officers and noncommissioned officers w r ill be specially drilled 
 in Practice " E." 
 
 Long orders must be broken into short phrases so that each 
 part may be shouted out before a new breath must be taken. 
 
 Practice " F." Drill to teach method of clearing mask from 
 gas which may have leaked in and is affecting the eyes. 
 
 On the command " Empty masks," press the mask close to the 
 face, forcing out foul air around the sides, and then fill again 
 w r ith air from the lungs by blowing out round the mouthpiece. 
 
 Practice " G." Drill to teach method of testing whether trench 
 or dugout is free from gas. 
 
 On the command " Test for gas," with right hand open the 
 face piece away from the right cheek, then loosen the nose clip 
 on the nose and smell gently (do not take a breath). If gas is 
 
15 
 
 smelt, the nose clip and mask are replaced. Then as in 
 Drill " F." 
 
 LECTURE NO. 2 (Second Day). 
 
 WARNING. 
 
 The gas mask if properly and promptly adjusted is a sure pre- 
 vention of gas casualties. Ample warning therefore is essential 
 in order that men may have time to adjust their masks. Every 
 means must be employed to detect an impending gas attack and 
 spread the alarm at the first sign of its approach. 
 
 The gas-cloud attack requires a good deal of preparation on 
 the enemy's part, in the matter of bringing up the containers 
 and digging them in under the trenches, and advance informa- 
 tion of an attack can be frequently obtained by aeroplane recon- 
 naissance and constant observation of the enemy's trenches by 
 outpost sentries. These two sources of information should be 
 continuously employed. The only certain signs of an actual 
 attack, however, are : 
 
 (a) The whistling sound of the gas as it escapes from the 
 containers. 
 
 ( b ) The smell of the gas. 
 
 (c) The appearance of a cloud of any color over the enemy's 
 trenches. 
 
 With all gases at night and with certain forms of gas in the 
 daytime the cloud is not visible at a distance. 
 
 Recently an English officer told me that one of the earliest 
 signs of a gas attack was a loss of taste in a cigarette or pipe ; 
 that he had frequently seen soldiers look suddenly at the cigar- 
 ette they were smoking and then with a startled face say " gas," 
 and begin to put on their masks. 
 
 WIND OBSERVATION. 
 
 The wind playing so important a part in gas-cloud attacks, a 
 meteorological service is established on all fronts. This organi- 
 zation reports to headquarters of corps or divisions whenever the 
 wind is in a dangerous quarter, showing the direction and 
 strength of the wind. As a result of these reports " Wind dan- 
 gerous " is announced from these headquarters. 
 
 These general reports, however, refer to large areas, and on 
 isolated stretches of front conditions of terrain or the align- 
 
16 
 
 ment of trenches may permit of local air currents which are 
 favorable to the enemy. For this reason company commanders 
 are responsible that wind observations are made in their com- 
 pany front every three hours or oftener if the wind is in or ap- 
 proaching a dangerous quarter, and the reports are forwarded 
 through the regimental commander to brigade headquarters. 
 
 In order to make these reports in each company a simple wind 
 vane, bearing a Beaufort flag, is set up. The vane must have 
 as little friction as possible, so that a wind of under 2 miles per 
 hour will turn it. 
 
 It must be set up sufficiently high to get a true observation 
 (e. g., 18 inches above the top of the dugout), and it must also 
 
 North. 
 
 N.N.W. 
 
 South. 
 
 be correctly oriented. An easy way to do this is to have two 
 sticks below the gauge crossed at right angles, one marked on 
 the end with " N " for north. The arms can then be so set 
 that " N " points to the north, as determined either by the sun 
 at midday, the polestar at night, or the compass (remembering 
 that the magnetic north is 13 west of the true north). 
 
 Direction of wind must be stated by points of the compass. 
 
 Before reading the direction of the wind from the vane the ob- 
 server should gauge the approximate direction by smoke, etc. 
 
 The Beaufort flag is a strip of linen 5 inches long by three- 
 fourths of an inch wide attached either to the wind vane itself 
 
17 
 
 or on the top of the post that supports it. With the aid of the 
 flag the strength of the wind may be determined by Beaufort's 
 scale. 
 
 Beaufort scale. 
 
 Beau- 
 forts 
 No. 
 
 Speed 
 (miles 
 per 
 hour). 
 
 Observation cf natural objects. 
 
 Behavior of flag. 
 
 
 
 Smoke straight up 
 
 No movement 
 
 1 
 
 2 
 
 Smoke slants 
 
 Do. 
 
 2 
 
 5 
 
 Feltinfacj... 
 
 Slight. 
 
 3 
 
 10 
 
 Paper etc. moved 
 
 Three-fourths up. 
 
 4 
 
 15 
 
 Bushes sway 
 
 Up and falling down. 
 
 5 
 6 
 
 20 
 30 
 
 Tree tops sway; wavelets on 
 water. 
 Trees sway and whistle 
 
 Up; falling less ollcn. 
 Up and napping. 
 
 
 
 
 
 To determine the number of seconds which it will take for a 
 gas cloud to move from the enemy's lines to our own, double 
 trench distance (in yards) and divide by speed of wind (in 
 miles per hour ) . Example : 
 100X2 
 
 10 
 
 -=20 seconds. 
 
 THE WIND-DANGEROUS PERIOD. 
 
 " Wind dangerous " is ordered when the wind is in a danger- 
 ous quarter, no matter what the strength of the wind may be. 
 At the same time it is advisable that the noncommissioned 
 officers be able to estimate the strength of the wind, as that 
 has some bearing on the likelihood of an attack. The Germans 
 seem to prefer a wind of from 4 to 12 miles. 
 
 The order is usually given from corps or division head- 
 quarters, but brigade or regimental commanders are empowered 
 to order a " Wind dangerous " as a result of observations for- 
 warded by company commanders. Such action will be reported 
 immediately to the next higher commander. When the order 
 is given " Wind dangerous," notices are posted at the entrance 
 to each main communication trench and at other proper points 
 within the divisional area. 
 
 PRECAUTIONS DURING WIND-DANGEROUS PERIOD. 
 
 (a) All masks should be carefully inspected and the inspec- 
 tion repeated daily. Steps must be taken to ascertain that all 
 gas-alarm appliances are in their position and in good order. 
 
 21168 17 3 
 
18 
 
 (&) All ranks .within 1 mile of the front line must carry 
 their haversacks in the " alert " position. During " Wind dan- 
 gerous" the chin strap of the helmet must on no account be 
 worn under the chin, as it will impede the rapid adjustment of 
 the mask. 
 
 (c) A sentry should be posted at each Strombos horn or 
 other alarm device and instructed in its use, and all working 
 parties should have a sentry posted to give instant warning 
 of a gas attack. 
 
 A sentry should be posted to every large shelter or group of 
 small shelters, and also to each headquarters, signal office, and 
 each independent body of men. 
 
 Arrangements must be made by the officer in charge of the 
 trench for warning the artillery observation post, if there is 
 one in the trench. 
 
 Commanders of u nits in billets within 8 miles of the front- 
 line trenches must organize a system of giving the alarm and 
 rousing all men in cellars or houses. 
 
 At night sentries should have at least two men within reach 
 of them, so that the alarm can be spread rapidly. 
 
 (d) When a gas attack is probable, men in front-line trenches 
 should sleep on the fire step instead of in dugouts. Men sleep- 
 ing in rearward lines, or in works where they are allowed to 
 take off their equipment, must sleep with their haversacks on 
 the person. 
 
 (e) Company gas noncommissioned officers will report to com- 
 pany headquarters in readiness to assist the company com- 
 mander should a gas attack occur. 
 
 GAS ALARM. 
 
 For the purpose of giving the gas alarm the British use, very 
 largely, the Strombos horn, which can be heard very long dis- 
 tances. This instrument is a large horn worked by compressed 
 air and comes in a box with two cylinders of compressed air 
 and a rubber connecting tube. They are placed at intervals 
 of not greater than 400 yards along the front line and at such 
 points behind the front as is required to insure transmission of 
 warning. 
 
 In addition to the Strombos horns, bells and gongs made from 
 shell cases, suspended rails, etc., are used, and the buzzer wire 
 is frequently employed to send warning to the rear. No reliance 
 can be placed on bugles, whistles, or such devices as require 
 the use of the lungs. 
 
19 
 
 ACTION TO BE TAKEN IN THE TRENCHES ON GAS ALARM. 
 
 (a) Masks to be put on immediately by all ranks. 
 
 (ft) Rouse all men in trenches, dugouts, and mine shafts, 
 warn officers and artillery observation posts and all employed 
 men. 
 
 (c) Artillery support to be called for by company commanders 
 by means of prearranged signals. 
 
 (d) Warn regimental headquarters and troops in rear . 
 
 (e) All ranks stand to arms in the front trenches and else- 
 where where the tactical situation demands. 
 
 (/) Blanket curtains at entrances to protected shelters to be 
 let down and carefully fixed. 
 
 (g) Movement to cease except where necessary. 
 
 ACTION TO BE TAKEN IN BILLETS AND BACK AREAS. 
 
 (a) All men in cellars or houses to be roused. 
 (&) The blanket curtains of protected cellars, etc., to be let 
 down and fixed in position. 
 
 (c) Masks to be put on immediately the gas is apparent. 
 
 WARNING OF GAS-SHELL ATTACKS. 
 
 Gas-shell attacks are local in their effects, and the gas does 
 not spread to so great a distance as does the gas cloud. There- 
 fore the character of the " gas alarm " for gas shells is different 
 from that for " gas cloud." In the case of gas shells every man 
 must be his own sentry and constantly on the lookout for that 
 form of attack, and give the alarm as soon as he detects gas. 
 For this reason a local gas-shell alarm must be arranged for each 
 individual unit. It must be distinct from the gas-cloud alarm, 
 and every man in the unit must know what it means. It is of 
 the utmost importance that every man within 300 yards of the 
 first gas shell or trench mortar gas bomb should get his mask on 
 at once. 
 
 Frequently gas shells do not burst at the commencement of a 
 bombardment but are used intermittently. For that reason 
 when anyone realizes that gas shells are being fired he must 
 give the alarm instantly. This can be done in two ways. 
 
 (a) By men who are not in the gas at the moment, or may 
 have their masks completely adjusted, shouting " Gas shells " 
 as loudly as possible. 
 
20 
 
 (6) By the prearranged signal for the unit being given by 
 the sentry or whoever has first realized that gas shells are being 
 fired. On this alarm may depend the safety of those men who 
 are in dugouts or in different parts of the position who would 
 not otherwise get warning. 
 
 Gas shells may be recognized by the following signs : 
 
 (a) Many gas shells make a peculiar wabbling noise as they 
 come through the air. This is due to their being filled with a 
 liquid instead of a solid. 
 
 (&) The noise of the burst is very small and might be mis- 
 taken for a " blind." There is a difference, however, and after 
 hearing a few gas shells burst one can recognize them. 
 
 (c) Most gas shells on bursting form a dense white cloud, 
 which hangs together in a peculiar way and is carried along by 
 the wind. This is the easiest sign by which the gas shell can be 
 recognized. The density of the cloud varies with the weather 
 conditions. It is greatest when the air is damp ; least when it 
 is dry. 
 
 ACTION DURING A GAS ATTACK. 
 
 Protective measures. There should be as little moving about 
 and talking as possible in the trenches. Men must be made to 
 realize that with the gas now used by the enemy, observance of 
 this may be essential for their safety. 
 
 When an attack is in progress, all bodies of troops or trans- 
 port on the move should halt and all working parties cease work 
 until the gas cloud has passed. 
 
 If a relief is going on, units should stand fast as far as pos- 
 sible until the gas cloud has passed. 
 
 Supports and parties bringing up bombs should only be moved 
 up if the tactical situation demands it. 
 
 If troops in support or reserve lines of trenches remain in or 
 go into dugouts, they must continue to wear their anti-gas 
 appliances. 
 
 Officers and noncommissioned officers must on no account open 
 up their masks to give orders. The mouthpiece may be removed 
 when it is necessary to speak, bat it must be immediately re- 
 placed. 
 
 Men must always be on the lookout to help each other in case 
 a mask is damaged. When a man is wounded he must be 
 watched to see that he does not remove his mask. If necessary 
 his hands should be tied. 
 
21 
 
 Men must be warned that if they are slightly " gassed " before 
 adjusting their masks they must not remove them. The effect 
 will wear off. After the cloud has passed and the trenches been 
 cleared of gas by the apparatus provided for the purpose, the 
 noncommissioned officer in charge of each trench section will 
 assure himself that the trench is free from gas by raising his 
 mask slightly and will then issue the order to take off masks. 
 Men will on no account take off their masks until the order to 
 do so has been given. Dugouts and bombproofs must be entered 
 with caution even after the trenches are clear, as gas frequently 
 remains in them some hours. 
 
 PRACTICAL INSTRUCTION (Second Day). 
 
 1. Repeat the exercises of the previous day several times and 
 note the improvement in the men. Those men not showing suffi- 
 cient improvement should be drilled individually or in small 
 squads and their faults corrected. 
 
 2. Ordinary infantry drill, including manual of arms, set- 
 ting-up exercises, and marching will be carried out for two 
 periods of 15 minutes each. Marching should occasionally in- 
 clude double-time for at least 200 yards. 
 
 3. Practice in bombing, rapid loading and aiming, judging 
 distance, and range practicing, 15-minute periods. 
 
 4. Fitting of masks. Each man is scrutinized to see that his 
 mask is not obviously too large or too small for him. Then the 
 command " Gas " is given and the class is marched into the gas 
 chamber. The lachrymator benzyl chloride is vaporized in the 
 chamber in the proportion of about 1 teaspoonful to 200 cubic 
 feet of air space either by heating in a tin over a candle flame 
 or by spraying. Each man remains five minutes in the room, 
 moving and talking. If a man's eyes are affected, he goes out 
 of the room and is examined to see if his adjustment is perfect 
 or if he needs a smaller mask. If the latter, he is given a 
 smaller mask, and then reenters the chamber. After five min- 
 utes all men are marched out and stand in the open air for some 
 minutes to free their clothes from the vapor. Then the order 
 " Take off masks " is given and the eyes of all men are examined. 
 If the eyes of any are affected, they are given smaller masks. 
 Any man whose face is marked on forehead or cheeks by too 
 much pressure from the face piece is given a larger mask. 
 
 After the fitting, the words " Fitted box respirator size X " 
 and the date are to be written on the man's descriptive list. 
 
22 
 
 In order to demonstrate the protection which has been afforded 
 by the mask, the class will now be put in the chamber without 
 masks. 
 
 LECTURE NO. 3 (Third Day). 
 
 ACTION TO BE TAKEN AFTER A GAS ATTACK. 
 
 Cloud-gas attacks are generally made in successive waves 
 (usually three), so that after a gas-cloud attack a sharp look- 
 out must be maintained as long as the wind continues in a dan- 
 gerous quarter. During an attack the gas sinks into the 
 trenches, and especially into those dugouts and cellars which are 
 not protected by blanket doors. When gas shells are used, the 
 gas sinks into the crater made by the shell and remains in all 
 of these places a long time. Dugouts, cellars, etc., must not be 
 entered, therefore, except by men wearing masks, until they 
 have been thoroughly cleared out. 
 
 CLEARING OF SHELTERS. 
 
 The only way in which dugouts and cellars can be cleared of 
 gas is through artificial ventilation by means of fires and anti- 
 gas fans. Formerly a Vermorel sprayer, very much like an 
 ordinary tree sprayer, was used with an alkaline solution which 
 neutralized the chlorine. With the advent of phosgene, how- 
 ever, the Vermorel sprayer lost its efficiency and now is only 
 useful in wetting the blankets at dugout entrances. 
 
 Unless a shelter has been thoroughly ventilated by artificial 
 means it must not be slept in or occupied without wearing 
 respirators until at least 12 hours have elapsed. It must not be 
 entered at all without respirators on for at least three hours. 
 The above refers to gas-cloud attacks. In the case of a gas- 
 shell bombardment, time limits can not be stated, as they depend 
 on the nature of the gas used and the severity of the bo.ubard- 
 ment. 
 
 With lachrymatory gases, the times after which shelters can 
 be used without discomfort may be considerably longer than 
 three hours. 
 
 Ventilation by fire. All kinds of shelters can be efficiently and 
 rapidly cleared of gas by the use of fires. Shelters with two 
 openings are the easiest to ventilate, and where possible dugouts 
 with only one entrance should have a second opening made, even 
 a very small one, to assist in ventilation. 
 
23 
 
 In dugouts provided with a single exit at the end of a short 
 passage, the best results are obtained if the fire is placed in the 
 center of the floor of the dugout and at a height of about 6 
 inches. In dugouts provided with a single exit at the end of a 
 long and nearly horizontal passage, the best results are obtained 
 if the fire is placed about one- third the distance from the inner 
 end of the passage. 
 
 In dugouts provided with two or more exits, the fire should be 
 placed at the inner end of one of the exit passages. 
 
 In general, 1 pound of dry wood per 200 cubic feet of air space 
 is sufficient for clearance of any gas. The best fuel is split 
 wood, but any fuel which does not smoulder or give off thick 
 smoke can be used. The materials for the fire, e. g., split wood, 
 newspaper, and a small bottle of paraffin for lighting purposes, 
 should be kept in a sandbag inclosed in a tin can provided with 
 a lid. An improvised brazier should be kept ready for use. 
 
 The fire should be kept burning for at least 10 minutes and 
 the atmosphere in the shelter should be tested from time to time. 
 
 Ventilation by fanning. Dugouts can be ventilated by produc- 
 ing air currents in them by means of special anti-gas fans. If 
 no anti-gas fans are available, ventilation can be assisted by 
 flapping with improvised fans, such as sand bags, sheets, etc. 
 
 Anti-gas fans. The anti-gas fan consists of a sheet of canvas 
 supported by braces of cane and reinforced in the middle. It is 
 made with two transverse hinges and is fitted with a hickory 
 handle. The flapping portion is, roughly, 15 inches square and 
 the handle is 2 feet long. 
 
 METHOD OF USE. 
 
 (a) Clearing trenches. The fan blade is placed on the ground 
 with the brace side downward, the man using it being in a 
 slightly crouching position with the left foot advanced, the right 
 hand grasping the handle at the neck and the left hand near the 
 butt end. The fan is brought up quickly over the right shoulder, 
 and then smartly flicked to the ground with quick slapping 
 strokes. This drives a current of air along the earth and. on the 
 top strokes, throws the gas out of the trench as if it were by a 
 shovel. 
 
 It is essential that the part of the fan blade nearest the handle 
 should touch the ground first, and this can be accomplished in all 
 cases by ending the stroke with the whole length of the handle 
 as close to the ground as possible. 
 
24 
 
 (6) In working round a traverse, etc., the fan should be 
 flapped round the corner with the hinge on the corner and the 
 lower edge of the fan as near the bottom of the trench as can 
 be managed. The brace side of the fan is to be outward and at 
 the end of the stroke the whole length of the handle should be 
 close up to the side of the trench. 
 
 If several fans are available, men should work in single filo 
 and with " out-of-step " strokes, i. e., one fan should be up while 
 the next is down. 
 
 (c) Clearing shelters. In the case of a dugout with a single 
 entrance not exceeding 12 feet in length the gas is first cleared 
 from the neighborhood of the shelter as in (a) and then the 
 corners worked round as in ( & ) . The worker now advanced to 
 the inner end of the entrance, beating rather slowly on the 
 ground to allow the gas time to get out of the tunnel and bring- 
 ing the fan as near the roof as possible on the return stroke. 
 
 It may be desirable to have a second fan working just outside 
 the dugout to throw the gas out of the trench as it comes out. 
 
 (d) In the case of dugouts with two entrances or with one 
 entrance and another opening, such as a chimney, it is only 
 necessary to use the fan round the corner of one entrance in the 
 manner described in (&). When the entrance is cleared, it Is 
 advisable to enter the shelter with a respirator on in order to 
 beat up the gas from the floor boards, etc. This greatly facili- 
 tates the removal of the last traces of gas. 
 
 VERMOREL SPRAYERS. 
 
 Vermorel sprayers are withdrawn from general use for clear- 
 ing out gas after an attack, but a certain number are retained 
 for moistening the blankets of protected shelters and for use in 
 medical dugouts, etc. They should be kept for this purpose only 
 and on no account relied on for clearing trenches or shelters of 
 gas. 
 
 Company Vermorel sprayers. Sprayers on the basis of two 
 per company are retained for moistening-blanket protection. 
 They should be kept by company gas noncommissioned officers 
 with other anti-gas trench stores and should be kept one-third 
 full of water. The solution must be kept in corked demijohns 
 or other closed receptacles close to each sprayer ; it must not be 
 kept in the sprayers owing to its corrosive nature. It is made 
 up as follows: Water, 3 gallons (one large bucket) ; sodium 
 thiosulphate (hypo.), 1| pounds (three-fourths mess tin) ; 
 sodium carbonate (washing soda), 3 pounds (1 mess tins). 
 
25 
 
 Three demijohns are required to hold the above quantity, and 
 the necessity for keeping them corked must be impressed on the 
 personnel responsible for it. 
 
 When no solution is obtainable water may be used for spray- 
 ing the blankets. 
 
 TREATMENT OF SHELL HOLES. 
 
 Shell holes which are so situated as to be obnoxious should be 
 filled up with fresh earth, care being taken to cover up all 
 places around the hole where the chemical liquid from the shell 
 has dropped. Shell holes so treated should not be disturbed, as 
 the chemical is not destroyed by burying, and only slowly dis- 
 appears. 
 
 CLEANING OF ARMS AND AMMUNITION. 
 
 Rifles and machine guns must be cleaned after a gas attack 
 and then reoiled. Oil cleaning will prevent corrosion for 12 hours 
 or more, but the first available opportunity must be taken to dis- 
 mantle machine guns and clean all parts in boiling w^ater con- 
 taining a little soda. If this is not done, corrosion continues 
 slowly, even after oil cleaning, and may ultimately put the gun 
 out of action. 
 
 After a gas attack small-arms ammunition should be carefully 
 examined. All rounds affected by gas must be replaced by new 
 cartridges immediately and the old ones cleaned and expended 
 as soon as possible. 
 
 All hand and rifle grenades exposed to the gas should have 
 their safety pins and working parts cleaned and reoiled. 
 
 All bright parts of light trench mortars, together with all 
 accessories and spare parts exposed to the gas, must be cleaned 
 and wiped dry as soon as possible after the attack and in any 
 case \vithin 24 hours, after \vhich they should be thoroughly 
 coated afresh with oil. The same applies to ammunition which 
 may have been exposed to the gas. 
 
 Ammunition which for any reason had not been oiled must 
 be cleaned and oiled and expended as soon as possible. 
 
 The following precautions apply to medium and heavy trench 
 mortars, as well as to guns and howitzers : 
 
 PROTECTION. 
 
 Batteries which are in constant danger of gas attacks, 
 whether from gas clouds or gas shells, should keep all bright 
 
26 
 
 parts of the gun or mortar, carriage, mounting, and accessories 
 well coated with oil. 
 
 Sights and all instruments should also be smeared with oil 
 and protected with covers when not in actual use, care being 
 taken that the oil does not come in contact with any glass or 
 find its way into the interior of the instrument. 
 
 Cartridge cases of the ammunition stored with the battery 
 and all uncapped fuzes, or fuzes which have been removed from 
 their cylinders, should be wiped over with oil as soon as possi- 
 ble and protected with a cover. 
 
 CLEANING. 
 
 All bright parts of guns and trench mortars, together with 
 all accessories and spart parts exposed to the gas, must be 
 cleaned and wiped dry as soon as possible after the attack, and 
 in any case within 24 hours, after which they should be thor- 
 oughly coated afresh with oil. 
 
 PROTECTION OF TELEPHONE INSTRUMENTS. 
 
 The only method of preventing corrosion of electrical appa- 
 ratus during a gas attack is to prevent the gas reaching it, 
 and the best way to do this is to have signal shelters thoroughly 
 protected against gas. As the corrosive effect on damp instru- 
 ments is very much greater than on dry instruments, the shel- 
 ters should be kept as dry as possible. 
 
 During a gas attack telephones must be kept in their leather 
 cases, and, unless the buzzer key is being used, the leather flap 
 must be kept down, leaving only the cords with the receiver 
 and hand sets out of the case. The backs of switchboard and 
 buzzer exchange must be kept closed. All apparatus such as 
 magneto telephones, test boards, space instruments, etc., which 
 it is not essential to have uncovered, should be well covered 
 up with cloths, blankets, or coats, etc. 
 
 CLEANING INSTRUMENTS AFTER GAS ATTACK. 
 
 After a gas attack, telephone apparatus that has been ex- 
 posed to gas should be treated as follows : The ends of the wires 
 should be removed from terminals and cleaned by being scraped 
 with a knife, wiped with a damp cloth, and dried. Terminals, 
 exchange plugs, and all exposed metal work should be cleaned 
 by being scraped with a knife, wiped w r ith a damp cloth, and 
 
27 
 
 dried. This process should be repeated after 12 hours have 
 elapsed. The metal work of the leather case of the telephone 
 and of other instrument cases should be cleaned with oil in the 
 same way as rifles, etc. The internal portions of the instru- 
 ments should not be interfered with. If an instrument has 
 been kept closed or covered up, it is very unlikely that internal 
 portions will have suffered, but if these portions show signs 
 of corrosion the instruments should be sent back to division 
 or corps headquarters, to be dealt with by an instrument 
 repairer. 
 
 PRACTICAL INSTRUCTION (Third Day). 
 
 1. Repeat mask drill. 
 
 2. Practice in cleaning trenches and dugouts with anti-gas 
 fans (show the method of holding the fan and making the 
 stroke as described in the morning lecture). Explain the effects 
 on the gas as each stroke is made. 
 
 3. Inspection of masks. Box respirators must normally be 
 inspected once a week and daily during " Gas alert." Attention 
 will be paid to the following points : 
 
 (a) Boxes, face piece, mouthpiece, nose clip, eyepieces, and 
 elastic must be in good order. If the box is rusted through, the 
 respirator must be condemned. 
 
 (I)) Face piece must be firmly attached to the mouthpiece 
 and to the elbow tube. 
 
 (c) The metal tube inside the mouthpiece must be about one- 
 eighth inch back from the opening of the latter. 
 
 (d) The rubber tube must be intact and firmly attached to the 
 box and elbow tube. 
 
 (e) The expiratory valve should be tested by removing the 
 box from the satchel and either closing the cap at the bottom 
 with the hand or pinching the rubber tube so as to prevent 
 inlet of air, at the same time attempting to draw in air through 
 the mouthpiece. It should not be possible to draw in any air. 
 This also proves the absence of Jeaks in the tube or box. It 
 must be possible to breathe out easily through the valve. If 
 the latter has stuck because of saliva drying in it, this must be 
 remedied by rubbing the valve between the fingers. 
 
 (/) See that the inlet valve is opening properly and that air 
 can be drawn freely through the box. 
 
 (ff) See that the whipcord is present and not knotted. 
 
28 
 
 (7i) Any small perforations in the face piece should be tem- 
 porarily repaired by applying pieces of adhesive plaster from 
 the repair outfit to the perforation, both inside and outside 
 the mask. The adhesive plaster should be large enough to 
 overlap the hole all around. 
 
 Respirators so repaired must be exchanged as soon as possible. 
 
 (Z) Replace the box in the satchel so that the face piece comes 
 to the face without twist on the tube. Fold face piece carefully 
 and replace in the satchel so that the expiratory valve is not 
 likely to crumple. 
 
 4. Exposure to chlorine gas in ffas house. Chlorine should be 
 generated in strength of 1 : +10,000 and men required to go to the 
 open door of the gas house and take several breaths of it. 
 
 They should then put on their masks and enter the gas house, 
 where they remain 10 minutes. During this time they should 
 exercise, give orders, etc. 
 
 LECTURE NO. 4 (Fourth Day). 
 
 THE ACTION AND TREATMENT OF POISONOUS GASES. 
 
 While the very detailed study of the action of the poisonous 
 gases used in warfare and the technical description of the ex- 
 act manner in which they damage the human being are matters 
 which are of interest chiefly to medical officers, a clear under- 
 standing by line officers of the importance of the means of 
 defense provided can hardly be obtained without at least a 
 general view of the ways in which these substances act upon 
 the human body. 
 
 KINDS OF GASES. 
 
 Gases which are used in modern warfare are : 
 
 1. Gases which act as irritants to the lungs and to the breath- 
 ing apparatus generally. 
 
 2. Gases which act as eye irritants, 
 
 3. Gases which act by preventing the blood from taking 
 oxygen. 
 
 4. Gases which act as direct poisons to the central nervous 
 system 
 
 THE EFFECT OF GASES. 
 
 In the beginning of the modern use of gas in warfare, chlorine 
 gas was used almost exclusively, and this gas is the type of the 
 first class the lung irritants. The curious fact may be here 
 
29 
 
 noted that this gas is at once the soldier's best friend and one 
 of his worst enemies, for it is upon the action of this gas that 
 we depend for the modern method of disinfection of water. 
 It is also the active principle in the new Carrel-Dakin method of 
 wound treatment. Just as chlorine is almost immediately fatal 
 to germ life in drinking water and in the depths of infected 
 wounds, even when used in very dilute solutions, so it is quite 
 promptly fatal to the human being when used in sufficient doses. 
 
 When one is exposed to chlorine gas his symptoms will de- 
 pend upon the strength of concentration of the gas in the air 
 which he breathes. He will at once feel greatly distressed 
 about his breathing and will cough, gasp, and choke. 
 
 If the concentration of the chlorine is no more- than 1 part 
 to 100,000 parts of air he will not be able to breathe for some 
 time, though there may be severe after effects. If the strength 
 is 1 part of chlorine to 10,000 of air he will not be able to take 
 more than two or three breaths. His eyes and nose will be 
 irritated, he will be choked by spasmodic contractions of his 
 throat, and he will quickly be incapacitated for any exertion. 
 
 There is, however, not only the temporary inconvenience to 
 be considered but the permanent damage which is done to the 
 tissues of the bronchial tubes and lungs. 
 
 We have in the breathing apparatus a very sensitive set of 
 tissues. The air cells or alveoli of the lungs are guarded from 
 contact with irritating substances by an elaborate system by 
 which the air which finally reaches this region does so only after 
 the most careful filtering through the nose and through the upper 
 air passages. When we realize further that when we are deal- 
 ing with chlorine we are dealing with one of the most powerful 
 caustic agents in the whole list of chemical elements, a substance 
 capable of causing severe burns v/hen it comes in contact with 
 the much more resistant skin, and even of combining with and 
 corroding steel and other metals, it will not be hard to under- 
 stand that the damage done to the tender tissues of the breathing 
 apparatus must be of the most severe type. 
 
 Experience proves that this is true, and that one or two 
 breaths of a concentration of chlorine gas, one part to a thou- 
 sand, has been sufficient to damage the lining of the bronchial 
 tubes and of the air cells of the lungs beyond hope of repair. 
 
 We are all familiar with the effects of injuries upon those 
 tissues of our bodies which we can see and where we can inspect 
 the results of the damage. We know that within a short time 
 
30 
 
 there will be swelling, the extent of which will depend upon the 
 looseness of the tissues injured. About the eye or lip, for ex- 
 ample, such swelling from a blow will be very prompt and often 
 very extensive, the swelling being due to the pouring out of- 
 fluid about the seat of the injury, as a first step in the process 
 of repair. A bee sting is an excellent example of the way in 
 which tissues react to damage. 
 
 The swelling thus produced is called oadema, and it is exactly 
 this sort of thing which takes place in the lungs when chlorine 
 gas, even in great dilution, is inhaled. 
 
 In response to the instant and what might be called an auto- 
 matic effort on the part of the tissues to wash away the offend- 
 ing material, great volumes of fluid are at once poured out 
 into the air cells, which become so filled with fluid that the air 
 does not have any opportunity to enter the cells. 
 
 Even momentary contact of chlorine gas with the delicate 
 membrane lining the fine air vesicles has so far injured them 
 that their capacity for handling the air in their normal way is 
 lost. 
 
 Life depends upon a sufficient aerating of the blood. The very 
 delicate machinery by which this is accomplished usually works 
 very efficiently, even in a dusty atmosphere, The nicely strained, 
 warmed, and moistened air is brought into gentle contact with 
 the delicate wall of the air cell, on the other side of which is the 
 network of thin-walled blood vessels, and an equitable exchange 
 takes place according to certain well-defined laws of the diffu- 
 sion of gases, between the coloring matter of the blood, which has 
 an affinity for the oxygen of the air, and the supply which has 
 been brought to it. 
 
 Very obviously, under the conditions which we are supposing, 
 this change can not take place, and the subject not only feels 
 suffocated but actually becomes blue from lack of air. 
 
 Owing to the caustic character of this gas, there is great dis- 
 comfort and pain in the chest, and coughing, gagging, and some- 
 times vomiting in the effort to clear the lungs. 
 
 The cough may be so violent and the injury to the cells so 
 great that the partitions between the air cells are broken and 
 air may leak out into the tissues. In the early cases of gassing 
 this was a very prominent feature of the symptoms. 
 
 When the blue stage of suffocation is reached the mind becomes 
 dulled and unconsciousness soon follows. Later, the breathing 
 being so much interfered with, the heart gets a poor supply of 
 
31 
 
 blood, its strength fails, the blue color of the sufferer gives way 
 to the leaden color of collapse, and he succumbs to heart failure. 
 When the dose has been insufficient to cause a fatal inflammation, 
 there results a long-continued bronchitis, and sometimes a 
 stretching of the air cells, from the violent cough, which leads 
 to shortage of breath and permanent disability. 
 
 In 1916 the cloud gas used showed somewhat different effects, 
 due to the fact that instead of being pure chlorine alone it was 
 a mixture of chlorine and phosgene, or in some instances 
 phosgene alone. 
 
 This gas, which has the formula " COC1 2 ," is a derivative of 
 Cl. It does not so quickly cause oedema of the lungs and is not 
 so immediately irritant to the breathing apparatus. 
 
 The cough and strangling are not so marked, and for an hour 
 or so the subject may be abe to go on with his work. A little 
 later he may then suddenly go into a fatal collapse. 
 
 The reaction which takes place in the lungs is due to the fact 
 that phosgene, where it comes into contact with a warm, moist 
 surface, as in the air cells of the lungs, forms HC1 (hydrochloric 
 acid ) , and it is upon the formation of this substance in the lungs 
 that the poisonous effects of the gas depend. 
 
 As there is not so much of the violent coughing and strangling 
 with this form of gas, there is not so likely to be a tearing of the 
 air cells and a leakage of air and gas into the tissues as with 
 chlorine. 
 
 The second group of lung irritants, the nitrous fumes, nitric 
 oxide, and nitrogen peroxide, do not cause so much immediate 
 irritation, but after a few hours of comparative freedom from 
 symptoms after exposure, sudden, fatal collapse may occur. 
 This delayed action is quite characteristic of gases of this group, 
 and it is important to remember, since men suffering from the 
 immediate effects of these fumes may die suddenly after 24 to 
 48 hours. 
 
 LACHRYMATORS. 
 
 The second type of gases are those which are used primarily 
 as eye irritants and have practically no permanent effect upon 
 the breathing apparatus. This is the group called lachrymators, 
 or tear producers. Benzyl bromide is the type of this gas. Even 
 in very minute concentration these gases cause a very profuse 
 flow of tears, the lining of the eyelids swell, and the subject 
 may be temporarily blinded. 
 
32 
 
 The effect passes off entirely in a day or two, leaving no per- 
 manent effects. In very concentrated states these gases may 
 also act as lung irritants to a certain extent. Formalin, the 
 use of which as a fumigating material is familiar to all, may 
 be used in this way. Protection against gases of this type is, 
 as a rule, easily afforded by goggles, but lachrymatory gases 
 are rarely used alone, and therefore the mask must always be 
 worn when their presence is detected. 
 
 Carbon monoxide is typical of the third group of gases, w r hich 
 act by combining with the oxygen-carrying substance in the 
 blood (hemoglobin), and is of importance, though it occurs acci- 
 dentally in warfare and is not used deliberately in cloud gas or 
 gas-shell attacks, its physical properties not lending themselves 
 readily to these purposes. 
 
 It is peculiarly liable to occur under circumstances where the 
 presence of gas would not ordinarily be expected ; from the im- 
 perfect combustions of explosives of the TNT type, from the 
 escape of illuminating gas, which is largely made up of CO, in 
 the fumes from firing of guns in close compartments, in burning 
 buildings, from the warming of sleeping quarters by charcoal 
 braziers, in mine galleries, in the coal bunkers and stokeholes of 
 battleships and transports, etc. Its chief danger lies in the fact 
 that it is odorless, tasteless, colorless, and nonirritant, so that 
 in places where carbon monoxide is liable to be generated every 
 precaution must be taken. Small animals, such as mice and 
 canary birds, are quickly affected by even small quantities of 
 carbon monoxide and are excellent means of warning. 
 
 The first symptom is usually a sense of weakness in the limbs. 
 The subject is then unable to handle himself, the coordination is 
 lost, the muscular weakness increases, he staggers, perhaps 
 becomes excited, and shouts, laughs, or sings like a drunken 
 man. Violent headache is one of the early symptoms. 
 
 PARALYZING GASES. 
 
 The fourth group of gases, of which hydrocyanic or prussic 
 acid is the type, act as direct poisons to the central nervous 
 system and in high concentration are instantaneously fatal. 
 
 The effects of a dose which is not immediately fatal are dizzi- 
 ness, confusion, headache, blurring of vision, palpitation, pain 
 in chest and over the heart, labored breathing. Convulsions 
 may occur. In fatal doses there is immediate unconsciousness, 
 dilation of the pupils, gasping respiration, and death with or 
 
33 
 
 without convulsions. HCN has an odor like that of bitter al- 
 monds or crushed peach kernels, and this odor is perceptible 
 even in very dilute concentrations insufficient to cause death. 
 
 FIRST AID AND TREATMENT IN GAS CASES, 
 
 Rest is the most important point of all in the general treat- 
 ment of gassed cases. Men, and especially officers, should be 
 warned that if even lightly gassed they must refrain from mov- 
 ing about or shouting out orders. Physical strain after being 
 gassed may easily cause the loss of a life that might otherwise 
 have been saved. 
 
 Warmth is needed in many of the severe cases, especially at 
 the outset, when they are collapsed and their skin is cold. To 
 attain this, it may even be necessary to transfer them tempo- 
 rarily indoors. Otherwise the fullest supply of fresh air is 
 needed for all cases. When outside, care should be taken to 
 protect against chill, which might lead to a subsequent broch- 
 pneumonia. 
 
 Every impediment to the easiest breathing should be removed. 
 Belts, suspenders, the blouse, etc., should be loosened. 
 
 If the patient is vomiting much the head should be turned so 
 as to empty the mouth. Frequently gassed men attempt to 
 remove their masks. This should be looked out for by the men 
 who are not gassed, and if a patient shows a disposition to re- 
 move his mask his hands should be tied. 
 
 All cases should be evacuated as soon as possible to the regi- 
 mental aid station, and, except in very slightly gassed men, all 
 cases should be carried. In no case should a man who has been 
 gassed attempt to carry his own equipment to the rear. 
 
 At the regimental aid station inhalations oi ! ammonia, stimu- 
 lating hot drinks, etc., may be given, and vomiting may be in- 
 duced' in certain cases by tepid salt water. 
 
 Oxygen is of great advantage in certain cases and each dress- 
 ing station is provided with several cylinders of oxygen. From 
 these the oxygen flows through a hose to a valved face mask, 
 which fits over the face tightly. The pure oxygen is admin- 
 istered every 15 minutes for 4 or 5 minutes each time. 
 
 Many drugs have been tried to combat the poison of gases, 
 but very few have been proved of value. A summary of the 
 treatment of gas cases seems to show that rest, warmth, fresh 
 
34 
 
 air when possible, oxygen inhalation, and gentle stimulation is 
 all that can be done. When these measures are employed, how- 
 ever, many cases recover. 
 
 PRACTICAL INSTRUCTION (Fourth Day). 
 
 1. Repeat mask drill, marking the time. Upon the alarm 
 " Gas " have squads of four men put on the mask. When the 
 mask is completely adjusted each man will step forward 'one 
 pace. Men should be drilled until they can complete the adjust- 
 ment in six seconds. 
 
 2. If the weather is favorable, liberate a gas-cloud attack on 
 the trench. Place three gas cylinders about 300 yards from the 
 trench and to windward of it. Have the men in the trenches 
 with sign " Wind dangerous." Two men posted as sentries with 
 alarm signals conveniently at hand. At a signal from the in- 
 structor the gas will be liberated and the alarm sounded by the 
 sentries. Men in the trenches will put on their masks and man 
 the parapets. After the attack has passed trench and' dugout 
 will be actually cleared of gas. 
 
 3. Demonstrate the protection afforded dugouts by means of 
 wet blankets. Have men enter the dugout in squads of four 
 and remove their masks. Masks should be replaced before 
 they reenter the trenches. 
 
 LECTURE NO. 5 (Fifth Day). 
 
 THE CHEMISTRY OF GAS WARFARE. 
 
 As you already know, gases are used in modern warfare in 
 two different ways, namely, as 
 
 1. The gas wave or cloud. 
 
 2. In shells, bombs, or grenades. 
 
 In order that a gas may be used in the first way, namely, for 
 the purpose of the cloud offensive, it must possess certain defi- 
 nite physical properties. 
 
 (a) It must be heavy, so that it will stay close to the ground 
 and not disperse rapidly, but will fill up all depressions, such as 
 trenches and dugouts. 
 
 (&) It must be easily obtainable. 
 
 (c) It must be easily liquefiable and capable of being trans- 
 ported in suitable containers. 
 
35 
 
 GAS USED IN CLOUD ATTACKS. 
 
 Chlorine and phosgene, either individually or mixed, are the 
 principal gases used in attacks of this type. Bromine has been 
 used, but is so corrosive that it is difficult to handle. Because it 
 is so heavy it is frequently mixed with one or both of the other 
 two gases. 
 
 PROPERTIES OF THESE GASES. 
 
 Chlorine is a greenish-yellow gas with a very irritating and 
 pungent odor. It is two and one-half times as heavy as air and 
 can be easily liquefied and transported in dry iron containers. 
 It does not attack iron when no moisture is present. 
 
 Phosgene is a colorless gas with an odor resembling that of 
 green corn that has begun to sour. It is slightly heavier than 
 chlorine and irritates the throat in such a manner as to produce 
 coughing, even though present in very small amounts. It is a 
 liquid below 45 P., and can also be transported in dry iron 
 containers. 
 
 Bromine is a reddish-brown gas, about five and one-half times 
 as heavy as air and is a liquid at about 43 F. It is an intense 
 irritant, producing severe burns of the skin when in contact 
 with it. However, it corrodes metals very rapidly and because 
 of this fact and its expense is used only in connection with one 
 or both of the other two. Because of its weight one can readily 
 see what an advantage it is when it is mixed with others. 
 
 Both chlorine and bromine are acid gases, and hence an alkali 
 is used to combat them. This is furnished in our mask by a 
 special chemical mixture of alkali substance. 
 
 GASES USED IN SHELLS, ETC. 
 
 The gases in shells are in some cases not gases but liquids, 
 which give off varying amounts of vapor when spilled upon the 
 ground. In other cases they are easily liquefiable gases. You 
 can readily see that unless this were the case the amount of gas 
 that could be sent to the enemy trench in a shell would be so 
 little as to make the range of effectiveness very slight. 
 
 Practically all the lachrymatory gases belong to the former 
 type that is, they are liquids. These liquids spill around a 
 shell hole and continue for weeks to give off their irritant or 
 poisonous vapors, for some of them are toxic as well as irritant. 
 
36 
 
 Most of these gases are from liquids derived from bromine and 
 the various liquid distillates obtained as by-products of the coke 
 industry. 
 
 Prussic acid and phosgene are representatives of the easily 
 liquefiable type. Prussic acid is a liquid below 79 F. As a gas 
 it is slightly heavier than air and lias an odor resembling that of 
 bitter almonds. A gas shell containing 7 liters of liquid prusslc 
 acid will liberate about 200 cubic feet of gas on exploding. This 
 is also an acid gas, and is taken care of by our absorber. 
 
 New gases are, however, being constantly devised, and all 
 countries have large laboratories ever at work to devise new 
 gases and also to devise new preventives against the enemy's 
 
 The detection of new and unusual gases require constant 
 watchfulness by troops at the front, and for this purpose certain 
 men are detailed to collect samples of gas after every gas attack, 
 either cloud or shell. These samples are collected from the air 
 in trenches and dugouts by means of vacuum bulbs (show sample 
 vacuum bulb) or by collecting samples of earth from shell 
 craters after a gas-shell bombardment. Samples so collected are 
 sent to laboratories in the rear, where they are studied in the 
 search for new gases. So far the English and American mask 
 has been found proof against all gases now in use, but surprise 
 is the main feature in gas attacks and the utmost vigilance must 
 be maintained to detect the first sign of new gases. 
 
 THE ORGANIZATION OF THE GAS SERVICE IN FOREIGN ARMIES. 
 
 The British gas service, upon which our gas service is mod- 
 eled, consists of a home service and an over-seas service. Both 
 the home service and the over-seas service are divided into a,n 
 offensive and a defensive. The offensive in England is under 
 the direction of the Royal Engineers, and the defensive is under 
 the direction of the Royal Army Medical Corps. In our Army 
 the offensive, so far as it concerns the production of gas shells, 
 etc., is under the direction of the Ordnance Department, and 
 the defensive, e. g., gas masks, resuscitating apparatus, etc., 
 is under the direction of the Medical Department. 
 
 The gas work for both departments in the home territory 
 consists of research work and providing of supplies, and this 
 must be all done on a la^-ge scale. 
 
 The research work for the Ordnance Department concerns 
 itself with the devising of ever-changing and ever more poison- 
 
37 
 
 ous gases for use in cloud attacks, shells, and other projectiles. 
 Research work for the Medical Department concerns itself with 
 the devising of chemical preventatives for nullifying the effect 
 of all gases which the enemy may bring against us. The supply 
 problem for the Ordnance Department is to produce 'the proper 
 projectiles in which to deliver the offensive gases ; that for the 
 Medical Department to produce the paper devices to carry the 
 neutralizing substances. 
 
 The research work, both offensive and defensive, is of a chemi- 
 cal and physiological character and requires the service of a 
 large number of scientists in those professions, whose whole 
 time must be devoted to a constant study of the various ele- 
 ments entering into the offensive and defensive side of gas 
 warfare. . ' 
 
 In England two laboratories are maintained for this purpose 
 one under the engineers for the study of offensive material and 
 another under the medical department for the study of pre- 
 ventive material. In our country we have one large laboratory 
 working on both the offensive and defensive material for both 
 the Army and Navy. The work that this laboratory is called 
 upon to do is enormous, as upon the chemical findings of the 
 laboratory the ultimate success or failure of gas warfare must 
 largely depend. 
 
 ANTI-GAS DUTIES WITHIN AN INFANTRY REGIMENT. 
 
 The gas service in the field forms an intimate part of all 
 tactical organizations. Attached to each army there is an 
 engineer brigade under command of a general officer charged 
 with the duty of making all the gas-cloud attacks with that 
 army, and a chemical adviser charged with all technical mat- 
 ters regarding gas warfare. 
 
 A special gas officer is appointed in each division, so that 
 technical advice is readily available on all matters connected 
 with gas defense. This officer is also charged with the instruc- 
 tion of the divisional anti-gas school. Standing orders are to 
 the effect that commanding officers will facilitate in every way 
 the duties of the divisional gas officer in visiting their lines 
 and inspecting anti-gas arrangements, testing alarms, etc. They 
 should take every opportunity of consulting with the divisional 
 gas officer on all technical questions relating to gas defense. 
 
 In order that there may be a thorough understanding in each 
 organization of all matters pertaining to gas defense, an anti-gas 
 
38 
 
 school is established in each division, and the following officers 
 and noncommissioned officers are required to attend a course of 
 instruction at this school. 
 
 OFFICERS. 
 
 (a) The commanding officer or the second in command and a 
 medical officer from each regiment. 
 (6) All company commanders, 
 (c) Other officers when possible. 
 
 NONCOMMISSIONED OFFICERS. 
 
 (a) Two per company. 
 
 (&) Two from headquarters company. 
 
 (c) Other noncommissioned officers when possible. 
 
 ANTI-GAS DUTIES WITHIN AN INFANTRY REGIMENT. 
 
 [To be modified for other units to suit their organization and duties.] 
 
 The commanding officer is directly responsible for all measures 
 against gas attacks, and company commanders are responsible 
 to the commanding officer for all anti-gas measures within their 
 companies. 
 
 In each company one noncommissioned officer who has been 
 trained at an anti-gas school, and who has been recommended by 
 the divisional gas officer as suitable for duty as " Company gas 
 noncommissioned officer," is specially detailed to assist the com- 
 pany commander in anti-gas measures. At least one other simi- 
 larly trained and recommended noncommissioned officer should 
 be immediately available to take the place of the gas noncom- 
 missioned officer in case of need. 
 
 A similarly trained noncommissioned officer is detailed to regi- 
 mental headquarters for duty with headquarters details. 
 
 The special duties of company gas noncommissioned officers 
 are as follows. Other duties may, however, be performed, pro- 
 vided they do not interfere with gas duties : 
 
 1. They will assist officers at the inspection of box respirators 
 and in making such local repairs as possible. They will assist 
 in training men in the use of anti-gas appliances. 
 
 2. Under the company commander they will have charge of all 
 anti-gas trench stores, as follows : 
 
39 
 
 (a) Strombos horns and other gas-alarm devices. Inspect 
 daily and see that sentries posted to them know how they should 
 be used. 
 
 ( 6 ) Gas-proof shelters. See that the blanket doorways fit and 
 are kept in good order. 
 
 (c) Anti-gas fans. See that they are in their proper position 
 and in serviceable condition. 
 
 (d) Stores of fuel for cleaning shelter. Insure sufficient sup- 
 ply for clearing dugouts, to be maintained under company ar- 
 rangements. 
 
 (e) Vermorcl sprayers. Maintain in working order and see 
 that supply of solution is available. 
 
 (/) Gas-sampling apparatus. Have charge of the vacuum 
 bulbs and gas-testing tubes. Keep a stock of corked bottles and 
 small tins with well-fitting lids for collecting samples of earth 
 and water after a gas-shell attack. 
 
 3. On relief they will assist the company commander in taking 
 over all anti-gas trench stores. The gas company noncommis- 
 sioned officers should accompany the advance party and take 
 over anti-gas trench stores (by daylight if possible). 
 
 4. They will make wind observations every three hours, or 
 more frequently if the wind is in or-nearing a dangerous quarter, 
 and will report any change of wind to the company commander. 
 
 5. During a gas-cloud attack they will take gas samples by 
 means of the vacuum bulbs and gas-testing tubes. 
 
 6. During or after the attack the noncommissioned officer must 
 note down in writing as much information regarding the attack 
 as possible. 
 
 7. As soon as possible after the conclusion of a gas-shell bom- 
 bardment, the gas noncommissioned officer must fill his bottles 
 and tins (two) and take samples of water, mud, or earth from 
 those parts of the line which are smelling most strongly of shell 
 gases. He should note the position of any blind shells. 
 
 8. As soon as possible after a gas attack, all samples and notes 
 will be handed in to the company commander for transmission to 
 the divisional gas officer. 
 
 PRACTICAL INSTRUCTION (Fifth Day). 
 
 1. Repeaj; gas-mask drill in its various forms. 
 
 2. Practical demonstration of lachrymatory gas in shell crater. 
 (Pour ?P5J? benzyl chloride in hole previously prepared. ) Then 
 
40 
 
 demonstrate method of filling shell craters to destroy effects oj 
 gas. 
 
 3. Familiarity with the smell of phosgene. (Liberate a small 
 quantity of phosgene under a closed tent. ) Have each man pull 
 back the flap and smell the phosgene. 
 
 (Sixth Day.) 
 
 General review of the subjects taught during the week. J$ 
 short written quiz is usually advisable for officer. 
 
 o 
 
 THIS BOOK IS DUE ON THE LAST DATE 
 STAMPED BELOW 
 
 AN INITIAL PINE OP 25 CENTS 
 
 WILL BE ASSESSED FOR FAILURE TO RETURN 
 THIS BOOK ON THE DATE DUE. THE PENALTY 
 WILL INCREASE TO SO CENTS ON THE FOURTH 
 DAY AND TO $1.OO ON THE SEVENTH DAY 
 OVERDUE. 
 
 JfiN 
 
V-r 
 
 664369 
 
 ' ' T"" ^- 
 
 UNIVERSITY OF CALIFORNIA UBRARY