Confidential 
 
 FOR OFFICIAL USE ONLY 
 
 MEMORANDUM ON 
 
 GAS POISONING IN WARFARE 
 
 WITH NOTES ON ITS 
 
 PATHOLOGY AND TREATMENT 
 
 NOTE. This Memorandum has been drawn up by a Committee of Con- 
 sultant Physicians and Physiologists for the information of Medical Officers. 
 IT IS TO BE TREATED AS CONFIDENTIAL, AND SHOULD ON NO 
 ACCOUNT BE TAKEN INTO THE TRENCHES. 
 
 EblTED AT THE ARMY WAR COLLEGE 
 MAY, 1917 
 
 WASHINGTON 
 
 GOVERNMENT PRINTING OFFICE 
 1917 
 
Confidential 
 
 FOR OFFICIAL USE ONLY 
 
 MEMORANDUM ON 
 
 GAS POISONING IN WARFARE 
 
 WITH NOTES ON ITS 
 
 PATHOLOGY AND TREATMENT 
 
 NOTE. This Memorandum has been drawn up by a Committee of Con- 
 sultant Physicians and Physiologists for the information of Medical Officers. 
 IT IS TO BE TREATED AS CONFIDENTIAL, AND SHOULD ON NO 
 ACCOUNT BE TAKEN INTO THE TRENCHES. 
 
 EDITED AT THE ARMY WAR COLLEGE 
 MAY, 1917 
 
 WASHINGTON 
 
 GOVERNMENT PRINTING OFFICE 
 1917 
 
uz. 
 
 WAR DEPARTMENT, 
 
 Document No. 593. 
 Office of The Adjutant General. 
 
WAR DEPARTMENT, 
 
 WASHINGTON, May 17, 1917. 
 
 The following Memorandum on Gas Poisoning in Warfare, with 
 notes on its pathology and treatment, is published for the informa- 
 tion and guidance of all concerned. 
 [2599035, A. G. 0.] 
 
 BY ORDER OP THE SECRETARY OP WAR I 
 
 TASKER H. BLISS, 
 Major General, Acting Chief of Staff. 
 
 OFFICIAL: 
 
 H. P. McCAIN, 
 
 The Adjutant General. 
 
 (3) 
 
 664381 
 
GENERAL CONSIDERATIONS. 
 
 The employment of poisonous gases as a means of offensive warfare 
 has made it imperative that medical officers should have some knowl- 
 edge of the action of the various gases that are likely to be met with 
 and of rational lines of treatment which may be adopted in cases of 
 gas poisoning. 
 
 Poisonous gases have been used in warfare with the intention of 
 putting men out of action, hampering Artillery, preventing supports 
 from advancing, and inspiring general terror, so that an advance may 
 be made with a minimum of opposition and some military advantage 
 secured. Apart from any question of an advance, poisonous gases 
 have been used merely as a means of causing a certain number of 
 casualties on the opposing side and of inspiring terror. 
 
 Besides this deliberate use of gas for offensive purposes, poisonous 
 gases are liable to be encountered under other circumstances e. g., 
 during mining operations, or as the result of the imperfect detonation 
 or burning of explosives. 
 
 THE MODE OP ACTION OP POISONOUS GASES. 
 
 Poisonous gases that are liable to be met with can be grouped 
 roughly, according to the main physiological action that they pro- 
 duce on the animal body. It must, however, be clearly understood 
 that it is impossible to draw absolute distinctions, since many of the 
 gases partake of the characters of at least two of the groups. 
 
 I. GASES WHICH ACT AS LUNG IRRITANTS. 
 
 The main characteristic of gases of this group is that they cause the 
 onset of a profuse pulmonary edema. The accumulation of fluid 
 in the lungs interferes with the respiratory exchange, causing intense 
 cyanosis and death by asphyxia. In addition to this these gases are 
 irritating to the respiratory passages, some of them intensely so, 
 causing great pain and discomfort in the chest. They may also cause 
 marked irritation of the eyes and lachrymation. In some cases 
 circulatory failure is a very marked feature, and the cyanosis may 
 then give place to the leaden pallor of collapse. With some gases of 
 this class mild poisoning may lead to a condition somewhat akin to 
 asthma. 
 
 (5) 
 
6 
 
 Type 1 Chlorine. A concentration of 1 in 100,000 can be respired 
 for a considerable time, though this may give rise to subsequent 
 bronchitis. 
 
 A concentration cf 1 in 10,000 is barely respirable by man and 
 experimentally in net borne for more than two or three breaths. It 
 produces i r ritc,tion o-* the ey^s, epasm of the glottis, a feeling of chok- 
 ing, and severe cough. If the inhalation is continued, the struggle 
 for breath becomes more acute and the man will be rapidly in- 
 capacitated. In such a concentration edema of the lungs com- 
 mences very soon and develops steadily. 
 
 Type 2 Nitrous fumes, i. e., nitric oxide and nitrogen peroxide. 
 Sensory irritation of the eyes and upper respiratory passages is slight 
 as a rule, and passes off in a short time after leaving the dangerous 
 atmosphere. For some time after this the man may feel perfectly 
 well and go about his ordinary business, but after the lapse of a few 
 hours acute symptoms of pulmonary edema suddenly come on and 
 progress with alarming rapidity. 
 
 In contradistinction to chlorine poisoning, there is, therefore, a 
 very definite delay before the onset of pulmonary edema, and the 
 slightness of the symptoms shown by the man while he is in the 
 dangerous atmosphere would not naturally lead one to anticipate 
 the disastrous effects which may develop later. 
 
 Type 3 Phosgene. In certain characteristics this gas holds an 
 intermediate position between chlorine and nitrous fumes. Though 
 it is a more intense eye irritant than chlorine, it is not so immedi- 
 ately irritant to the upper respiratory passages and there is some 
 delay before the onset of pulmonary edema. Circulatory failure 
 is apt to be a prominent feature and cases exhibiting a leaden pallor 
 and collapse are the rule rather than the exception. Phosgene 
 incapacitates a man more slowly than chlorine but is a more serious 
 poison. 
 
 II. GASES WHICH ACT AS EYE IRRITANTS OR LACHRYMATORS. 
 
 The main characteristics of this group of gases are that in exceed- 
 ingly small concentrations they exert an intense irritant effect on 
 the eyes and cause so profuse a flow of tears and often so much pain 
 that vision may be impossible. In stronger concentration they may 
 also act as acute lung irritants. 
 
 Type Benzyl bromide. A very minute concentration causes 
 marked lachrymation. A high concentration, when the eyes are 
 protected, rapidly causes respiratory discomfort, irritation of the 
 throat, and nausea. 
 
 
III. GASES WHICH ACT AS DIRECT POISONS OF THE NERVOUS SYSTEM. 
 
 The characteristics of this group of gases are that in sufficient con- 
 centration they act on the central nervous system with great rapidity, 
 causing a cessation and finally a total abolition of its functions. 
 Some of these gases cause delayed pulmonary edema in cases which 
 have not succumbed rapidly from the effects on the central nervous 
 system. 
 
 Type Hydrocyanic acid. Minute concentrations are practically 
 innocuous. High concentrations cause immediate unconsciousness 
 and death in a few seconds. 
 
 Animals if taken out of the poisonous atmosphere as soon as they 
 have fallen down paralyzed, may recover perfectly in a short time. 
 
 IV. GASES WHICH ACT BY INTERFERING WITH THE RESPIRATORY 
 
 PROPERTIES OF THE BLOOD. 
 
 Under this heading may be grouped cases which cause destruction 
 of red cells, alter the hemoglobin, or combine with the hemoglobin 
 to the exclusion of oxygen, so that severe symptoms arise because 
 the oxygen-carrying power of the blood is interfered with. Certain 
 cases may, for instance, lead to destruction of red cells, accom- 
 panied by hemoglobinuria or jaundice. Again, nitrous fumes in 
 strong concentration may cause the alteration of hemoglobin into 
 methemoglobin in addition to producing the intense irritation of the 
 lungs mentioned above. 
 
 Carbon monoxide. This gas owes its poisonous action to the fact 
 that it combines with hemoglobin to form a dissociable compound 
 and thereby takes the place of oxygen. Carbon monoxide has about 
 300 times the affinity for hemoglobin that oxygen has. If therefore 
 a small proportion of carbon monoxide is present in the air breathed, 
 the hemoglobin in the body will divide itself between the two gases, 
 the final partition being determined by the relative concentration 
 of the two gases. The oxygen-carrying power of the blood is pro- 
 gressively diminished as the hemoglobin becomes more and more 
 saturated with carbon monoxide, and symptoms arise owing to the 
 interference with the oxygen supply to the tissues from this cause. 
 
 CIRCUMSTANCES UNDER WHICH GAS POISONING MAY BE MET WITH 
 IN WARFARE. 
 
 Some poisonous gases of the foregoing groups are well adapted for 
 use as offensive agents in warfare, while others are unsuitable owing 
 to various causes, such as difficulty of manufacture or of storage, 
 chemical instability, limited toxicity save in high concentrations 
 
8 
 
 or after prolonged exposure, or insufficient density. Though the 
 acute lung irritants as a whole must be classed among the more 
 powerful methods of destruction, nitrous fumes do not lend them- 
 selves to deliberate offensive use. They may be met with during 
 warfare accidentally under certain circumstances. Carbon mon- 
 oxide, too, is not adapted to offensive use, though it may prove a 
 very serious factor indeed when met with during mining operations. 
 
 THE USE OF GAS FOR OFFENSIVE PURPOSES. 
 
 (a) Cloud gas. The rate at which the cloud gas is carried over the 
 ground intervening between the trenches of the two opposing forces 
 depends entirely on the velocity of the wind. With winds at the 
 rates of 3, 9, and 15 miles per hour, the gas cloud would move 
 forward at the rate of 90, 270, and 450 yards per minute, respectively; 
 and with a wind of 9 miles per hour, the distance of 100 yards would 
 be covered in about 20 seconds. These figures indicate how short 
 may be the time available for warning men in the front trenches of 
 the commencement of a cloud gas attack and emphasize the extreme 
 importance of training troops thoroughly in the use of protective 
 devices. 
 
 (6) Gas shells and gas bombs. In this case the poisonous substance 
 is contained in liquid form in the shell or bomb and is converted into 
 a cloud of vapor on the explosion . As a rule these shells are employed 
 to produce a toxic effect at a distance over a limited area and are 
 most frequently used against batteries, or in the form of a "tir de 
 barrage" to interfere with the movements of supports during an 
 engagement. 
 
 The commonest gas shell used by the Germans contains the 
 lachrymators, benzyl, and xylyl bromides, but shells containing 
 acute lung irritants have also been employed. 
 
 A cloud gas attack necessitates a favorable wind blowing toward 
 the enemy's position, but gas shells can be used even if the wind 
 is blowing toward the user, since if the gas is blown back, it will 
 have been so diluted with air as to be harmless to him. A cloud gas 
 attack may be preceded or accompanied by a gas shell attack, and 
 gas shells of different forms may be fired not only on points behind 
 the trenches but also on the front line and support trenches as well. 
 
 Medical officers must, therefore, remember that more than one 
 method may be used at the same time during a gas attack and that 
 different chemical substances may be simultaneously employed. 
 They must in consequence be on the watch for differences in the 
 symptoms presented by gassed cases so that they may report the 
 facts to headquarters and adopt suitable treatment. 
 
9 
 
 CIRCUMSTANCES UNDER WHICH POISONOUS GASES OTHER THAN 
 THOSE USED DELIBERATELY FOR OFFENSIVE PURPOSES ARE 
 LIABLE TO BE ENCOUNTERED. 
 
 (a) Mine gases. During mining operations^the most dangerous gas 
 met with is carbon monoxide. This arises from the imperfect 
 detonation or combustion of the explosives used for charging the 
 mine or for blasting. The galleries may be flooded with the gas 
 after the explosion of either our own or a hostile mine, as the result 
 of the explosion of a hostile camouflet designed to blow in our gal- 
 leries, or as the result of the explosion or burning of a blasting charge. 
 The gas is liable to be driven into the ground disturbed by the 
 explosion and to come welling out later, especially if the barometer 
 commences to fall after the explosion, or it may be met with in the 
 form of pockets of gas when new galleries are driven through ground 
 disturbed by a previous explosion. Carbon monoxide has even 
 been known to be driven out of the shafts into the adjacent trenches 
 after the explosion of a mine. 
 
 Besides carbon monoxide, nitrous fumes may arise if a charge 
 does not explode properly, and especially if it burns instead of 
 exploding. Nitrous fumes are quickly absorbed by moist ground, 
 and so cases of nitrous fumes poisoning are seldom met with unless 
 men are exposed to the fumes immediately after the explosion or 
 the burning of the charge. 
 
 (6) Fumes from high-explosive shells. Nitrous fumes have so far 
 given rise to no cases of poisoning after the explosion of high-explosive 
 shells. Cases of carbon monoxide poisoning have been known to 
 arise under special circumstances e. g., when a shell has penetrated 
 into a deep dugout before bursting. Such cases are, however, un- 
 likely to arise unless the shell explodes in a confined space, since 
 either a high concentration or a prolonged exposure is required for the 
 production of symptoms. 
 
 (c) Fumes from the firing of guns. In closed machine-gun emplace- 
 ments, owing to the blowback from the gun, enough CO sometimes 
 gets into the air to give rise to symptoms. Symptoms of CO poisoning 
 are also sometimes caused in gun pits owing to the blowback on open- 
 ing the breech when certain forms of powder are used. 
 
 (d) Burning ofnitro explosives. If nitro explosives are accidently 
 set on fire and continue to burn without explosion, there is great 
 danger of poisoning from nitrous fumes. Carbon monoxide poisoning 
 may also occur. 
 
 99456-1? 2 
 
10 
 
 (e) Burning buildings. It must be remembered that when com- 
 bustion takes place in a limited supply of air, as in the interior of a 
 burning building, there is a considerable risk of carbon monoxide 
 poisoning. 
 
 (/) Warming of billets. A burning coke brazier in a small, ill- 
 ventilated billet is very likely to give rise to cases of carbon monoxide 
 poisoning. 
 
 POISONING BY GAS CLOUD. 
 
 The gas used by the Germans in attacks made on the English 
 trenches by poisonous clouds drifting forward on the wind was in the 
 early summer of 1915 chiefly, if not solely, chlorine. Later it 
 became apparent from the change of symptoms in casualties that a 
 different form of gas was being employed and this is believed, though 
 not proved, to be a mixture of chlorine with varying proportions of 
 carbonyl chloride or phosgene gas. It is, therefore, necessary to 
 describe separately the action of each type of cloud gas. 
 
 CLOUD GAS OF SUMMER OP 1915. 
 
 The following account of the pathological changes is based entirely 
 upon observations made on men injured by German cloud gas in 1915, 
 and these observations coincide with what has been noted in labora- 
 tory experiments with chlorine. The effects may be classified under 
 the following headings: 
 
 Irritation and inflammation of the respiratory tract. 
 
 Interference with the circulation. 
 
 General toxic effects. 
 
 RESPIRATORY TRACT. 
 
 Chlorine is very irritant. Sensory nerves are violently stimulated, 
 causing immediate pain and uncontrollable reflex movements, such 
 as coughing or spasmodic gasping, which interfere with respiration. 
 Lachrymation is relatively slight. A heavy concentration of the gas 
 seems almost irrespirable, but the spasmodic check to breathing 
 ultimately gives way, and no case of death from asphyxia immedia- 
 tely upon exposure to the gas has been proved to have occurred in 
 the English lines. Breathing continues, but it is of a spasmodic 
 character and accompanied by violent coughing which, as will be 
 described later, has a very harmful effect on the lungs. 
 
 The irritation of the sensory nerves, however, is not the fatal factor. 
 An inflammatory reaction, with congestion of the vessels, edema of 
 the tissues and an abundant discharge of serous effusion through the 
 
 
11 
 
 dying epithelium occurs all the way down the respiratory tract. 
 This begins at the back of the throat; the larynx, with its resistant 
 epithelium, escapes injury, but the damage to the surface tissues 
 increases progressively down the trachea, the bronchi and their finer 
 branchings, and ultimately attains its maximum in the air sacs. 
 The bronchioles are rapidly filled with a serous exudate which passes 
 up into the trachea and is coughed out. 
 
 A universal obstruction in this way of the bronchioles alone would 
 suffice to cause death by simple blockage of the airway and asphyxia. 
 But the injury is not confined to the bronchial tree, and probably the 
 effusion in the tubes alone is not dense enough to hinder the passage 
 of some air up and down, though even this thin fluid may constitute 
 a very serious mechanical obstruction when it is churned up into a 
 continuous foam by violent respiratory efforts. At first there may be 
 so much spasmodic contraction of the muscles of the smaller bron- 
 chioles that the gas is denied access to many areas of the lungs. 
 Sooner or later these relax, and the irritant vapors then destroy the 
 pulmonary epithelium, while the air sacs rapidly, fill up with inflam- 
 matory exudate and become utterly useless for the purpose of respira- 
 tory exchange. The edematous effusion must ultimately compress 
 the capillaries and cause great hindrance to the flow of blood through 
 the lungs. The irritation spreads so widely that a blood-stained 
 serous effusion soon accumulates in the pleural cavity, but this is 
 never so abundant as to require aspiration. 
 
 In addition to this inflammatory edema, which chokes the circula- 
 tion and prevents gaseous exchange, there is often some actual 
 damage to the structure of the lungs. The violent coughing and 
 inspiratory efforts which may result from inhalation of the gas may 
 be so forcible that the partitions between the alveoli are torn and 
 air may even burst its way out into the areolar tissue and escape 
 along the hilum of the lung and up into the subcutaneous tissues 
 of the neck. Such disruptive emphysema adds at once to the 
 disability of the sufferer, since it throws out of action that part of 
 the lung which is not yet submerged in the rising flood of edema fluid, 
 and it may lead to permanent shortness of breath if the man survives. 
 
 There are, therefore, four factors which develop in rapid suc- 
 cession and prevent exchange of respiratory gases through the lungs: 
 
 (1) Narrowing of the bronchioles by spasmodic contraction of 
 muscles in their walls. 
 
 (2) Disruptive emphysema. 
 
 (3) Obstruction of the bronchial tubes by exudate. 
 
12 
 
 (4) Flooding of the pulmonary air sacs by serous effusion into 
 them. 
 
 The result of these changes in the lungs, of which (3) and (4) are 
 the most important, is that the intake of oxygen and the elimination 
 of carbon dioxide are seriously interfered with, and the man passes 
 into a state of asphyxial cyanosis in which mental failure and 
 unconsciousness may rapidly supervene. During this state the 
 breathing is labored, rapid, and interrupted by spasmodic bouts of 
 coughing. The blue color of the face shows the urgent need for 
 oxygen, and every muscular effort made by the body and by the 
 heart increases that need. Coughing is helpful in so far as it may 
 dislodge exudate from the bronchi, but the violent effort is prodigal 
 of such oxygen as can be supplied and it tends to increase the dis- 
 ruptive emphysema. The increased respiration is caused both by 
 the accumulation of carbon dioxide and by the want of oxygen 
 and not by the absorption of any poisonous substance from the gas. 
 In itself, this increased breathing does no harm and it helps in 
 eliminating C0 2 and increasing the intake of oxygen which are the 
 chief needs of the moment. 
 
 Interference with circulation. The ordinary phenomena in as- 
 phyxia of mechanical origin are that the blood pressure rises and 
 that the heart soon loses its full driving power because its muscle 
 can not maintain this increased effort when it is working with a 
 scanty supply of oxygen. Consequently the pulse rate quickens, 
 the right heart dilates and the blood tends to be pooled up behind 
 it in the great veins. If this failure proceeds apace, a patient who 
 at the beginning showed congestive cyanosis of the face with a full 
 pulse will gradually assume a gray pallor while the pulse accele- 
 rates and falls off in power. These changes are present in cloud 
 gas poisoning and they are augmented by the edema of the lungs, 
 which directly obstructs the pulmonary circulation and causes an 
 earlier failure of the right side of the heart. 
 
 If the patient during this critical time tries to carry on his 
 work and remain standing, he will use up still more rapidly the 
 little oxygen that he is receiving, extra work will be loaded on to 
 a heart which is already overstrained and the circulation will be 
 likely to fail still more speedily on account of the difficulty of 
 maintaining compensation in the upright posture. 
 
 There is no interference with the respiratory properties of the 
 blood which can at once take up any oxygen that reaches it through 
 the lungs. 
 
13 
 
 General toxic effects. Experiments indicate that chlorine is not 
 absorbed from the lungs and that the effects produced by this gas 
 are only a direct and local inflammation with secondary results 
 which are either of a mechanical nature or caused by oxygen want, 
 or due to a nervous reflex from the seat of injury. Changes of a 
 general nature do undeniably appear in the nervous, circulatory, 
 alimentary, and renal systems of a man who has been poisoned by 
 cloud gas, but these are probably the result of the asphyxia rather 
 than of the direct action of the gas. Thus in the mild cases there 
 is a sense of fatigue and of being altogether done up, and in the 
 serious cases even unconsciousness, but these features are not in 
 excess of what may result from oxygen want. The retching and 
 vomiting that generally occur in the first stages of poisoning may be 
 due only to direct irritation of the back of the throat and of the 
 stomach by the gas, or may be the direct sequence of violent bouts 
 of coughing;, while the diarrhea, which sometimes is an early feature, 
 may be that of emotion. 
 
 Microscopic examination of the kidneys in death, a few days after 
 gassing, reveals very definite inflammatory and destructive changes, 
 and such kidneys may be swollen and enlarged as though with a 
 parenchymatous nephritis. This change, however produced, rarely 
 leads to any clinical feature of renal trouble. In the first few days 
 the urine contains neither sugar nor albumen nor many casts, and 
 it is very unusual for albuminuria to develop later. 
 
 The circulation may fail with unexpected rapidity and the patient 
 soon present the aspect of a leaden gray cyanosis. But in general 
 terms the clinical picture with chlorine may be summed up as that 
 of a man suffering from intense irritation of the respiratory tract 
 and dying by asphyxia from the fluid that has drowned his lungs. 
 It does not suggest a deeper toxic action. 
 
 Post-mortem findings. In a case of death at 24 hours after gas- 
 sing, the trachea and bronchi are purple red and congested, while 
 a thin serous exudate wells up into them from the lungs. The 
 latter organs are heavy and edematous, while aerated islets of 
 emphysematous overdistention alternate with depressed purple 
 patches of collapse. On section, serous fluid drips abundantly 
 from the lung tissue. Air that has escaped from ruptured vesicles 
 is seen in chains of bubbles on the surface of the lungs, along the 
 interlobar fissure and even penetrating the tissues of the medias- 
 tinum. In some of the earliest cases the most intense disruptive 
 emphysema was observed, destroying the air sacs and interfering 
 with the circulation in their walls. 
 
14 
 
 fetecmal hemorrhages appear on the surface of the lungs, on 
 the heart, and also on the inner surface of the stomach. All the 
 veins are greatly distended and the abdominal viscera are en- 
 gorged with dark blood that clots very early after death. The 
 heart itself may fail to show right-sided dilatation, for this does not 
 of necessity appear post mortem in cases of asphyxial death. 
 
 If the man succumbs at a later date, inflammatory complica- 
 tions appear in the lungs. There is superficial pleurisy, scattered 
 broncho-pneumonia, and a purulent secretion in the bronchi. The 
 serous exudate will then be found to have disappeared and no fluid 
 drips from the cut surface of the lungs. 
 
 CLOUD GAS OF 1916. 
 
 The symptoms tend to differ from those produced by chlorine in 
 three main details. 
 
 (1) Subjective respiratory irritation is much less in evidence. 
 The men do not suffer with such violent coughing when first ex- 
 posed to the gas. There is consequently less disruptive emphy- 
 sema of the lungs, and subcutaneous emphysema of the neck is 
 rare, while post-mortem examination in early cases often fails to 
 find anything more than a little escape of air along the inter lobar 
 fissure. 
 
 (2) The poisonous effects may appear speedily with cyanotic 
 asphyxia, but sometimes they are more insidious in their onset. A 
 man may feel able to carry on his work for an hour or two with 
 only trivial symptoms; then he rapidly becomes worse and passes 
 into a state of grayish white collapse, with progressive edema of 
 the lungs that may soon be fatal. It has even been reported from 
 the trenches that men who have passed through a gas attack and 
 seemed to have suffered but slightly have died abruptly some 
 hours later upon attempting some bodily effort. 
 
 (3) Features suggestive of general collapse are more in evidence. 
 There is a much greater tendency to circulatory failure. Many of 
 the cases that die on the first day show a leaden gray tint of the 
 face rather than a purple red cyanosis; the pulse is rapid and of 
 poor tension. Mental confusion or mild delirium with restlessness 
 and unconsciousness become more prominent in the severe cases. 
 
 No case has been reported in the armies of death immediately 
 upon exposure to the gas, although men have gone through an 
 attack of gas in high concentration without wearing a mask at 
 all and succumbed in consequence an hour or more later. 
 
 
15 
 
 The action of phosgene (COC1 2 ) differs from that of chlorine in 
 certain respects. Upon meeting moist surfaces it is broken up and 
 hydrochloric acid is liberated. It excites less spasm than does 
 chlorine in the upper respiratory tract, and so can penetrate to the 
 innermost recesses of the lungs, where it causes an irritant edema 
 which may be a little delayed in its development, -like that caused 
 by the acids formed from nitrous fumes, although the delay in the 
 latter case is more prolonged. Experiments do not show that the 
 products of phosgene are absorbed from the lung and act as general 
 poisons apart from their local action. 
 
 POST-MORTEM FINDINGS. 
 
 Two hours after exposure to gas. In a case of death by asphyxial 
 cyanosis where inflammatory effusion had developed with great 
 rapidity the lungs were smaller than normal, heavy, uniformly 
 airless and purple, so that each resembled a big spleen. There was 
 no disruptive emphysema. Thin serous fluid ran abundantly from 
 the surface when cut across. Each pleural cavity contained about 
 15 ounces of serous effusion. 
 
 Second and third day. There is no striking difference between 
 the cases which had shown pallid collapse and those which suc- 
 cumbed in extreme cyanosis. The condition of the heart is found 
 to be variable, but there is always evidence in the viscera of vas- 
 cular engorgement from failure of circulation. The lungs never 
 show voluminous emphysema, and indeed the earlier the death the 
 greater is the serous edema in their substance. On the second 
 day the fluid does not drip quite so freely from the cut surface as 
 on the first, and toward the beginning of the third day the general 
 aeration of the lung is everywhere greater, while relatively large 
 islets of well-aerated and slightly emphysematous lung may be 
 present between areas of edema or of collapse. This aerated con- 
 dition appears at first in the lower lobes of the lungs where they 
 are in contact with the diaphragm, while edema persists longest 
 and is most profuse in the upper lobes. 
 
 A day later and no serous fluid at all escapes from the cut sur- 
 face. At this date inflammatory complications tend to appear in 
 a surface pleurisy, and areas of the lung are found to be slightly 
 friable and entering into a condition of broncho-pneumonia. 
 
 It may be that cases of extensive and overwhelming edema 
 succumb at once, while those in which on the second or third day 
 larger islets of aerated lung alternating with edematous patches 
 are seen, had from the beginning been in that state, so that they 
 
16 
 
 succumbed later than the completely edematous group because 
 the injury to the lung was less. But the general evidence favors 
 a more hopeful view, namely, that the edema fluid is rapidly 
 absorbed from the second day onward, and that the later post 
 mortems illustrate the stages in this recovery. The chief fact in 
 support of this view is that patients who had been deeply cyan- 
 osed at first, with the usual signs of extensive pulmonary edema, 
 and so asphyxiated as to be unconscious for a couple of days, may 
 yet recover so completely that eight or nine days after exposure 
 to gas it is difficult to discover any physical signs of edema in the 
 lung. 
 
 SYMPTOMS. 
 
 Onset. Upon exposure to chlorine alone, a man feels immediate 
 respiratory distress. He coughs violently and speech is made im- 
 possible by his spluttering gasps. With the later forms of drift 
 gas, the onset is slightly altered. There is some lachrymation. 
 The throat feels gripped and the chest tight. Breathing is difficult 
 but not impossible. Coughing develops a quarter of an hour or 
 more later. Nausea and vomiting appear quickly, so that a man 
 who was slow in getting protection may vomit inside his gas mask. 
 Headache and throbbing sensations in the body are experienced. 
 
 Development. Coughing and retching increase. The respiration 
 becomes very hurried and labored, though shallow. The patient's 
 face assumes a cyanotic hue; he may lose muscular power and con- 
 sciousness and die in an hour or two. Those who survive longer 
 show the following features: 
 
 Headache, pain behind the sternum and in the epigastrium. 
 Extreme restlessness and anxiety, or a semicoma with a mutter- 
 ing delirium, from which as a rule they can be roused to answer 
 questions. Varying cough, sometimes slight, sometimes reiterant 
 with a croupous rattling from exudate in the trachea. There is 
 practically no laryngitis. A cyanotic blueness in the lips and ears, 
 which may accompany a flushed lividity of the face or the grayish- 
 yellow pallor of collapse. Extremely rapid respiration, from 40 up 
 to even 80 a minute, of a shallow type on a distended chest, and often 
 marked by a jerking grunt of expiration. A pulse of about 100, 
 which may rise to a higher rate and fall to a very low pressure in 
 the gray examples of collapse. The skin is dry, and either hot or 
 cold in correspondence with the state of collapse. Expectoration 
 may be very slight, though in others there soon develops an 
 abundant discharge of thin watery fluid, often streaked with blood, 
 which simply flows from the mouth as the dying patient loses power 
 
17 
 
 to expel it. After death, the foam from this fluid]may dry to a white 
 efflorescence around the mouth. The percussion note is slightly 
 flattened over the lungs behind, where the breath sounds are much 
 weakened, but otherwise unchanged in quality. Fine rales are 
 heard behind and in the axillae. There are no tubular breath sounds. 
 In front there may be extremely little change beyond harshness in 
 the breath sounds. The physical signs fail altogether to indicate 
 the extent to which the lungs are damaged, for in any area examined 
 there is always some aeration of the bronchioles and alveoli which 
 suffices to produce relatively normal sounds on auscultation. 
 
 The color, the pulse, and the rate of respiration are the chief 
 guides to prognosis. 
 
 Progress. Four-fifths of the deaths occur in the first 24 hours. 
 Very few succumb after the third day. A man, who at first seemed 
 to be lightly gassed, may, toward the end of the first day, develop 
 cyanosis and die; but from the end of the second day onward, there is 
 no danger to be apprehended for the less grave cases. On the second 
 day the sputum becomes less abundant, more viscous and yellow 
 tinted. The dyspnea persists and the temperature is raised. If 
 complications develop subsequently from infections of the raw 
 respiratory tract, they will be shown by persistence of fever, by a 
 purulent sputum, and by signs of broncho-pneumonic consolidation. 
 
 But as a rule the patient recovers rapidly after the third day, and 
 at the end of a week he is fully convalescent. Cough, pain in the 
 chest, which is often very severe beneath the rib margins, shortness 
 of breath, loss of appetite with gastric pain, and general lassitude 
 persist longest of the symptoms. There are no serious after results to 
 be apprehended. A man who has been badly gassed requires a long 
 rest; but the majority, if free from neurasthenic symptoms, are fit for 
 light duty in a very few weeks, provided that they are allowed 
 sufficient rest at first. The heart and circulation are severely 
 strained by gas poisoning. Convalescents who show tachycardia 
 must be carefully watched lest too heavy physical effort early in the 
 first month of recovery induces further strain and lead to the condi- 
 tion of irritable soldier's heart, from which recovery will be long 
 delayed. 
 
 RARITIES. 
 
 Brain. In some cases that died after two or three days of persistent 
 cyanosis and unconsciousness the white matter of the brain was 
 found to be peppered with tiny petechial hemorrhages. These are 
 the direct outcome of the asphyxial state and have little clinical 
 
18 
 
 significance. Large cerebral hemorrhages have, however, been 
 noted, occurring on the first or second day in cases of plethoric 
 cyanosis. 
 
 Vascular obstruction. Occasionally the peripheral arteries to the 
 limbs may become occluded. As a rule, the threatening gangrene 
 clears up in these cases. 
 
 Stomach. Petechial hemorrhages and a slight superficial ulcera- 
 tion are often seen post mortem over the inner surface of the cardiac 
 fundus. The stomach has occasionally at autopsy been found to be 
 full of blood from an extension of this ulcerative process, but only in 
 one case has death occurred with hematemesis. The gastric derange- 
 ments, which generally persist during convalescence, are not of a 
 type suggesting the result of an ulcerative process. 
 
 Kidney. Clinical nephritis is rare, and its occurrence may in each 
 case have been a chance coincidence. 
 
 TREATMENT. 
 GENERAL CONSIDERATIONS. 
 
 REST IS THE MOST IMPORTANT POINT OF ALL IN THE GENERAL 
 TREATMENT OF GAS CASUALTIES. 
 
 Men, and especially officers, should be warned beforehand that 
 if lightly gassed they must refrain from moving about or shouting 
 out orders. Physical strain after gassing may easily involve the 
 loss of a life that might otherwise have been restored to the fighting 
 line in a short time. The principle of attaining complete rest as 
 soon as possible underlies the detailed advice for dealing with gas 
 casualties that is given below, and is the reason for their detention 
 at the casualty clearing stations. All kit that hinders the play of 
 the respiratory muscles, especially belts and suspenders, should be 
 undone. Sleep brings improvement, and restless excited cases 
 should be quieted by morphia. It is important that arrangements 
 should be planned beforehand at each casualty clearing station so 
 that even a large number of gas casualties can be handled with such 
 discipline and control as will at once introduce a sense of order and 
 quietude, and by separating those who are more dangerously ill from 
 the remainder, enable the less severe cases to get to sleep at once. 
 
 Next in importance to rest comes the use of oxygen, protection 
 from cold, special stimulants or drugs, venesection, and methods for 
 removing serous exudate from the lungs. 
 
 Bronchial spasm does not seem to be a serious danger with the 
 present form of cloud gas. Life or death is decided by the degree 
 
19 
 
 of pulmonary edema and asphyxia with circulatory failure. The 
 edema fluid tends to be absorbed quickly, and if the patient can 
 be carried alive through the first two days, he should recover. 
 Precautions in the meantime need to be taken to lessen the chance 
 that secondary respiratory infections may develop as a later com- 
 plication. 
 
 Oxygen, if rightly administered, will generally lessen cyanosis, 
 and therefore improve the patient's chance of life. But the lung 
 surface available for absorption is so small that the oxygen must 
 be given in high concentration. The simple admixture with air 
 obtained by open flow from a funnel or a tube placed in the 
 patient's mouth is useless, and since it wastes valuable oxygen it 
 should be forbidden. Given as the pure gas from a bag with a 
 valved face mask, as described in Treatment at Casualty Clearing 
 Stations (see p. 22), say for 3 or 4 minutes every quarter of an hour, 
 an oxygen cylinder of 20 feet capacity will last about 4 hours. By 
 this means life can undoubtedly be saved in some of the apparently 
 desperate cases. The administration must be continued night and 
 day, so as to hold cyanosis in check. The consumption of oxygen 
 by this method is so large that all care must be taken to economize 
 cylinders, the provision of which, under active service conditions 
 is necessarily limited by considerations of transport. Many casual- 
 ties are so severely poisoned that their condition is seen in the first 
 few hours to be hopeless. Some selection of the cases for oxygen 
 treatment must therefore generally be made, and it is especially 
 with the intermediate group who are surviving into the second day 
 that oxygen has the best chance of acting with ultimate advantage. 
 It is quite unnecessary to use it for relatively mild cases. Deep 
 cyanosis, whether of the congestive or pallid type, is the indication 
 of need, and the lividity can always almost be lessened if the face- 
 mask is properly applied. 
 
 The subcutaneous injection of oxygen is useless. 
 
 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 temporarily 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 broncho-pneumonia. 
 
 Special stimulants and drugs. Ammonia is very useful as an inha- 
 lation from the small ampoules supplied. It is necessary to warn 
 orderlies that these ampoules are to be held at some distance from 
 the patient's mouth, and that their use should not be persisted in 
 
20 
 
 where they seem to aggravate the difficulty of breathing. The 
 action is more as a stimulant than in chemical antagonism to the 
 chlorine. 
 
 Brandy and water is a good restorative when given in small sips. 
 Cases of gray collapse with a rapid pulse of poor tension do not 
 react well to stimulant drugs and are almost hopeless when they 
 develop this condition in the first day. Pituitrin, 0.5 cc. hypo- 
 dermically every three hours, gives some aid to a failing heart. The 
 benefit of digitalin and strychnine is more doubtful. 
 
 Venesection gives real relief to men with deep cyanosis and a 
 full pulse. The headache is lessened, the breathing feels easier, and 
 the patient may soon fall into a sleep that conserves his strength. 
 It appears to be harmful in collapsed cases with a poor pulse, and it 
 should not be postponed until the patient passes into this dangerous 
 state. 
 
 Methods for aiding the discharge ofexudatefrom the lungs. (1) Emetics 
 have been given at various times in the hope that the lungs would 
 be partly emptied in the act of vomiting. The effort is very ex- 
 hausting and the results do not justify the treatment in late cases. 
 But in the first few hours, before the patient is gravely ill, vomiting 
 is probably good and retching may be encouraged by simple means. 
 Later, it is better to try and allay gastric pain or retching by the 
 use of drinks with sodium bicarbonate. Beef tea is not to be recom- 
 mended in view of the possibility of slight gastric ulceration. 
 
 (2) In the first day, if there is much fluid expectoration, good 
 results may be obtained by postural treatment, such as by turning 
 the head of the patient sideways and then raising the foot end of 
 the stretcher two or three feet, or even higher, for a few minutes 
 at a time. 
 
 (3) Schafer's artificial respiration has occasionally proved of 
 service in expelling fluid from the chest, but it is necessary to watch 
 its effect on the patient very closely lest disaster ensue. 
 
 (4) Expectorants in large doses, such as 10 or 15 grains of ammo- 
 nium carbonate, are probably harmful at the beginning, for they 
 will cause nausea and an irritant cough which will interfere with 
 sleep and may augment the tendency to disruptive emphysema of 
 the lungs. Patients who are not seriously ill should be given a 
 simple mixture such as amm. carb. gr. v and vin. ipecac, m. x. 6 
 hourly on the second day. Later treatment might comprise ordi- 
 nary medicinal measures such as potassium iodide, atropine, steam 
 tents with tincture benzoin compound, etc., for symptoms as they 
 arise. 
 
 
21 
 
 REGULATIONS FOB TREATMENT OF GASSED CASES. 
 TREATMENT BY REGIMENTAL MEDICAL OFFICERS. 
 
 1. All ranks should be warned of the need for seeing that the 
 gas masks of wounded men are kept properly in position until 
 the danger from gas has passed away, and also of the importance 
 to lightlj- gassed cases of remaining absolutely quiet. 
 
 While the gas cloud is concentrated, all ranks should refrain as 
 far as possible from movement, so that they may breathe slowly 
 and keep the current of air through the gas mask at a low velocity. 
 
 2. After the order has been given for removal of masks, ammonia 
 inhalations from the capsules should be given by stretcher bearers 
 to all gassed men with difficulty in breathing, but their use should 
 not be persisted with in those special cases where the ammonia 
 seems to increase the discomfort of the patient. 
 
 3. Clothing over the chest should be loosened, the suspenders and 
 belt undone in front and equipment removed. 
 
 4. Vomiting at first is beneficial and it may be encouraged by 
 drinks of tepid water, either alone or with salt (1 tablespoonful to 
 half a pint or more of water), and the back of the throat should be 
 tickled shortly after the drink has been taken. 
 
 5. Experience has shown that atropine is of no use in the early 
 stages ot gas poisoning. 
 
 6. All gas casualties must be evacuated as soon as possible to 
 dressing stations. All except the lightest cases should, as far as 
 possible, be evacuated lying down, and walking cases should be 
 warned to seek assistance in going back along the trenches so as 
 to avoid physical effort as much as possible. Special attention 
 should be paid to men who complain of feeling collapsed, though 
 they show no manifest features of having been gassed, since these 
 may develop later the serious form of delayed poisoning. 
 
 Rest is the one point that is essential from beginning to end of 
 the treatment of gas casualties. Gassed men should not be allowed 
 to carry their own equipment back from the trenches. It is sug- 
 gested that arrangements for the disposal of kit should be made 
 regimentally in advance. 
 
 TREATMENT IN DRESSING STATIONS. 
 
 1. Casualties should be kept lying down in the open air, so far 
 as weather permits. Suspenders must be undone and clothing over 
 the chest loosened, so as to give freedom for breathing. 
 
22 
 
 2. Ammonia inhalations should be given. Experience has shown 
 that atropine injections are of very doubtful value. 
 
 3. If the patient still feels inclined to vomit, he may be given 
 tepid drafts of salt and water, and the back of the throat tickled. 
 
 4. Eestless cases, if fully conscious, may be given one quietening 
 injection of one-fourth grain morphia. The time of injection and 
 the dose must be recorded on the diagnosis tag. 
 
 5. Severe cases fall into two groups: The "collapsed" with a 
 poor pulse and leaden gray tint, and the "cyanotic" or "blue" 
 with a full pulse and general asphyxial lividity. 
 
 6. Collapsed cases may be retained at the dressing station for a 
 short time, and their state of collapse combated by stimulants 
 such as external warmth, hot drinks, brandy, pituitary extract, or 
 other drugs. If there is much fluid flowing up through the mouth, 
 the feet of the stretcher should be raised to a height of about 4 feet 
 and the patient's head turned slightly sideways. This position 
 should not be maintained for more than a few minutes and it should 
 be abandoned if it aggravates the cyanosis or fails to increase the 
 discharge of fluid. 
 
 7. Blue cases of severe cyanosis require continuous treatment 
 with oxygen in high concentration. They should therefore be 
 evacuated as soon as possible to the nearest casualty clearing station 
 or field hospital, unless special apparatus for their treatment is avail- 
 able at the dressing station. If there is unavoidable delay before 
 transference the treatment recommended at the casualty clearing 
 station, paragraphs 7 and 8, should be tried. 
 
 8. All cases except the mildest should be evacuated lying down, 
 and the severe cases, with the exception of those of grave collapse, 
 should be transferred first of all. 
 
 TREATMENT AT FIELD HOSPITALS AND CASUALTY CLEARING STATIONS. 
 
 1. Serious cases should at once be separated from the slight, so 
 that the latter may lose their anxiety and get to sleep. 
 
 2. Ammonia inhalations may be useful on admission at any time 
 up to 24 hours after exposure to gas. 
 
 3. Open air treatment is best, if the weather permits, and com- 
 plete rest is essential for the first two days. The clothing and 
 suspenders should be loosened, and the worst cases should be un- 
 dressed and put to bed wherever this is possible. 
 
 No patient should be allowed to leave his bed or stretcher for 
 any purpose whatsoever. 
 
23 
 
 4. Restless cases, if not unconscious, may be quieted by one 
 injection of one-quarter grain morphia. 
 
 5. Collapsed cases should be treated with warmth and stimulants 
 as described in dressing station 6, and oxygen should be used in 
 addition. Atropine is harmful to these patients. 
 
 6. Attention should be paid to the posture of unconscious cases, 
 both to aid discharge of any fluid that may be escaping from the 
 lungs and to avoid injury to nerves or skin by pressure, e. g., from 
 a clasp knife or the edge of the stretcher, if the patient is not 
 undressed and in bed. 
 
 7. Cyanosis can be lessened by the administration of oxygen in 
 high concentration. For this purpose the flow from a simple 
 funnel or a tube in the mouth is inadequate and wasteful of the 
 gas. An apparatus should be used with a valved face mask, such 
 as that for nitrous oxide anesthesia, the valves being so set that 
 the patient breathes in oxygen from the bag and breathes out into 
 the open air. The treatment should be continued hour after hour 
 with brief intervals until the edema of the lungs clears up. Cases 
 may recover after being cyanosed and unconscious for two days. 
 
 8. Venesection, performed slowly, to the amount of 15 or 20 
 ounces may be of use to "blue" cases if practiced early and before 
 the pulse begins to fall. 
 
 9. Expectorants. Drugs such as ammonium carbonate and vinum 
 ipecac are recommended for use in expectorant doses from the 
 second day onward. 
 
 10. The diet should be light and simple. Measures should be 
 taken to open the bowels. 
 
 11. As far as circumstances permit, no case should be evacuated 
 to the line of communication until definite cyanosis or serious symp- 
 toms have disappeared. A note should be sent down with those 
 cases which have passed through a condition of gravity, so as to guide 
 the medical officer on the line of communication as to the future 
 treatment of the case. 
 
 LINES OF COMMUNICATION. 
 
 The methods of treatment advised at casualty clearing stations 
 are applicable for use in hospitals on the line of communication 
 when circumstances necessitate the early evacuation of cases. 
 
 A very large proportion of the casualties sent to the base as "gassed 
 cases " are likely to become fit for duty after a short rest. Wastage 
 by transfer to home territory is to be avoided, and medical officers 
 should exercise the greatest care in selecting cases for evacuation 
 to home hospitals. 
 
24 
 
 As a rule, only cases in which there was a clear history of grave 
 cyanosis or collapse, or in which secondary infections of the respi- 
 ratory tract have developed, should be sent farther than the base. 
 It may be taken for granted that all casualties which had been 
 detained in a casualty clearing station for five days were of a serious 
 nature, whatever their condition on arrival at the base hospital. 
 
 Rest stations. Rest, with the possibility of lying down on a bed 
 at any time of the day, must be provided during the first two or 
 three weeks for all cases except the very mildest. Arrangements 
 should, when possible, be made at the base to give accommodation, 
 if the patients can not be retained in the main hospitals, for an easy 
 life of this nature which is not permitted in the usual routine of 
 convalescent depots. 
 
 ^Convalescent depots. Gas casualties, who show neurasthenic or 
 cardio- vascular weakness after three weeks' treatment at the depot, 
 should be transferred to home hospitals. 
 
 INDEX TO DRUGS WHICH HAVE AT VARIOUS TIMES BEEN USED. 
 
 Ammonia. The benefit of occasional inhalations of ammonia 
 during the fir?t day is universally admitted. Spiritus ammon. 
 aromat. in 4 cc. doses with plenty of water is useful as a direct 
 stimulant, but it does not ease breathing in the same way as does 
 vapor. 
 
 Ammonium carbonate. In large doses of gr. xv as an emetic has 
 proved harmful and never done good in the early stages. As an 
 expectorant it should only be used in small doses of gr. v. 
 
 Apomorphine. In hypodermic doses of gr. ^ has been recom- 
 mended as an emetic. The vomiting often fails, the drug is depres- 
 sant, and its use had never proved to be of the least value. 
 
 Atropine has been supposed to be useful in the early stages of 
 poisoning, both to relieve bronchial spasm and to check the secretion 
 of edema fluid. The drug has been extensively tried, both in the 
 French and British medical services, and no conclusive evidence of 
 such benefit has been found. On the other hand, atropine does tend 
 to accelerate the heart beat, and a result of this nature is an actual 
 disadvantage to an asphyxiated patient. Its use in the first two or 
 three days should therefore be discontinued. 
 
 Camphor in conjunction with ether forms a useful stimulant in 
 cases of collapse. Th3 Japanese in the Russian War used as a general 
 stimulant a hypodermic injection of 10 or 15 minims of camphor 1 
 part, ether 4-5 parts, olive oil 4 parts. It is possible that this might 
 also be of value in cases of gas poisoning associated with collapse. 
 
25 
 
 Digitolin, grain 1/100, hypodermically, has so slight an action that 
 it probably is not worth using in the two or three critical days of 
 acute pulmonary edema. 
 
 Ipecacuanha has been recommended as having a specific action 
 in promoting the absorption of edema fluid. For this purpose, 
 20 to 30 minims of the Vinum have been given two-hourly. Nausea 
 and emesis are not aimed at. The evidence as to its action in this 
 sense is inconclusive, though it is useful in smaller doses as an 
 ordinary expectorant. The drug should not be given as an emetic, 
 because it produces depression. 
 
 The extractive, Emetine, has been tried hypodermically in 
 repeated doses of gr. J and without any apparent benefit whatso- 
 ever. 
 
 Morphia is most useful as a sedative and may be given even to 
 deeply cyanosed patients for extreme restlessness. The dose should 
 not be large, gr. , followed, if need be by gr. |, or 15 to 20 minims 
 of tinct. opii. 
 
 Phenacetin and Aspirin have been given to relieve the headache 
 caused by mine-gas poisoning, and they were found to produce a 
 dangerous state of collapse in these patients. It is therefore in- 
 advisable to use them for the headache that follows the inhalation 
 of cloud gas. 
 
 Pituitrin 0-5 cc. into the muscles or hypodermically increases 
 card io- vascular tone for a short time and gives aid to a failing heart. 
 If a second injection is given 15 to 20 minutes after the first, it may 
 cause the pressure to fall. An interval of three hours should be 
 observed if the dose is repeated. 
 
 Sodium lactate taken by the mouth every four hours in 2 drachm 
 doses of a 50 per cent solution has been employed with a view to 
 augmenting the alkaline bases of the blood, fixing some of the 
 excess of carbon dioxide, and thereby tending to lessen the rate 
 of respiration. The main features of gas poisoning are not influenced 
 by this method of treatment. 
 
 Sparteine has erroneously been supposed to be a cardiac tonic and 
 a useful drug in the place of digitalin. Actually it is a poison which 
 slows and weakens the heartbeat. 
 
 Strychnine, one-thirtieth grain, may be employed in the early 
 stages of pallid collapse. 
 
 NITROUS FUMES. 
 
 Though no cases of nitrous fumes poisoning have hitherto been 
 recorded, the possibility of their occurrence owing to exposure to 
 the fumes of burning explosives should not be lost sight of. 
 
26 
 
 The great danger of nitrous fumes arises from the fact that in the 
 concentrations usually met with there is comparatively little irrita- 
 tion of the eyes or upper respiratory passages, and a man working 
 in such an atmosphere will not recognize its deadly nature. Air 
 which contains enough nitrous fumes to cause feelings of irritation 
 in the nose or air passages must be regarded as very dangerous. 
 Nitrous fumes are very soluble in water, and the gas may be readily 
 removed from the atmosphere by means of a water spray, whilst a 
 few folds of a handkerchief or a towel wetted with water and tied 
 over the nose and mouth will give efficient protection in the ab- 
 sence of a mask. The possibility of the simultaneous occurrence of 
 carbon monoxide in atmospheres containing nitrous fumes must be 
 remembered. 
 
 Owing to the delay in the onset of serious symptoms, it is essential 
 that any man who is suspected of having been exposed to nitrous 
 fumes should be sent to hospital with as little delay as possible and 
 detained there for 24 hours for observation. 
 
 Pathological changes. The pathological changes found post-mortem 
 in a fatal case of nitrous-fumes poisoning are identical with those 
 described above as characteristic of chlorine poisoning. If the con- 
 centration of nitrous fumes to which the case has been exposed is 
 very high, the blood may be somewhat chocolate colored owing to 
 the formation of methaemoglobin. 
 
 Symptoms. If the gas is in very great concentration, rapid fatal 
 asphyxiation takes place, but in the concentrations that are usually 
 encountered, the characteristics which distinguish this from chlorine 
 poisoning are the slightness of the initial symptoms due to irritation 
 of the upper respiratory passages and delay in the onset of acute 
 pulmonary edema. 
 
 The typical sequence of events is 
 
 (1) Slight irritation of the nose and throat, feeling of constric- 
 tion of the chest, headache and slight smarting of the eyes and 
 coughing while actually exposed to the fumes. 
 
 (2) On leaving the poisonous atmosphere a latent period during 
 which the case may, and usually does, feel quite well and has no 
 hesitation in taking a meal. 
 
 (3) The sudden onset after four to eight hours of acute symp- 
 toms. These commence with marked and increasing distress in 
 breathing, coughing, and often severe pain in the chest. The cough 
 is at first dry, and auscultation may reveal no moist sounds. This 
 condition is speedily followed by the urgent signs of acute pul- 
 monary edema which have been already detailed under chlorine 
 poisoning (p. 13), and death may ensue in a few hours. 
 
27 
 
 Treatment. When once pulmonary edema has developed, the 
 treatment should follow the lines already laid down for chlorine 
 poisoning (p. 18). The experience of medical officers attached 
 to mines on the Band, where nitrous fumes are frequently met 
 with during blasting operations, points to the value of inducing 
 emesis as soon after exposure to the fumes as possible, followed by 
 a dose of such a stimulant as spir. ammon. aromat. A case of nitrous- 
 iumes poisoning should be under medical observation at the time 
 when acute pulmonary edema is likely to develop and a venesection 
 of from 15 to 20 ounces should be made as soon as there is the slightest 
 sign of its onset. Venesection must not be delayed until the patient's 
 condition is grave and the stage of lividity has been reached, or it 
 will be useless. 
 
 LACHRYMATORS. 
 
 Hitherto, no serious cases of poisoning have occurred as the result 
 of exposure to the effects of shells containing substances employed 
 merely on account of their lachrymatory properties. 
 
 The immediate effect of a trace of the vapor of such a lachrymator 
 as benzyl bromide in the air is to cause profuse watering of the 
 eyes, accompanied by smarting. If the concentration is somewhat 
 greater, the smarting and pain in the eyes may become intolerable, 
 so that it is impossible to keep the eyes open. The smarting and 
 watering of the eyes will be quite sufficient to put a man completely 
 out of action, because he is incapable of seeing, but protection of the 
 eyes is easily obtained by the use of goggles. 
 
 With increasing concentrations of the vapor, other effects show 
 themselves. The vapor is irritant to the lungs and upper respiratory 
 passages and this leads to a burning sensation in the throat and 
 coughing. Nausea is often present and not infrequently leads to 
 vomiting, accompanied, it may be, by pain in the epigastrium. If 
 it is impossible to withdraw from exposure to the fumes, slight con- 
 fusion of mind and torpor may show themselves. 
 
 Under ordinary conditions the symptoms do not develop further, 
 and though the case may become somewhat collapsed as a result of 
 the vomiting and general discomfort, this is only temporary, and 
 within an hour or two after getting into air free from the lachry- 
 mator there may be very little amiss with the man. The nausea and 
 irritation of the throat soon pass off, though the eyes may remain 
 sore for some little time, and even after the lapse of 12 hours redness 
 of the eyelids and slight injection of the conjunctiva may still be 
 evident. There are no subsequent toxic effects and the case will be 
 fit for duty as soon as the primary effects have passed off. 
 
28 
 
 It must not be forgotten that some of the acute lung irritants are 
 also extremely powerful lachrymators, and that such substances 
 may be used with a view to securing a double effect, viz, immediate 
 blinding and simultaneous intense toxic effect on the lungs. In 
 order to secure such an effect it is essential that the substance used 
 shall be gaseous or shall vaporize with sufficient rapidity to attain a 
 high enough concentration in the air to produce these intense toxic 
 effects. Lachrymators such as benzyl bromide, which are liquid 
 at ordinary temperatures, vaporize too slowly to produce such a 
 concentration, and the symptoms caused by a lachrymator of this 
 type, therefore, very rarely attain a degree of severity greater than 
 those described above in detail. 
 
 The smell of benzyl bromide when in great dilution suggests the 
 flavor of mustard and cress. Lachrymators as a rule have aromatic, 
 pungent odors. 
 
 HYDROCYANIC ACID. 
 
 When in sufficient concentration this gas acts as a very rapid and 
 sometimes almost instantaneous poison, affecting directly the central 
 nervous system. 
 
 Symptoms. These follow one another in rapid sequence: Giddi- 
 ness, confusion, headache, indistinct sight, palpitation and pain in 
 the chest and over the heart. Labored respiration. Unconscious- 
 ness, convulsions, failure of the respiration and finally of the heart. 
 In la^ge doses, immediate unconsciousness, dilatation of the pupils, 
 a few gasping respirations, and death with or without convulsions. 
 
 The gas paralyzes the respiratory center very quickly, and with 
 small fatal percentages the heart may continue to beat for a brief 
 time after the respiration has ceased. With larger concentrations 
 the heart may be stopped almost at once by the direct action of the 
 poison. 
 
 When death is caused by inhalation of hydrocyanic-acid gas, it is 
 unlikely that the smell of the gas will be detected at autopsy, as 
 may be the case when poisoning is due to the ingestion by the 
 mouth of a large dose of prussic acid. 
 
 Treatment. Immediate treatment is the only measure of any 
 avail if a man falls unconscious from hydrocyanic-acid poisoning. 
 The case must be at once dragged into fresh air, and if the respiration 
 has stopped, or is very weak and gasping, artificial respiration must 
 be instantly applied by Schafer's method. It is possible by this 
 means to resuscitate a case, and if this is so recovery will be perfect. 
 Cold water may be splashed oh the face and chest and friction 
 applied to the limbs, but time should not be wasted on these meas- 
 
29 
 
 ures before commencing artificial respiration. The same immediate 
 treatment holds good for any other gas that causes rapid unconscious- 
 ness from its effects on the central nervous system. 
 
 CAJIBON MONOXIDE. 
 
 The great danger of carbon monoxide arises from the fact that the 
 gas is colorless, odorless, and nonirritant, and that the onset of 
 symptoms is so insidious that very often the first warning that a man 
 may receive is failure in the power of his limbs which will prevent 
 him from retreating into safety. Neither the box respirator nor 
 other masks give protection against carbon monoxide; protection 
 can only be attained by the use of special oxygen breathing 
 apparatus. 
 
 Pathological changes. At the autopsy, the blood may be red in 
 color instead of dark if there is a considerable degree of saturation 
 of the hemoglobin with carbon monoxide. If the case has continued 
 to breathe for some time after reaching an atmosphere free from 
 carbon monoxide, this gas will have been partly or entirely displaced 
 from the hemoglobin and the blood after death will have its normal 
 color. 
 
 The simplest method of detecting the presence of carbon mo- 
 noxide in blood is to compare the color of a dilute solution of the sus- 
 pected blood with a similar solution of normal blood. Take a drop or 
 two of blood from the finger of a normal person and dilute it in a test 
 tube very considerably with water (a one-half of 1 per cent solution is a 
 convenient strength), so that when examined by transmitted daylight 
 the color of this solution is a reddish-yellow. Then take a drop or 
 two of the suspected blood and dilute it similarly with water, so that 
 the depth of color of the solution is the same as that of the solution of 
 normal blood when both are viewed by transmitted light. On exam- 
 ining the quality of the color it will be found that the solution made 
 with the suspected blood, if it contains carbon monoxide hemoglobin, 
 is definitely pinker than that made with the normal blood, though 
 it will not have the full pink tint of the same normal blood solution 
 if the latter be shaken with coal gas so as to saturate it quite com- 
 pletely with carbon monoxide. 
 
 The lungs show no abnormal changes in cases of rapid death. 
 Small punctate hemorrhages may be found in the white matter of 
 the brain and sometimes ecchymoses in the meninges if the case 
 has been exposed to a concentration of carbon monoxide sufficient 
 to cause prolonged unconsciousness. 
 
30 
 
 Symptoms. Except with very massive doses, when loss of con- 
 sciousness is very rapid, the symptoms develop very gradually, as 
 the gas is only absorbed slowly. If a man is at rest in a concen- 
 tration of the gas of 1 part in 1,000 it will take about two hours 
 before definite giddiness appears and he will not be definitely dis- 
 abled until the lapse of two and one-half hours. The rate of ab- 
 sorption of the gas is much quickened when the breathing is deep- 
 ened during muscular exercise and the exercise also leads to great 
 accentuation of the symptoms. With a concentration of 2 parts in 
 1,000 a man will be seriously affected in half an hour if he is per- 
 forming a moderate amount of muscular work, and this concentra- 
 tion may prove fatal with prolonged exposure. 
 
 Small animals are far more quickly affected by carbon monoxide 
 than man is, owing to the natural great ventilation of their lungs 
 and the rapidity of their circulation. A mouse or a canary will 
 show definite symptoms of carbon monoxide poisoning in a tenth of 
 the time that a man will. If small animals are used to give an 
 index of the presence of carbon monoxide in a suspected atmos- 
 phere, it must be remembered that though they show symptoms 
 long before a man feels any effects, the man will in the end be 
 reduced to the same condition as the animal, and he ought there- 
 fore to leave the dangerous atmosphere directly the animal shows 
 signs of being affected, unless he is protected by special apparatus. 
 
 The first sign that tells a man that something is amiss is very 
 frequently a feeling of loss of power in the limbs. Giddiness, 
 slight confusion of mind, and breathlessness and palpitation on the 
 least exertion also show themselves. The confusion of mind and 
 loss of power in the legs frequently preclude a man from with- 
 drawing from danger, even though he is dimly aware that safety is 
 only a few yards distant. The failure of power in the limbs and 
 mental confusion rapidly increase and the man may appear drunk, 
 shouting incoherently, laughing, swearing, or praying. Apathy and 
 complete helplessness supervene, and failure of the intellectual 
 powers gradually passes into complete unconsciousness, which may 
 finally terminate in a painless death. 
 
 The symptoms may remain stationary at any stage, since the 
 degree of saturation of the hemoglobin with carbon monoxide reaches 
 a final end point which is determined by the relative concentra- 
 tions of the carbon monoxide and the oxygen which are simul- 
 taneously trying to combine with the hemoglobin. 
 
 Even in cases of mild gassing with carbon monoxide, a severe 
 headache accompanied by nausea is very likely to develop. 
 
 
31 
 
 Treatment. The symptoms detailed above are due to the gradual 
 diminution of the oxygen-carrying power of the blood and the 
 exposure of all the organs of the body to increasing want of oxygen. 
 It is clear that any increase in the oxygen demands of the body 
 is to be avoided, and any man, therefore, who shows definite signs 
 of gassing should be carried to a place of safety. If he attempts 
 to walk himself he is quite likely to fall down unconscious. When 
 a moderately gassed case reaches fresh air he sometimes falls un- 
 conscious, while other cases may commence to shout and struggle, 
 in which case their movements need to be controlled. 
 
 Any case showing definite symptoms should be removed as soon 
 as possible to some place of safety where he can remain at rest for 
 an hour or two before evacuation. Rest is essential. 
 
 As carbon monoxide hemoglobin is a dissociable compound, the 
 carbon monoxide is gradually driven out of its combination with 
 hemoglobin by the oxygen of the air as soon as an atmosphere free 
 from carbon monoxide is reached. In fresh air it will take an 
 hour or two before the blood is entirely freed from carbon monoxide, 
 but the process can be rendered five times as rapid by giving the 
 patient pure oxygen to breathe. It is important therefore to begin 
 the administration of oxygen by some efficient method as soon as 
 possible after the case has been removed from the poisonous at- 
 mosphere. A suitable method has been described under chlorine 
 poisoning (p. 19) and the oxygen apparatus that is kept at mine 
 rescue stations is also most efficient. Administration of oxygen 
 should be kept up as continuously as possible for half an hour to 
 an hour, depending on the severity of the symptoms. It should be 
 remembered that if a case can be kept at rest for half an hour and 
 oxygen administered immediately after being removed from the 
 poisonous atmosphere, he will be in far better condition to travel 
 than if he has to be removed to a more distant point. If the breath- 
 ing is very shallow, administration of oxygen may be combined with 
 artificial respiration. 
 
 Collapse should be combated by external warmth and by friction 
 of the limbs. 
 
 In chlorine poisoning the pulmonary edema and damage to the 
 lungs and the consequent interference with the gaseous exchange 
 taking place between the blood and the air in the lungs persist for 
 some time and may necessitate the administration of oxygen for 
 several days. In carbon monoxide poisoning the structure of the 
 lungs is not interfered with and oxygen is administered with the 
 deliberate intention of accelerating the discharge of carbon mon- 
 
32 
 
 oxide from the blood. When once this has been accomplished, 
 i. e., after half an hour's or an hour's administration, there is no 
 need to continue the oxygen administration, as the oxygen-carrying 
 power of the blood has now become normal again. Any symptoms 
 that persist are due to effects that were produced while the blood 
 was charged with carbon monoxide and are unlikely to be influenced 
 by oxygen administration when once the carbon monoxide has been 
 got rid of. Further oxygen administration is therefore required 
 only if cyanosis begins to develop subsequently from secondary 
 cardiac or respiratory failure. 
 
 Cases of carbon monoxide poisoning have been known to recover, 
 even when they have remained unconscious for so long as 48 hours 
 after removal from the poisonous atmosphere. In cases that liave 
 been severely gassed the possibility of subsequent cardiac dilatation 
 must not be lost sight of, and cases of severe gassing should not be 
 returned to duty until confidence is felt that the circulation has 
 recovered from the strain. As a result of damage to the nervous 
 system while the blood was charged with carbon monoxide, paralysis 
 of single muscles or of groups of muscles, or different forms of mental 
 disturbance are sometimes found as sequelae. 
 
 NEED FOR FURTHER INVESTIGATION. 
 
 Knowledge on the various points discussed in this pamphlet is 
 still far from being stable. Medical officers are therefore asked to 
 assist by making further observations and at once writing down notes 
 on any of the following particulars, about which chance may enable 
 them to supply useful information. Such notes should be forwarded 
 to the division surgeon. 
 
 1. Smells of the gas. This may be musty, pungent, aromatic 
 like lilac, garlic, mustard and cress, bitter almonds, and so on. 
 
 2. The symptoms in gassed men, especially those of onset, when 
 they are in any way remarkable or differ from those described for 
 cloud gas in this pamphlet. All points not observed by the medical 
 officer himself should be subjected to careful cross-examination. 
 
 3. The findings at autopsy of very early cases of gas poisoning, 
 with an account of the manner of death. 
 
 4. The value of various methods of treatment of severely gassed 
 cases, with control observations where possible. 
 
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