,transcriber's ,notes3 ,underscores 80 before and after a word or phrase indicate italics in the original text4 ,equal signs 80 before and after a word or phrase indicate bold in the original text4 ,small capitals have been converted to ,,solid capitals4 ,illustrations have been moved so they do not break up paragraphs4 ,typographical and punctuation errors have been silently corrected4 ,,chemical ,,warfare ,mc,graw-,hill ,book ,co4 ,inc4 ,,publishers ,,of ,,books ,,for ,coal ,age ,electric ,railway ,journal ,electrical ,world ,engineering ,news-,record ,american ,machinist ,ingeniera ,internacional ,engineering ,mining ,journal ,power ,chemical ,metallurgical ,engineering ,electrical ,merchandising ,illustration ,,chemical ,,warfare ,,by ,,amos ,a4 ,,fries ,brigadier ,general1 ,c4 ,w4 ,s41 ,u4 ,s4 ,a4 ,chief1 ,chemical ,warfare ,service ,,and ,,clarence ,j4 ,,west ,major1 ,c4 ,w4 ,s4 ,reserve ,corps1 ,u4 ,s4 ,a4 ,national ,research ,council ,,first ,,edition ,mc,g,r,a,w-,,hill ,,book ,,company1 ,inc4 ,,new ,,york3 #cgj ,,seventh ,,avenue ,,london3 #f #h ,,bouverie ,,st41 ,e4 ,c4 #d #aiba ,,copyright1 #aiba1 ,,by ,,the ,,mcgraw-,,hill ,,book ,,company1 ,,inc4 ,,preface ,shortly after the signing of the ,armistice1 it was realized that the story of ,chemical ,warfare should be written1 partly because of its historical value1 and partly because of the future needs of a textbook covering the fundamental facts of the ,service for the ,army1 the ,reserve ,officer1 the ,national ,guard1 and even the ,civilian ,chemist4 ,the present work was undertaken by both authors as a labor of patriotism and because of their interest in the ,service4 ,the two years which have elapsed since the initial discussion of the outlines of the book have thoroughly convinced us of the need of such a work4 ,the ,engineers1 the ,medical ,department1 and most of the other branches of the ,army have their recognized textbooks and manuals4 ,there has been no way1 however1 by which the uninformed can check the accuracy of statements regarding ,chemical ,warfare4 ,the present volume will serve1 in a measure1 to fill this gap4 ,that it does not do so more completely is due in part to the fact that secrecy must still be maintained about some of the facts and some of the new discoveries which are the property of the ,service4 ,those familiar with the work of the ,chemical ,warfare ,service will discover1 though1 that the following pages contain many statements which were zealously guarded secrets two years ago4 ,this enlarged program of publicity on the part of the ,chief of the ,service is being justified every day by the ever increasing interest in this branch of warfare4 ,where five men were discussing ,chemical ,warfare two years ago1 fifty men are talking about the work and the possibilities of the ,service today4 ,it is hoped that the facts here presented may further increase the interest in ,chemical ,warfare1 for there is no question but that it must be recognized as a permanent and a very vital branch of the ,army of every country4 ,reasons for this will be found scattered through the pages of this book4 ,it should be explained that this is in no sense a complete historical sketch of the development and personnel of the ,chemical ,warfare ,service4 ,at least two more volumes are needed1--one on the ,manufacture of ,poisonous ,gases and one on the ,tactics of ,chemical ,warfare4 ,we have purposely refrained from an attempt to give credit to individuals for the accomplishments of the various ,divisions of the ,service1 because such an attempt would have made the book too voluminous1 and would have defeated the primary purpose1 namely1 that it should present the information in as concise manner as possible4 ,the published and unpublished materials of the files of all the ,divisions have been freely drawn upon in writing the various chapters1 and many old ,c4 ,w4 ,s4 men will undoubtedly recognize whole sentences which they wrote under the stress of the laboratory or plant 8battle front40 ,may these few lines be an acknowledgment of their contributions4 ,those who desire to consult the literature of ,chemical ,warfare will find a fairly complete bibliography 7to about the middle of #aiai7 in 8,special ,libraries0 for ,november1 #aiai4 ,special acknowledgment is made to ,dr4 ,g4 ,j4 ,esselen1 ,jr41 for having read the manuscript and for helpful and constructive criticisms4 ,many of the figures are reproduced by permission of the ,journal of ,industrial and ,engineering ,chemistry2 those showing the ,nelson cell were furnished by the ,samuel ,m4 ,green ,company4 ,,amos ,a4 ,,fries1 ,,clarence ,j4 ,,west4 ,aug4 #a1 #aiba4 ,,foreword ,after all peaceful means of settling disputes between nations have been resorted to and have failed1 war is often declared by one of the disputants for the purpose of imposing its will upon the other by force4 ,in order to accomplish this1 a superiority must be established over the adversary in trained men and in implements of war4 ,men are nothing in modern war unless they are equipped with the most effective devices for killing and maiming the enemy's soldiers and thoroughly trained in the use of such implements4 ,history proves that an effective implement of war has never been discarded until it becomes obsolete4 ,it is impossible to humanize the act of killing and maiming the enemy's soldiers1 and there is no logical grounds on which to condemn an appliance so long as its application can be so confined4 ,experiments in this and other countries during the ,world ,war completely established the fact that gas can be so confined4 ,the range of gas clouds is no greater than that of artillery and the population in the area behind the front line must1 if they remain in such range1 take their chance4 ,the danger area in the future will be known to all4 ,as the first ,director of the ,chemical ,warfare ,service1 ,u4 ,s4 ,army1 ,i speak with some experience when ,i say that there is no field in which the future possibilities are greater than in chemical warfare1 and no field in which neglect to keep abreast of the times in research and training would be more disastrous4 ,notwithstanding the fact that gas was used in the ,world ,war two years before the ,united ,states entered the fray1 practically nothing was done in this country before ,april1 #aiag1 towards the development of any chemical warfare appliances1 offensive or defensive1 and had it not been for the ability of an ally to supply our troops with such appliances1 they would have been as defenseless as the ,canadians were at ,ypres when the ,germans sent over their first gas cloud4 ,this book recites the troubles and successes of this new service under the stress of war for which it was unprepared and ,i trust that its perusal will create a public opinion that will insist upon chemical preparation for war4 ,i feel that this book will show that the genius and patriotism displayed by the chemists and chemical engineers of the country were not surpassed in any other branch of war work and that to fail to utilize in peace times this talent would be a crime4 ,,william ,l4 ,,sibert1 ,major ,general1 ,united ,states ,army1 ,retired4 ,,contents ,,page ,,preface vii ,,foreword ix ,,chapter ,i4 ,,the ,,history ,,of ,,poison ,,gases #a ,,ii4 ,,modern ,,development ,,of ,,gas ,,warfare #aj ,,iii4 ,,development ,,of ,,the ,,chemical ,,warfare ,,service #ca ,,iv4 ,,the ,,chemical ,,warfare ,,service ,,in ,,france #gb ,v4 ,,chlorine #aaf ,,vi4 ,,phosgene #abf ,,vii4 ,,lachrymators #acg ,,viii4 ,,chloropicrin #add ,,ix4 ,,dichloroethylsulfide 7,,mustard ,,gas7 #aej ,x4 ,,arsenic ,,derivatives #ahj ,,xi4 ,,carbon ,,monoxide #aij ,,xii4 ,,development ,,of ,,the ,,gas ,,mask #aie ,,xiii4 ,,absorbents #bcg ,,xiv4 ,,testing ,,absorbents ,,and ,,gas ,,masks #bei ,,xv4 ,,other ,,defensive ,,measures #bgb ,,xvi4 ,,screening ,,smokes #bhe ,,xvii4 ,,toxic ,,smokes #cac ,,xviii4 ,,smoke ,,filters #cbb ,,xix4 ,,signal ,,smokes #ccj ,,xx4 ,,incendiary ,,materials #ccf ,,xxi4 ,,the ,,pharmacology ,,of ,,war ,,gases #cec ,,xxii4 ,,chemical ,,warfare ,,in ,,relation ,,to ,,strategy ,,and ,,tactics #cfc ,,xxiii4 ,,the ,,offensive ,,use ,,of ,,gas #che ,,xxiv4 ,,defense ,,against ,,gas #dje ,,xxv4 ,,peace ,,time ,,uses ,,of ,,gas #dbg ,,xxvi4 ,,the ,,future ,,of ,,chemical ,,warfare #dce ,,index #ddj ,,chemical ,,warfare ,,chapter ,i ,,the ,,history ,,of ,,poison ,,gases#a ,the introduction of poison gases by the ,germans at ,ypres in ,april1 #aiae1 marked a new era in modern warfare4 ,the popular opinion is that this form of warfare was original with the ,germans4 ,such1 however1 is not the case4 ,quoting from an article in the ,candid ,quarterly ,review1 #d1 #efa1 8,all they can claim is the inhuman adoption of devices invented in ,england1 and by ,england rejected as too horrible to be entertained even for use against an enemy40 ,but the use of poison gases is even of an earlier origin than this article claims4 ,footnote #a3 ,this chapter originally appeared in ,science1 ,vol4 #di1 pp4 #dab-dag 7#aiai74 ,the first recorded effort to overcome an enemy by the generation of poisonous and suffocating gases seems to have been in the wars of the ,athenians and ,spartans 7#dca-djd ,b4,c47 when1 besieging the cities of ,platea and ,belium1 the ,spartans saturated wood with pitch and sulfur and burned it under the walls of these cities in the hope of choking the defenders and rendering the assault less difficult4 ,similar uses of poisonous gases are recorded during the ,middle ,ages4 ,in effect they were like our modern stink balls1 but were projected by squirts or in bottles after the manner of a hand grenade4 ,the legend is told of ,prester ,john 7about the eleventh century71 that he stuffed copper figures with explosives and combustible materials which1 emitted from the mouths and nostrils of the effigies1 played great havoc4 ,the idea referred to by the writer in the ,candid ,quarterly ,review1 is from the pen of the ,english ,lord ,dundonald1 which appeared in the publication entitled 8,the ,panmure ,papers40 ,this is an extremely dull record of an extremely dull person1 only rendered interesting by the one portion1 concerned with the use of poison gases1 which1 it is said1 8should never have been published at all40 ,that portion of the article from the ,candid ,quarterly ,review dealing with the introduction of poisonous gas by the ,germans1 and referred to in the first paragraph above1 is quoted in full as follows3 8,the great ,admiral ,lord ,dundonald--perhaps the ablest sea captain ever known1 not even excluding ,lord ,nelson--was also a man of wide observation1 and no mean chemist4 ,he had been struck in #ahaa by the deadly character of the fumes of sulphur in ,sicily2 and1 when the ,crimean ,war was being waged1 he communicated to the ,english government1 then presided over by ,lord ,palmerston1 a plan for the reduction of ,sebastopol by sulphur fumes4 ,the plan was imparted to ,lord ,panmure and ,lord ,palmerston1 and the way in which it was received is so illustrative of the trickery and treachery of the politician that it is worth while to quote ,lord ,palmerston's private communication upon it to ,lord ,panmure3 8,,lord ,,palmerston ,,to ,,lord ,,panmure 8#8,,house ,,of ,,commons1 #gth ,august1 #ahee 8#8,i agree with you that if ,dundonald will go out himself to superintend and direct the execution of his scheme1 we ought to accept his offer and try his plan4 ,if it succeeds1 it will1 as you say1 save a great number of ,english and ,french lives2 if it fails in his hands1 we shall be exempt from blame1 and if we come in for a small share of the ridicule1 we can bear it1 and the greater part will fall on him4 ,you had best1 therefore1 make arrangement with him without delay1 and with as much secrecy as the nature of things will admit of4' 8,inasmuch as ,lord ,dundonald's plans have already been deliberately published by the two persons above named1 there can be no harm in now republishing them4 ,they will be found in the first volume of #8,the ,panmure ,papers' 7pp4 #cdj-cdb7 and are as follows3 8#87,,enclosure7 8#8,,brief ,,preliminary ,,observations 8#8,it was observed when viewing the ,sulphur ,kilns1 in ,july1 #ahaa1 that the fumes which escaped in the rude process of extracting the material1 though first elevated by heat1 soon fell to the ground1 destroying all vegetation1 and endangering animal life to a great distance1 and it was asserted that an ordinance existed prohibiting persons from sleeping within the distance of three miles during the melting season4 8#8,an application of these facts was immediately made to ,military and ,naval purposes1 and after mature consideration1 a ,memorial was presented on the subject to ,his ,royal ,highness the ,prince ,regent on the #abth of ,april1 #ahab1 who was graciously pleased to lay it before a ,commission1 consisting of ,lord ,keith1 ,lord ,exmouth and ,general and ,colonel ,congreve 7afterwards ,sir ,william71 by whom a favorable report having been given1 ,his ,royal ,highness was pleased to order that secrecy should be maintained by all parties4 8#87,signed7 ,,dundonald 8#8#gth ,august1 #ahee' 8#8,,memorandum 8#8,materials required for the expulsion of the ,russians from ,sebastopol3 ,experimental trials have shown that about five parts of coke effectually vaporize one part of sulphur4 ,mixtures for land service1 where weight is of importance1 may1 however1 probably be suggested by ,professor ,faraday1 as to operations on shore ,i have paid little attention4 ,four or five hundred tons of sulphur and two thousand tons of coke would be sufficient4 8#8,besides these materials1 it would be necessary to have1 say1 as much bituminous coal1 and a couple of thousand barrels of gas or other tar1 for the purpose of masking fortifications to be attacked1 or others that flank the assailing positions4 8#8,a quantity of dry firewood1 chips1 shavings1 straw1 hay or other such combustible materials1 would also be requisite quickly to kindle the fires1 which ought to be kept in readiness for the first favourable and steady breeze4 8#8,,dundonald 8#8#gth ,august1 #ahee' 8#8,note4--,the objects to be accomplished being specially stated the responsibility of their accomplishment ought to rest on those who direct their execution4 8#8,suppose that the ,malakoff and ,redan are the objects to be assailed it might be judicious merely to obscure the ,redan 7by the smoke of coal and tar kindled in #8,the ,quarries'71 so that it could not annoy the ,mamelon1 where the sulphur fire would be placed to expel the garrison from the ,malakoff1 which ought to have all the cannon that can be turned towards its ramparts employed in overthrowing its undefended ramparts4 8#8,there is no doubt but that the fumes will envelop all the defenses from the ,malakoff to the ,barracks1 and even to the line of battleship1 the ,twelve ,apostles1 at anchor in the harbour4 8#8,the two outer batteries1 on each side of the ,port1 ought to be smoked1 sulphured1 and blown down by explosion vessels1 and their destruction completed by a few ships of war anchored under cover of the smoke4' 8,that was ,lord ,dundonald's plan in #ahee1 improperly published in #aijh1 and by the ,germans1 who thus learnt it1 ruthlessly put into practise in #aiae4 8,lord ,dundonald's memoranda1 together with further elucidatory notes1 were submitted by the ,english government of that day to a committee and subsequently to another committee in which ,lord ,playfair took leading part4 ,these committees1 with ,lord ,dundonald's plans fully and in detail before them1 both reported that the plans were perfectly feasible2 that the effects expected from them would undoubtedly be produced2 but that those effects were so horrible that no honorable combatant could use the means required to produce them4 ,the committee therefore recommended that the scheme should not be adopted2 that ,lord ,dundonald's account of it should be destroyed4 ,how the records were obtained and preserved by those who so improperly published them in #aijh we do not know4 ,presumably they were found among ,lord ,panmure's papers4 ,admiral ,lord ,dundonald himself was certainly no party to their publication40 ,one of the early1 if not the earliest suggestion as to the use of poison gas in shell is found in an article on 8,greek ,fire10 by ,b4 ,w4 ,richardson4#b ,footnote #b3 ,popular ,science ,review1 #c1 #agf 7#ahfd74 ,he says3 8,i feel it a duty to state openly and boldly1 that if science were to be allowed her full swing1 if society would really allow that #8all is fair in war1' war might be banished at once from the earth as a game which neither subject nor king dare play at4 ,globes that could distribute liquid fire could distribute also lethal agents1 within the breath of which no man1 however puissant1 could stand and live4 ,from the summit of ,primrose ,hill1 a few hundred engineers1 properly prepared1 could render ,regent's ,park1 in an incredibly short space of time1 utterly uninhabitable2 or could make an army of men1 that should even fill that space1 fall with their arms in their hands1 prostrate and helpless as the host of ,sennacherib4 8,the question is1 shall these things be8 ,i do not see that humanity should revolt1 for would it not be better to destroy a host in ,regent's ,park by making the men fall as in a mystical sleep1 than to let down on them another host to break their bones1 tear their limbs asunder and gouge out their entrails with three-cornered pikes2 leaving a vast majority undead1 and writhing for hours in torments of the damned8 ,i conceive1 for one1 that science would be blessed in spreading her wings on the blast1 and breathing into the face of a desperate horde of men prolonged sleep--for it need not necessarily be a death--which they could not grapple with1 and which would yield them up with their implements of murder to an enemy that in the immensity of its power could afford to be merciful as ,heaven4 8,the question is1 shall these things be8 ,i think they must be4 ,by what compact can they be stopped8 ,it were improbable that any congress of nations could agree on any code regulating means of destruction2 but if it did1 it were useless2 for science becomes more powerful as she concentrates her forces in the hands of units1 so that a nation could only act1 by the absolute and individual assent of each of her representatives4 ,assume1 then1 that ,france shall lay war to ,england1 and by superior force of men should place immense hosts1 well armed1 on ,english soil4 ,is it probable that the units would rest in peace and allow sheer brute force to win its way to empire8 ,or put ,english troops on ,french soil1 and reverse the question8 8,to conclude4 ,war has1 at this moment1 reached1 in its details1 such an extravagance of horror and cruelty1 that it can not be made worse by any art1 and can only be made more merciful by being rendered more terribly energetic4 ,who that had to die from a blow would not rather place his head under ,nasmyth's hammer1 than submit it to a drummer-boy armed with a ferrule80 ,the ,army and ,navy ,register of ,may #bi1 #aiae1 reports that 8among the recommendations forwarded to the ,board of ,ordnance and ,fortifications there may be found many suggestions in favor of the asphyxiation process1 mostly by the employment of gases contained in bombs to be thrown within the lines of the foe1 with varying effects from peaceful slumber to instant death4 ,one ingenious person suggested a bomb laden to its full capacity with snuff1 which should be so evenly and thoroughly distributed that the enemy would be convulsed with sneezing1 and in this period of paroxysm it would be possible to creep up on him and capture him in the throes of the convulsion40 ,that the probable use of poisonous gas has often been in the minds of military men during recent times is evidenced by the fact that at the ,hague ,conference in #ahii several of the more prominent nations of ,europe and ,asia pledged themselves not to use projectiles whose only object was to give out suffocating or poisonous gases4 ,many of the ,powers did not sign this declaration until later4 ,germany signed and ratified it on ,sept4 #d1 #aijj1 but the ,united ,states never signed it4 ,further1 this declaration was not to be binding in case of a war in which a non-signatory was or became a belligerent4 ,admiral ,mahan1 a ,united ,states delegate1 stated his position in regard to the use of gas in shell 7at that time an untried theory7 as follows3 8,the reproach of cruelty and perfidy addressed against these supposed shells was equally uttered previously against fire-arms and torpedoes1 although both are now employed without scruple4 ,it is illogical and not demonstrably humane to be tender about asphyxiating men with gas1 when all are prepared to admit that it is allowable to blow the bottom out of an ironclad at midnight1 throwing four or five hundred men into the sea to be choked by the water1 with scarcely the remotest chance to escape40 ,at the ,hague ,congress of #aijg1 article #bc of the rules adopted for war on land states3 8,it is expressly forbidden 7a71 to employ poisons or poisonous weapons40 ,before the ,war suffocating cartridges were shot from the cartridge-throwing rifle of #bf mm4 ,these cartridges were charged with ethyl bromoacetate1 a slightly suffocating and non-toxic lachrymator4 ,they were intended for attack on the flanking works of permanent fortifications1 flanking casements or caponiers1 into which the enemy tried to make the cartridges penetrate through the narrow slits used for loopholes4 ,the men who were serving the machine guns or the cannon of the flanking works would have been bothered by the vapor from the ethyl bromoacetate1 and the assailant would have profited by their disturbance to get past the obstacle presented by the fortification4 ,the employment of these devices1 not entailing death1 did not contravene the ,hague conventions4 ,the only memorable operations in the course of which these devices were used before the ,war was the attack on the ,bonnet gang at ,choisy-le-roi4 ,in connection with the suggested use of sulfur dioxide by ,lord ,dundonald and the proposed use of poisonous gases in shell1 the following description of a charcoal respirator by ,dr4 ,j4 ,stenhouse1#c communicated by ,dr4 ,george ,wilson in #ahed1 is of interest4 ,footnote #c3 ,trans4 ,royal ,scottish ,soc4 ,arts1 #d1 ,appendix ,o1 #aih 7#ahed74 8,dr4 ,wilson commenced by stating that1 having read with much interest the account of ,dr4 ,stenhouse's researches on the deodorizing and disinfecting properties of charcoal1 and the application of these to the construction of a new and important kind of respirator1 he had requested the accomplished chemist to send one of his instruments for exhibition to the society1 which he had kindly done4 ,two of the instruments were now on the table1 differing1 however1 so slightly in construction1 that it would be sufficient to explain the arrangement of one of them4 ,externally1 it had the appearance of a small fencing-mask of wire gauze1 covering the face from the chin upwards to the bridge of the nose1 but leaving the eyes and forehead free4 ,it consisted1 essentially1 of two plates of wire gauze1 separated from each other by a space of about one-fourth or one-eighth of an inch1 so as to form a small cage filled with small fragments of charcoal4 ,the frame of the cage was of copper1 but the edges were made of soft lead1 and were lined with velvet1 so as to admit of their being made to fit the cheeks tightly and inclose the mouth and nostrils4 ,by this arrangement1 no air could enter the lungs without passing through the wire gauze and traversing the charcoal4 ,an aperture is provided with a screw or sliding valve for the removal and replenishment of the contents of the cage1 which consist of the siftings or riddlings of the lighter kinds of wood charcoal4 ,the apparatus is attached to the face by an elastic band passing over the crown of the head and strings tying behind1 as in the case of the ordinary respirator4 ,the important agent in this instrument is the charcoal1 which has so remarkable a power of absorbing and destroying irritating and otherwise irrespirable and poisonous gases or vapors that1 armed with the respirator1 spirits of hartshorn1 sulphuretted hydrogen1 hydrosulphuret of ammonia and chlorine may be breathed through it with impunity1 though but slightly diluted with air4 ,this result1 first obtained by ,dr4 ,stenhouse1 has been verified by those who have repeated the trial1 among others by ,dr4 ,wilson1 who has tried the vapors named above on himself and four of his pupils1 who have breathed them with impunity4 ,the explanation of this remarkable property of charcoal is two-fold4 ,it has long been known to possess the power of condensing into its pores gases and vapors1 so that if freshly prepared and exposed to these1 it absorbs and retains them4 ,but it has scarcely been suspected till recently1 when ,dr4 ,stenhouse pointed out the fact1 that if charcoal be allowed to absorb simultaneously such gases as sulphuretted hydrogen and air1 the oxygen of this absorbed and condensed air rapidly oxidizes and destroys the accompanying gas4 ,so marked is this action1 that if dead animals be imbedded in a layer of charcoal a few inches deep1 instead of being prevented from decaying as it has hitherto been supposed that they would be by the supposed antiseptic powers of the charcoal1 they are found by ,dr4 ,stenhouse to decay much faster1 whilst at the same time1 no offensive effluvia are evolved4 ,the deodorizing powers of charcoal are thus established in a way they never have been before2 but at the same time it is shown that the addition of charcoal to sewage refuse lessens its agricultural value contemporaneously with the lessening of odor4 ,from these observations1 which have been fully verified1 it appears that by strewing charcoal coarsely powdered to the extent of a few inches1 over church-yards1 or by placing it inside the coffins of the dead1 the escape of noisome and poisonous exhalations may be totally prevented4 ,the charcoal respirator embodies this important discovery4 ,it is certain that many of the miasma1 malaria and infectious matters which propagate disease in the human subjects1 enter the body by the lungs1 and impregnating the blood there1 are carried with it throughout the entire body1 which they thus poison4 ,these miasma are either gases and vapors or bodies which1 like fine light dust1 are readily carried through the air2 moreover1 they are readily destroyed by oxidizing agents1 which convert them into harmless1 or at least non-poisonous substances1 such as water1 carbonic acid and nitrogen4 ,there is every reason1 therefore1 for believing that charcoal will oxidize and destroy such miasma as effectually as it does sulphuretted hydrogen or hydrosulphuret of ammonia1 and thus prevent their reaching and poisoning the blood4 ,the intention accordingly is that those who are exposed to noxious vapors1 or compelled to breathe infected atmospheres1 shall wear the charcoal respirator1 with a view to arrest and destroy the volatile poisons contained in these4 ,some of the non-obvious applications of the respirator were then referred to3 8#a4 ,certain of the large chemical manufacturers in ,london are now supplying their workmen with the charcoal respirators as a protection against the more irritating vapors to which they are exposed4 8#b4 ,many deaths have occurred among those employed to explore the large drains and sewers of ,london from exposure to sulphuretted hydrogen1 etc4 ,it may be asserted with confidence that fatal results from exposure to the drainage gases will cease as soon as the respirator is brought into use4 8#c4 ,in districts such as the ,campagna of ,rome1 where malaria prevails and to travel during night or to sleep in which is certainly followed by an attack of dangerous and often fatal ague1 the wearing of the respirator even for a few hours may be expected to render the marsh poison harmless4 8#d4 ,those1 who as clergymen1 physicians or legal advisers1 have to attend the sick-beds of sufferers from infectious disorders1 may1 on occasion1 avail themselves of the protection afforded by ,dr4 ,stenhouse's instrument during their intercourse with the sick4 8#e4 ,the longing for a short and decisive war has led to the invention of #8a suffocating bombshell1' which on bursting1 spreads far and wide an irrespirable or poisonous vapor2 one of the liquids proposed for the shell is the strongest ammonia1 and against this it is believed that the charcoal respirator may defend our soldiers4 ,as likely to serve this end1 it is at present before the ,board of ,ordnance4 8,dr4 ,wilson stated1 in conclusion1 that ,dr4 ,stenhouse had no interest but a scientific one in the success of the respirators4 ,he had declined to patent them1 and desired only to apply his remarkable discoveries to the abatement of disease and death4 ,charcoal had long been used in filters to render poisonous water wholesome2 it was now to be employed to filter poisonous air40 ,,chapter ,,ii ,,modern ,,development ,,of ,,gas ,,warfare ,the use of toxic gas in the ,world ,war dates from ,april #bb1 #aiae1 when the ,germans launched the first cylinder attack1 employing chlorine1 a common and well known gas4 ,judging from the later experience of the ,allies in perfecting this form of attack1 it is probable that plans for this attack had been under way for months before it was launched4 ,the suggestion that poisonous gases be used in warfare has been laid upon ,prof4 ,nernst of the ,university of ,berlin 7,auld1 8,gas and ,flame10 page #ae71 while the actual field operations were said to have been under the direction of ,prof4 ,haber of the ,kaiser ,wilhelm ,physical ,chemical ,institute of ,berlin4 ,some writers have felt that the question of preparation had been a matter of years rather than of months1 and refer to the work on industrial gases as a proof of their statement4 ,the fact that the gas attack was not more successful1 that the results to be obtained were not more appreciated1 and that better preparation against retaliation had not been made1 argues against this idea of a long period of preparation1 except possibly in a very desultory way4 ,that such was the case is most fortunate for the allied cause1 for had the ,german high command known the real situation at the close of the first gas attack1 or had that attack been more severe1 the outcome of the war of #aiad would have been very different1 and the end very much earlier4 ,,first ,,gas ,,attack ,the first suggestion of a gas attack came to the ,british ,army through the story of a ,german deserter4 ,he stated that the ,german ,army was planning to poison their enemy with a cloud of gas1 and that the cylinders had already been installed in the trenches4 ,no one listened to the story1 because1 first of all1 the whole procedure seemed so impossible and also because1 in spite of the numerous examples of ,german barbarity1 the ,english did not believe the ,germans capable of such a violation of the ,hague rules of warfare4 ,the story appeared in the summary of information from headquarters 78,comic ,cuts07 and as ,auld says 8was passed for information for what it is worth40 ,but the story was true1 and on the afternoon of the #bbnd of ,april1 all the conditions being ideal1 the beginning of 8gas warfare0 was launched4 ,details of that first gas attack will always be meager1 for the simple reason that the men who could have told about it all lie in ,flanders field where the poppies grow4 ,the place selected was in the northeast part of the ,ypres salient1 at that part of the line where the ,french and ,british lines met1 running southward from where the trenches left the canal near ,boesinghe4 ,the ,french right was held by the ---- ,regiment of ,turcos1 while on the ,british left were the ,canadians4 ,auld describes the attack as follows3 8,try to imagine the feelings and the condition of the colored troops as they saw the vast cloud of greenish-yellow gas spring out of the ground and slowly move down wind towards them1 the vapor clinging to the earth1 seeking out every hole and hollow and filling the trenches and shell holes as it came4 ,first wonder1 then fear2 then1 as the first1 fringes of the cloud enveloped them and left them choking and agonized in the fight for breath--panic4 ,those who could move broke and ran1 trying1 generally in vain1 to outstrip the cloud which followed inexorably after them40 ,it is only to be expected that the first feeling connected with gas warfare was one of horror4 ,that side of it is very thrillingly described by ,rev4 ,o4 ,s4 ,watkins in the ,methodist ,recorder 7,london74 ,after describing the bombardment of the ,city of ,ypres from ,april #bjth to #bbnd he relates that in the midst of the uproar came the poison gas6 ,illustration3 ,,fig4 #a4--;,french ,gas ,attack as seen from an ,aeroplane4 ,the ,french front1 second and third line trenches are plainly visible4 ,the gas is seen issuing over a wide front from the front line and drifting towards the ,german lines4 8,going into the open air for a few moments' relief from the stifling atmosphere of the wards1 our attention was attracted by very heavy firing to the north1 where the line was held by the ,french4 ,evidently a hot fight--and eagerly we scanned the country with our field glasses hoping to glean some knowledge of the progress of the battle4 ,then we saw that which almost caused our hearts to stop beating--figures running wildly and in confusion over the fields4 8#8,the ,french have broken1' we exclaimed4 ,we hardly believed our words4444 ,the story they told we could not believe2 we put it down to their terror-stricken imaginings--a greenish-gray cloud had swept down upon them1 turning yellow as it traveled over the country1 blasting everything it touched1 shriveling up the vegetation4 ,no human courage could face such a peril4 8,then there staggered into our midst ,french soldiers1 blinded1 coughing1 chests heaving1 faces an ugly purple color--lips speechless with agony1 and behind them1 in the gas-choked trenches1 we learned that they had left hundreds of dead and dying comrades4 ,the impossible was only too true4 8,it was the most fiendish1 wicked thing ,i have ever seen40 ,it must be said here1 however1 that this was true only because the ,french had no protection against the gas4 ,indeed1 it is far from being the most horrible form of warfare1 provided both sides are prepared defensively and offensively4 ,medical records show that out of every #ajj ,americans gassed less than two died1 and as far as records of four years show1 very few are permanently injured4 ,out of every #ajj ,american casualties from all forms of warfare other than gas more than #be per cent died1 while from #b to #e per cent more are maimed1 blinded or disfigured for life4 ,various forms of gas1 as will be shown in the following pages1 make life miserable or vision impossible to those without a mask4 ,yet they do not kill4 ,thus instead of gas warfare being the most horrible1 it is the most humane where both sides are prepared for it1 while against savage or unprepared peoples it can be made so humane that but very few casualties will result4 ,the development of methods of defense against gas will be discussed in a later chapter4 ,it will suffice to say here that1 in response to an appeal from ,lord ,kitchener1 a temporary protection was quickly furnished the men4 ,this was known as the 8,black ,veiling0 respirator1 and consisted of a cotton pad soaked in ordinary washing soda solution1 and later1 in a mixture of washing soda and 8hypo10 to which was added a little glycerine4 ,these furnished a fair degree of protection to the men against chlorine1 the only gas used in the early attacks4 ,,phosgene ,,introduced ,the use of chlorine alone continued until the introduction on ,december #ai1 #aiae1 of a mixture of phosgene with the chlorine4 ,this mixture offered many advantages over the use of chlorine alone 7see ,chapter ,,vi74 ,the ,allies were able1 through warning of the impending use of phosgene1 to furnish a means of protection against it4 ,it was at this time that the ,p and the ,,ph helmets were devised1 the cotton filling being impregnated with sodium phenolate and later with a mixture of sodium phenolate and hexamethylenetetramine4 ,this helmet was used until the ,standard ,box ,respirator was developed by the late ,lt4 ,col4 ,harrison4 ,,allies ,,adopt ,,gas ,for a week or two the ,allies were very hesitant about adopting gas warfare4 ,however1 when the repeated use of gas by the ,germans made it evident that1 in spite of what the ,hague had to say about the matter1 gas was to be a part1 and as later developments showed1 a very important part of modern warfare1 they realized there was no choice on their part and that they had to retaliate in like manner4 ,this decision was reached in ,may of #aiae4 ,it was followed by the organization of a ,gas ,service and intensive work on the part of chemists1 engineers and physiologists4 ,it was ,september #be1 #aiae1 however1 before the ,english were in a position to render a gas attack4 ,from then on the ,service grew in numbers and in importance1 whether viewed from the standpoint of research1 production1 or field operations4 ,the ,allies of course adopted not only chlorine but phosgene as well1 since both were cheap1 easy of preparation and effective4 ,they felt during the early part of the ,war that they should adopt a substance that would kill instantly1 and not one that would cause men to suffer either during the attack or through symptoms which would develop later in a hospital4 ,for this reason a large amount of experimental work was carried out on hydrocyanic acid1 particularly by the ,french4 ,since this gas has a very low density1 it was necessary to mix with it substances which would tend to keep it close to the ground during the attack4 ,various mixtures1 all called 8vincennite10 were prepared1--chloroform1 arsenic trichloride and stannic chloride being used in varying proportions with the acid4 ,it was some time before it was definitely learned that these mixtures were far from being successful1 both from the standpoint of stability and of poisonous properties4 ,while the ,french actually used these mixtures in constantly decreasing quantities on the field for a long time1 they were ultimately abandoned1 though not until ,american chemists had also carried out a large number of tests4 ,however1 following the recommendation of the ,american ,gas ,service in ,france in ,december1 #aiag1 no vincennite was ever manufactured by the ,united ,states4 ,,lachrymators ,almost simultaneously with the introduction of the gas wave attacks1 in which liquefied gas under pressure was liberated from cylinders1 came the use of lachrymatory or tear gases4 ,these1 while not very poisonous in the concentrations used1 were very effective in incapacitating men through the effects produced upon their eyes4 ,the low concentration required 7one part in ten million of some lachrymators is sufficient to make vision impossible without a mask7 makes this form of gas warfare very economical as well as very effective4 ,even if a mask does completely protect against such compounds1 their use compels an army to wear the mask indefinitely1 with an expenditure of shell far short of that required if the much more deadly gases were used4 ,thus ,fries estimates that one good lachrymatory shell will force wearing the mask over an area that would require #ejj to #ajjj phosgene shell of equal size to produce the same effect4 ,while the number of actual casualties will be very much lower1 the total effect considered from the standpoint of the expenditure of ammunition and of the objectives gained1 will be just as valuable4 ,so great is the harassing value of tear and irritant gases that the next war will see them used in quantities approximating that of the more poisonous gases4 ,the first lachrymator used was a mixture of the chlorides and bromides of toluene4 ,benzyl chloride and bromide are the only valuable substances in this mixture1 the higher halogenated products having little or no lachrymatory value4 ,xylyl bromide is also effective4 ,chloroacetone and bromoacetone are also well known lachrymators1 though they are expensive to manufacture and are none too stable4 ,because of this the ,french modified their preparation and obtained mixtures to which they gave the name 8martonite40 ,this is a mixture of #hj per cent bromoacetone and #bj per cent chloroacetone1 and can be made with nearly complete utilization of the halogen4 ,methyl ethyl ketone may also be used1 which gives rise to the 8homomartonite0 of the ,french4 ,during the early part of the ,war1 when bromine was so very expensive1 the ,english developed ethyl iodoacetate4 ,this was used with or without the addition of alcohol4 ,later the ,french developed bromobenzyl cyanide1 ,c,h,,ch7,br7,,cn4 ,this was probably the best lachrymator developed during the ,war and put into large scale manufacture1 though very little of it was available on the field of battle before the ,war ended4 ,chloroacetophenone would have played an important part had the ,war continued4 ,,disadvantage ,,of ,,wave ,,attacks ,as will be discussed more fully in the chapters on 8,the ,tactics of ,gas10 the wave attacks became relatively less important in #aiaf through the use of gas in artillery shell4 ,this was the result of many factors4 ,cloud gas attacks1 as carried out under the old conditions1 required a long time for the preliminary preparations1 entailed a great deal of labor under the most difficult conditions1 and were dangerous of execution even when weather conditions became suitable4 ,the difficulties may be summarized as follows3 7#a7 ,the heavy gas cylinders used required a great deal of transportation1 and not only took the time of the ,infantry but rendered surprise attacks difficult owing both to the time required and to the unusual activity behind the lines that became1 with the development of aeroplanes1 more and more readily discerned4 7#b7 ,few gases were available for wave attacks--chlorine1 phosgene and1 to a less extent1 chloropicrin proving to be the only ones successfully used by either the ,allies or the ,germans4 ,hydrogen sulfide1 carbon monoxide and hydrocyanic acid gas were suggested and tried1 but were abandoned for one reason or another4 7#c7 ,gas cloud attacks were wholly dependent upon weather conditions4 ,not only were the velocity and direction of the wind highly important as regards the successful carrying of the wave over the enemy's line1 but also to prevent danger to the troops making the attack due to a possible shift of the wind1 which would carry the gas back over their own line4 7#d7 ,the use of gas in artillery shell does not require especially trained troops inasmuch as gas shell are fired in the same manner as ordinary shell1 and by the same gun crews4 ,moreover1 since artillery gas shell are used generally only for ranges of a mile or more1 the direction and velocity of the wind are of minor importance4 ,another factor which adds to the advantage of artillery shell in certain cases is the ability to land high concentrations of gas suddenly upon a distant target through employing a large number of the largest caliber guns available for firing gas4 ,notwithstanding the above named disadvantages of wave attacks it was felt by the ,americans from the beginning that successful gas cloud attacks were so fruitful in producing casualties and were such a strain upon those opposed to it1 that they would continue4 ,furthermore1 since artillery shell contain about #aj per cent gas1 while gas cylinders may contain #ej per cent1 or even more of the total weight of the cylinder1 the efficiency of a cloud gas attack for at least the first mile of the enemy's territory is far greater than that of the artillery gas attack4 ,it was accordingly felt that the only thing necessary to make cloud gas attacks highly useful and of frequent occurrence in the future was the development of mobile methods--methods whereby the gas attack could be launched on the surface of the ground and at short notice4 ,for these reasons gas wave attacks may be expected to continue and to eventually reach a place of very decided importance in ,chemical ,warfare4 ,,gas ,,shell ,the firing of gas in artillery shell and in bombs has another great advantage over the wave attack just mentioned4 ,there is a very great latitude in the choice of those gases which have a high boiling point or which1 at ordinary temperatures1 are solids4 ,mustard gas is an example of a liquid with a high boiling point1 and diphenylchloroarsine an example of a gas that is ordinarily solid4 ,for the above reason the term 8gas warfare0 was almost a misnomer at the close of the ,war1 and today is true only in the sense that all the substances used are in a gaseous or finely divided condition immediately after the shell explode or at least when they reach the enemy4 ,,projector ,,attacks ,still another method of attack1 developed by the ,british and first used by them in ,july1 #aiag1 was the projector 7invented by ,captain ,livens74 ,this was used very successfully up to the close of the ,war1 and though the ,german attempted to duplicate it1 his results were never as effective4 ,the projector consists of a steel tube of uniform cross section1 with an internal diameter of about #h inches4 ,by using nickel steel the weight may be decreased until it is a one man load4 ,the projector was set against a pressed steel base plate 7about #af inches in diameter7 placed in a very shallow trench4 ,illustration3 ,,fig4 #b4--,livens' ,projector4 ,the ,type shown is an #ah cm4 ,german ,gas ,projector1 captured during the #b;d ,battle of the ,marne4 ,until about the close of the war projectors were installed by digging a triangular trench deep enough to bring the muzzles of the projectors nearly level with the surface of the ground4 ,they were then protected by sand bags or canvas covers1 or camouflaged with wire netting to which colored bits of cloth were tied to simulate leaves and shadows4 ,the projectors were fired by connecting them in series with ordinary blasting machines operated by hand from a convenient point in the rear4 ,the digging in of the projectors in ,no ,man's ,land or very close to it was a dangerous and laborious undertaking4 ,the ,americans early conceived the idea that projectors could be fired just as accurately by digging a shallow trench just deep enough to form a support for the base plate1 and then supporting the outer ends of the projector on crossed sticks or a light frame work of boards4 ,this idea proved entirely practical except for one condition4 ,it was found necessary to fire with a single battery all the projectors near enough together to be disturbed by the blast from any portion of them4 ,inasmuch as most of the blasting machines used for firing had a capacity of only #bj to #cj projectors1 it was necessary to so greatly scatter a large projector attack that the method was very little used4 ,however1 investigations were well under way at the close of the ,war to develop portable firing batteries that would enable the discharge of at least #ajj and preferably #ejj projectors at one time4 ,by this arrangement a projector attack could be prepared and launched in two to four hours1 depending upon the number of men available4 ,this enabled the attack to be decided upon in the evening 7if the weather conditions were right71 and to have the attack launched before morning1 thereby making it impossible for aeroplane observers1 armed with cameras1 to discover the preparation for the projector attack4 ,since the bombs used in the projector may carry as high as #cj pounds of gas 7usually phosgene71 some idea of the amount of destruction may be gained when it is known that the ,british fired nearly #bejj at one time into ,lens4 ,,stokes' ,,mortar ,another ,british invention is the ,stokes' gun or trench mortar4 ,the range of this gun is about #hjj to #ajjj yards4 ,it is therefore effective only where the front lines are relatively close together4 ,the shell consists of a case containing the high explosive1 smoke material or gas1 fitted to a base filled with a high charge of propelling powder4 ,the shell is simply dropped into the gun4 ,at the bottom of the gun there is a projection or stud that strikes the primer1 setting off the small charge and expelling the projectile4 ,in order to obtain any considerable concentration of gas in a particular locality1 it is necessary to fire the ,stokes' continuously 7#ae shots per minute being possible under battle conditions7 for two to five minutes since the bomb contains only seven pounds of gas4 ,,superpalite ,it is believed that the first gas shell contained lachrymators or tear gases4 ,although the use of these shell continued up to and even after the introduction of mustard gas1 they gradually fell off in number--the true poison gas shell taking their place4 ,towards the end of #aiae ,auld states that the ,germans were using chloromethyl chloroformate 7palite7 in shell4 ,in #aiaf1 during the battle of the ,somme1 palite was replaced by superpalite 7trichloromethyl chloroformate1 or diphosgene7 which is more toxic than palite1 and about as toxic as phosgene4 ,it has the advantage over phosgene of being much more persistent4 ,in spite of the fact that ,american chemists were not able to manufacture superpalite on a large scale1 or at least so successfully that it would compete in price with other war gases1 the ,germans used large quantities of it1 alone and mixed with chloropicrin1 in shell of every caliber up to and including the #ae cm4 ,howitzer4 ,illustration3 ,,fig4 #c4--,stokes' ,mortar4 ,,chloropicrin ,the next gas to be introduced was chloropicrin1 trichloronitromethane or 8vomiting gas40 ,it has been stated that a mixture of chloropicrin 7#be per cent7 and chlorine 7#ge per cent7 has been used in cloud attacks1 but the high boiling point of chloropicrin 7#aab ,c47 makes its considerable use for this purpose very unlikely4 ,the gas is moderately toxic and somewhat lachrymatory1 but it was mainly used because of its peculiar property of causing vomiting when inhaled4 ,its value was further increased at first because it was particularly difficult to prepare a charcoal which would absorb it4 ,its peculiar properties are apt to cause it to be used for a long time4 ,,sneezing ,,gas ,during the summer of #aiag two new and very important gases were introduced1 and1 as before1 by the ,germans4 ,one of these was diphenylchloroarsine1 8sneezing gas0 or 8,blue ,cross40 ,this is a white solid which was placed in a bottle and embedded in ,,tnt in the shell4 ,upon explosion of the shell the solid was atomized into very fine particles4 ,since the ordinary mask does not remove smoke or mists1 the sneezing gas penetrates the mask and causes violent sneezing4 ,the purpose1 of course1 is to compel the removal of the mask in an atmosphere of lethal gas4 7,the firing regulations prescribed its use with phosgene or other lethal shell47 ,the latest type masks protect against this dust1 but as it is extraordinarily powerful1 its use will continue4 ,,mustard ,,gas ,the second gas was dichloroethyl sulfide1 mustard gas1 ,yellow ,cross or ,yperite4 ,mustard gas1 as it is commonly designated1 is probably the most important single poisonous substance used in gas warfare4 ,it was first used by the ,germans at ,ypres1 ,july #ab1 #aiag4 ,the amount of this gas used is illustrated by the fact that at ,nieuport more than #ej1jjj shell were fired in one night1 some of which contained nearly three gallons of the liquid4 ,mustard gas is a high boiling and very persistent material1 which is characterized by its vesicant 7skin blistering7 action4 ,men who come in contact with it1 either in the form of fine splashes of the liquid or in the form of vapor1 suffer severe blistering of the skin4 ,the burns appear from four to twelve hours after exposure and heal very slowly4 ,ordinary clothing is no protection against either the vapor or the liquid4 ,other effects will be considered in ,chapter ,,ix4 ,since then there has been no important advance so far as new gases are concerned4 ,various arsenic derivatives were prepared in the laboratory and tested on a small scale4 ,the ,germans did actually introduce ethyldichloroarsine and the ,americans were considering methyldichloroarsine4 ,attempts were made to improve upon mustard gas but they were not successful4 ,,lewisite ,it is rather a peculiar fact that so few new chemical compounds were used as war gases4 ,practically all the substances were well known to the organic chemist long before the ,world ,war4 ,one of the most interesting and valuable of the compounds which would have found extensive use had the ,war continued1 is an arsenic compound called ,lewisite from its discoverer1 ,capt4 ,w4 ,lee ,lewis1 of ,northwestern ,university4 ,the chemistry of this compound is discussed in ,chapter ,x4 ,because of the early recognized value of this compound1 very careful secrecy was maintained as to all details of the method of preparation and its properties4 ,as a result1 strange stories were circulated about its deadly powers4 ,characteristic of these was the story that appeared in the ,new ,york ,times early in #aiai4 ,now that the ,english have published the chemical and pharmacological properties1 we can say that1 although ,lewisite was never proven on the battle field1 laboratory tests indicate that we have here a very powerful agent4 ,not only is it a vesicant of about the same order of mustard gas1 but the arsenical penetrates the skin of an animal1 and three drops1 placed on the abdomen of a mouse1 are sufficient to kill within two to three hours4 ,it is also a powerful respiratory irritant and causes violent sneezing4 ,its possible use in aeroplane bombs has led ,general ,fries to apply the term 8,the ,dew of ,death0 to its use in this way4 ,,camouflage ,,gases ,considerable effort was spent on the question of camouflage gases4 ,this involved two lines of research3 7#a7 ,to prevent the recognition of a gas when actually present on the field1 by masking its odor4 ,,table ,i ,,chemical ,,warfare ,,gases ---------------------------------------- ------------------------- ,chemical ,belligerent ,effect ,means of ,projection ---------------------------------------- ------------------------- ,acrolein ,french ,lachrymatory ,hand grenades 7allylaldehyde7 ,lethal ,arsenic chloride 7,in mixtures4 ,see below7 ,benzyl iodide ,french ,lachrymatory ,artillery shell ,benzyl chloride ,french ,lachrymatory ,artillery shell ,bromoacetone ,french ,lachrymatory ,artillery shell ,lethal ,bromobenzylcyanide ,french ,lachrymatory ,artillery shell ,bromomethylethylketone ,german ,lachrymatory ,artillery shell ,lethal ,artillery shell ,benzyl bromide ,german ,lachrymatory ,artillery shell ,french ,chlorine ,german ,lethal ,cylinders ,british 7cloud gas7 ,french ,american ,chlorosulfonic acid ,german ,irritant ,hand grenades1 light minenwerfer ,chloroacetone ,french ,lachrymatory ,artillery shell ,chlorobenzene ,german ,lachrymatory ,artillery shell 7as solvent7 ,chloropicrin ,british ,lethal ,artillery shell ,french ,lachrymatory ,trench mortar ,german bombs ,american ,projectors ,cyanogen bromide ,austrian ,lethal ,artillery shell ,dichloromethylether ,german ,lachrymatory ,artillery shell 7as solvent7 ,diphenylchloroarsine ,german ,sternutatory ,artillery shell ,lethal ,dichloroethylsulfide ,german ,vesicant ,artillery shell ,french ,lethal ,british ,irritant ,american ,ethyldichloroarsine ,german ,lethal ,artillery shell ,ethyliodoacetate ,british ,lachrymatory ,artillery shell1 #d-;in4 ,stokes' mortars1 hand grenades ,hydrocyanic acid ,french 7,in mixtures4 ,see below7 ,methylchlorosulfonate ,german ,irritant ,minenwerfer ,monochloromethyl- ,german ,lethal ,artillery shell chloroformate ,french ,lachrymatory ,phosgene ,british ,lethal ,projectors1 ,french trench mortars1 ,german artillery shell1 ,american cylinders ,phenylcarbylamine ,german ,lachrymatory ,artillery shell chloride ,irritant ,trichlormethyl ,german ,lethal ,artillery shell chloroformate ,stannic chloride ,british ,irritant ,hand grenades ,french ,cloud forming,artillery ,american ,projectors #d-;in4 ,stokes' mortar bombs ,sulfuric anhydride ,german ,irritant ,hand grenades1 minenwerfer1 artillery shell ,xylyl bromide ,german ,lachrymatory ,artillery shell ---------------------------------------- ------------------------- ,,table ,i--,continued ---------------------------------------- ------------------------- ,chemical ,belligerent ,effect ,means of ,projection ---------------------------------------- ------------------------- ,,mixtures#d ,bromoacetone 7#hj7 and ,chloroacetone 7#bj7 ,french ,lachrymatory,artillery shell ,lethal ,chlorine 7#ej7 and ,british ,lethal ,cylinders ,phosgene 7#ej7 ,german ,chlorine 7#gj7 and ,british ,lethal ,cylinders ,chloropicrin 7#cj7 ,lachrymatory ,chloropicrin 7#fe7 and ,british ,lethal ,cylinders ,hydrogen sulfide 7#ce7 ,lachrymatory ,chloropicrin 7#hj7 and ,british ,lethal ,artillery shell ,stannic chloride 7#bj7 ,french ,lachrymatory,trench mortar bombs ,american ,irritant ,projectors ,chloropicrin 7#ge7 and ,british ,lethal ,artillery shell ,phosgene 7#be7 ,lachrymatory,trench mortar bombs1 projectors ,dichloroethyl sulfide 7#hj7 ,german ,vesicant ,artillery shell and ,french ,lethal ,chlorobenzene 7#bj7 ,british ,american ,ethyl carbazol 7#ej7 and ,german ,sternutatory,artillery shell ,diphenylcyanoarsine 7#ej7 ,lethal ,ethyldichloroarsine 7#hj7 ,german ,lethal ,artillery shell and ,lachrymatory ,dichloromethylether 7#bj7 ,ethyliodoacetate 7#ge7 and ,british ,lachrymatory,artillery shell1 ,alcohol 7#be7 #d-;in4 ,stokes' mortars1 hand grenades ,hydrocyanic acid 7#ee7 ,british ,lethal ,artillery shell ,chloroform 7#be7 and ,arsenious chloride 7#bj7 ,hydrocyanic acid 7#ej71 ,french ,lethal ,artillery shell ,arsenious chloride 7#cj71 ,stannic chloride 7#ae7 and ,chloroform 7#e7 ,phosgene 7#ej7 and ,british ,lethal ,artillery shell ,arsenious chloride 7#ej7 ,dichloroethyl sulfide 7#hj7 ,german ,vesicant ,artillery shell and ,french ,lethal ,carbon tetrachloride 7#bj7 ,british ,american ,phosgene 7#fj7 and ,british ,lethal ,artillery shell ,stannic chloride 7#dj7 ,french ,irritant ,methyl sulfate 7#ge7 and ,french ,lachrymatory,artillery shell ,chloromethyl sulfate 7#be7 ,irritant ---------------------------------------- ------------------------- ,footnote #d3 ,in the mixtures the percentages indicate proportions by weight4 7#b7 ,to simulate the presence of a toxic gas4 ,this may be done either by using a substance whose odor in the field strongly suggests that of the gas in question1 or by so thoroughly associating a totally different odor with a particular 8gas0 in normal use that1 when used alone1 it still seems to imply the presence of that gas4 ,this use of imitation gas would thus be of service in economizing the use of actual 8gas0 or in the preparation of surprise attacks4 ,while there was some success with this kind of 8gas10 very few such attacks were really carried out1 and these were in connection with projector attacks4 ,,gases ,,used ,table ,i gives a list of all the gases used by the various armies1 the nation which used them1 the effect produced and the means of projection used4 ,table ,,ii gives the properties of the more important war cases 7compiled by ,major ,r4 ,e4 ,wilson1 ,c4 ,w4 ,s474 ,the gases used by the ,germans may also be classified by the names of the shell in which they were used4 ,table ,,iii gives such a classification4 ,,markings ,,for ,,american ,,shell ,in selecting markings for ,american chemical shell1 red bands were used to denote persistency1 white bands to denote non-persistency and lethal properties1 yellow bands to denote smoke1 and purple bands to denote incendiary action4 ,the number of bands indicates the relative strength of the property indicated2 thus1 three red bands denote a gas more persistent than one red band4 ,the following shell markings were actually used3 #a ,white ,diphenylchloroarsine #b ,white ,phosgene #a ,white1 #a red ,chloropicrin #a ,white1 #a red1 #a white #ge ,chloropicrin1 #be ,phosgene #a ,white1 #a red1 #a yellow #hj ,chloropicrin1 #bj ,stannic ,chloride #a ,red ,bromoacetone #b ,red ,bromobenzylcyanide #c ,red ,mustard ,gas #a ,yellow ,white ,phosphorus #b ,yellow ,titanium ,tetrachloride ,,table ,,ii ,,physical ,,constants ,,of ,,important ,,war ,,gases ---------------------------------------- ------------------ ,liquid ,density ,name of ,gas ,formula ,molecular at #bj ,c4 ,weight under ,own ,pressure ---------------------------------------- ------------------ ,bromoacetone ,c,h,br,o #acf4ih #a4g787 ,carbon monoxide ,,co #bh4jj 7,gas7 ,cyanogen bromide ,br,c,n #ajf4jb #b4ja ,cyanogen chloride ,cl,c,n #fa4ef #a4ahf ,chlorine ,cl #gj4ib #a4djh ,chloropicrin ,cl,c7,,no7 #afd4ci #a4fed ,dichloroethyl sulfide 7,,ch,c,h,cl7,s #afi4jf #a4bgd ,diphenylchloroarsine 7,c,h7,as,cl #bfd4ef #a4dbb ,hydrocyanic acid ,,hcn #bg4aa 4#fig ,phenyldichloroarsine ,c,h,as,cl #baj4if #a4fdj ,phosgene ,c,o,cl #ih4ib #a4ch ,stannic chloride ,sn,cl #bfj4ed #b4bbf ,superpalite ,c,cl,c,o,o,cl #aig4he #a4fe ,xylyl bromide 7 ,,ch7,c,h,,ch,br #ahe4jc #a4cha ---------------------------------------- ------------------- ---------------------------------------- ---------- ,vapor ,name of ,gas ,melting ,boiling ,pressure point1 point1 at #bj ,c4 ,c4 ,c4 7mm4 ,hg7 ---------------------------------------- ---------- ,bromoacetone - #ed #abf #i787 ,carbon monoxide -#bjg -#aij 7,gas7 ,cyanogen bromide #eb #fa4c #hi ,cyanogen chloride - #f #ae #ajjb ,chlorine -#aja4e #cc4f #eabf ,chloropicrin - #fi4b #aab #ah4i ,dichloroethyl sulfide #ab4e #baf 4#jf ,diphenylchloroarsine #dd #ccc 4#jjbe ,hydrocyanic acid - #ad #bf4a #fjc ,phenyldichloroarsine 444 #bec 4#jbb ,phosgene 444 #h4b #abae ,stannic chloride - #cc #aad #ah4eh ,superpalite 444 #abh #aj4c ,xylyl bromide - #b #bad4e 444 ---------------------------------------- ---------- ,,table ,,iii ,,german ,,shell ---------------------------------------- ------------------------ ,name of ,shell ,shell ,filling ,nature of ,effect ---------------------------------------- ------------------------ ,b-shell ,k shell ,bromoketone 7,bromo- ,lachrymator 7,white ,b or ,,bm7 methylethyl ketone7 ,blue ,cross 7a7 ,diphenylchloroarsine ,sternutator 7b7 ,diphenylcyanoarsine ,sternutator 7c7 ,diphenylchloroarsine1 ,ethyl carbazol ,c-shell 7,green ,cross7 ,superpalite ,asphyxiant 7,white ,c7 ,d-shell 7,white ,d7 ,phosgene ,lethal ,green ,cross 7a7 ,superpalite ,asphyxiant 7b7 ,phenylcarbylamine chloride ,green ,cross #a ,superpalite #fe1 ,asphyxiant ,chloropicrin #ce ,green ,cross #b ,superpalite1 ,phosgene1 ,diphenylchloroarsine ,asphyxiant ,green ,cross #c ,ethyldichloroarsine1 ,asphyxiant 7,yellow ,cross #a7 ,methyldibromoarsine1 ,dichloromethyl ether ,k-shell 7,yellow7 ,chloromethyl ,lachrymator chloroformate 7,palite7 ,asphyxiant ,t-shell ,xylyl bromide1 ,lachrymator 7,black or green ,t7 ,bromo ketone ,yellow ,cross ,mustard gas1 ,vesicant ,diluent 7,c,cl1 ,c,h,cl1 ,c,h,,no7 ,yellow ,cross #a ,see ,green ,cross #c ---------------------------------------- ------------------------ ,,chapter ,,iii ,,development ,,of ,,the ,,chemical ,,warfare ,,service ,modern chemical warfare dates from ,april #bb1 #aiae4 ,really1 however1 it may be said to have started somewhat earlier1 for ,germany undoubtedly had spent several months in perfecting a successful gas cylinder and a method of attack4 ,the ,allies1 surprised by such a method of warfare1 were forced to develop1 under pressure1 a method of defense1 and then1 when it was finally decided to retaliate1 a method of gas warfare4 8,offensive organizations were enrolled in the ,engineer ,corps of the two armies and trained for the purpose of using poisonous gases2 the first operation of this kind was carried out by the ,british at the battle of ,loos in ,september1 #aiae4 8,shortly after this the ,british ,army in the field amalgamated all the offensive1 defensive1 advisory and supply activities connected with gas warfare and formed a #8,gas ,service' with a ,brigadier ,general as ,director4 ,this step was taken almost as a matter of necessity1 and because of the continually increasing importance of the use of gas in the war 7,auld740 ,at once the accumulation of valuable information and experience was started4 ,later this was very willingly and freely placed at the disposal of ,american workers4 ,too much cannot be said about the hearty co-operation of ,england and ,france4 ,without it and the later exchange of information on all matters regarding gas warfare1 the progress of gas research in all the allied countries would have been very much retarded4 ,while many branches of the ,american ,army were engaged in following the progress of the war during #aiae-aiaf1 the growing importance of gas warfare was far from being appreciated4 ,when the ,united ,states declared war on ,germany ,april #f1 #aiag1 there were a few scattered observations on gas warfare in various offices of the different branches1 but there was no attempt at an organized survey of the field1 while absolutely no effort had been made by the ,war ,department to inaugurate research in a field that later had #b1jjj men alone in pure research work4 ,equally important was the fact that no branch of the ,service had any idea of the practical methods of gas warfare4 ,the only man who seemed to have the vision and the courage of his convictions was ,van ,h4 ,manning1 ,director of the ,bureau of ,mines4 ,since the establishment of the ,bureau in #aijh it had maintained a staff of investigators studying poisonous and explosive gases in mines1 the use of self-contained breathing apparatus for exploring mines filled with noxious gases1 the treatment of men overcome by gas1 and similar problems4 ,at a conference of the ,director of the ,bureau with his ,division ,chiefs1 on ,february #g1 #aiag1 the matter of national preparedness was discussed1 and especially the manner in which the ,bureau could be of most immediate assistance with its personnel and equipment4 ,on ,february #h1 the ,director wrote ,c4 ,d4 ,walcott1 ,chairman of the ,military ,committee of the ,national ,research ,council1 pointing out that the ,bureau of ,mines could immediately assist the ,navy and the ,army in developing1 for naval or military use1 special oxygen breathing apparatus similar to that used in mining4 ,he also stated that the ,bureau could be of aid in testing types of gas masks used on the fighting lines1 and had available testing galleries at the ,pittsburgh experiment station and an experienced staff4 ,dr4 ,walcott replied on ,february #ab that he was bringing the matter to the attention of the ,military ,committee4 ,a meeting was arranged between the ,bureau and the ,war ,college1 the latter organization being represented by ,brigadier ,general ,kuhn and ,major ,l4 ,p4 ,williamson4 ,at this conference the ,war ,department enthusiastically accepted the offer of the ,bureau of ,mines and agreed to support the work in every way possible4 ,the supervision of the research on gases was offered to ,dr4 ,g4 ,a4 ,burrell1 for a number of years in charge of the chemical work done by the ,bureau in connection with the investigation of mine gases and natural gas4 ,he accepted the offer on ,april #g1 #aiag4 ,the smoothness with which the work progressed under his direction and the importance of the results obtained were the result of ,colonel ,burrell's great tact1 his knowledge of every branch of research under investigation and his imagination and general broad-mindedness4 ,once1 however1 that the importance of gas warfare had been brought to the attention of the chemists of the country1 the response was very eager and soon many of the best men of the university and industrial plants were associated with ,burrell in all the phases of gas research4 ,the staff grew very rapidly and laboratories were started at various points in the ,east and ,middle ,west4 ,it was immediately evident that there should be a central laboratory in ,washington to co-ordinate the various activities and also to considerably enlarge those activities under the joint direction of the ,army1 the ,navy and the ,bureau of ,mines4 ,fortunately a site was available for such a laboratory at the ,american ,university1 the use of the buildings and grounds having been tendered ,president ,wilson on ,april #cj1 #aiag4 ,thus originated the ,american ,university ,experiment ,station1 later to become the ,research ,division of the ,chemical ,warfare ,service4 ,meanwhile other organizations were getting under way4 ,the procurement of toxic gases and the filling of shell was assigned to the ,trench ,warfare ,section of the ,ordnance ,department4 ,in ,june1 #aiag1 ,general ,crozier1 then ,chief of the ,ordnance ,department1 approved the general proposition of building a suitable plant for filling shell with toxic gas4 ,in ,november1 #aiag1 it was decided to establish such a plant at ,gunpowder ,neck1 ,maryland4 ,owing to the inability of the chemical manufacturers to supply the necessary toxic gases1 it was further decided1 in ,december1 #aiag1 to erect at the same place such chemical plants as would be necessary to supply these gases4 ,in ,january1 #aiah1 the name was changed to ,edgewood ,arsenal1 and the project was made a separate ,bureau of the ,ordnance ,department1 ,col4 ,william ,h4 ,walker1 of the ,massachusetts ,institute of ,technology1 being soon afterwards put in command4 ,while1 during the latter part of the ,war1 gas shell were handled by the regular artillery1 special troops were needed for cylinder attacks1 ,stokes' mortars1 ,livens' projectors and for other forms of gas warfare4 ,general ,pershing early cabled1 asking for the organization and training of such troops1 and recommended that they be placed1 as in the ,english ,army1 under the jurisdiction of the ,engineer ,corps4 ,on ,august #ae1 #aiag1 the ,general ,staff authorized one regiment of ,gas and ,flame troops1 which was designated the 8#cjth ,engineers10 and was commanded by ,major 7later ,colonel7 ,e4 ,j4 ,atkisson4 ,this later became the ,first ,gas ,regiment1 of the ,chemical ,warfare ,service4 ,about this time 7,september1 #aiag7 the need of gas training was recognized by the organization of a ,field ,training ,section1 under the direction of the ,sanitary ,corps1 ,medical ,department4 ,later it was recognized that neither the ,training ,section nor the ,divisional ,gas ,officers should be under the ,medical ,department1 and1 in ,january1 #aiah1 the organization was transferred to the ,engineer ,corps4 ,all of these1 with the exception of the ,gas and ,flame regiment1 were for service on this side4 ,the need for an ,overseas force was recognized and definitely stated in a letter1 dated ,august #d1 #aiag4 ,on ,september #c1 #aiag1 an order was issued establishing the ,gas ,service1 under the command of ,lt4 ,col4 7later ,brigadier ,general7 ,a4 ,a4 ,fries1 as a separate ,department of the ,a4 ,e4 ,f4 in ,france4 ,in spite of a cable on ,september #bfth1 in which ,general ,pershing had said 8,send at once chemical laboratory1 complete equipment and personnel1 including physiological and pathological sections1 for extensive investigation of gases and powders44440 it was not until the first of ,january1 #aiah1 that ,colonel ,r4 ,f4 ,bacon of the ,mellon ,institute sailed for ,france with about fifty men and a complete laboratory equipment4 ,meantime a ,chemical ,service ,section had been organized in the ,united ,states4 ,this holds the distinction of being the first recognition of chemistry as a separate branch of the military service in any country or any war4 ,this was authorized ,october #af1 #aiag1 and was to consist of an officer of the ,engineers1 not above the rank of colonel1 who was to be ,director of ,gas ,service1 with assistants1 not above the rank of lieutenant colonel from the ,ordnance ,department1 ,medical ,department and ,chemical ,service ,section4 ,the ,section itself was to consist of #dg commissioned and #ie non-commissioned officers and privates4 ,colonel ,c4 ,l4 ,potter1 ,corps of ,engineers1 was appointed ,director and ,professor ,w4 ,h4 ,walker was commissioned ,lieutenant ,colonel and made ,assistant ,director of the ,gas ,service and ,chief of the ,chemical ,service ,section4 ,this was increased on ,feb4 #ae1 #aiah to #bbg commissioned and #fbe enlisted men1 and on ,may #f1 #aiah to #cic commissioned and #ibj enlisted men4 ,meanwhile ,lt4 ,col4 ,walker had been transferred to the ,ordnance and ,lt4 ,col4 ,bogert had been appointed in his place4 ,at this time practically every branch of the ,army had some connection with ,gas ,warfare4 ,the ,medical ,corps directed the ,gas ,defense production4 ,offense production was in the hands of the ,ordnance ,department4 ,alarm devices1 etc41 were made by the ,signal ,corps4 ,the ,engineers contributed their #cjth ,regiment 7,gas and ,flame7 and the ,field ,training ,section4 ,the ,research ,section was still in charge of the ,bureau of ,mines1 in spite of repeated attempts to militarize it4 ,and in addition1 the ,chemical ,service ,section had been formed primarily to deal with overseas work4 ,while the ,director of the ,gas ,service was expected to co-ordinate all these activities1 he was given no authority to control policy1 research or production4 ,in order to improve these conditions ,major ,general ,wm4 ,l4 ,sibert1 a distinguished ,engineer ,officer who built the ,gatun ,locks and ,dam of the ,panama ,canal and who had commanded the ,first ,division in ,france1 was appointed ,director of the ,chemical ,warfare ,service on ,may #aa1 #aiah4 ,under his direction the ,chemical ,warfare ,service was organized with the following ,divisions3 ,overseas ,brigadier ,general ,amos ,a4 ,fries ,research ,colonel ,g4 ,a4 ,burrell ,development ,colonel ,f4 ,m4 ,dorsey ,gas ,defense ,production ,colonel ,bradley ,dewey ,gas ,offense ,production ,colonel ,wm4 ,h4 ,walker ,medical ,colonel ,w4 ,j4 ,lyster ,proving ,lt4 ,col4 ,w4 ,s4 ,bacon ,administration ,brigadier ,general ,h4 ,c4 ,newcomer ,gas and ,flame ,colonel ,e4 ,j4 ,atkisson ,the final personnel authorized1 though never reached owing to the signing of the ,armistice1 was #d1jff commissioned officers and #dd1fae enlisted men2 this was including three gas regiments of eighteen companies each4 ,general ,sibert brought with him not only an extended experience in organizing and conducting big business1 but a strong sympathy for the work and an appreciation of the problem that the ,american ,army was facing in ,france4 ,he very quickly welded the great organization of the ,chemical ,warfare ,service into a whole1 and saw to it that each department not only carried on its own duties but co-operated with the others in carrying out the larger program1 which1 had the war continued1 would have beaten the ,german at his own game4 ,more detailed accounts will now be given of the various ,divisions of the ,chemical ,warfare ,service4 ,,administration ,,division ,the ,administration ,division was the result of the development which has been sketched in the preceding pages4 ,it is not necessary to review that1 but the organization as of ,october #ai1 #aiah will be given3 ,director ,major ,general ,wm4 ,l4 ,sibert ,staff3 ,medical ,officer ,colonel ,w4 ,j4 ,lyster ,ordnance ,officer ,lt4 ,col4 ,c4 ,b4 ,thummel ,british ,military ,mission ,major ,j4 ,h4 ,brightman ,assistant ,director ,colonel ,h4 ,c4 ,newcomer ,office ,administration ,major ,w4 ,w4 ,parker ,relations ,section ,colonel ,m4 ,t4 ,bogert ,personnel ,section ,major ,f4 ,e4 ,breithut ,contracts and ,patents ,section ,captain ,w4 ,k4 ,jackson ,finance ,section ,major ,c4 ,c4 ,coombs ,requirements and ,progress ,section ,capt4 ,s4 ,m4 ,cadwell ,confidential ,information ,section ,major ,s4 ,p4 ,mullikin ,transportation ,section ,captain ,h4 ,b4 ,sharkey ,training ,section ,lt4 ,col4 ,g4 ,n4 ,lewis ,procurement ,section ,lt4 ,col4 ,w4 ,j4 ,noonan ,the administrative offices were located in the ,medical ,department ,building4 ,the function of most of the sections is indicated by their names4 ,the ,industrial ,relations ,section was created to care for the interests of the industrial plants which were considered as essential war industries4 ,through its activity many vitally important industries were enabled to retain1 on deferred classification or on indefinite furlough1 those skilled chemists without which they could not have maintained a maximum output of war munitions4 ,in the same way the ,university ,relations ,section cared for the educational and research institutions4 ,in this way our recruiting stations for chemists were kept in as active operation as war conditions permitted4 ,another important achievement of the ,administration ,section was to secure the order from ,the ,adjutant ,general1 dated ,may #bh1 #aiah1 that read3 8,owing to the needs of the military service for a great many men trained in chemistry1 it is considered most important that all enlisted men who are graduate chemists should be assigned to duty where their special knowledge and training can be fully utilized4 99 99 99 99 99 8,enlisted men who are graduate chemists will not be sent overseas unless they are to be employed on chemical duties44440 ,while this undoubtedly created a great deal of feeling among the men who naturally were anxious to see actual fighting in ,france1 it was very important that this order be carried out in order to conserve our chemical strength4 ,the following clipping from the ,september1 #aiah1 issue of ,the ,journal of ,industrial and ,engineering ,chemistry shows the result of this order4 8,,chemists ,,in ,,camp 8,as the result of the letter from ,the ,adjutant ,general of the ,army1 dated ,may #bh1 #aiah1 #a1gdi chemists have been reported on4 ,of these the report of action to ,august #a1 #aiah1 shows that #bha were ordered to remain with their military organization because they were already performing chemical duties1 #cd were requested to remain with their military organization because they were more useful in the military work which they were doing1 #ab were furloughed back to industry1 #afe were not chemists in the true sense of the word and were1 therefore1 ordered back to the line1 and #a1bid now placed in actual chemical work4 ,there were being held for further investigation of their qualifications on ,august #a1 #aiah1 #dcb men4 ,the remaining #bc men were unavailable for transfer1 because they had already received their overseas orders4 8,the #a1bid men1 who would otherwise be serving in a purely military capacity and whose chemical training is now being utilized in chemical work1 have1 therefore1 been saved from waste4 8,each case has been considered individually1 the man's qualifications and experience have been studied with care1 the needs of the ,government plants and bureaus have been considered with equal care1 and each man has been assigned to the position for which his training and qualifications seem to fit him best4 8,undoubtedly1 there have been some cases in which square pegs have been fitted into round holes1 but1 on the whole1 it is felt that the adjustments have been as well as could be expected under the circumstances40 ,,research ,,division ,the ,american ,university ,experiment ,station1 established by the ,bureau of ,mines in ,april1 #aiag1 became ,july #a1 #aiah the ,research ,division of the ,chemical ,warfare ,service4 ,for the first five months work was carried out in various laboratories1 scattered over the country4 ,in ,september1 #aiag1 the buildings of the ,american ,university became available2 a little later portions of the new chemical laboratory of the ,catholic ,university1 ,washington1 were taken over4 ,branch laboratories were established in many of the laboratories of the ,universities and industrial plants1 of which ,johns ,hopkins1 ,princeton1 ,yale1 ,ohio ,state1 ,massachusetts ,institute of ,technology1 ,harvard1 ,michigan1 ,columbia1 ,cornell1 ,wisconsin1 ,clark1 ,bryn ,mawr1 ,nela ,park and the ,national ,carbon ,company were active all through the war4 ,at the time of the signing of the armistice the organization of the ,research ,division was as follows3 ,col4 ,g4 ,a4 ,burrell ,chief of ,research ,division ,dr4 ,w4 ,k4 ,lewis ,in ,charge of ,defense ,problems ,dr4 ,e4 ,p4 ,kohler#e ,in ,charge of ,offense ,problems ,dr4 ,reid ,hunt ,advisor on ,pharmacological ,problems ,lt4 ,col4 ,w4 ,d4 ,bancroft ,in ,charge of ,editorial ,work and ,catalytic ,research ,lt4 ,col4 ,a4 ,b4 ,lamb#f ,in ,charge of ,defense ,chemical ,research ,dr4 ,l4 ,w4 ,jones#g ,in ,charge of ,offense ,chemical ,research ,major ,a4 ,c4 ,fieldner ,in ,charge of ,gas ,mask ,research ,major ,g4 ,a4 ,richter ,in ,charge of ,pyrotechnic ,research ,capt4 ,e4 ,k4 ,marshall#h ,in ,charge of ,pharmacological ,research ,dr4 ,a4 ,s4 ,loevenhart#i ,in ,charge of ,toxicological ,research ,major ,r4 ,c4 ,tolman ,in ,charge of ,dispersoid ,research ,major ,w4 ,s4 ,rowland#aj ,in ,charge of ,small ,scale ,manufacture ,major ,b4 ,b4 ,fogler#aa ,in ,charge of ,mechanical ,research and ,development ,captain ,g4 ,a4 ,rankin ,in ,charge of ,explosive ,research ,major ,richmond ,levering ,in ,charge of ,administration ,section ,footnote #e3 ,succeeded ,dr4 ,john ,johnson who went to the ,national ,research ,council4 ,footnote #f3 ,at first ,lt4 ,col4 ,j4 ,f4 ,norris was in charge of all chemical research4 ,about ,december1 #aiag1 it was divided into ,offense and ,defense1 and ,lt4 ,col4 ,lamb was placed in charge of ,defense4 ,when ,col4 ,norris went to ,england as ,liaison ,officer1 ,dr4 ,jones took his place4 ,footnote #g3 ,at first ,lt4 ,col4 ,j4 ,f4 ,norris was in charge of all chemical research4 ,about ,december1 #aiag1 it was divided into ,offense and ,defense1 and ,lt4 ,col4 ,lamb was placed in charge of ,defense4 ,when ,col4 ,norris went to ,england as ,liaison ,officer1 ,dr4 ,jones took his place4 ,footnote #h3 ,at first ,lt4 ,col4 ,j4 ,f4 ,norris was in charge of all chemical research4 ,about ,december1 #aiag1 it was divided into ,offense and ,defense1 and ,lt4 ,col4 ,lamb was placed in charge of ,defense4 ,when ,col4 ,norris went to ,england as ,liaison ,officer1 ,dr4 ,jones took his place4 ,footnote #i3 ,in the early organization of the ,bureau of ,mines1 ,dr4 ,yandall ,henderson was in charge of the ,medical ,sciences4 ,associated with him were ,dr4 ,f4 ,p4 ,underhill1 in charge of ,therapeutic ,research2 ,major ,m4 ,c4 ,winternitz1 in c of ,pathological ,research and ,captain ,e4 ,k4 ,marshall in charge of ,pharmacological ,research4 ,about ,may #a1 #aiah1 ,pharmacological ,research became so extensive that the ,section was made into two1 with ,marshall and ,loevenhart in charge1 while ,dr4 ,hunt was appointed special adviser on pharmacological problems4 ,when the transfer to the ,war ,department was made1 ,henderson1 ,underhill1 ,winternitz and ,marshall were transferred to the ,medical ,division4 ,footnote #aj3 ,lt4 ,col4 ,mc,pherson was formerly in charge1 and was later transferred to ,ordnance4 ,footnote #aa3 ,this ,section was originally under ,h4 ,h4 ,clark4 ,later it was split into two1 with ,clark and ,fogler in charge1 and finally consolidated under ,fogler4 ,the chief functions of the ,research ,division were3 #a4 ,to prepare and test compounds which might be of value in gas warfare1 determining the properties of these substances and the conditions under which they might be effective in warfare4 #b4 ,to develop satisfactory methods of making such compounds as seemed promising 7,small ,scale74 #c4 ,to develop the best methods of utilizing these compounds4 #d4 ,to develop materials which should absorb or destroy war gases1 studying their properties and determining the conditions under which they might be effective4 #e4 ,to develop satisfactory methods of making such absorbents as might seem promising4 #f4 ,to develop masks1 canisters1 protective clothing1 etc4 #g4 ,to develop incendiaries1 smokes1 signals1 etc41 and the best methods of using the same4 ,illustration3 ,,fig4 #d4--;,american ,university ,experiment ,station1 showing ,small ,scale ,plants4 #h4 ,to co-operate with the manufacturing divisions in regard to difficulties arising during the operations of manufacturing war gases1 absorbents1 etc4 #i4 ,to co-operate with other branches of the ,government1 civil and military1 in regard to war problems4 #aj4 ,to collect and make available to the ,director of the ,chemical ,warfare ,service all information in regard to the chemistry of gas warfare4 ,the relation of the various sections may best be shown by outlining the general procedure used when a new toxic substance was developed4 ,the substance in question may have been used by the ,germans or the ,allies2 it may have been suggested by someone outside the station2 or the staff may have thought of it from a search of the literature1 from analogy or from pure inspiration4 ,the ,offense ,research ,section made the substance4 ,if it was a solid it was sent to the ,dispersoid ,section1 where methods of dispersing it were worked out4 ,when this had been done1 or1 at once1 if the compound was a liquid or vapor1 it was sent to the ,toxicological ,section to be tested for toxicity1 lachrymatory power1 vesicant action1 or other special properties4 ,if these tests proved the compound to have a high toxicity or a peculiar physiological behavior1 it was then turned over to a number of different sections4 ,the ,offense ,research ,section tried to improve the method of preparation4 ,when a satisfactory method had been found1 the ,chemical ,production or ,small ,scale ,manufacturing ,section endeavored to make it on a large scale 7#ej pounds to a ton7 and worked out the manufacturing difficulties4 ,if further tests showed that the substance was valuable1 the manufacture was then given to the ,development ,division or the ,gas ,offense ,production ,division for large scale production4 ,meanwhile the ,analytical ,section had been working on a method for testing the purity of the material and for analyzing air mixtures1 and the ,gas ,mask ,section had run tests against it with the standard canisters4 ,if the protection afforded did not seem sufficient1 the ,defense ,chemical ,section studied changes in the ingredients of the canister or even developed a new absorbent or mixture of absorbents to meet the emergency4 ,if a change in the mechanical construction of the canister was necessary1 this was referred to the ,mechanical ,research ,section2 this work was especially important in case the material was to be used as a toxic smoke4 ,the compound was also sent to the ,pyrotechnic ,section1 which studied its behavior when fired from a shell1 or1 if suitable1 when used in a cylinder4 ,if it proved stable on detonation1 large field tests were then made by the ,proving ,division1 in connection with the ,pyrotechnic and ,toxicological ,sections of the ,research ,division1 to learn the effect when shell loaded with the compound were fired from guns on a range1 with animals placed suitably in or near the trenches4 ,the ,analytical ,section worked out methods of detecting the gas in the field1 wherever possible4 ,the ,medical ,division1 working with the ,toxicological and ,pharmacological ,sections1 studied pathological details1 methods of treating gassed cases1 the effect of the gas on the body1 and in some cases even considered other questions1 such as the susceptibility of different men4 ,if the question of an ointment or clothing entered into the matter of protection1 these were usually attacked by several ,sections from different points of view4 ,out of the #bej gases prepared by the ,offense ,chemical ,research ,section1 very few were sufficiently valuable to pass all of these tests and thus the number of gases actually put into large scale production were less than a dozen4 ,this had its advantages1 for it made unnecessary a large number of factories and the training of men in the manufacturing details of many gases4 ,as one ,british report stated1 8,the ultimate object of chemical warfare should be to produce two substances only2 one persistent and the other non-persistent2 both should be lethal and both should be penetrants40 ,they might well have added that both should be instantly and powerfully lachrymatory4 ,since most of the work of the ,research ,division will be covered in detail in later chapters1 only a brief summary of the principal problems will be given here4 ,the first and most important problem was the development of a gas mask4 ,this was before ,sections had been organized and was the work of the entire ,division4 ,after comparing the existing types of masks it was decided that the ,standard ,box ,respirator of the ,british was the best one to copy4 ,because we were entirely new at the game that meant work on charcoal1 soda-lime1 and the various mechanical parts of the mask1 such as the facepiece1 elastics1 eyepieces1 mouthpiece1 noseclip1 hose1 can1 valves1 etc4 ,the story of the 8first twenty thousand0 is very well told by ,colonel ,burrell4#ab ,footnote #ab3 ,j4 ,ind4 ,eng4 ,chem41 #aa1 #ic 7#aiai74 8,,the ,,first ,,twenty ,,thousand 8,about the first of ,may1 #aiag1 ,major ,l4 ,p4 ,williamson1 acting as liaison officer between the ,bureau of ,mines and the ,war ,department1 put the last ounce of #8pep' into the organization by asking us to build #bj1jjj gas masks for shipment overseas4 #bj1jjj masks did not seem like a very large order4 ,we did not fully appreciate all the conditions which a war gas mask had to encounter1 so we readily and willingly accepted the order4 ,then began a struggle with can manufacturers1 buckle makers1 manufacturers of straps1 rubber facepieces1 eyepieces1 knapsacks1 etc4 ,the country was canvassed from the ,atlantic ,coast to the ,mississippi ,river for manufacturers who could turn out the different parts acceptably and in a hurry4 8,charcoal was made from red cedar by the ,day ,chemical ,co4 of ,westline1 ,pennsylvania2 soda-lime permanganate was manufactured by the ,general ,chemical ,company2 knapsacks by the ,simmons ,hardware ,company in ,st4 ,louis2 facepieces by the ,goodrich and ,goodyear ,rubber ,companies at ,akron2 canisters by the ,american ,can ,company2 and the assembly made at one of the plants of the ,american ,can ,company in ,long ,island ,city4 8,the writer cannot recall all the doubts1 fears1 optimism1 and enthusiasm felt in turn by different members of the organization during the fabrication of those first #bj1jjj masks4 ,we were performing an important task for the ,war ,department4 ,night became day4 ,dewey1 ,lewis1 ,henderson1 ,gibbs1 and others stepped from one train to another1 and we used the telephone between ,washington and ,st4 ,louis or ,boston as freely as we used the local ,washington telephone4 8,we thought we could improve on the ,english box respirator on various points4 ,we made the canister larger1 and have been glad ever since that we did4 ,we thought the ,english mouthpiece was too flexible and too small1 and made ours stiff and larger1 and were sorry we made the change4 ,we tested the fillings against chlorine1 phosgene1 prussic acid1 etc41 and had a canister that was all that was desired for absorbing these gases4 ,but1 alas1 we did not know that chloropicrin was destined to be one of the most important war gases used by the various belligerents4 ,further1 it was not fully appreciated that the rubberized cloth used in making the facepiece had to be highly impermeable against gases1 that hardness as much as anything else was desired in the make-up of the soda-lime granules in order to withstand rough jolting so that the fines would not clog the canister1 and raise the resistance to breathing to a prohibitive figure4 ,neither was it appreciated at that time by any of the allies1 that the gas mask really should be a be a fighting instrument1 one that men could work hard in1 run in1 and wear for hours1 without too serious discomfort4 8,the first #bj1jjj masks sent over to ,england were completed by the ,research ,division in record time4 ,as compared with the ,french masks1 they were far superior1 giving greater protection against chlorine1 phosgene1 superpalite1 prussic acid1 xylyl bromide1 etc4 ,the ,french mask was of the cloth type1 conforming to the face1 and consisting of twenty layers of cheesecloth impregnated with sodium phenate and hexamethylenetetramine4 ,chloropicrin went through this like a shot4 ,just before the masks were sent abroad1 we received disturbing rumors of the contemplated use of large quantities of chloropicrin4 ,the ,french1 apparently1 had no intention of changing the design of their mask1 and did not do so for months to come4 ,we therefore released the masks1 they were sent abroad1 and an anxious research group on this side of the water waited expectantly for the verdict4 ,it came4 ,a brief cablegram told us what our ,english cousins thought of us4 ,it was a subject they had been wrestling with for two years and a half4 ,they had had battlefield experience2 they had gone through the grief of developing poor masks into better ones1 knew the story better than we did1 and after a thorough test #8hammered' the ,american design unmercifully4 8,this experience put the ,research ,division on its mettle4 ,our first attempt had given us the necessary preliminary experience2 cablegrams and reports traveled back and forth2 an expert or two eventually came to this country from ,england in response to previous appeals for assistance1 and we turned with adequate information to the development of a real mask40 ,the story of mustard gas is given later4 ,it probably occupied more time and thought on the part of the ,research ,division1 as well as that of ,edgewood ,arsenal and the ,development ,division1 than any other gas4 ,diphenylchloroarsine led to the preparation of a series of arsenic compounds1 some more easily prepared and more or less effective4 ,cyanogen chloride and cyanogen bromide1 reported by the ,italians as having been used by the ,germans1 were extensively studied4 ,the ,inorganic ,section was early interested in special incendiary materials which were developed for bombs1 shells1 darts and grenades1 and which were later taken over by the ,pyrotechnic ,section1 and finally adopted by the ,ordnance ,department4 ,in discussing the work one can very well start with the ,offense ,section4 ,this ,section had two aims in view always1 to develop methods of making the gases used by the ,germans more economically than they were making them1 and to develop better gases if possible4 ,when we entered the war1 chlorine1 phosgene and chloropicrin were the lethal gases used1 while bromoacetone and xylyl bromide were the lachrymators4 ,it was not a difficult matter to prepare these4 ,but the introduction of mustard gas in the summer of #aiag and of diphenylchloroarsine in the autumn of the same year1 not only made our chemists ponder over a manufacturing method1 but also so revised our notions of warfare that the possibility of using other substances created the need for extensive research4 ,the development of bromobenzylcyanide by the ,french likewise opened a new field among lachrymatory substances4 ,colored rockets and smokes were developed for the ,navy and ,army4 ,the smoke box was also studied but the work was taken over by the ,pyrotechnic ,section4 ,a large amount of pure inorganic research on arsine and arsenides1 fluorine1 hydrofluoric acid and fluorides1 cyanides1 cyanogen sulfide and nitrogen tetroxide was carried out1 sometimes successfully and at other times with little or no success4 ,the ,analytical ,section not only carried out all routine analyses but developed methods for many new gases4 ,the ,offense ,section worked in very close contact with the ,small ,scale ,manufacturing ,section 7,chemical ,production ,section74 ,often it happened that a method1 apparently successful in the laboratory1 was of no value in the plant4 ,small scale plants were developed for mustard gas1 hydrocyanic acid1 cyanogen chloride1 arsenic trichloride1 arsenic trifluoride1 magnesium arsenide1 superpalite and bromobenzylcyanide4 ,the ,chemical ,defense ,section1 organized ,january1 #aiah1 was occupied with problems relating to protection1 such as charcoal1 soda-lime1 and special absorbents1 eyepieces1 smoke filters1 efficiency of absorbents1 and special work with mustard gas4 ,charcoal demanded extensive research4 ,raw materials required a world-wide search1 carbonizing methods had to be developed1 and impregnating agents were thoroughly studied4 ,this story is told in ,chapter ,,xiii4 ,soda-lime was likewise a difficult problem4 ,starting with the ,british formula1 the influence of the various factors was studied and a balance between a number of desirable qualities1 absorptive activity1 capacity1 hardness1 resistance to abrasion1 chemical stability1 etc41 obtained4 ,the final product consisted of a mixture of lime1 cement1 kieselguhr1 sodium permanganate and sodium hydroxide4 ,equally valuable work was performed in the perfection of two carbon monoxide absorbents for the ,navy4 ,the better of these consisted of a mixture of suitably prepared oxides which acts catalytically under certain conditions1 and causes the carbon monoxide to react with the oxygen of the air4 ,since there are color changes connected with the iodine pentoxide reaction 7the first absorbent7 it has been possible to develop this so as to serve as a very sensitive detector for the presence of carbon monoxide in air4 ,while the question of smoke filters was so important that it occupied the attention of several ,sections1 the ,defense ,section developed1 as a part of its work1 a standard method of testing and comparing filters1 and did a great deal of work on the preparation of paper for this purpose4 ,various problems related to mustard gas were also studied4 ,the question of a protective ointment was solved as successfully as possible under the circumstances1 but was dropped when it appeared doubtful if under battlefield conditions of concentration and length of exposure1 any ointment offered sufficient protection to pay for the trouble of applying it4 ,the removal of mustard gas from clothing was investigated1 especially by the accelerating effect of turkey red oil4 ,another phase of the work concerned the destruction of mustard gas on the ground1 while a fourth phase related to the persistency of mustard 7and other gases7 on the field of battle4 ,the ,gas ,mask ,research ,section concerned itself largely with developing methods of testing canisters and with routine tests4 ,when one considers the number of gases studied experimentally1 the large number of experimental canisters developed1 all of which were tested against two or more gases1 and further that the ,section assisted in the control of the production at ,long ,island ,city1 it is seen that this was no small job4 ,in addition1 the effect of various conditions1 such as temperature1 humidity1 ageing1 size of particles1 were studied in their relation to the life of absorbents and canisters4 ,man tests and mechanical tests will be discussed in a later chapter4 ,other studies were concerned with weathering tests of gas mask fabrics1 mustard gas detector1 and covering for dugout entrances 7dugout blankets71 which were impregnated with a mixture of mineral and vegetable oils4 ,in studying the course of gases through a canister the 8wave front0 method was of great value in detecting defects in canister design and filling4 ,the ,pyrotechnic ,section was composed of a number of units1 each with its own problem4 ,the gas shell was studied1 with special reference to the stability of gases and toxic solids1 both on storage and on detonation4 ,extensive work was carried out on smoke screens--a ,navy funnel1 an ,army portable smoke apparatus1 using silicon tetrachloride1 a grenade1 a ,livens1 and various shell being developed for that purpose4 ,the smoke screen was adapted to the tank and the airplane as well as to the funnel of a ship4 ,several types of incendiary bombs and darts were perfected4 ,the liquid fire gun was studied but the results were never utilized because of the abandonment as useless of that form of warfare4 ,various forms of signal lights1 flares1 rockets and colored smokes were studied and in most cases specifications were written4 ,extensive studies were also carried out on gas shell linings1 from which a lead and an enamel lining were evolved4 ,many physical properties of war gases and their mixtures were determined4 ,the ,dispersoid ,section studied the production of smokes or mists from various solid and liquid substances4 ,apparatus were developed to study the concentration of smoke clouds and their rate of settling4 ,the efficiency of various filters and canisters was determined1 and among other things1 a new smoke candle was perfected4 ,mechanical research at first was related to design and construction of a canister and mask1 based on the ,english type4 ,during the latter part of #aiag the ,tissot type of mask was studied and then turned over to the ,gas ,defense ,division4 ,a ,navy ,head ,mask and canister was perfected4 ,the horse mask was developed along the lines of the ,british type1 and also a dog mask of the same general nature4 ,horse boots were also constructed1 though they never were used at the front4 ,many ,ordnance and ,pyrotechnic problems were also successfully completed1 not the least of which was a noiseless gas cylinder4 ,this section developed the first special poison gas suit1 composed of an oilcloth suit1 a mask and helmet and a special canister4 ,the ,manufacturing ,development ,section had general charge of the defense problems1 and really acted as an emergency section1 filling in as occasion demanded4 ,they developed mustard gas clothing and a horse mask4 ,they constructed a hydrogen plant at ,langley ,field1 assisted in solving the difficulties relating to ,batchite charcoal at ,springfield1 ,mass41 and co-operated in the study of paper and felt as filtering materials for smokes4 ,towards the close of the war the ,section was interested in the application of the gas mask to the industries4 ,the ,physiological work is discussed under the ,medical ,division4 ,the ,editorial ,section received reports from all the other ,sections1 from which a semi-monthly report was written1 and distributed to authorized representatives of the ,army and ,navy and to our ,allies4 ,reports were also received from abroad and the information thus received was made available to the ,research ,division4 ,as the number of reports increased the work was collected together into monographs on the various war gases1 absorbents1 smokes1 etc4 ,after the signing of the armistice these were revised and increased in number1 so that about fifty were finally turned over to the ,director of the ,chemical ,warfare ,service4 ,,gas ,,defense ,,division ,the story of the ,gas ,defense ,division is largely the story of the gas mask4 ,colonel 7then ,mr47 ,bradley ,dewey was in charge of the 8first twenty thousand40 ,soon after that work was undertaken1 he was commissioned ,major in the ,gas ,defense ,division of the ,sanitary ,corps and was placed in charge of the entire manufacturing program4 ,the work of the ,division included the development and manufacture as well as the testing and inspection of gas masks1 and other defense equipment4 ,the magnitude of the work is seen from the following record of production3 #e1fib1jjj completed gas masks1 #c1fad1ibe of which were produced at the ,long ,island ,city ,plant1 while the remainder were assembled at the ,hero ,manufacturing ,company's ,plant at ,philadelphia1 #cgg1hha horse masks1 #aia1chh dugout blankets1 #b1dej protective suits and #a1ggc pairs of gloves1 #a1bdf tons of protective ointment1 #de1ijf gas warning signals 7largely hand horns71 #ej1edi trench fans and many oxygen inhalators4 ,illustration3 ,,fig4 #e4--,the ,defective ,gas ,mask4 ,successfully used by the ,gas ,defense ,division to stimulate care in every part of the operation of the manufacture of ,gas ,masks4 ,the story of the 8first twenty thousand0 has already been told on page #dc4 ,that these masks were far from satisfactory is no reflection upon the men who made them4 ,even with the standard design of the ,british as a pattern1 it was impossible to attain all the knowledge concerning gas masks in two months4 ,the experience gained in this struggle enabled the ,army to take up the manufacture of gas masks1 in ,july1 #aiag1 with a more complete realization of the seriousness of the task4 ,the masks were not lost1 either1 for they were sent to the various camps as training masks and served a very useful purpose4 ,the first order after this was for #a1ajj1jjj masks1 to be completed within a year from date4 ,for this production there was authorized one major1 two captains1 and ten lieutenants4 ,how little the problem was understood is evident when we realize that in the end there were #ab1jjj employees in the ,gas ,defense ,plant at ,long ,island ,city1 ,n4 ,y4 ,the first attempts were to secure these through existing concerns4 ,the ,hero ,manufacturing ,company of ,philadelphia undertook the work and carried on certain portions of it all through the ,war4 ,experience soon showed1 however1 that because of the necessity for extreme care in the manufacture and inspection of the mask1 the ordinary commercial organization was not adapted to carry on their manufacture on the scale necessitated by the ,army program4 ,consequently1 on ,nov4 #ba1 #aiag1 the ,secretary of ,war authorized the establishment of a government operated plant1 and experienced officials were drawn from ,new ,york1 ,chicago1 ,boston and other manufacturing centers to carry on the work4 ,buildings in ,long ,island ,city1 not far from the chemical plant 7charcoal and soda lime7 at ,astoria1 were taken over by the officers of the ,gas ,defense ,service1 until in ,july1 #aiah1 five large buildings were occupied1 having a total floor space of #a1jjj1jjj square feet 7#bc acres74 ,the organization grew from the original thirteen officers until it included some #ab1jjj employees of whom about #h1ejj were women4 ,because of the care required in all the work1 attempt was made to secure1 as far as possible1 those who had relatives with the ,a4 ,e4 ,f4 ,the thought was that their personal interest in the work would result in greater care in manufacture and inspection4 ,the personnel was unique in that the authority was apparently divided between civilian and military1 but there was no friction because of this4 ,the efficiency of the entire organization is shown by the fact that the masks manufactured at ,long ,island ,city cost fifty cents less per mask than those manufactured under contract4 ,the first actual shipment 7overseas7 of box respirators was made from the ,gas ,defense ,plant on ,march #d1 #aiah4 ,from this date the production increased by leaps and bounds4 ,as mentioned above1 between this date and ,november #bf1 when the last mask was manufactured1 #c1adf1dac masks of the box respirator type were passed through final inspection in the plant4 ,the greatest daily production1 #dc1ibf masks1 was reached on ,october #bf1 #aiah4 ,the process of manufacture will be discussed under the chapter on the ,gas ,mask4 ,during the last half of #aiah the ,kops ,tissot mask was manufactured4 ,this mask had been perfected during the months preceding ,august1 #aiah1 when its manufacture was started4 ,considerable difficulty was encountered in its production1 but the first mask was completed on ,september #ad1 and between that time and the ,armistice1 #ahi1fjc masks of this type had been manufactured4 ,along with this manufacturing development went the building up of an elaborate procurement force charged with the responsibility of providing parts to be assembled at the ,gas ,defense ,plant and at the ,hero ,manufacturing ,company4 ,this ,section faced a hard and intricate task1 but1 though there were instances where the shortage of parts temporarily caused a slowing down of production1 these were remarkably rare4 ,not only had the parts to be standardized1 and specifications written1 but a field inspection force had to be trained in order that the finished parts might be suitable for the final assembly plant4 ,the problem was further complicated by the fact that the design was constantly changing1 as improvement followed improvement4 ,officers1 trained in inspection in a day1 were sent out to train inspectors in the industrial centers4 ,in ,february1 #aiah1 shortly before the ,german drive commenced1 requisitions were received for sample lots of oiled mittens and oiled union suits as protection against mustard gas4 ,these were prepared in quantity and sent to the front1 as was also a considerable amount of chloride of lime for neutralizing the mustard gas in the field4 ,another phase of the work consisted of the ,field ,testing ,section1 which was organized to provide field testing conditions for the regular product and for the development organization4 ,later there were added a preliminary course of training for officers for overseas duty in chemical warfare1 the military training of the ,gas ,defense officers located in and near ,new ,york and the training of boat crews engaged in carrying offensive gas supplies4 ,the ,field ,testing ,section rendered valuable service in pointing out weaknesses of designs as developments took place and especially those uncomfortable features of the masks which were apparent only through long wear4 ,during the course of this work the section built a complete trench system in the ,pennsylvania ,railroad yards with an elaborate dugout1 the equal of any of the famous ,german quarters on the ,western front4 ,the chapters on ,charcoal1 ,soda-,lime and the ,gas ,mask must be read in this connection to gain an idea of the work carried out by this ,division4 ,it is summed up in the statement that ,american soldiers were provided with equipment which neutralized the best effects of ,german chemical knowledge as evidenced by the offensive methods and materials employed4 ,the organization of the ,gas ,defense ,division1 as of ,nov4 #aa1 #aiah1 was as follows3 ,colonel ,bradley ,dewey ,officer in ,charge ,lieut4 ,col4 ,a4 ,l4 ,besse ,asst4 ,officer in ,charge ,major ,m4 ,l4 ,emerson ,administration ,section ,major ,h4 ,p4 ,schuit ,comptrolling ,section ,mr4 ,r4 ,skemp ,procurement ,section ,major ,c4 ,r4 ,johnson ,technical ,director ,capt4 ,k4 ,atterbury ,field ,testing ,section ,major ,j4 ,c4 ,woodruff ,chemical ,manufacturing and ,development ,mr4 ,r4 ,r4 ,richardson ,manager1 ,gas ,defense ,plant ,capt4 ,h4 ,p4 ,scott ,officer in ,charge1 ,hero ,manufacturing ,co4 ,major ,l4 ,w4 ,cottman ,engineering ,branch ,major ,t4 ,l4 ,wheeler ,chemical ,development ,major ,i4 ,w4 ,wilson ,astoria ,branch ,capt4 ,w4 ,e4 ,brophy ,san ,francisco ,branch ,lt4 ,e4 ,j4 ,noble ,cleveland ,branch ,lt4 ,l4 ,merrill ,springfield ,branch ,,edgewood ,,arsenal ,the ,ordnance ,department1 in making plans for a shell filling plant1 thought to interest existing chemical firms in the manufacture of the required toxic materials4 ,as plans developed1 however1 difficulties arose in carrying out this program4 ,the manufacture of such material at private plants necessitated its shipment to the filling plant at ,edgewood4 ,the transportation of large quantities of highly toxic gases seemed attended with great danger4 ,the ,director ,general of ,railroads ruled that all such shipments must be made by special train1 a very expensive method of transportation4 ,still more serious objections were encountered in the attempt to enlist the co-operation of existing firms4 ,they recognized that the manufacture of such material would be attended by very great danger2 that the work would be limited to the duration of the war2 and that the processes involved1 as well as the plants necessary for carrying out their processes1 would have little post-war value4 ,moreover1 such firms as had the personnel and equipment were already over-worked4 ,with a few exceptions 7notably the ,american ,synthetic ,color ,company1 the ,oldbury ,electro-,chemical ,co41 ,zinsser ,co41 and the ,dow ,chemical ,company7 they were unwilling to undertake work of this character on any terms whatever4 ,early in ,december1 #aiag1 therefore1 it was decided to erect1 on the site of the shell filling plant1 such chemical plants as would be necessary to furnish the toxic materials required for filling the shell4 ,the ,arsenal is situated in an isolated district1 twenty miles east of ,baltimore1 ,maryland1 on the ,pennsylvania ,railroad1 and comprises #c1djj acres4 ,since the main line of the ,pennsylvania ,railroad runs on one side of the tract1 while on another is the ,bush ,river1 only a few miles from its mouth in ,chesapeake ,bay1 the tract was ideally situated for shipping4 ,this site was referred to1 at first1 as 8,gunpowder ,reservation10 but on ,may #d1 #aiah1 the name was officially changed to 8,edgewood ,arsenal40 ,illustration3 ,,fig4 #f4--;,edgewood ,arsenal4 ,the upper view shows the site as it appeared ,oct4 #bd1 #aiag4 ,the lower view shows the same as it appeared nine months later4 ,some idea of the extent of the work may be gained from the following facts4 ,on ,october #a1 #aiah1 there were #bcc officers1 #f1idh enlisted men and #c1jff civilians engaged in work at ,edgewood4 #hf cantonments were built1 accommodating about #h1ejj men1 while the five officers' barracks provided accommodations for #bij4 ,the completed hospital unit consisted of #cd buildings1 accommodating #dbj patients under ordinary conditions4 ,the total number of buildings erected on the ,arsenal grounds was #eej4 #ad4h miles of improved roads were built1 and #ba miles of standard gauge and #ae miles of narrow gauge railway4 ,a system furnishing #i4e million gallons of salt water and another furnishing two millions of fresh water daily were successfully installed4 ,large power plants were built in connection with the shell filling plants and the chlorine plant4 ,plants for phosgene1 chloropicrin1 mustard gas1 chlorine and sulfur chloride were built and placed in successful operation4 ,most of the raw materials1 with the exception of sulfur chloride1 were obtained from commercial firms4 ,the other gases and manufactured materials used1 such as phosphorus1 tin and silicon tetrachlorides1 bromobenzylcyanide and arsenic derivatives were supplied by various plants scattered through the ,east and ,middle ,west ,states4 ,the raw materials used by the ,arsenal in #aiah were as follows3 ,salt #ag1ceh1jjj pounds ,bleach #db1chd1jjj 8 ,picric acid #c1gah1jjj 8 ,alcohol #c1gah1jjj 8 ,sulfur #bd1iab1jjj 8 ,sulfur chloride #f1fbd1jjj 8 ,bromine #bch1jjj 8 ,benzyl chloride #bf1jjj 8 ,the production of toxic materials and the amount shipped overseas in bulk follow3 ---------------------------------------- --------- ,production1 ,shipped in ,pounds ,bulk1 ,pounds ---------------------------------------- --------- ,chlorine3 ,liquid #e1ddf1jjj #b1igf1jjj ,gaseous #b1bjh1jjj ,chloropicrin #e1eeb1jjj #c1hjf1jjj ,phosgene #c1bcc1jgj #hdj1jjj ,mustard gas #a1dbb1jjj #chj1jjj ,bromobenzyl cyanide #aj1jjj ,white phosphorus #b1jab1jjj #cdb1jjj ,tin tetrachloride #b1jab1jjj #bab1jjj ,titanium tetrachloride #cfb1jjj ---------------------------------------- --------- ,for nearly a month previous to the signing of the ,armistice1 the various plants at the ,arsenal had shut down or were operated only to an extent sufficient to maintain the machinery and equipment in good working order1 on account of the lack of shell into which to fill the gas1 so that the above figures do not at all represent maximum productive capacity4 ,these plants will be described in the appropriate chapters4 ,the shell filling plant was really composed of several small plants1 each of which was made up of units radiating from a central refrigeration plant which would serve all the units4 ,each unit could then be fitted with machinery adapted for filling shell of a different size1 and for a particular gas4 ,moreover1 an accident in one of the units would in no way impair the working of the remainder4 ,the problem involved in the filling of a shell with toxic material 7which is always a liquid or a solid and never a gas under the conditions in which it is loaded in the shell7 is similar in a way to that of filling bottles with carbonated water4 ,in the development of plans for the filling plant1 many suggestions were obtained from a study of the apparatus used in commercial bottling plants4 ,it was necessary to keep in mind not only the large number of shell to be filled1 but also the highly toxic character of the filling material to be used4 ,it was essential that the work of filling and closing the shell should be done by machinery in so far as that was possible1 and that the operation should be carried out in a thoroughly ventilated room or tunnel1 arranged so that the machinery contained in the tunnel could be operated from the outside4 ,special care was taken in closing the shell1 the closing being accomplished by motors actuated by compressed air1 which1 in the closing process were driven until they stalled4 ,in this way a uniform closing torque was obtained4 ,the final results secured were admirable1 as is evidenced by the fact1 reported by the ,quartermaster ,officer at ,vincennes on ,november #ae1 #aiah1 that not a single leaky shell had been found among the #bjj1jjj shell received up to that date4 ,illustration3 ,,fig4 #g4--;,a ,typical ,shell filling ,plant at ,edgewood ,arsenal4 ,details of the filling process will be found in the chapter on ,phosgene4 ,besides the ordinary gas filling plants 7of which one was completed and two were #hj per cent completed7 there was a plant for stannic chloride grenades1 one for white phosphorus grenades1 and one for smoke shell also filled with phosphorus and a plant for filling incendiary bombs4 ,shell are designated by their diameter in inches or millimeters4 ,the approximate amount of toxic gas required for filling each type of shell 7#aj4e per cent void7 is as follows3 ---------------------------------------- ---- ,shell ,phosgene1 ,n4 ,c41#ac ,mustard ,gas1 ,pounds ,pounds ,pounds ---------------------------------------- ---- #ge mm #a4cb #a4ge #a4ce #d4g inch #d4bg #f4bj #d4bj #aee mm #aa4jj #ae4dj #aj4ce #h inch #bb4jj #cj4cj #ba4fj ,livens #cj4jj ---------------------------------------- ---- ,footnote #ac3 ,n4,c4 is a mixture of #hj per cent chloropicrin and #bj per cent stannic chloride4 ,the gas grenades held #j4ddf pound of stannic chloride1 and the smoke grenades held #j4fg pound of white phosphorus4 ,the only type of shell filled was the #ge mm4 variety1 because either the shell of the other sizes or the accompanying boosters 7bursting charges7 were not available4 ,the work done by the filling plant is shown by the following figures1 representing the number of shell1 grenades1 etc4 #ge mm4 ,shell ------------------------------------ ,filled ,shipped ,overseas ------------------------------------ ,phosgene #b1jji ,n4 ,c4 #dbg1gga #cjj1jjj ,mustard gas #aee1jbe #aej1jjj ------------------------------------ ,livens ,drum ------------------------------------ ,phosgene #be1fhi #ah1fjj ------------------------------------ ,grenades ------------------------------------ ,white phosphorus #ddj1aec #bbd1ihd ,tin tetrachloride #cfc1ggf #age1jhj ------------------------------------ ,incendiary ,drop ,bomb ------------------------------------ ,mark ,i4 #edb ,mark ,,ii4 #b1ajd ------------------------------------ ,the total monthly capacity of the filling plants at the date of the ,armistice was as follows3 ,pounds #ge mm4 shell #b1djj1jjj #d4g inch shell #dej1jjj #aee mm4 shell #edj1jjj #f inch shell #ahj1jjj ,gas grenade #gej1jjj ,smoke grenade #dhj1jjj ,livens drum #cj1jjj ,one point relating to the casualties resulting from the work should perhaps be mentioned here4 ,the number of casualties should change the mind of anyone who feels that men chose this work as being 8safe0 instead of going to ,france4 ,during the six months from ,june to ,december there were #ibe casualties1 of which three were fatal1 two being due to phosgene and one to mustard gas4 ,these were divided among the different gases as follows3 ,mustard gas #fgd ,stannic chloride #ej ,phosgene #ej ,chloropicrin #dd ,chlorine #fb ,other material #de ,of these #bgi occurred during ,august1 #aig during ,september and #bic during ,october4 ,since production stopped early in ,november1 there were only #ad during that month and three during ,december4 ,the ,staff at ,edgewood ,arsenal at the signing of the ,armistice was as follows3 ,commanding ,officer ,colonel ,wm4 ,h4 ,walker ,lt4 ,colonel ,george ,cahoon1 ,jr4 ,administrative ,officers ,lt4 ,col4 ,edward ,m4 ,ellicott ,lt4 ,col4 ,wm4 ,c4 ,gallowhur ,lt4 ,col4 ,wm4 ,mc,pherson ,in ,charge of ,outside ,plants ,major ,adrian ,nagelvoort ,major ,charles ,r4 ,wraith ,captain ,john ,d4 ,rue ,shell ,filling ,plant ,lt4 ,col4 ,edwin ,m4 ,chance ,chlorine ,plant ,lt4 ,col4 ,charles ,vaughn ,chemical ,plants ,major ,dana ,j4 ,demorest ,chemical ,laboratory ,major ,william ,l4 ,evans ,as the work of the ,arsenal expanded it was necessary to manufacture certain of the chemicals at outside plants4 ,the men in charge of these plants were3 ,bound ,brook1 ,n4 ,j4 ,lt4 ,william ,r4 ,chappell ,stamford1 ,conn4 ,lt4 ,v4 ,e4 ,fishburn ,hastings-on-,hudson1 ,n4 ,y4 ,major ,f4 ,g4 ,zinnsser ,niagara ,falls1 ,n4 ,y4 ,major ,a4 ,nagelvoort ,buffalo1 ,n4 ,y4 ,lt4 ,a4 ,w4 ,davison ,kingsport1 ,tenn4 ,lt4 ,e4 ,m4 ,hayden ,charleston1 ,w4 ,va4 ,lt4 ,m4 ,r4 ,hoyt ,midland1 ,mich4 ,major ,m4 ,g4 ,donk ,croyland1 ,pa4 ,capt4 ,a4 ,s4 ,hulburt ,after the ,armistice1 ,edgewood ,arsenal was selected as the logical home of the ,chemical ,warfare ,service1 and all the outside activities of the ,service were gradually closed up and the physical property and files moved to ,edgewood4 ,at first the command of the ,arsenal was in the hands of ,lt4 ,col4 ,fries1 but when he was appointed ,chief of the ,service1 ,major ,e4 ,j4 ,atkisson1 who had so successfully commanded the ,first ,gas ,regiment1 ,a4 ,e4 ,f41 was happily chosen his successor4 ,at the present time 7,july #a1 #aiba71 the organization of ,edgewood ,arsenal is as follows3 ,commanding ,officer ,major ,e4 ,j4 ,atkisson ,executive ,officer ,major ,r4 ,c4 ,ditto ,technical ,director ,dr4 ,j4 ,e4 ,mills ,chemical ,division ,mr4 ,d4 ,b4 ,bradner ,mechanical ,division ,mr4 ,s4 ,p4 ,johnson ,plant ,division ,capt4 ,e4 ,g4 ,thompson ,chemical ,warfare ,school ,major ,o4 ,r4 ,meredith ,property ,major ,a4 ,m4 ,heritage ,first ,gas ,regiment ,major ,c4 ,w4 ,mason ,mask ,production ,division ,lt4 ,l4 ,a4 ,elliott ,medical ,department ,major ,t4 ,l4 ,gore ,pathological ,division ,lt4 ,h4 ,a4 ,kuhn ,quartermaster ,department ,capt4 ,h4 ,l4 ,hudson ,finance ,department ,capt4 ,c4 ,r4 ,insley ,,development ,,division ,the ,development ,division had its origin in the research laboratories of the ,national ,carbon ,company and of the ,national ,lamp ,works of the ,general ,electric ,company4 ,both of these companies knew charcoal1 and they were asked to produce a satisfactory absorbent charcoal4 ,the success of this undertaking will be seen in the chapter on ,absorbents4 ,after a short time all the laboratory work was taken over by the ,national ,carbon ,co41 while the developmental work was assigned to the ,national ,lamp ,works4 ,when the final organization of the ,chemical ,warfare ,service took place1 the ,national ,carbon ,laboratory became part of the ,research ,division1 while the ,national ,lamp ,works became the ,defense ,section of the ,development ,division4 ,the ,development ,division may be considered as having been composed of the following sections3 #a4 ,defense #b4 ,offense #c4 ,midland #d4 ,willoughby #e4 ,special ,investigation4 ,the work of the ,defense ,section consisted of the development of a charcoal suitable for use in gas masks1 and its manufacture4 ,while the details will be given later1 it may be mentioned here that three weeks after the organization of the ,section 7,april #bh1 #aiag7 the furnaces of the ,national ,carbon ,company were turning out cedar charcoal1 using a straight distillation procedure4 ,cedar was selected from a large variety of materials as giving the highest absorptive value against chlorine4 ,but phosgene and chloropicrin were also being used1 and it was found that the cedar charcoal was not effective against either4 ,proceeding on a definite hypothesis1 fifty materials were investigated to find the charcoal with the highest density4 ,cocoanut hulls furnished the raw material1 which yielded the most active charcoal4 ,by a process of air activation a charcoal was obtained which possessed high absorptive power for such gases as chloropicrin and phosgene4 ,later this air process was changed to one in which steam is used2 the cocoanut shell charcoal activated with steam was given the name 8,dorsite40 ,complete apparatus for this air process was installed at the plant of the ,astoria ,light1 ,heat ,power ,company1 ,long ,island ,city1 and the first charcoal was prepared during ,september1 #aiag4 ,this was followed by a large amount of experimental work1 relating to the raw material1 the method of activation1 and the type of furnace used4 ,because of the shortage of cocoanut hulls1 it later became necessary to use a mixture of cocoanuts with cohune nuts1 apricot and peach pits1 cherry pits and vegetable ivory4 ,another substitute for cocoanut charcoal was found in a steam activated product from high grade anthracite coal1 called 8,batchite40 ,the ,offense ,section and the ,midland ,section were concerned with the manufacture of mustard gas4 ,this work was greatly delayed because of the unsatisfactory nature of the so-called chlorohydrin process4 ,another difficulty was the development of a satisfactory ethylene furnace4 ,finally in ,february1 #aiah1 ,pope in ,england discovered the sulfur chloride method of making mustard gas4 ,at once all the energies of the ,research ,division were concentrated on this process1 and in ,march steps were taken to put this process into production4 ,an experimental plant was established at ,cleveland2 no attempt was made to manufacture mustard gas on a large scale1 but the results obtained in the experimental studies were immediately transmitted to the manufacturing plants at ,edgewood ,arsenal1 the ,hastings-on-,hudson plant1 the ,national ,aniline ,chemical ,company 7,buffalo7 plant1 and the ,dow ,chemical ,company 7,midland7 plant4 ,the details of the work on mustard gas will be given in a later chapter4 ,special investigations were undertaken to develop a booster casing and adapter for #ge mm4 gas shell1 and to duplicate the ,french process of lining gas shell with glass4 ,the organization of the ,development ,division at the signing of the ,armistice was as follows3 ,colonel ,f4 ,m4 ,dorsey ,chief of the ,division ,major ,l4 ,j4 ,willien ,supt41 ,offense ,section ,capt4 ,o4 ,l4 ,barnebey ,supt41 ,defense ,section ,lt4 ,col4 ,w4 ,g4 ,wilcox ,supt41 ,experimental ,station ,capt4 ,duncan ,mac,rae ,special ,investigation ,section ,dr4 ,a4 ,w4 ,smith ,midland ,section ,capt4 ,j4 ,r4 ,duff ,administrative ,section ,,proving ,,division ,the ,proving ,division had its origin in the decision to build an ,experimental ,ground for gas warfare under the direction of the ,trench ,warfare ,section of the ,ordnance ,department4 ,while this decision was reached about ,september1 #aiag1 actual work on the final location 7,lakehurst1 ,n4 ,j47 was not started until ,march #bf1 #aiah1 and the construction work was not completed until ,august #a1 #aiah4 ,however1 firing trials were started on ,april #be1 #aiah1 and in all #hb were carried out4 ,the ,proving ,division was created to do two things3 ,to experiment with gas shell before they reached the point where they could be manufactured safely in large numbers for shipment overseas2 and to prove gas shell1 presumably perfect and ready for shipment1 to guard against any mechanical inaccuracies in manufacture or filling4 ,it is evident that the second proposition is dependent upon the first4 ,shell can not be proved to ascertain the effect of gases under various conditions and concentrations until the mechanical details of the shell itself1 purely an ,ordnance matter1 have been standardized4 ,unfortunately many of the tests carried out had to do with this very question of testing ,ordnance4 ,for field concentration work two complete and separate lines of trenches were used and also several impact grounds4 ,the trenches were built to simulate the trenches actually used in warfare4 ,each line of trench contained several concrete shell-proof dugouts and was also equipped with shelves into which boxes could be placed for holding the sample bottles4 ,at intervals of one yard throughout the trenches there were electrical connections available for electrical sampling purposes4 ,the various impact grounds were used for cloud gas attacks1 and experiments with mustard gas or in many cases for static trials4 ,the samples were collected by means of an automatic sampling apparatus4 ,the work of the ,division consisted in the first instance of determining the proper bursting charge4 ,while a great deal of this work had been carried out in ,europe1 ,american gas shell were enough different to require that tests be carried out on them4 ,the importance of this work is obvious1 since phosgene1 a substance with a low boiling point1 would require a smaller bursting charge to open the shell and allow the substance to vaporize than would mustard gas1 where the bursting charge must be not only sufficient to fragment the shell but also to scatter the liquid so that it would be atomized over the largest possible area4 ,in the case of low boiling liquids it was necessary that the charge be worked out very carefully as a difference of one or two grams would seriously affect the concentration4 ,too small a charge would allow a cup to be formed by the base of the shell which would carry some of the liquid into the ground1 while too great an amount of explosive tended to throw the gas too high into the air4 ,after the bursting charge had been determined a large number of shell were repeatedly fired into the trenches1 wooded areas1 rolling and level ground1 and the concentration of gas produced and the effect upon animals placed within the area ascertained4 ,from the results of these experiments the ,proving ,division was able to furnish the artillery with data regarding how many shell of given caliber should be used1 with corrections for ranges1 wind velocities1 temperatures1 ground conditions1 etc4 ,trials were also held to determine how many high explosive 7,h4,e47 shell could be fired with gas shell on the same area without unduly affecting the concentration4 ,this was important1 because ,h4,e4 shell were useful in disguising gas bombardments4 ,gas shell can usually be distinguished by the small detonation on bursting4 ,experiments were performed to determine the decomposition of various gases on detonation4 ,the shell were fired at a large wooden screen and burst on impact4 ,samples of gas were taken immediately and analyzed4 ,co-operative tests were carried out with the ,gas ,defense ,division to determine the value of given masks under field conditions4 ,companies of infantry1 fully equipped for the field1 would wear masks for hours at a time digging trenches1 cutting timber1 drilling1 etc41 and imitating in every way1 as far as possible1 actual field conditions4 ,during these activities tons of gas in cylinders were released in such a way that the men were enveloped in a far higher concentration than would probably ever be the case in actual battle4 ,these tests gave valuable data for criticizing gas mask construction4 ,another line of activity consisted of a study of the persistency and relative effectiveness of various samples of mustard gas1 in which the liquid was distributed uniformly upon the surface of grassy zones one to three feet in width1 which formed the periphery of circular areas #ad to #ba feet in diameter1 the central part of each circle being occupied by animals4 ,the work of the ,proving ,division was brought to an end 7by the ,armistice7 just at the time when it had reached its greatest usefulness4 ,not only were the physical properties and personnel of the ,division developed to the maximum degree1 but the production of gas shell in this country for shipment to ,france had just reached the stage where the ,proving ,ground could have been used to its fullest extent in their proving4 ,,training ,,division ,from the standpoint of the man at the front the ,training ,division is one of the most important4 ,to him gas warfare is an ever present titanic struggle between poisonous vapors that kill on one side1 and the gas mask and a knowledge of how and when to wear it1 on the other4 ,because of this it is rather surprising that we did not hear more about this branch of the ,service4 ,it did exist1 however1 and credit must be given to those camp gas officers who remained in the ,united ,states performing an inconspicuous and arduous duty in the face of many local obstacles4 ,illustration3 ,,fig4 #h4 ,the ,field ,training ,division of the ,gas ,defense ,service in the ,united ,states was organized in ,september1 #aiag1 and consisted of ,major ,j4 ,h4 ,walton and #de first lieutenants1 all chemists4 ,these men were given a three months' military training at the ,american ,university4 ,the arrival of ,major 7now ,colonel7 ,auld during this time was very helpful1 as he was able to give the ,section first-hand knowledge4 ,about #ab of the #de men wore sent to ,france1 while the remainder1 together with ,british ,gas ,officers1 were assigned to various ,divisions still in training4 ,there was little idea at that time as to what constituted real gas training4 ,no one knew how much gas training would be received in ,france1 and since little was often received due to lack of time1 many men went into action with no idea of what this training really meant4 ,moreover1 an order that the gas officers should not go to ,france with their ,divisions had1 as was only natural1 a discouraging effect upon the men and upon gas training and discipline generally4 ,in ,january1 #aiah1 the gas officers were transferred to the ,engineers1 and designated as the #dgc;d ,engineers4 ,later an ,army ,gas ,school was established at ,camp ,humphreys4 ,because of the rapidly changing personnel1 owing to overseas assignments1 the policy was adopted of sending specialized gas officers only to ,divisional ,camps and the larger training centers4 ,the need of a larger unit and increased authority was recognized by all intimately associated with the work1 but little was accomplished until the transfer to the ,chemical ,warfare ,service4 ,upon the appointment of ,brigadier ,general ,h4 ,c4 ,newcomer as ,assistant ,director of the ,chemical ,warfare ,service1 he was placed in charge of all military affairs of the ,service1 and the administrative officers of the ,training ,section became his 8military assistants40 ,a few weeks later the ,training ,section of the ,administration ,division1 ,c4,w4,s4 was formed4 ,at this time new duties fell to the lot of this ,section1 among the more important being3 7#a7 ,the organization of gas troops and casual detachments for overseas duty2 7#b7 ,the establishment of a ,chemical ,warfare ,training ,camp2 7#c7 ,the procurement and training of officers for overseas duty4 ,for this purpose a training camp was established near the ,proving ,ground 7,camp ,kendrick7 to hold #acjj officers and men4 ,line officers were sent from the larger camps for training1 the best of whom might later be transferred to the ,chemical ,warfare ,service for duty as ,gas ,officers4 ,the work of the ,section eventually grew to such proportions that it was recognized as the ,training ,division of the ,chemical ,warfare ,service4 ,it differed from other ,divisions in that all administrative routine was carried on through the offices of the ,director1 and with the assistance and co-operation of its various ,sections4 ,because of the formation of the ,chemical ,warfare ,service and the apparent need for officers1 the office was soon flooded with applications for commissions4 ,these were carefully examined and the men were sent first1 by courtesy of the ,chief of ,engineers1 to ,camp ,humphreys for a month's course of military training4 ,at the end of this period they were sent to ,camp ,kendrick as students of the ,army ,gas ,school4 ,toward the last of ,october all the officers and enlisted men were transferred to ,camp ,kendrick where an ,officers' ,training ,battalion was organized4 ,it is obvious that the gas training of troops was the most responsible duty of the ,training ,division4 ,there was constantly in mind an ideal of supervised and standardized training for all troops in the ,united ,states1 and the ,division1 at the time of the ,armistice1 for the first time found itself with a nearly adequate corps of officers through whom this ideal could be realized4 ,,medical ,,division ,dr4 ,yandell ,henderson of ,yale ,university was the logical man to inaugurate the medical work of the ,bureau of ,mines1 because of his experience with oxygen rescue apparatus4 ,a member of the first committee of the ,bureau1 he secured1 in ,july1 #aiag1 an appropriation for the study of toxic gases at ,yale4 ,this was in charge of ,doctors ,underhill1 therapy2 ,marshall1 pharmacology2 and ,winternitz1 pathology4 ,when the ,american ,university ,station was opened ,marshall was given charge of the pharmacology4 ,about the same time a factory protection unit was organized under the direction of ,doctors ,bradley1 ,eyster and ,loevenhart4 ,at first this committee reported to the ,ordnance ,department1 but later the work was transferred to the ,gas ,defense ,service4 ,in ,december1 #aiag1 the ,medical ,advisory ,board was organized4 ,this included all the men who were carrying on experimental work of a medical nature4 ,this board had as its object the correlation of all medical work2 new work was outlined and attempts were made to secure the co-operation of scientific men throughout the country4 ,the following groups of workers assisted in this effort3 ,at ,yale1 ,underhill studied therapy1 turning his animals over to ,winternitz for pathological study4 ,henderson was specially interested in the physiology of aviation4 ,at the ,american ,university ,marshall carried on pharmacological research1 specially as regards mustard gas1 the toxicology being covered by ,loevenhart4 ,a pathological laboratory was also started1 under ,winternitz1 where many valuable studies were made4#ad ,at ,cleveland ,sollmann was busy with mustard gas and protective agents4 ,pearce1 working in co-operation with ,dr4 ,geer of the ,goodrich ,rubber ,company1 perfected the ,goodrich ,lakeside ,mask4 ,his study was very valuable as concerning the physiology of the gas mask4 ,at ,ann ,arbor ,warthin and ,weller#ae were studying the physiology and pathology of mustard gas4 ,wells1 ,amberg1 ,helmholz and ,austin of the ,otho ,sprague ,memorial ,institute were interested in protective clothing1 while at ,madison1 ,eyster1 ,loevenhart and ,meek were engaged in a study of the chronic effect of long exposures to low concentrations1 and later expanded their work to protective ointments and certain problems in pathology4 ,footnote #ad3 ,see the ,pathology of ,war ,gas ,poisoning1 #aibj1 ,yale ,press4 ,footnote #ae3 ,see ,medical ,aspects of ,mustard ,gas ,poisoning1 #aiai1 ,c4 ,o4 ,mosby ,co4 ,in the spring of #aiah many of these men were commissioned into the ,gas ,defense ,service of the ,sanitary ,corps1 and were later transferred to the ,chemical ,warfare ,service as the ,medical ,division1 with ,colonel ,w4 ,j4 ,lyster1 ,m4,c41 in charge4 ,one of the most important functions of this ,division was the daily testing of a large number of compounds for toxicity1 lachrymatory or vesicant properties4 ,the accuracy of these tests might and probably did save a large amount of unnecessary experimental work on the part of the ,research ,division4 ,these tests are described in a later chapter4 ,very interesting and likewise valuable was the study of mustard gas by ,marshall1 ,lynch and ,smith4 ,they were able to work out the mechanism of its action and the varying degrees of susceptibility in individuals 7see page #aga74 ,another interesting point was the fact that in the case of certain gases there is a cumulative effect4 ,with superpalite and mustard gas the lethal concentration 7that concentration which is fatal after a given exposure7 is lower on longer exposures4 ,on the other hand there is no cumulative effect with hydrocyanic acid4 ,whether the action is cumulative or not depends on the rate at which the system destroys or eliminates the poison4 ,,liaison ,,officers ,this chapter should not be closed without reference to the ,liaison ,service that was established between the ,united ,states and her ,allies1 especially ,england4 ,during the early days no one in the ,states was familiar with the details of gas warfare4 ,at the request of the ,medical ,corps1 upon the urgent representations of the ,gas ,service1 ,a4,e4,f41 ,captain 7now ,major7 ,h4 ,w4 ,dudley was sent to this country 7,sept41 #aiag7 to assist in the development and manufacture of gas masks4 ,for some time he was the ,court of ,appeal on nearly all technical points regarding matters of defense4 ,dudley's continual insistence on the need for maintaining the highest possible standard of factory inspection was one of the factors resulting in the excellent construction of the ,american ,mask4 ,in ,march1 #aiah1 ,lieut4 ,col4 ,dewey and ,captain ,dudley made a trip to ,england and ,france1 during which the idea of a liaison between the defense organizations of the two countries originated4 ,dudley was transferred to the ,engineers1 promoted and placed in charge of the ,liaison service4 ,while the time until the ,armistice was too short to really test the idea1 enough was accomplished to show the extreme desirability of some such arrangement4 ,probably the best known liaison officer from the ,british was ,colonel ,s4 ,j4 ,m4 ,auld1 also sent upon the urgent representations of the ,gas ,service1 ,a4,e4,f4 ,he arrived in this country about the middle of ,october1 #aiag1 in charge of #bh officers and #bh non-commissioned officers1 who were to act as advisers in training and many other military subjects besides gas warfare4 ,since ,auld had had personal experience with gas warfare as then practiced at the front1 his advice was welcomed most heartily by all the different branches of the ,army then handling gas warfare4 ,on questions of general policy ,auld was practically the sole foreign adviser4 ,the matter of gas training was transferred from the ,medical ,corps to the ,engineers1 and was greatly assisted by four pamphlets on ,gas ,warfare issued by the ,war ,college1 which were prepared by ,major ,auld with the assistance of ,captain ,walton and ,lieut4 ,bohnson4 ,later ,auld gave the ,american public a very clear idea of gas warfare in his series of articles appearing in the ,saturday ,evening ,post1 and re-written as 8,gas and ,flame40 ,major ,h4 ,r4 ,le,sueur1 who was at ,porton previous to his arrival in this country in ,december1 #aiag1 rendered valuable aid in establishing the ,experimental ,proving ,ground and in its later operations4 ,towards the close of the war the ,british ,war ,office had drawn up a scheme for a ,gas ,mission1 which was to correlate all the gas activities of ,england and ,america4 ,this was never carried through because of the signing of the ,armistice4 ,the ,french representatives1 ,m4 ,grignard1 ,capt4 ,hanker and ,lt4 ,engel furnished valuable information as to ,french methods1 but they were handicapped by the fact that ,french manufacturers did not disclose their trade secrets even to their own ,government4 ,about ,august1 #aiah1 ,lieut4 ,col4 ,james ,f4 ,norris opened an office in ,london4 ,his duties were to establish cordial and intimate relations not only with the various agencies of the ,british ,government which were connected with gas warfare1 but also with the various laboratories where experiments were being conducted1 that important changes might be transmitted to ,america with the least possible delay4 ,the ,english made ,colonel ,norris a member of the ,british ,chemical ,warfare ,committee4 ,here again the signing of the ,armistice prevented a full realization of the importance of this work4 ,,chapter ,,iv ,,the ,,chemical ,,warfare ,,service ,,in ,,france ,it is worth noting here that the ,chemical ,warfare ,service was organized as a separate service in the ,american ,expeditionary ,forces nearly ten months before it was organized in the ,united ,states1 and that the organization in the ,united ,states as heretofore described was patterned closely on that found so successful in ,france4 ,very soon after the ,united ,states declared war against the ,central ,powers1 a commission was sent abroad to study the various phases of warfare as carried on by the ,allies1 and as far as possible by the enemy4 ,certain members of this commission gave attention to chemical warfare4 ,one of those who did this was ,professor ,hulett of ,princeton ,university4 ,he1 with certain ,general ,staff officers1 gathered what information they could in ,england and ,france concerning the gases used and methods of manufacturing them1 and to a very slight extent the methods of projecting those gases upon the enemy4 ,some attention was paid to gas masks1 but there being nobody on the ,general ,staff1 or anywhere else in the ,regular ,army1 whose duty it was to look out particularly for chemical warfare materials1 these studies produced no results4 ,as has already been stated1 the ,medical ,department started the manufacture of masks1 and the ,bureau of ,mines1 under the leadership of the ,director1 ,mr4 ,manning1 began studies upon poisonous gases and the methods of manufacturing them just before or shortly after war was declared4 ,nevertheless1 although ,american troops left for ,france in ,may1 #aiag1 it was not until the end of ,august--the #agth to be exact--that definite action was taken toward establishing a ,chemical ,warfare ,service1 or1 as it was then known1 a ,gas ,service in the ,american ,expeditionary ,forces4 ,on that date a cablegram was sent to the ,united ,states to the effect that it was desired to make ,lieut4 ,col4 ,amos ,a4 ,fries1 ,corps of ,engineers1 ,chief of the ,gas ,service1 and requesting that no assignments to the regiment of gas troops authorized in the ,united ,states be made which would conflict with this appointment4 ,on ,august #bb;d1 ,lieut4 ,col4 ,fries entered upon his duties as ,chief of the ,gas ,service4 ,there were then in ,france about #cj miles from the ,german lines1 some #ab1jjj ,american troops without any gas masks or training whatever in ,chemical ,warfare4 ,immediate steps were taken to teach the wearing of the masks1 and ,english and ,french gas masks were obtained for them at the earliest possible moment4 ,at the same time efforts were made to obtain officer personnel for the ,c4 ,w4 ,s41 and to have sent to ,france a laboratory for making such emergency researches1 experiments1 and testing as might become necessary4 ,from that time to the end of the war the ,c4 ,w4 ,s4 continued to develop on broad lines covering research1 development1 and manufacture2 the filling of shell and other containers with poisonous gases1 smoke and incendiary materials2 the purchase of gas masks and other protective devices1 as well as the handling and supply of these materials in the field2 the training of the ,army in chemical warfare methods1 both in offense and defense2 and the organization1 equipment and operation of special gas troops4 ,this gave an ideal organization whereby research was linked with the closest possible ties to the firing line1 and where the necessities of the firing line were brought home to the supply and manufacturing branches and to the development and research elements of the ,service instantly and with a force that could not have been obtained in any other manner4 ,the success of the ,c4 ,w4 ,s4 in the field and at home was due to this complete organization4 ,to the ,commander-in-,chief1 ,general ,pershing1 is due the credit for authorizing this organization and for backing it up whenever occasion demanded4 ,other details of this work will be considered under the following heads3 ,administrative2 ,training2 ,chemical ,warfare ,troops2 ,supply2 ,technical2 ,intelligence2 and ,medical4 ,,administrative ,,duties ,the duties of administration covered those necessary for a general control of research1 of supply1 of training1 and the operation of special gas troops4 ,at first the ,chief of the ,gas ,service comprised the whole of the ,service since he was without personnel1 material1 rules1 regulations1 or anything else of a chemical warfare nature4 ,the experience in getting together this organization should be sufficient to insure that the ,united ,states will never place on any other man's shoulders the burden of organizing a new and powerful service in the midst of war1 #d1jjj miles from home1 without precedent1 material1 or anything else on which to base action4 ,it is true the ,americans had available the experience of the ,english and the ,french1 and it should be said to the credit of both of these nations that they gave of their experience1 their time1 and their material with the greatest freedom and willingness1 but just as ,americans are ,americans and were ,americans in #aiag1 just so the methods of the ,french and ,english or of the enemy were not entirely suitable to ,american conditions4 ,if there is any one thing needed in the training of ,u4 ,s4 ,army leaders of today and for the future1 it is vision--vision that can foresee the size of a conflict and make preparations accordingly4 ,we do not mean vision that will order1 as happened in some cases1 ten times as much material as could possibly be used by even #e1jjj1jjj troops1 but the sort of vision that could foresee in the fall of #aiag that #b1jjj1jjj men might be needed in ,france and then make preparations to get materials there for those troops by the time they arrived4 ,in order to cover the early formative period of the ,c4 ,w4 ,s4 in ,france and to show some of the difficulties encountered1 the following running account is given of some of the early happenings without regard to the subdivisions under which they might properly be considered4 ,assignment of ,chief of the ,gas ,service4 ,sailing from the ,united ,states on the #bc;d of ,july1 #aiag1 ,fries arrived in ,paris on the morning of ,august #ad1 #aiag1 and was immediately assigned the task of organizing a highway service for the ,american ,expeditionary ,forces4 ,five days later and before the highway order was issued1 he was asked what he would think if his orders were changed so as to make him ,chief of the newly proposed ,gas ,service4 ,being given one night to think it over he told the ,general ,staff he would undertake the work4 ,the road work was immediately closed up and on the #bb;d of ,august the organization of a ,gas ,service was actively started4 ,at that time some information concerning gases and gas troops had been gathered by ,colonel ,barber of the ,general ,staff4 ,likewise1 ,colonel 7later ,brigadier ,general7 ,hugh ,a4 ,drum had made a rough draft of an order accompanied by a diagram for the establishment of the ,gas ,service4 ,this information was turned over to ,fries who was told to complete the draft of the order1 together with an organization chart1 for the action of the ,commander-in-,chief4 ,after one and a half days had been put on this work the draft and chart were considered in good enough shape to submit to ,general ,pershing1 ,commander-in-,chief4 ,first ,trip to ,british ,gas ,headquarters4 ,noting that the proposed organization provided for the handling of #d-;inch ,stokes' mortars by gas troops1 ,general ,pershing asked why this work could not be done by regular trench mortar companies4 ,he was told that gas operations were too technical and dangerous to be intrusted to any but especially trained troops1 and that1 furthermore1 it was understood that #d-;inch ,stokes' mortars were used only by the ,british troops4 ,general ,pershing said1 8,you had better beat it to the ,british ,gas ,headquarters in the field and settle definitely that and certain other minor points40 ,fries told him he was only too glad to do this1 and1 having completed preparations1 left on the morning of ,august #beth with ,colonel ,church and ,captain ,boothby1 both of the ,medical ,department1 for ,st4 ,omer1 ,headquarters of the ,british ,gas ,service in the ,field4 ,colonel ,church of the ,medical ,department had been in ,france nearly one and a half years prior to the entry of the ,united ,states into the war1 and had taken sufficient interest in ,gas ,warfare to collect considerable information and a number of documents from ,french sources bearing on the defensive side of the subject4 ,captain ,boothby had done the same with the ,british1 including a course in a ,british ,gas ,defense ,school4 ,on this trip they took up the defensive side with the ,british1 while ,fries took up the offensive side of the ,service4 ,the latter included gases used1 gas troops1 and ammunition and guns used in ,gas ,warfare by the ,artillery and other branches of the ,service4 ,the trip included a brief visit to the headquarters of the ,first ,british ,army in the vicinity of ,lens1 where the ,british ,gas ,service had a large depot of offensive gas material4 ,order ,forming ,service4 ,returning on the #bhth of ,august the order1 together with a chart organizing the ,service1 was completed and submitted to the ,general ,staff4 ,this was published as ,g4 ,o4 #ca1 ,september #c1 #aiag4 ,as a result of a study of the information submitted by ,colonel ,barber and ,general ,drum1 together with his own observations of ,british organization and work1 ,fries decided it was advisable to make the ,service cover as complete a scope as possible and to make the order very general1 leaving details to be worked out as time and experience permitted4 ,this proved to be a very wise decision1 because the entire absence of gas knowledge among ,americans either in ,france or the ,united ,states made it necessary to build from the bottom up and do it rapidly4 ,at that time1 and at all times since1 it was found utterly impossible to separate the defensive side from the offensive side4 ,indeed1 many of the worst troubles of the ,british with their ,gas ,service throughout nearly the whole war arose from such a division of duties in their ,service4 ,thus1 the development of masks must be kept parallel with the development of gases and methods of discharging them4 ,otherwise a new gas invented may penetrate existing masks and preparations be carried far towards using it before the development of masks are undertaken to care for the new gas4 ,obviously a gas which our own masks will not take care of cannot be safely used by our own troops until new masks are developed to protect against it4 ,american and ,british ,masks4 ,just prior to ,fries's assignment as ,chief of the ,gas ,service twenty thousand ,american-made masks or box respirators were received from the ,united ,states4 ,through the energy of ,captain ,boothby several of these had been sent at once to the ,british for test4 ,the test showed that the granules in the canisters were entirely too soft1 the charcoal of poor quality1 and more than all else1 the fabric of the face piece was so pervious to gases that chloropicrin became unbearable to the eyes in less than a minute under the standard test used by the ,british4 ,a cable containing this information had been framed and sent to the ,united ,states just prior to ,fries's appointment as ,chief of the ,service4 ,august #bc;d1 the day after ,fries took charge1 it was decided to adopt the ,british mask or box respirator as the principal mask and the ,french ,m-#b as an emergency1 both to be carried by the soldier1 the ,french ,m-#b1 however1 to be used only when the ,british mask became lost or unfit for use4 ,a requisition for one hundred thousand of each was at once submitted and very shortly approved by the ,general ,staff4 ,getting ,gas ,supplies4 ,it should be stated here that inasmuch as no ,gas ,service had been organized in the ,united ,states1 no money appropriation had been made for it1 thereby making it necessary for the ,gas ,service to obtain all its supplies through other departments ordinarily handling the same or similar materials4 ,thus defensive supplies were obtained through the ,medical ,department and offensive supplies through the ,ordnance ,department1 while other miscellaneous equipment was obtained through the ,engineer ,department1 the ,quartermaster ,department1 or the ,signal ,corps4 ,this procedure proved exceedingly embarrassing1 cumbersome and inefficient4 ,to begin with it was necessary to get some agreement between the departments as to what each would supply4 ,this was very difficult1 resulting in delays and consumption of time which was urgently needed on other work4 ,not only was there trouble in getting orders accepted and started on the way but following them up became practically impossible4 ,none of the ,departments furnishing the materials were especially interested in them nor in many instances did they realize the vital nature of them4 ,accordingly in order to get any action it was necessary to continually follow up all orders and doing this through another department created friction and misunderstanding4 ,officers of these departments took the attitude that the whole question of obtaining supplies should be left to them1 once the requisition was turned in4 ,this could not be done4 ,the ,chief of the ,gas ,service was absolutely responsible for gas supplies1 and he fully realized that no excuses would be accepted1 no matter who stood in the way4 ,it was necessary to get action4 ,finally the matter was settled1 some six months after the ,service was organized1 by giving the ,chemical ,warfare ,service the right of direct purchase4 ,purchase of ,offensive ,gas ,supplies4 ,realizing the difficulty that would probably be encountered in getting supplies at all times from the ,british and ,french1 two requisitions for offensive gas supplies to be purchased from the ,british were submitted on ,september #hth and #ajth respectively4 ,it would seem proper to state here that investigation showed the ,british gas organization to be far superior to the ,french4 ,indeed1 the latter practically had no organization4 ,consequently it was determined to purchase complete equipment for gas troops and for the defensive side of the service from the ,british and to make no attempt to produce new materials1 methods or equipment until ample supplies of the standard equipment of the ,british were at hand or in process of manufacture or delivery4 ,this was another exceedingly wise conclusion4 ,no supplies of any kind were received from the ,united ,states for the next eight months1 and then only masks and certain defensive supplies4 ,indeed1 no cylinders1 mortars1 projectors or artillery shell containing gas were received from the ,united ,states until just before the ,armistice1 though gas had been available in the ,united ,states for months in large quantities1 over #c1fjj tons having been shipped in one ton containers to the ,english and ,french4 ,the ,ordnance material was what was lacking4 ,obtaining ,personnel4 ,on ,september4 #h1 ,colonel ,r4 ,w4 ,crawford was assigned to duty with the ,gas ,service4 ,this matter of obtaining personnel became immediately1 and continued for almost a year to be1 one of the most serious difficulties facing the new ,gas ,service4 ,the troubles here again were the same as those in respect to supplies4 ,none of the old departments were especially interested in gas and hence none of them desired to let good officers be transferred4 ,officers were scarce in the early days in ,france in every department of the ,service1 consequently a new department with no organization in the ,united ,states and no precedents or opportunities for promotion made the obtaining of officers almost a matter of impossibility4 ,further than this1 while the ,engineer ,department was at first supposed to furnish most of the officer personnel1 it failed to do so1 apparently looking upon the ,gas ,service as an unimportant matter when compared with the regular work of the ,engineers4 ,it was necessary to make direct application to the ,chief of ,staff to obtain ,colonel ,crawford and shortly thereafter to cable directly to the ,united ,states for officers4 ,a year later enough officers were obtained but only after the organization of a separate ,service in the ,united ,states4 ,supplies for ,gas ,troops4 ,colonel ,crawford was at once put in ,charge of all supplies for the ,gas ,service1 including the location and construction of separate depots for that ,service4 ,prior to this the ,general ,staff had decided to have chemical supplies stored in depots separate from those of other supplies on account of the poisonous nature of the gases which might prove very annoying if leakage occurred near any other class of supplies4 ,colonel ,crawford took hold of this work with zeal and energy and so conducted it as to relieve the ,chief of the ,gas ,service of all anxiety in that matter4 ,as before stated1 on the #ajth of ,september a requisition for a very large quantity of offensive supplies for gas troops was submitted to the ,general ,staff for approval4 ,inasmuch as this involved approximately #ej1jjj gas cylinders1 #ej1jjj ,liven's drums1 with at least #bj1jjj ,liven's projectors and a large number of ,stokes' mortars and bombs1 there was considerable difficulty in getting it approved4 ,finally ,colonel ,malone of the ,training ,section1 who took an active interest in the ,chemical ,warfare ,service1 got it approved4 ,then began the difficulty of getting the order placed and of trying to expedite the filling of the order on time4 ,these difficulties were never overcome until after the entire purchase of supplies was1 as previously related1 taken care of by the ,gas ,service4 ,first ,inter-allied ,gas ,conference4 ,the first inter-allied gas conference was held in ,paris on ,september #afth1 and consisted of ,american1 ,british1 ,french1 ,italian1 and ,belgian delegates4 ,the conference busied itself mainly with questions of the medical treatment of gassed cases and of defense against gas4 ,mustard ,gas4 ,the principal topic under consideration at this conference was the effects of the new mustard gas first used at ,ypres against the ,british on the nights of the #aath and #abth of ,july1 #aiag4 ,the ,british suffered nearly #bj1jjj casualties from this gas during the first six weeks of its use1 and were so worried over it that the start of the attacks carried out later in the fall of #aiag against ,ypres were delayed several days4 ,the casualties were particularly heavy because the smell of the gas was entirely new and not unpleasant and because of the delayed action of the gas1 whereby men got no indication of its seriousness until #d to #h hours after exposure4 ,for these reasons men simply took shelter from the bombardment without putting on masks or taking other precautions4 ,as a result of the ,paris conference a long cable was sent to the ,united ,states asking among other things that immediate report be made on the possibilities of producing ethylene chlorhydrin1 one of the essentials in the manufacture of mustard gas by the only method then known4 ,within two weeks after this conference1 there occurred an incident which illustrates the very great danger in taking the views of any one man unless certain that he is in a position to be posted on all sides of the question under discussion4 ,a high ,british official was asked what he had heard in regard to the new mustard gas1 and what and how it was considered4 ,he said with emphasis that the ,british had no further fear of it since they had learned what it was and how to take care of themselves and that it had ceased to be any longer a problem with them4 ,fries1 knowing what he did1 was convinced that this did not represent the attitude of the ,british authorities who knew what the gas was doing1 and the statement was not allowed to influence the ,american ,gas ,service in the least4 ,this was a very fortunate thing as events later proved4 ,it should also be added that a quite similar report was made by a ,french officer in regard to mustard gas some time in the month of ,october4 ,the ,french officer had more reason for his attitude than the ,british officer as up to that time mustard gas had not been largely used against the ,french4 ,however1 both cases simply emphasize the danger of accepting the views of any man who has seen but one angle of a problem so complicated as gas in war4 ,,training ,training in ,gas ,defense4 ,in the latter part of ,october seventeen young engineer officers1 who had just arrived in ,france1 were assigned to the ,gas ,service and were promptly sent to ,british ,gas ,schools for training in mask inspection1 salvage and repair and in training men to wear masks and take other necessary precautions against gas in the field4 ,it was also necessary at this time to establish gas training in the ,first ,division1 and ,captain ,boothby was assigned to that work4 ,illustration3 ,,fig4 #i4--;,destroying ,mustard ,gas on the ,battle ,field4 ,it is important to note that the ,gas ,service had to begin operations immediately upon its organization although it had almost no facilities of any kind to work with4 ,at one and the same time it was necessary to decide upon the kinds of masks to be used and then to obtain them2 to decide upon methods of training troops in gas defense and start at once to do it2 to decide upon gases to be used and manufactured in the ,united ,states and then obtain and send the necessary data and finally to decide what weapons gas troops were to use and to purchase those weapons1 since none of them existed in the ,united ,states4 ,worse still no one in the ,united ,states was taking any interest in them4 ,new ,mask4 ,about ,november #a1 ,major ,karl ,connell of the ,medical ,department1 ,national ,guard of ,new ,york1 reported for duty in response to a cablegram that had been sent asking for him by name4 ,it was intended to send him to a ,british ,school to learn the art of teaching gas defense4 ,however1 learning after a short talk with him that he had been interested in making masks for administering ansthesia1 there was at once turned over to him samples of all the masks in use by both the ,allies and the ,germans1 with a view to getting his ideas for a new mask4 ,within two or three hours he suggested a new mask having a metal face piece with sponge rubber against the face and with a canister to be carried on the back of the head4 ,at that early date it was realized that a new mask must be invented which would be far more comfortable and give better vision than the ,british respirators adopted for use4 ,connell1 thirty-six hours after reporting1 had so far developed his idea that he was sent to ,paris to make the first model1 which he succeeded in doing in about three weeks4 ,this first mask was good enough to risk testing in a high concentration of chlorine and while it leaked to some extent it indicated that the idea was sound4 ,the problem then was to perfect the mask and determine how it could be produced commercially on the large scale necessary to equip an army4 ,since the ,british at this time and practically throughout the war were much ahead of the ,french in all phases of gas warfare1 ,connell was sent to ,london4 ,there he succeeded in getting additional models in such shape that one of them was sent to the ,united ,states during the first few days of ,january1 #aiah4 ,connell's work and experiments were continued so successfully that after a model had been submitted to the ,general ,staff1 as well as to ,general ,pershing himself1 one thousand were ordered to be made early in ,may with a view to an extensive field test preparatory to their adoption for general use in the ,united ,states ,army4 ,in this connection1 during ,november1 #aiag1 a letter was written to the ,united ,states stating that while the ,gas ,service in ,france insisted on the manufacture of ,british respirators exactly as the ,british were making them1 they desired to have experiments pushed on a more comfortable mask to meet the future needs of the ,army4 ,the following four principles were set down in that letter3 7a7 ,that the mask must give protection and that experience had shown that suitable protection could only be obtained by drawing the air through a box filled with chemicals and charcoal4 7b7 ,that there must be clear vision and that experience to date indicated that the ,tissot method of bringing the inspired air over the eyepieces was by far the best1 7c7 ,that the mask must be as comfortable as compatible with reasonable protection1 and that this meant the mouthpiece and noseclip must be omitted4 7d7 ,that the mask must be as nearly fool proof as it could be made4 ,that is1 it should be of quick and accurate adjustment1 in the dark or in the trenches1 and be difficult to disarrange or injure once in position4 ,gas ,training and ,battle of ,picardy ,plains4 ,on ,march #ba1 #aiah1 as is known to everyone1 the ,germans began their great drive from ,cambrai across the ,picardy ,plains to ,amiens4 ,while the battle was expected it came as a complete surprise so far as the tactics used1 and the extent and force of the attack1 were concerned4 ,lieutenant ,colonel ,g4 ,n4 ,lewis1 who had been sent about ,march #a to ,british ,gas ,schools1 and had been assigned to one of the schools run by the ,canadians1 was thus just on the edge of the attack4 ,this gave him an opportunity to actually observe some of that attack and to learn from eye-witnesses a great deal more4 ,the school1 of course1 was abandoned hurriedly and the students ordered back to their stations4 ,lewis submitted two brief reports covering facts bearing on the use of gas and smoke by the ,germans4 ,these reports exhibited such a grasp of gas and smoke battle tactics that he was immediately ordered to headquarters as assistant on the ,defense side of gas work1 that is1 on training in gas defense4 ,up to that time no one had been able to organize the ,defensive side of gas work in the way it was felt it must be organized if it were to prove a thorough success4 ,a month later he was put at the head of the ,gas ,defense ,section1 and in two months he had put the ,defense ,division on a sound basis4 ,he was then ordered to the ,united ,states to help organize ,gas ,defense ,training there4 ,illustration3 ,,fig4 #aj4--;,close ,burst of a ,gas ,shell4 ,the #fth ,marines in the ,sommediene ,sector near ,verdun1 ,april #cj1 #aiah4 ,cabled ,report on ,picardy ,battle4 ,based partly on ,colonel ,lewis's written and oral reports1 and also on information contained in ,intelligence dispatches and the newspapers1 a cablegram of more than #cjj words was drafted reciting the main features of the battle so far as they pertained to the use of gas4 ,this cablegram ended with the statement that 8the above illustrates the tremendous importance of comfort in a mask0 and that 8the future mask must omit the mouthpiece and noseclip40 ,keeping the ,general ,staff ,informed of ,work4 ,in the early part of ,may1 #aiah1 the ,americans arrived in the vicinity of ,montdidier1 south of ,amiens1 on the most threatened point of the western front4 ,it was on ,may #ah1 #aiah1 that the ,americans attacked1 took1 and held against several counter-attacks the town of ,cantigny4 ,shortly afterward they were very heavily shelled with mustard gas and suffered in one night nearly #ijj casualties4 ,investigation showed that these casualties were due to a number of causes more or less usual1 but also to the fact that the men had to wear the mask #ab to #ae hours if they were to escape being gassed4 ,such long wearing of the ,british mask with its mouthpiece and noseclip is practically an impossibility and scores became gassed simply through exhaustion and inability to wear the mask4 ,an inspector from ,general ,headquarters in reporting on supplies and equipment in the ,first ,division1 stated that one of the most urgent needs was a more comfortable mask4 ,the ,first ,division suggested a mask on the principles of the new ,french mask which was then becoming known and which omitted the mouthpiece and noseclip4 ,the efforts of the ,american ,gas ,service in ,france to perfect a mask without a mouthpiece and noseclip were so well known and so much appreciated that they did not even call upon the ,gas ,service for remark4 ,the assistant to the ,chief of ,staff who drew up the memorandum to the ,chief simply said the matter was being attended to by the ,gas ,service4 ,this illustrates the value of keeping the ,general ,staff thoroughly informed of what is being done to meet the needs of the troops on the firing line4 ,then1 as always1 it was urged that a reasonably good mask was far more desirable than the delay necessary to get a more perfect one4 ,based on these experiences with mask development1 the authors are convinced that the whole tendency of workers in general1 in laboratories far from the front1 is to over-estimate the value of perfect protection based on laboratory standards4 ,it is difficult for laboratory workers to realize that battle conditions always require a compromise between perfection and getting something in time for the battle4 ,it was early evident to the ,gas ,service in ,france that we were losing1 and would continue to lose1 vastly more men through removal of masks of the ,british type1 due to discomfort and exhaustion1 than we would from a more comfortable but less perfect mask4 ,in other words when protection becomes so much of a burden that the average man cannot or will not stand it1 it is high time to find out what men will stand1 and then supply it even at the expense of occasional casualties4 ,protection in battle is always relative4 ,the only perfect protection is to stay at home on the farm4 ,the man who cannot balance protection against legitimate risks has no business passing on arms1 equipment or tactics to be used at the ,front4 ,as early as ,september1 #aiag1 gas training was begun in the ,first ,division at ,condrecourt4 ,this training school became the ,first ,corps ,school4 ,later a school was established at ,langres known as the ,army ,gas ,school while two others known as the ,second and ,third ,corps ,gas ,schools were established elsewhere4 ,the first program of training for troops in ,france provided for a total period of three months4 ,of this1 two days were allowed the ,gas ,service4 ,later this was reduced to six hours1 notwithstanding a vigorous protest by the ,gas ,service4 ,however1 following the first gas attacks against the ,americans with ,german projectors in ,march1 #aiah1 followed a little later by extensive attacks with mustard gas1 the ,a4 ,e4 ,f4 ,gas ,defense ,school was established at the ,experimental ,field4 ,arrangements were made for the accommodation of #bjj officers for a six-day course4 ,the number instructed actually averaged about #aej1 due to the feeling among ,division ,commanders that they could not spare quite so many officers as were required to furnish #bjj per week4 ,this school was conducted under the ,commandant of ,hanlon ,field1 ,lieutenant ,colonel ,hildebrand1 by ,captain ,bush of the ,british ,service4 ,this ,gas ,defense ,school became one of the most efficient schools in the ,a4 ,e4 ,f41 and was developing methods of teaching that were highly successful in protecting troops in the field4 ,failure of ,german ,gas4 ,the losses of the ,americans from ,german gas attacks fluctuated through rather wide limits4 ,there were times in the early days during training when this reached #fe per cent of the total casualties4 ,there were other times in battle1 when due to extremely severe losses from machine gun fire in attacks1 that the proportion of gas losses to all other forms of casualties was very small4 ,on the whole the casualties from gas reached #bg4c of all casualties4 ,this small percentage was due solely to the fact that when the ,americans made their big attacks at ,san ,mihiel and the ,argonne1 the ,german supply of gas had run very low4 ,this was particularly true of the supply of mustard gas4 ,illustration3 ,,fig4 #aa4--;,german ,gas ,alarms4 ,fries was at the front visiting the ,headquarters of the ,first ,army and the ,headquarters of the #ast1 #c;d1 and #eth ,corps from two days before the beginning of the battle of the ,argonne to four days afterwards4 ,he watched reports of the battle on the morning of the attack at the ,army ,headquarters and later at the #ast1 #eth and #c;d ,corps headquarters in the order named4 ,no reports of any gas casualties were received4 ,this situation continued throughout the day4 ,it was so remarkable that he told the ,chief of ,staff he could attribute the ,german failure to use gas to only one of two possible conditions2 first1 the enemy was out of gas2 second1 he was preparing some master stroke4 ,the first proved to be the case as examination after the ,armistice of ,german shell dumps captured during the advance revealed less than #a per cent of mustard gas shell4 ,even under these circumstances the ,germans caused quite a large number of gas casualties during the later stages of the fighting in the ,argonne-,meuse sector4 ,evidently the ,germans1 immediately after the opening of the attack1 or more probably some days before1 began to gather together all available mustard gas and other gases along the entire western battle front1 and ship them to the ,american sector4 ,this conclusion seems justified because the enemy never had a better chance to use gas effectively than he did the first three or four days of the ,argonne fight1 and knowing this fact he certainly would never have failed to use the gas if it had been available4 ,had he possessed #ej per cent of his artillery shell in the shape of mustard gas1 our losses in the ,argonne-,meuse fight would have been at least #ajj1jjj more than it was4 ,indeed1 it is more than possible we would never have succeeded in taking ,sedan and ,mezieres in the fall of #aiah4 ,officers' ,training ,camp4 ,the first lot of about #ajj officers were sent to ,france in ,july1 #aiah1 with only a few days' training1 and in some cases with no training at all4 ,accordingly1 arrangements were made to train these men in the duties of the soldier in the ranks1 and then as officers4 ,their training in gas defense and offense followed a month of strenuous work along the above mentioned lines4 ,this camp was established near ,hanlon 7,experimental7 ,field1 at a little town called ,choignes4 ,the work as laid out included squad and company training for the ordinary soldier1 each officer taking turns in commanding the company at drill4 ,they were given work in map reading as well as office and company administration4 ,this little command was a model of cleanliness and military discipline1 and attracted most favorable comment from staff officers on duty at ,general ,headquarters less than two miles distant4 ,just before the ,armistice arrangements were made to transfer this work to ,chignon1 about #be miles southeast of ,tours1 where ample buildings and grounds were available to carry out not alone training of officers but of soldiers along the various lines of work they would encounter1 from the handling of a squad1 to being ,chief ,gas ,officer of a ,division4 ,educating the ,army in the ,use of ,gas4 ,as has been remarked before1 the ,medical ,department in starting the manufacture of gas masks and other defensive appliances1 and the ,bureau of ,mines in starting researches into poisonous gases as well as defensive materials1 were the only official bodies who early interested themselves in gas warfare4 ,due to this early work of the ,bureau of ,mines and the ,medical ,department in starting mask manufacture as well as training in the wearing of gas masks1 the defensive side of gas warfare became known throughout the army very far in advance of the offensive side4 ,on the other hand1 since the ,ordnance ,department1 which was at first charged with the manufacture of poisonous gases1 made practically no move for months1 the offensive use of gas did not become known among ,united ,states troops until after they landed in ,france4 ,moreover1 no gas shell was allowed to be fired by the artillery in practice even in ,france1 so that all the training in gas the artillery could get until it went into the line was defensive1 with lectures on the offensive4 ,the work of raising gas troops was not begun until the late fall of #aiag and as their work is highly technical and dangerous1 they were not ready to begin active work on the ,american front until ,june1 #aiah4 ,by that time the army was getting pretty well drilled in gas defense and despite care in that respect were getting into a frame of mind almost hostile to the use of gas by our own troops4 ,among certain staff officers1 as well as some commanders of fighting units1 this hostility was outspoken and almost violent4 ,much the hardest1 most trying and most skillful work required of ,chemical ,warfare ,service officers was to persuade such ,staffs and ,commanders that gas was useful and get them to permit of a demonstration on their front4 ,repeatedly ,chemical ,warfare ,service officers on ,division staffs were told by officers in the field that they had nothing to do with gas in offense1 that they were simply defensive officers4 ,and yet no one else knew anything about the use of gas4 ,gradually1 however1 by constantly keeping before the ,general ,staff and others the results of gas attacks by the ,germans1 by the ,british1 by the ,french1 and by ourselves1 headway was made toward getting our ,armies to use gas effectively in offense4 ,but so slow was this work that it was necessary to train men particularly how to appeal to officers and commanders on the subject4 ,indeed the following phrase1 used first by ,colonel ,mayo-,smith1 became a watchword throughout the ,service in the latter part of the war--8,chemical ,warfare ,service officers have got to go out and sell gas to the ,army40 ,in other words we had to adopt much the same means of making gas known that the manufacturer of a new article adopts to make a thing manufactured by him known to the public4 ,illustration3 ,,fig4 #ab4--;,a ,typical ,shell ,dump near the ,front4 ,this work was exceedingly trying1 requiring great skill1 great patience and above all a most thorough knowledge of the subject4 ,as illustrating some of these difficulties1 the ,assistant ,chief of ,staff1 ,g-#c 7,operations7 of a certain ,american ,corps refused to consider a recommendation to use gas on a certain point in the battle of the ,argonne unless the gas officer would state in writing that if the gas was so used it could not possibly result in the casualty of a single ,american soldier4 ,such an attitude was perfectly absurd4 ,the ,infantry always expects some losses from our own high explosive when following a barrage1 and though realizing the tremendous value of gas1 this staff officer refused to use it without an absolute guarantee in writing that it could not possibly injure a single ,american soldier4 ,another argument often used was that a gas attack brought retaliatory fire on the front where the gas was used4 ,such objectors were narrow enough not to realize that the mere fact of heavy retaliation indicated the success of the gas on the enemy for everyone knows an enemy does not retaliate against a thing which does not worry him4 ,but on the other hand1 when the value of gas troops had become fully known1 the requests for them were so great that a single platoon had to be assigned to brigades1 and sometimes even to whole ,divisions4 ,thus it fell to the ,lieutenants commanding these platoons to confer with ,division ,commanders and ,staffs1 to recommend how1 when and where to use gas1 and do so in a manner which would impress the ,commanding ,general and the ,staff sufficiently to allow them to undertake the job4 ,that no case of failure has been reported is evidence of the splendid ability of these officers on duty with the gas troops4 ,efficiency in the big ,american battles was demanded to an extent unheard of in peace1 and had any one of these officers made a considerable failure1 it certainly would have been reported and ,fries would have heard of it4 ,equally hard1 and in many cases even more so1 was the work of the gas officers on ,division1 ,corps and ,army ,staffs1 who handled the training in ,divisions1 and who also were required to recommend the use of gas troops1 the use of gas in artillery shell and in grenades1 and the use of smoke by the infantry in attack4 ,however1 the success of the ,chemical ,warfare ,service in the field with these ,staff officers was just as great as with the ,regiment4 ,to the everlasting credit of those ,staff ,officers and the ,officers of the ,gas ,regiment from ,colonel ,atkisson down1 both ,staff ,gas officers and officers of the ,gas ,regiment worked together in the fullest harmony with the single object of defeating the ,germans4 ,,chemical ,,warfare ,,troops ,chemical ,warfare troops were divided into two distinct divisions--gas regiments and staff troops4 ,illustration3 ,,fig4 #ac4--;,firing a #aee-,millimeter ,howitzer4 ,the men are wearing gas masks to keep out the enemy gas fired at them in ,oct41 #aiah4 ,staff ,troops4 ,the staff troops of the ,chemical ,warfare ,service performed all work required of gas troops except that of actual fighting4 ,they handled all ,chemical ,warfare ,service supplies from the time they were unloaded from ships to the time they were issued to the fighting troops at the front1 whether the fighting troops were ,chemical ,warfare or any other4 ,they furnished men for clerical and other services with the ,army1 ,corps and ,division ,gas ,officers1 and they manufactured poisonous gases1 filled gas shells and did all repairing and altering of gas masks4 ,though these men received none of the glamour or glory that goes with the fighting men at the front1 yet they performed services of the most vital kind and in many cases did work as dangerous and hair raising as going over the top in the face of bursting shell and screaming machine gun bullets4 ,think of the intense interest these men must have felt when carrying from the field of battle to the laboratory or experimental field1 shell loaded with strange and unheard of compounds and which might any moment burst and end forever their existence6 ,or watch them drilling into a new shell knowing not what powerful poison or explosive it might contain or what might happen when the drill 8went through06 ,and again what determination it took to work #ab or #af hours a day way back at the depots repairing or altering masks1 and1 as was done at ,chateroux1 alter and repair #ae1jjj masks a day and be so rushed that at times they had a bare day's work of remodeled masks ahead4 ,but they kept ahead and to the great glory of these men no ,american soldier ever had to go to the front without a mask4 ,and what finer work than that of these men who1 in the laboratory and testing room1 toyed with death in testing unknown gases with ,american and foreign masks even to the extent of applying the gases to their own bodies4 ,heroic1 real ,american work1 all of it and done in real ,american style as part of the day's work without thought of glory and without hope of reward4 ,the ,first ,gas ,regiment4 ,in the first study of army organization made by the ,general ,staff it was decided to recommend raising under the ,chief of ,engineers one regiment of six companies of gas troops4 ,shortly after the cable of ,august #ag1 #aiag1 was sent stating that ,lieut4 ,colonel ,fries would be made ,chief of the ,gas ,service1 the ,war ,department promoted him to be ,colonel of the #cjth ,engineers which later became the ,first ,gas ,regiment4 ,at almost the same time1 ,captain ,atkisson1 ,corps of ,engineers1 was appointed ,lieut4 ,col4 of the ,regiment4 ,although ,colonel ,fries remained the nominal ,commander of the regiment1 he never acted in that capacity1 for his duties as ,chief of the ,gas ,service left him neither time nor opportunity4 ,all the credit for raising1 training1 and equipping the ,first ,gas ,regiment belongs to ,colonel ,e4 ,j4 ,atkisson and the officers picked by him4 ,immediately upon the formation of the ,gas ,service1 the ,chief urged that many more than six companies of gas troops should be provided4 ,these recommendations were repeated and urged for the next two months or until about the first of ,november1 when it became apparent that an increase could not be obtained at that time and that any further urging would only cause irritation4 ,the matter was therefore dropped until a more auspicious time should arrive4 ,this arrived the next spring when the first ,german projector attack against ,united ,states troops produced severe casualties1 exactly as had been forecasted by the ,gas ,service4 ,about the middle of ,march1 #aiah1 an increase from two battalions to six battalions 7eighteen companies7 was authorized4 ,a further increase to three regiments of six battalions each 7a total of fifty-four companies7 was authorized early in ,september1 #aiah1 after the very great value of gas troops had been demonstrated in the fight from the ,marne to the ,vesle in ,july4 ,illustration3 ,,fig4 #ad4--,receiving and ,transmitting ,data for ,firing ,gas ,shell while ,wearing ,gas ,masks4 ,battlefield of the ,argonne1 ,october1 #aiah4 ,no ,equipment for ,gas ,troops4 ,about the first of ,december a cablegram was received from the ,united ,states stating that due to lack of equipment the various regiments of special engineers recently authorized1 including the #cjth 7,gas and ,flame7 would not be organized until the spring of #aiah4 ,an urgent cablegram was then sent calling attention to the fact that gas troops were not service of supply troops but first line fighting troops1 and consequently that they should be raised and trained in time to take the field with the first ,americans going into the line4 ,at this same time the #cjth regiment was given early priority by the ,general ,staff1 ,a4 ,e4 ,f41 on the priority lists for troop shipments from the ,united ,states4 ,the raising of the first two companies was then continued under ,colonel ,atkisson at the ,american ,university in ,washington4 ,about ,january #ae word was received that the ,headquarters of the regiment and the ,headquarters of the ,first ,battalion together with ,companies ,a and ,b of the #cjth ,engineers 7later the ,first ,gas ,regiment7 were expected to arrive very soon4 ,some months prior ,general ,foulkes1 ,chief of the ,british ,gas ,service in the field1 had stated that he would be glad to have the gas troops assigned to him for training4 ,it was agreed that the training should include operations in the front line for a time to enable the ,american ,gas ,troops to carry on gas operations independently of anyone else and with entire safety to themselves and the rest of the ,army4 ,due to the fact that the ,british were occupying their gas school1 the ,british ,general ,headquarters were a little reluctant to take the ,american troops ,feb4 #a4 ,however1 ,general ,foulkes made room for the ,american troops by moving his own troops out4 ,he then placed his best officers in charge of their training and at all times did everything in his power to help the ,american ,gas ,troops learn the gas game and get sufficient supplies to operate with4 ,colonel ,hartley1 ,assistant to ,general ,foulkes1 also did everything he could to help the ,american ,gas ,service4 ,these two officers did more than any other foreign officers in ,france to enable the ,chemical ,warfare ,service to make the success it did4 ,second ,battle of the ,marne4 ,the ,chief of the ,gas ,service1 following a visit to the ,british ,gas ,headquarters1 and the ,headquarters of the ,american #b;d ,corps then operating with the ,british1 arrived on the evening of ,july #ag1 #aiah1 at #ast ,corps ,headquarters at ,la ,ferte sous ,jouarre about #aj miles southeast of ,chteau-,thierry4 ,two companies of the ,first ,gas ,regiment would have been ready in #dh hours to put off a projector attack against an excellent target just west of ,belleau ,wood had not the #b;d battle of the ,marne opened when it did4 ,it is said that ,general ,foch had kept this special attack so secret that the ,first ,american ,corps ,commander knew it less than #dh hours prior to the hour set for its beginning4 ,certainly the ,chief of the ,gas ,service knew nothing of it until about #i3jj ,p4,m41 the night of ,july #agth4 ,consequently the gas attack was not made4 ,at that time so little was known of the usefulness of gas troops that they were started on road work4 ,at ,colonel ,atkisson's suggestion that gas troops could clean out machine gun nests1 he was asked to visit the ,first ,corps headquarters and take up his suggestion vigorously with the ,first ,corps ,staff4 ,attacking ,machine ,gun ,nests4 ,thereupon the ,gas troops were allowed to try attacking machine gun nests with phosphorus and thermite4 ,this work proved so satisfactory that not long afterwards the ,general ,staff authorized an increase in gas troops from #ah companies to #ed companies1 to be formed into three regiments of two battalions each4 ,the #f companies in ,france did excellent work with smoke and thermite during all the second battle of the ,marne to the ,vesle river1 where by means of smoke screens they made possible the crossing of that river and the gaining of a foothold on the north or ,german side4 ,with the assembling of ,american troops in the sector near ,verdun in ,september1 #aiah1 the gas troops were all collected there with the exception of one or two companies and took a very active part in the capture of the ,st4 ,mihiel salient4 ,it was at this battle that the ,chemical ,warfare ,service really began to handle offensive gas operations in the way they should be handled4 ,plans were drawn for the use of gas and smoke by artillery and gas troops both4 ,the use of high explosives in ,liven's bombs was also planned4 ,those plans were properly co-ordinated with all the other arms of the service in making the attack4 ,gas was to be used not alone by gas troops but by the artillery4 ,plans were made so that the different kinds of gases would be used where they would do the most good4 ,while these plans and their execution were far from perfect1 they marked a tremendous advance and demonstrated to everyone the possibilities that lay in gas and smoke both with artillery and with gas troops4 ,following the attack on the ,st4 ,mihiel salient1 came the battle of the ,argonne1 where plans were drawn as before1 using the added knowledge gained at ,st4 ,mihiel4 ,the work was accordingly more satisfactory4 ,however1 the attempt to cover the entire ,american front of nine divisions with only six companies proved too great a task4 ,practically all gas troops were put in the front line the morning of the attack4 ,due to weather conditions they used mostly phosphorus and thermite with #d inch ,stokes' mortars4 ,having learned how useful these were in taking machine gun nests1 plans were made to have them keep right up with the ,infantry4 ,this they did in a remarkable manner considering the weight of the ,stokes' mortar and the base plates and also that each ,stokes' mortar bomb weighed about #be pounds4 ,there were cases where they carried these mortars and bombs for miles on their backs1 while in other cases they used pack animals4 ,illustration3 ,,fig4 #ae4--,setting ,up a ,smoke ,barrage with ,smoke ,pots4 ,not expecting the battle to be nearly continuous as it was for three weeks1 the men1 as before stated1 were all put in the front line the morning of the attack4 ,this resulted in their nearly complete exhaustion the first week1 since they fought or marched day and night during nearly the whole time4 ,taking a lesson from this1 in later attacks only half the men were put in the line in the first place1 no matter if certain sectors had to be omitted4 ,fully as good results were obtained because1 as the men became worn out1 fresh ones were sent in and the others given a chance to recuperate4 ,officers relate many different occurrences showing the discipline and character of these gas troops4 ,on one occasion where a battalion of infantry was being held up by a machine gun nest1 volunteers were called for4 ,only two men1 both from the gas regiment1 volunteered though they were joined a little later by two others from the same regiment1 and these four took the guns4 ,while it was not considered desirable for gas troops to attempt to take prisoners1 yet the regiment took quite a number1 due solely to the fact that they were not only with the advancing infantry but at times actually in front of it4 ,on another occasion a gas officer1 seeing a machine gun battalion badly shot up and more or less rattled1 took command and got them into action in fine shape4 ,at this stage the ,second ,army was formed to the southeast of ,verdun and plans were drawn for a big attack about ,november #ad4 ,the value of gas troops was appreciated so much that the ,second ,army asked to have ,british gas troops assigned to them since no ,american gas troops were available4 ,accordingly in response to a request made by the ,american ,general ,headquarters1 the ,british sent #aj companies of their gas troops4 ,these reached the front just before the ,armistice1 and hence were unable to carry out any attacks there4 ,this short history of the operations of the ,first ,gas ,regiment covers only the high spots in its organization and work4 ,it covers particularly its early troubles1 as those are felt to be the ones most important to have in mind if ever it be necessary again to organize ,c4 ,w4 ,s4 troops on an extensive scale4 ,the ,regiment engaged in nearly #bjj separate actions with poisonous gases1 smoke and high explosives1 and took part in every big battle from the second battle of the ,marne to the end of the ,war4 ,they were the first ,american troops to train with the ,british1 and were undoubtedly the first ,american troops to take actual part in fighting the enemy as they aided the ,british individually and as entire units in putting off gas attacks1 in ,february and ,march1 #aiah4 ,it would be a long history itself to recite the actions in which the ,first ,gas ,regiment took part and in which it won distinction4#af ,footnote #af3 ,story of the ,first ,gas ,regiment1 ,james ,t4 ,addison4 ,houghton ,mifflin ,co41 #aiai4 ,no better summary of the work of this ,regiment can be written than that of ,colonel ,atkisson in the four concluding paragraphs of his official report written just after the ,armistice3 8,the ,first ,gas ,regiment was made up largely of volunteers--volunteers for this special service4 ,little was known of its character when the first information was sent broadcast over the ,united ,states1 bringing it to the attention of the men of our country4 ,the keynote of this information was a desire for keen1 red-blooded men who wanted to fight4 ,they came into it in the spirit of a fighting unit1 and were ready1 not only to develop1 but to make a new service4 ,no effort was spared to make the organization as useful as the strength of the limited personnel allowed4 8,the first unit to arrive in ,france moved to the forward area within eight weeks of its arrival1 and1 from that time1 with the exception of four weeks1 was continuously in forward areas carrying on operations4 ,the third and last unit moved forward within six weeks of its arrival in ,france1 and was continuously engaged until the signing of the ,armistice4 8,that the regiment entered the fight and carried the methods developed into execution where they would be of value1 is witnessed by the fact that over thirty-five percent of the strength of the unit became casualties4 8,it is only fitting to record the spirit and true devotion which prompted the officers and men who came from civil life into this ,regiment1 mastered the details of this new service1 and1 through their untiring efforts and utter disregard of self1 made possible any success which the ,regiment may have had4 ,it was truly in keeping with the high ideals which have prompted our entire ,army and ,country in this conflict4 ,they made the motto of #8,service1' a real1 living1 inspiring thing40 ,,supply ,as previously stated it was decided early that the ,chemical ,warfare ,service should have a complete supply service including purchase1 manufacture1 storage and issue1 and accordingly separate supply depots were picked out for the ,gas ,service early in the fall by ,col4 ,crawford4 ,where practicable these were located in the same area as all other depots though in one instance the ,french forced the ,gas ,service to locate its gas shell and bomb depot some fifteen miles from the general depots through an unreasonable fear of the gas4 ,manufacture of ,gases4 ,due to the time required and the cost of manufacturing gases1 an early decision became imperative as to what gases should be used by the ,americans1 and into what shells and bombs they should be filled4 ,as there was no one else working on the subject the sole responsibility fell upon the ,chief of the ,gas ,service4 ,the work was further complicated by the fact that the ,british and ,french did not agree upon what gases should be used4 ,the ,british condemned viciously ,vincennite 7hydrocyanic acid gas with some added ingredients7 of the ,french1 while the ,french stated that chloropicrin1 used by the ,british principally as a lachrymator1 was worthless4 ,fries felt the tremendous responsibility that rested upon him and finally after much thought and before coming to any conclusion1 wrote the first draft of a short paper on gas warfare4 ,in that paper he took up the tactical uses to which gases might be put and then studied the best and most available gases to meet those tactical needs4 ,without stating further details it was decided to recommend the manufacture and use of chlorine1 phosgene1 chloropicrin1 bromoacetone and mustard gas4 ,as the gas service was also charged with handling smoke and incendiary materials1 smoke was prescribed in the proportion of #e per cent of the total chemicals to be furnished4 ,the smoke material decided upon was white phosphorus4 ,the paper on ,gas ,warfare was then re-drafted and submitted to the ,french and ,british and written up in final form prescribing the gases above mentioned on ,october #bf4 ,following this a cable was drawn and submitted to the ,general ,staff4 ,after many conferences and some delay the cable went forward on ,november #c4 ,,cable #bfh1 ,,november #d1 #aiag ,paragraph #ab4 ,for chief of ,ordnance4 ,with reference to paragraph #b my cablegram #aha1 desire prompt information as to whether recommendation is approved that phosgene1 chloropicrin1 hydrocyanic acid1 and chlorine be purchased in ,france or ,england and filling plants established in ,france for filling shells and bombs with those gases4 ,subparagraph ,a4 ,reference to your telegram #bec1 recommend filling approximately #aj per cent all shells with gases as given below1 but that filling plants and gas factories be made capable of filling a total of #be per cent4 ,unless ordinary name is given1 gases are designated by numbers in chemical code ,war ,gas investigations4 ,of #ge millimeter shells fill #a per cent ,vincennite1 #d per cent phosgene or trichloromethyl chloroformate1 #b per cent chloropicrin1 #b per cent mustard gas1 per cent with bromoacetone and per cent with smoke material4 ,according to ,french #ge millimeter steel shells should not be filled with ,vincennite more than three months before being used4 ,no trouble with other gases or other sized shells except that bromoacetone must be in glass lined shells4 ,of #d4g inch shells fill #e per cent with phosgene or trichloromethyl chloroformate1 #b per cent with chloropicrin1 #b per cent with mustard gas1 per cent with bromoacetone and per cent with smoke material4 ,provide same percentage for all other shells up to and including #h inch caliber as for #d4g inch shells4 #d inch ,stokes' mortar will use same gases and smoke shells and in addition thermit4 #h inch projector bombs will use the same as the ,stokes' mortar and also oil to break into flame on bursting4 ,cloud gas cylinders will be filled with #ej or #fj per cent phosgene1 mixed with #dj to #ej per cent chlorine1 or phosgene and some other gas4 ,renew recommendation that filling plants be established in ,france to provide sudden shifts in gas warfare of all kinds1 as well as for filling all #d inch ,stokes' mortar bombs1 #h inch projector bombs and cloud gas cylinders4 ,it is strongly recommended that efforts be made to produce white phosphorus on large scale for its usefulness both as smoke screens and to produce casualties4 ,subparagraph ,b4 ,for the ,adjutant ,general of the ,army4 ,with reference to paragraph #b1 my cablegram #aha1 desire information as to whether recommendation is approved that an engineer officer assisted by ,professor ,hulett be assigned to ,gas ,service in ,washington to handle all orders and correspondence concerning gas4 ,subparagraph ,c4 ,for ,surgeon ,general4 ,with reference to paragraph #b your cablegram #bje1 and paragraph #b1 my cablegram #aha1 what is status of chemical laboratory for ,france8 ,also have the #ab selected ,reserve ,officers for training in gas defense sailed for ,france8 ,subparagraph ,d4 ,with reference to paragraph #ag your cablegram #afe and paragraph #b my cablegram #aha1 ,tissot has constructed simpler model of his mask for attachment to any box4 ,have ordered #f which will be completed in two weeks1 #c of which will be forwarded at once4 ,a simple type such as this may prove useful for large number of troops4 ,letter of permission to manufacture ,tissot masks being forwarded4 ,subparagraph ,e4 ,with reference to paragraph #h your cablegram #adc1 and paragraph #d your cablegram #bdg1 in considering charcoal and other fillers for canister of box respirator it should be remembered that the front is very damp1 the air being nearly saturated during greater part of winter1 fall and spring4 ,this cable is given in full to show that not later than ,november #d1 #aiag1 it was known in the ,united ,states not only what gases would be required but also in what shells1 bombs1 guns and mortars each would be used4 ,while a small quantity of ,vincennite was recommended in this cable1 another cable sent within a month requested that no ,vincennite whatever be manufactured4 ,this decision as to gases and guns in which they were to be used1 while very progressive1 proved entirely sound and remained unchanged1 with slight exceptions due to new discoveries1 until the end of the war4 ,without a thorough understanding of tactics a proper choice of gases could not have been made4 ,this fact emphasizes the necessity of having a trained technical army man at the head of any gas service4 ,due to the absence of a ,chemical ,warfare ,service in the ,united ,states at this time1 a very great deal of the information sent from ,france1 whether by cable or by letter1 never reached those needing it4 ,smoke4 ,about the first of ,december after a study of results obtained by the ,british and the ,germans in the use of smoke in artillery shells for screening purposes1 the ,gas ,service decided that much more smoke than had been stated in cable #bfh to the ,united ,states was desirable4 ,the ,general ,staff1 however1 refused to authorize any increase1 but did allow to be sent in a cable a statement to the effect that a large increase in smoke materials might be advisable for smoke screens1 and that accordingly the amount of phosphorus needed in a year of war would probably be three or four times the one and a half million pounds of white phosphorus stated to have been contracted for by the ,ordnance ,department in the ,united ,states4 ,this advanced position of the ,gas ,service in regard to smoke proved sound in #aiah1 when every effort was made to increase the quantity of white phosphorus available and to extend its use in artillery shells including even the #c inch ,stokes' mortar4 ,illustration3 ,,fig4 #af4--,troops ,advancing ,behind a ,smoke ,barrage 7,phosphorus74 ,overseas ,repair ,section ,no4 #a4 ,during the latter part of ,november1 #aiag1 ,overseas ,repair ,section ,no4 #a1 under the command of ,captain ,mayo-,smith1 ,sanitary ,corps1 with four other officers and #acj men1 arrived in ,france4 ,since mask development and manufacture in the ,united ,states was still under the ,medical ,department1 this mask repair section was organized as a part of the ,sanitary ,corps4 ,as there were at that time no masks to be repaired and no laboratory equipment or buildings for that purpose on hand and none likely to be for months to come1 ,captain ,mayo-,smith was assigned to duty under ,colonel ,crawford1 ,chief ,gas ,officer with the ,line of ,communication1 in ,paris4 ,a site for a mask repair plant was located at ,chteauroux1 and a site for a gas depot at ,gievres was investigated4 ,inasmuch as there was at that time greater need for men to learn the handling of poisonous gases than to repair masks1 some #dj or #ej of the company were put in gas shell filling plants at ,aubervilliers and ,vincennes in the suburbs of ,paris1 while later still others were assigned to ,pont de ,claix near ,grenoble4 ,the remainder of the company were used in the ,gas ,depot at ,gievres and in the office in ,paris4 ,it was not until the latter part of ,june1 #aiah1 that the mask repair plant began operations4 ,in the meantime these men did very valuable work in shell filling and in learning the manufacture of gases4 ,several of them were sent to the ,united ,states1 some of them remaining throughout the war to aid in gas manufacture and in shell filling4 ,construction ,division1 ,gas ,service4 ,the ,construction ,division under ,colonel ,crawford in ,paris made complete plans for phosgene manufacturing plants1 for shell filling plants and for the ,mask ,repair ,plant4 ,these plans included a complete layout of the work for all persons to be employed in the plants4 ,during this same time a very careful study of the possibilities for manufacturing gas for filling shell in ,france was made4 ,finally about ,march #a1 in accordance with the strong recommendations of these men1 ,fries reported to ,general ,pershing in person that the manufacture of gas as well as the filling of shell in ,france was inadvisable from every point of view and accordingly he recommended that gas manufacture and shell filling in ,france be given up4 ,general ,pershing strongly approved the recommendation and a cablegram was at once sent to the ,united ,states to that effect4 ,the main reason for this action was the lack of chlorine1 since chlorine was the principal ingredient of nearly all poisonous gases then in use4 ,chlorine takes1 besides salt1 electric power and lots of it4 ,electric power requires coal or water power4 ,neither of the latter sources were available in ,france4 ,this question was gone into very thoroughly4 ,the only place where power might have been developed was in a remote spot near ,spain1 and the outlook there was such that it appeared impossible to begin the manufacture of chlorine under two years4 ,on the other hand the shipment of chlorine from the ,united ,states required from #ge per cent to #ajj per cent of the tonnage required to ship the manufactured gases themselves1 to say nothing of the labor1 raw materials1 and the machinery that would have had to be shipped in order to manufacture gas in ,france4 ,mustard ,gas4 ,as previously stated ,mustard ,gas was first used by the ,germans against the ,british at ,ypres on the nights of ,july #aa and #ab1 #aiag4 ,it was not used much against the ,french until more than two months later4 ,indeed1 gas was never used by the ,germans to the same extent against the ,french as against the ,english4 ,there are probably two reasons for this2 first1 the ,germans had a deeper hatred for the ,british than the ,french2 second1 the ,british morale was higher than the ,french in #aiag1 and the ,german thought that if he could break down this ,british morale1 he could win the war4 ,the first attack came as a surprise and accordingly got an unusually large number of casualties4 ,as previously stated the casualties numbered about #bj1jjj in about six weeks4 ,this number was considered so serious that the beginning of the series of attacks against ,ypres in the fall of #aiag1 was delayed by the ,british for #aj days or two weeks until they could study better how to avoid such great losses from mustard gas4 ,while the composition of the gas was known within two or three days1 as well as the laboratory method by which it was first manufactured by ,victor ,meyer in #ahhf1 it took some #aa months to develop reliable and practical methods of manufacturing it on a large scale4 ,the ,inter-allied ,gas ,conference in ,september1 #aiag1 gave a great deal of attention to mustard gas and methods of combating it both from the view point of prevention and of curing those gassed by it4 ,just following the close of that conference a cable was sent to the ,united ,states asking the possibility of manufacturing ethylene chlorhydrin1 the principal element in the manufacture of mustard gas by the only process then known4 ,later1 that is about the middle of ,october1 a cablegram was sent urging investigation into the manufacture of this gas4 ,it is believed a great deal of time might have been saved had the policy of undue secrecy not been adopted by the ,british and others before the ,americans entered the war4 ,in fact we were only told in whispers the formula for mustard gas1 and where a description of it could be found in ,german chemistries4 ,this was arrant nonsense since if the ,germans had gotten all mustard gas information then in the hands of the ,british they would have received far less information than they already possessed on mustard gas4 ,illustration3 ,,fig4 #ag4--8,who ,said ,gas80 ,whether the information sent to the ,united ,states on mustard gas ultimately proved of any great value is an open question since the methods adopted in the ,united ,states were very greatly superior to those used in ,england and in ,france4 ,it probably helped by suggestion rather than by actual details of design4 ,anyhow it all emphasizes the difficulties encountered in war when so vital a substance as mustard gas must be investigated after the enemy has begun using it on a large scale4 ,delay of ,british ,masks4 ,as ,december #a approached1 and as nothing further had been heard of the order for #cjj1jjj ,british ,respirators placed about the middle of ,october1 a telegram was sent to ,england asking if deliveries would be made as required in the order for the masks4 ,this order required the first #ge1jjj to be delivered ,december #a1 #aiag4 ,in reply it was stated that the ,british could not furnish these masks1 and that they understood that the ,americans were just beginning a large output of masks in the ,united ,states4 ,an exchange of cablegrams with the ,united ,states showed that no masks could be expected from there for #c to #e months4 ,moreover it became increasingly evident that the ,americans were going into the battle line sooner than at first contemplated4 ,another cablegram was then sent to ,england urging the delivery of these masks4 ,the reply was to the effect that the ,english ,government could not deliver the masks because they did not have enough for their own use4 ,this situation was very serious4 ,unless the order for #cjj1jjj masks placed with the ,british could be filled1 we were facing the necessity of sending ,american troops into the front line with only the ,french ,m-#b mask4 ,while the ,m-#b mask was then the only mask used by the ,french1 it was well known to afford practically no protection against the high concentrations of phosgene obtained from cloud or projector attacks4 ,and it was just such attacks as these that our men would encounter in the front line during training4 ,accordingly arrangements were made for a hurried trip to ,england4 ,colonel ,harrison of the ,british ,royal ,engineers was in charge of the ,british manufacture of masks and it is desired here to express appreciation of his uniform courtesy and great helpfulness4 ,he exhibited their methods and facilities and assured us they could meet any requirements of ours for masks up to a half million1 or even more if necessary1 provided they were given time to establish additional facilities4 ,finally after a further exchange of cables the masks were obtained4 ,during ,december1 #aiag and ,january1 #aiah1 when every effort was being made to hurry a lot of masks from ,havre--,havre being the ,british supply base in ,france from which the masks were issued to the ,united ,states1 the severe cold and snow had so disorganized ,french traffic that it was extremely difficult to get cars moving at all4 ,in an effort to get the masks1 priority of shipment was obtained and two or three officers were assigned to convoy the cars4 ,notwithstanding convoying1 one carload of #d1jjj masks1 mainly threes and fours1 became lost and only turned up five weeks later4 ,to make matters worse the ,british were sending us very many more of the small sized ,no4 #b masks than we could use4 ,the loss of this carload of #d1jjj number threes and fours was all but a tragedy4 ,indeed1 in order to get the ,first ,brigade of the ,first ,division equipped in time it was necessary to take a large number of masks already issued to men of the ,second ,brigade4 ,these masks were first thoroughly washed and disinfected and then re-issued4 ,this all emphasizes the great difficulties that are encountered when a new and vital service must be organized in war #d1jjj miles overseas without material1 home supplies1 or men to draw from4 ,this struggle to get sufficient masks to keep all men fully equipped remained very acute until in ,july1 #aiah1 when the arrival of hundreds of thousands of masks from the ,united ,states made the situation entirely safe4 ,even then the necessity of weakening the elastics and shortening the rubber tubing of the mouthpieces on some #gjj1jjj masks1 doubled up our work tremendously1 and added enormously to our troubles in getting masks to the front in time4 ,notwithstanding these troubles the ,chemical ,warfare ,supply ,service never failed and finally forged to the very forefront of all ,american supply services4 ,its method of issuing supplies to troops at the front has been adopted as the standard for ,american field armies of the future4 ,,technical ,gas ,laboratory in ,paris4 ,early in ,january1 #aiah1 the first members of the ,chemical ,service ,section1 ,national ,army1 under the command of ,colonel ,r4 ,f4 ,bacon1 arrived in ,france and reported for duty4 ,previously1 a laboratory site at ,puteaux1 a suburb of ,paris1 had been selected4 ,this plant had been built by a society for investigation into tuberculosis4 ,previous to the arrival of the ,chemical ,service ,section1 information had been requested from the ,united ,states by cable as to the size of the laboratory section to be sent over4 ,the reply stated that the number would probably total about #ajj commissioned and enlisted4 ,the site at ,puteaux was accordingly definitely decided upon4 ,just following this decision two cables1 one after the other1 came from the ,united ,states recommending certain specified buildings in ,paris for the laboratory4 ,it was found upon investigation in both cases that the buildings were either absolutely unsuited or unfinished4 ,this was another case of trying to fight a war over #d1jjj miles of cable4 ,colonel ,bacon was made head of the ,technical ,division1 which position he held throughout the war4 ,illustration3 ,,fig4 #ah4--,shaper for ,opening ,captured ,gas ,shell4 ,technically ,trained ,men4 ,in ,january1 #aiah1 in response to a cable from the ,united ,states a request had been made on the ,french ,government to send six of their ablest glass blowers to the ,united ,states to aid in making glass lined shells4 ,the ,french ,gas authorities said that it would be impossible to send those or indeed any other men trained in the manufacture or handling of poisonous gases or gas containers as they did not have enough such men for their own work4 ,accordingly a cablegram was drafted and sent to the ,united ,states1 requesting that #ej men experienced in various lines of technical and chemical work be sent to ,france4 ,the ,french authorities said they would put them in any factories1 laboratories or experimental places that the ,chief of the ,gas ,service desired4 ,a second inquiry about these men was sent but nevertheless no answer was ever received and no men were sent4 ,protection ,against ,particulate ,clouds4 ,just at this time1 about the first of ,february1 #aiah1 the danger that the ,germans might devise some better method of sending over diphenylchloroarsine than by pulverizing it in high explosive shell was felt to be serious4 ,the ,british had just then perfected protection against diphenylchloroarsine by employing unsized sulfate wood pulp paper--#dh to #fj layers being required4 ,this number of layers was found to be necessary as they are very thin and porous4 ,the ,british had developed a method of putting this paper around a canister and yet keeping the canister small enough to fit into the knapsack by reversing its position therein2 that is1 putting the canister in the compartment of the knapsack made for the face piece and putting the face piece in the other compartment4 ,some of our own officers and enlisted men were sent to ,england to work with the ,british on this and an order given them for #bjj1jjj of the protected canisters4 ,they improved on the methods of the ,british and as it was found that sulfate paper was very scarce1 investigations were made to see if any of it could be manufactured in ,france4 ,very soon thereafter such a place was located near the city of ,nancy4 ,following this a cablegram was sent to the ,united ,states giving complete specifications for making this diphenylchloroarsine protection4 ,from this cablegram successful samples were made though somewhat more bulky than those developed in ,england4 ,very few1 however1 of these were made in the ,united ,states due1 we were informed1 to the poor quality of the sulfate paper4 ,work was however begun energetically in the ,united ,states on other methods of protection against diphenylchloroarsine4 ,numbers of ,chemists ,needed4 ,it was figured that out of a total force of some #a1djj gas officers there would be needed in the ,a4 ,e4 ,f41 exclusive of those in regiments1 approximately #bjj chemists1 i4e41 about #ae per cent of the whole4 ,we arranged to have a good chemist on each ,division1 ,corps and ,army ,staff1 and a certain number with the gas troops4 ,it was proposed to put #bj to #dj in the laboratory in ,paris and not to exceed #bj at the experimental field4 ,this subject of personnel is touched on for the reason that a few people seem to have the idea that the ,chemical ,warfare ,service should be made up of chemists exclusively4 ,this is very far from being true4 ,it was and is believed that the ,chemical ,warfare ,service should be composed of men from every walk of life4 ,in three positions out of every four in the field a good personality combined with energy1 hard work and common sense count for more than mere technical training4 ,hanlon 7,experimental7 ,field4 ,as early as ,december #ae1 #aiag1 it was decided that an experimental field in ,france was necessary1 and a letter was written to the ,general ,staff requesting authority to establish one4 ,after considerable delay the authority was granted and search for a site begun4 ,this was no easy task4 ,while the ,french were loading millions of gas shells at the edge of ,paris1 they appeared unwilling at first to have us establish a gas experimental field except in abandoned or inaccessible spots4 ,finally a very good site was found and agreed to by the ,french some #g miles south of ,general ,headquarters4 ,just when we were ready to start work the ,french discovered that the proposed field included a portion of one of their artillery firing ranges4 ,they then suggested another site within #c miles of ,general ,headquarters4 ,this was a rather fortunate accident as the site suggested was a better one than at first picked out4 ,the field was roughly rectangular from #g to #h miles in length1 and #c to #d miles in width4 ,the total area was about #bj square miles4 ,the work of this experimental field proved a great success and was rapidly becoming the real center of the ,gas ,service in ,france4 ,the old saying that the history of a happy country is very brief applies to this story of the ,technical ,section of the ,gas ,service in ,france4 ,its work did not begin as early as that of the other sections1 and as considerable of it was of a nature that could be put off without immediate fatal effects1 the ,section was enabled to grow without the very serious drawbacks encountered by other ,sections of the ,gas ,service4 ,nevertheless its usefulness was very great4 ,those of the ,technical ,section either at the experimental field or at the laboratory were charged with the opening of all sorts of known and unknown gas and high explosive shells1 fuses and similar things to determine their contents and their poisonous or explosive qualities4 ,this was work of a very technical nature1 and at the same time highly dangerous4 ,as stated elsewhere1 the determination of the life of the masks became one of the problems which the laboratory was trying to solve4 ,hundreds of canisters were tested1 and hundreds per month would have continued to have been tested throughout the remainder of the war had the war gone into #aiai4 ,it was on the ,technical ,section that devolved the duty of determining at the earliest possible moment the physical properties as well as the physiological effects of any new gas4 ,also on that ,section fell the preliminary reports as to the probable usefulness in war of a new gas whether sent over by the enemy or suggested by our own ,technical men1 or those of our ,allies4 ,this was indeed a task by itself1 as it required a wide knowledge of the methods of using gases1 methods of manufacturing them1 and methods of projecting them on the field of battle4 ,in addition1 it was the duty of the ,technical ,section to keep the ,chief of the ,service fully informed on all the latest developments in gases and to get that information in shape so that the ,chief with his increasingly wide range of duties would be enabled to keep track of them without reading the enormous amount ordinarily written4 ,a much earlier start on technical work would have proved of immense advantage4 ,in case of another war1 the technical side of chemical warfare should be taken up with the very first expedition that proceeds to the hostile zone4 ,had that been done in ,france1 we would have had masks and gases and proper shells and bombs at least six months before we did4 ,,intelligence ,while ,intelligence was for a long time under the ,training or ,technical ,divisions1 it finally assumed such importance that it was made a separate ,division4 ,it was so thoroughly organized that by the time of the ,armistice the ,chief of the ,division could go anywhere among the ,united ,states forces down to companies and immediately locate the ,gas ,intelligence officer4 ,intelligence ,division4 ,this work was started by ,lieutenant ,colonel ,goss within a month after he reported in ,october1 #aiag4 ,the ,intelligence ,division developed the publication of numerous occasional pamphlets and also a weekly gas bulletin4 ,so extensive was the work of this ,division that three mimeograph machines were kept constantly going4 ,the weekly bulletin received very flattering notice from the ,british ,assistant ,chief of ,gas ,service in the ,field4 ,he stated that it contained a great deal of information he was unable to get from any other source4 ,among other work undertaken by this ,intelligence ,division was the compilation of a ,history of the ,chemical ,warfare ,service in ,france4 ,this alone involved a lot of work4 ,in order that this history might be truly representative1 about three months before the ,armistice both moving and still pictures were taken of actual battle conditions1 as well as of numerous works along the ,service of ,supplies4 ,without going into further detail it is sufficient to say that when the ,armistice was signed there were available some #bjj still pictures1 and some #h1jjj feet of moving picture films4 ,steps were immediately taken to have this work continued along definite lines to give a complete and continuous history of the ,chemical ,warfare ,service in ,france in all its phases4 ,the intelligence work of the ,gas ,service1 while parallel to a small extent with the ,general ,intelligence ,service of the ,a4 ,e4 ,f41 had to spread to a far greater extent in order to get the technical details of research1 manufacture1 development1 proving1 and handling poisonous gases in the field4 ,it included also obtaining information at the seats of ,government of the ,allies1 as well as from the enemy and other foreign sources4 ,the most conspicuous intelligence work done along these lines was by ,lieutenant ,colonel ,j4 ,e4 ,zanetti1 who was made ,chemical ,warfare liaison officer with the ,french in ,october1 #aiag4 ,he gathered together and forwarded through the ,headquarters of the ,chemical ,warfare ,service to the ,united ,states more information concerning foreign gases1 and foreign methods of manufacturing and handling them1 than was sent from all other sources combined4 ,by his personality1 energy and industry he obtained the complete confidence of the ,french and ,british4 ,this confidence was of the utmost importance in enabling him to get information which could have been obtained in no other way4 ,suffice to say that in the #ac months he was liaison officer with the ,french during the war1 he prepared over #gej reports1 some of them very technical and of great length4 ,as a whole1 the ,intelligence ,division was one of the most successful parts of the ,chemical ,warfare ,service4 ,starting #b years after the ,british and ,french1 the weekly bulletin and occasional papers sent out by the ,chemical ,warfare ,service on chemical warfare matters came to be looked upon as the best available source for chemical warfare information1 not alone by our own troops but also by the ,british4 ,,medical ,the ,medical ,section of the ,chemical ,warfare ,service was composed of officers of the ,medical ,department of the ,army attached to the ,chemical ,warfare ,service4 ,these were in addition to others who worked as an integral part of the ,chemical ,warfare ,service1 either at the laboratory or on the experimental field in carrying out experiments on animals to determine the effectiveness of the gases4 ,the ,medical ,section was important for the reason that it formed the connecting link between the ,chemical ,warfare ,service and the ,medical ,department4 ,through this ,section1 the ,medical ,department was enabled to know the kinds of gases that would probably be handled1 both by our own troops and by the enemy1 and their probable physiological effects4 ,colonel ,h4 ,l4 ,gilchrist1 ,medical ,department1 was the head of this ,section4 ,it was through his efforts that the ,medical ,department realized in time the size of the problem that it had to encounter in caring for gas patients4 ,indeed1 records of the war showed that out of #bbd1jhi men1 exclusive of ,marines1 admitted to the hospitals in ,france1 #gj1eeb were suffering from gas alone4 ,these men received a total of #bff1aab wounds1 of which #hh1ihj1 or #cc4d per cent1 were gas4 ,thus of all wounds received by men admitted to the hospital were gas4 ,while the records show that the gas cases did not remain on the average in the hospitals quite as long as in the case of other classes of wounds1 yet gas cases became one of the most important features of the ,medical ,department's work in the field4 ,the ,medical ,section1 through its intimate knowledge of what was going on in the ,chemical ,warfare ,service as well as what was contemplated and being experimented with1 was enabled to work out methods of handling all gas cases far in advance of what could have been done had there been no such section4 ,one instance alone illustrates this fully4 ,it became known fairly early that if a man who had been gassed with mustard gas could get a thorough cleansing and an entire change of clothing within an hour after exposure1 the body burns could be eliminated or largely decreased in severity4 ,this led to the development of degassing units4 ,these consisted of #a1bjj gallon tanks on five-ton trucks equipped with a heater4 ,accompanying this were sprinkling arrangements whereby a man could be given a shower bath1 his nose1 eyes and ears treated with bicarbonate of soda1 and then be given an entire change of clothing4 ,these proved a very great success1 although they were not developed in time to be used extensively before the war closed4 ,there is an important side to the ,medical ,section during peace1 that must be kept in mind4 ,the final decision as to whether a gas should be manufactured on a large scale and used extensively on the field of battle depends upon its physiological and morale effect upon troops4 ,in the case of the most powerful gases1 the determination of the relative values of those gases so far as their effects on human beings is concerned is a very laborious and exacting job4 ,such gases have to be handled with extreme caution1 necessitating many experiments over long periods of time in order to arrive at correct decisions4 ,,chapter ,v ,,chlorine ,chlorine is of interest in chemical warfare1 not only because it was the first poison gas used by the ,germans1 but also because of its extensive use in the preparation of other war gases4 ,the fact that1 when ,germany decided upon her gas program1 her chemists selected chlorine as the first substance to be used1 was the direct result of an analysis of the requirements of a poison gas4 ,to be of value for this purpose1 a chemical must satisfy at least the following conditions3 7#a7 ,it must be highly toxic4 7#b7 ,it must be readily manufactured in large quantities4 7#c7 ,it must be readily compressible to a liquid and yet be more or less easily volatilized when the pressure is released4 7#d7 ,it should have a considerably higher density than that of air4 7#e7 ,it should be stable against moisture and other chemicals4 ,considering the properties of chlorine in the light of these requirements1 we find3 7#a;a7 ,chlorine is fairly toxic1 though its lethal concentration 7#b4e milligrams per liter of air7 is very high when compared with some of the later gases developed4 ,this figure is the concentration necessary to kill a dog after an exposure of thirty minutes4 ,its effects during the first gas attack showed that1 with no protection1 the gas was very effective4 7#b;a7 ,chlorine is very readily manufactured by the electrolysis of a salt 7sodium chloride7 solution4 ,the operation is described below4 ,in #ajj-pound cylinders1 the commercial product sold before the ,war for #e cents a pound4 ,therefore on a large scale1 it can be manufactured at a very much smaller figure4 7#c;a7 ,chlorine is easily liquefied at the ordinary temperature by compression1 a pressure of #af4e atmospheres being required at #ah ,c4 ,the liquid which is formed boils at -#cc4f ,c4 at ordinary atmospheric pressure1 so that it readily vaporizes upon opening the valve of the containing cylinder4 ,such rapid evaporation inside would cause a considerable cooling of the cylinder1 but this is overcome by running the outlet pipe to the bottom of the tank1 so that evaporation takes place at the end of the outlet pipe4 7#d;a7 ,chlorine is #b4e times as heavy as air1 and therefore the gas is capable of traveling over a considerable distance before it dissipates into the atmosphere4 7#e;a7 ,the only point in which chlorine does not seem to be an ideal gas1 is in the fact that it is a reactive substance4 ,this is best seen in the success of the primitive protection adopted by both the ,british and the ,french during the days immediately following the first gas attack4 ,at first1 however1 chlorine proved a very effective weapon4 ,during the first six months of its use1 its value was maintained by devising new methods of attack4 ,when these were exhausted1 phosgene was added 7see next chapter74 ,with the decline in importance of cloud gas attacks1 and the development of more deadly gases1 chlorine was all but discarded as a true war gas1 but remained as a highly important ingredient in the manufacture of other toxic gases4 ,,manufacture ,,in ,,the ,,united ,,states ,it was at first thought that the existing plants might be able to supply the government's need of chlorine4 ,the pre-war production averaged about #dej tons 7#ijj1jjj pounds7 per day4 ,the greater amount of this was used in the preparation of bleach1 only about #fj1jjj pounds per day being liquefied4 ,only a few of the plants were capable of even limited expansion4 ,in an attempt to conserve the supply1 the paper mills agreed to use only half as much bleach during the war1 which arrangement added considerably to the supply available for war purposes4 ,it was soon recognized that even with these accessions1 large additions would have to be made to the chlorine output of the country in order to meet the proposed toxic gas requirements4 ,after a careful consideration of all the factors1 the most important of which was the question of electrical energy1 it was decided to build a chlorine plant at ,edgewood ,arsenal1 with a capacity of #ajj tons 7#bjj1jjj pounds7 per day4 ,the ,nelson cell was selected for use in the proposed plant4 ,during the process of erection of the plant1 the ,warner-,klipstein ,chemical ,company1 which was operating the ,nelson cell in its plant in ,charleston1 ,west ,virginia1 agreed that men might be sent to their plant to acquire the special knowledge required for operating such a plant4 ,thus when the plant was ready for operation1 trained men were at once available4 ,illustration3 ,,fig4 #ai4--;,chlorine ,plant1 ,edgewood ,arsenal4 ,illustration3 ,,fig4 #bj4--;,ground ,plan of ,chlorine ,caustic ,soda ,plant1 ,edgewood ,arsenal4 ,the following description of the plant is taken from an article by ,s4 ,m4 ,green in ,chemical and ,metallurgical ,engineering for ,july #a1 #aiai3 8,the chlorine plant building1 a ground plan of which is shown in ,figure #bj1 consisted of a salt storage and treating building1 two cell buildings1 a rotary converter building1 etc4 ,in connection with the chlorine plant1 there was also constructed a liquefying plant for chlorine and a sulfur chloride manufacturing and distilling plant4 8,the salt storage and treating building was located on ground much below the cell buildings1 which allowed the railroad to enter the brine building on the top of the salt storage tanks4 ,these tanks were constructed of concrete4 ,there were seven of these tanks1 #cd feet long1 #bh feet wide and #bj feet deep having a capacity for storing #d1jjj tons of salt4 ,there would have been #bjj tons of salt used per day when the plant was running at full capacity4 8,on the bottom of each tank distributing pipes for dissolving-water supply were installed1 and at the top of each1 at the end next to the building1 there was an overflow trough and skimmer board arranged so that the dissolving-water after flowing up through the salt1 overflowed into this trough and then into a piping system and into either of two collecting tanks4 ,the system was so arranged that1 if the brine was not fully saturated1 it could be passed through another storage tank containing a deep body of salt4 ,the saturated brine was pumped from the collecting tanks to any one of #bd treating tanks1 each of which had a capacity of #gb1jjj gallons4 8,the eighth storage bin was used for the storage of soda ash1 used in treating the saturated brine4 ,this was delivered from the bin on the floor level of the salt building to the soda ash dissolving tanks4 ,from these tanks it was pumped to any one of the #bd treating tanks4 ,after the brine was treated and settled1 the clear saturated brine was drawn from the treating tanks through decanting pipes and delivered by pumps to any one of the four neutralizing tanks4 ,these were located next to a platform on the level of the car body4 ,this was to provide easy handling of the hydrochloric acid1 which was purchased at first1 though later prepared at the plant from chlorine and hydrogen4 ,the neutralized brine was delivered from the tanks by a pump to a tank located at a height above the floor so that the brine would flow by gravity to the cells in the cell building4 8,there were to be two cell buildings1 each #eda feet long by #hb feet wide1 and separated by partitions into four sections1 containing six cell circuits of #gd cell units4 ,each section is a complete unit in itself1 provided with separate gas pump1 drying and cooling equipment1 and has a guaranteed capacity of #ab4e tons of chlorine gas per #bd hours4 8,each ,nelson electrolytic cell unit consists of a complete fabricated steel tank #ac by #cb by #hj inches1 a perforated steel diaphragm spot welded to supporting angle irons1 plate glass dome1 fourteen ,acheson graphite electrodes #b4e inches in diameter1 #ab inches long and fourteen pieces of graphite #d by #d by #ag inches1 and various accessories4 7,the cell is completely described in ,chemical and ,metallurgical ,engineering1 ,august #ast1 #aiai47 ,each cell is operated by a current of #cdj amperes and #c4h volts and is guaranteed to produce #fj pounds of chlorine gas and #fe pounds of caustic soda using not more than #abj pounds of salt per #bd hours1 the gas to be at least #ie per cent pure4 ,illustration3 ,,fig4 #ba4--;,interior ,view of the ,cell ,building4 8,the salt solution from the cell feed tank1 located in the salt treating building1 flows by gravity through a piping system located in a trench running the length of each cell building1 and is delivered to each cell unit through an automatic feeding device which maintains a constant liquor level in the cathode compartment4 8,the remaining solution percolates from the cathode compartment through the asbestos diaphragm into the anode compartment and flows from the end of the cell1 containing from #h to #ab per cent caustic soda1 admixed with #ad to #af per cent salt1 into an open trough and into a pipe in the trench and through this pipe by gravity to the weak caustic storage tanks located near the caustic evaporator building4 ,illustration3 ,,fig4 #bb4--,nelson ,electrolytic ,cell1 showing the ,interior ,arrangement of the ,cell4 8,the gas piping from the individual cell units to and including the drying equipment is of chemical stoneware4 ,the piping is so designed that the gas can be drawn from the cells through the drying equipment at as near atmospheric pressure as possible in order that the gas can be kept nearly free of air4 ,when operating1 the suction at the pump was kept at _/ inch or less4 ,the quality of the gas was maintained at a purity of #ih4e to #ii per cent4 ,the coolers used were very effective1 the gas being cooled to within one degree of the temperature of the cooling water1 no refrigeration being necessary4 ,the drying apparatus consisted of a stoneware tower of special design containing a large number of plates1 and thus giving a very large acid exposure4 ,there was practically no loss of vacuum through the drying tower and cooler4 ,the gas pumping equipment consisted of two hydroturbine pumps using sulfuric acid as the compressing medium4 ,the acid was cooled by circulation through a double pipe cooler similar to those used in refrigerating work4 ,the gas was delivered under about five pounds pressure into large receiving tanks located just outside the pump rooms1 and from these tanks into steel pipe mains which conducted the gas to the chemical plant40 ,the purity of the gas was such that it was not found necessary to liquefy it for the preparation of phosgene4 ,,properties ,chlorine1 at ordinary atmospheric pressure and temperature1 is a greenish yellow gas 7giving rise to its name71 which has a very irritating effect upon the membranes of the nose and throat4 ,as mentioned above1 at a pressure of #af4e atmospheres at #ah ,c41 chlorine is condensed to a liquid4 ,if the gas is first cooled to #j1 the pressure required for condensation is decreased to #c4g atmospheres4 ,this yellow liquid has a boiling point of -#cc4f ,c4 at the ordinary pressure4 ,if very strongly cooled1 chlorine will form a pale yellow solid 7at -#ajb ,c474 ,chlorine is #b4e times as heavy as air1 one liter weighing #c4bb grams4 #bae volumes of chlorine gas will dissolve in #ajj volumes of water at #bj4 ,it is very slightly soluble in hot water or in a concentrated solution of salt4 ,chlorine is a very reactive substance and is found in combination in a large number of compounds4 ,among the many reactions which have proved important from the standpoint of chemical warfare1 the following may be mentioned3 ,chlorine reacts with 8hypo0 7sodium thiosulfate7 with the formation of sodium chloride4 ,hypo is able to transform a large amount of chlorine1 so that it proved a very satisfactory impregnating agent for the early cloth masks4 ,water reacts with chlorine under certain conditions to form hypochlorous acid1 ,h,o,cl4 ,in the presence of ethylene1 this forms ethylene chlorhydrin1 which was the basis for the first method of preparing mustard gas4 ,in the later method1 in which sulfur chloride was used1 chlorine was used in the manufacture of the chloride4 ,chlorine reacts with carbon monoxide1 in the sunlight1 or in the presence of a catalyst1 to form phosgene1 which is one of the most valuable of the toxic gases4 ,chlorine and acetone react to form chloroacetone1 one of the early lachrymators4 ,the reaction of chlorine with toluene forms benzyl chloride1 an intermediate in the preparation of bromobenzylcyanide4 ,in a similar way1 it is found that the greater number of toxic gases use chlorine in one phase or another of their preparation4 ,one author has estimated that #ie per cent of all the gases used may be made directly or indirectly by the use of chlorine4 ,chlorine has been used in connection with ammonia and water vapor for the production of smoke clouds4 ,the ammonium chloride cloud thus produced is one of the best for screening purposes4 ,in combination with silicon or titanium as the tetrachloride it has also been used extensively for the same purpose4 ,on the other hand one may feel that1 whatever bad reputation chlorine may have incurred as a poison gas1 it has made up for it through the beneficial applications to which it has lent itself4 ,among these we may mention the sterilization of water and of wounds4 ,in war1 where stationary conditions prevail only in a small number of cases1 the use of liquid chlorine for sterilization of water is impractical4 ,to meet this condition1 an ampoule filled with chlorine water of medium concentration has been developed1 which furnishes a good portable form of chlorine as a sterilizing agent for relatively small quantities of water4 ,chlorine has also been applied1 in the form of hypochlorite1 to the sterilization of infected wounds4 ,the preparation of the solution and the technique of the operation were worked out by ,dakin and ,carrel4 ,this innovation in war surgery has decreased enormously the percentage of deaths from infected wounds4 ,,chapter ,,vi ,,phosgene ,the first cloud attack1 in which pure chlorine was used1 was very effective1 but only because the troops attacked with it were entirely unprotected4 ,later1 in spite of the varied methods of attack1 the results were less and less promising1 due to the increased protection of the men and also to the gas discipline which was gradually being developed4 ,during this time the ,allies had started their gas attacks 7,sept41 #aiae71 and it soon became evident that1 if ,germany was to keep her supremacy in gas warfare1 new gases or new tactics would have to be introduced4 ,the second poison gas was used in ,december1 #aiae1 when about #bj-be per cent of phosgene was mixed with the chlorine4 ,here again the ,germans made use of an industry already established4 ,phosgene is used commercially in the preparation of certain dyestuffs1 especially methyl violet1 and was manufactured before and during the war by the ,bayer ,company and the ,badische ,anilin und ,soda ,fabrik4 ,phosgene can not be used alone in gas cylinders because of its high boiling point 7#h ,c474 ,while this is considerably below ordinary temperatures1 especially during the summer months1 the rate of evaporation is so slow that a cloud attack could never be made with it alone4 ,however1 when a mixture of #be per cent phosgene and #ge per cent chlorine1 or #ej per cent phosgene and #ej per cent chlorine is used in warm weather there is no difficulty in carrying out gas attacks from cylinders4 ,at the same time the percentage of phosgene in the mixture is sufficiently high to secure the advantages which it possesses4 ,these advantages are at least three3 7a7 ,phosgene is more toxic than chlorine4 ,it requires #b4e milligrams per liter of chlorine to kill a dog on an exposure of #cj minutes1 but #j4c milligram of phosgene will have the same effect4 ,this of course means that a cloud of phosgene containing one-eighth 7by weight7 of the concentration of a chlorine cloud will have the same lethal properties4 7b7 ,phosgene is much less reactive than chlorine1 so that the matter of protection becomes more difficult4 ,fortunately1 word was received by the ,british of the intended first use of phosgene against them and consequently they were able to add hexamethylenetetramine to the impregnating solution used in the cloth masks4 7c7 ,the third1 and a very important1 factor in the use of phosgene is the so-called delayed effect4 ,in low concentrations1 men may breathe phosgene for some time with apparently no ill effects4 ,ten or twelve hours later1 or perhaps earlier if they attempt any work1 the men become casualties4 ,pure phosgene has been used in projector attacks 7described in ,chapter ,,ii74 ,the substance has also been used in large quantities in shell2 the ,germans also used shell containing mixtures with superpalite 7trichloromethyl chloroformate7 or sneezing gas 7diphenylchloroarsine74 ,,manufacture ,phosgene was first prepared by ,john ,davy in #ahab1 by exposing a mixture of equal volumes of carbon monoxide and chlorine to sunlight2 ,davy coined the name 8phosgene0 from the part played by light in the reaction4 ,while phosgene may be prepared in the laboratory by a number of other reactions1 it was quite apparent that the first mentioned reaction is the most economical of these for large scale production4 ,the reaction is a delicate one1 however1 and its application required extended investigation4 ,the ,united ,states was fortunate in that1 for some months previous to the war1 the ,oldbury ,electrochemical ,company had been working on the utilization of their waste carbon monoxide in making phosgene4 ,the results of these investigations were given to the government and aided considerably in the early work on phosgene at the ,edgewood plant4 ,illustration3 ,,fig4 #bc4--;,furnace for ,generating ,carbon ,monoxide4 ,of the raw materials necessary for the manufacture of phosgene1 the chlorine was provided1 at first by purchase from private plants1 but later through the ,edgewood chlorine plant4 ,after a sufficient supply of chlorine was assured the next question was how to obtain an adequate supply of carbon monoxide4 ,a method for this gas had not been developed on a large scale because it had never been necessary to make any considerable quantity of it4 ,the ,french and ,english passed oxygen up through a gas producer filled with coke2 the oxygen combines with the carbon1 giving carbon monoxide4 ,the oxygen was obtained from liquid air1 for which a ,claude liquid air machine may be used4 ,the difficulty with this method of preparing carbon monoxide was that the amount of heat generated was so great that the life of the generators was short4 ,our engineers conceived the idea of using a mixture of carbon dioxide and oxygen4 ,the union of carbon dioxide with carbon to form carbon monoxide is a reaction in which heat is absorbed4 ,therefore by using the mixture of the two gases1 the heat of the one reaction was absorbed by the second reaction4 ,in this way a very definite temperature could be maintained1 and the production of carbon monoxide was greatly increased4 ,illustration3 ,,fig4 #bd4--;,catalyzer ,boxes ,used in the ,manufacture of ,phosgene4 ,carbon dioxide was prepared by the combustion of coke4 ,the gas was washed and then passed into a solution of potassium carbonate4 ,upon heating1 this evolved carbon dioxide4 ,phosgene was then prepared by passing the mixture of carbon monoxide and chlorine into catalyzer boxes 7#h feet long1 #b feet #i inches deep and #aa inches wide71 which are made of iron1 lined with graphite and filled with a porous form of carbon4 ,two sets of these boxes were used4 ,in the first the reaction proceeds at room temperature1 and is about #hj per cent complete4 ,the second set of boxes were kept immersed in tanks filled with hot water1 and there the reaction is completed4 ,the resulting phosgene was dried with sulfuric acid and then condensed by passing it through lead pipes surrounded by refrigerated brine4 ,the ,germans prepared their phosgene by means of a prepared charcoal 7wood or animal74 ,carbon monoxide was manufactured by passing carbon dioxide over wood charcoal contained in gas-fired muffles and was washed by passing through sodium hydroxide4 ,this was mixed with chlorine and the mixture passed downward through a layer of about #bj cm4 of prepared charcoal contained in a cast iron vessel #hj cm4 in diameter and #hj cm4 deep4 ,by regulating the mixture so that there was a slight excess of carbon monoxide1 the phosgene was obtained with only one-quarter of one per cent free chlorine4 ,the charcoal 7wood7 was prepared by washing with hydrochloric and other acids until free from soluble ash2 it was then washed with water and dried in vacuum4 ,the size of the granules was about one-quarter inch mesh4 ,their life averaged about six months4 ,,properties ,phosgene is a colorless gas at room temperatures1 but becomes a liquid at #h4 ,the odor of phosgene is suggestive of green corn or musty hay4 ,one liter of phosgene vapor weighs #d4d grams 7chlorine weights #c4bb grams74 ,at #j ,c41 the liquid is heavier than water1 having a specific gravity of #a4dcb4 ,at #be1 the vapor exerts a pressure of about #be pounds per square inch4 ,phosgene is absorbed by solid materials1 such as pumice stone and celite4 ,pumice stone absorbs more than its own weight of phosgene4 ,thus #e4g grams of pumice absorbed #g4d grams phosgene1 which completely evaporated in #fj minutes4 ,german shell have been found which contained such a mixture 7phosgene and pumice stone74 ,while the apparent reason for their use is to prevent the rapid evaporation of the phosgene1 it is a question whether such is the case1 for a greater surface is really present in the case of pumice stone than where the phosgene is simply on the ground4 ,phosgene is slowly decomposed by cold water1 rapidly by hot water4 ,this reaction is important because there is always moisture in the air1 which would tend to lower the concentration of the gas4 ,phosgene is absorbed and decomposed by hexamethylenetetramine 7urotropine74 ,this reaction furnished the basis of the first protection used by the ,british4 ,later the catalytic decomposition of phosgene into carbon dioxide and hydrochloric acid by the charcoal in the mask furnished protection4 ,for most purposes a trace of chlorine in phosgene is not a disadvantage2 for example1 when it is used in cylinders or projectors4 ,under certain conditions1 as when used as a solvent for sneezing gas1 the presence of chlorine must be avoided1 since it reacts with the substance in solution1 usually producing a harmless material4 ,chlorine may be removed from phosgene by passing the mixture through cotton seed oil4 ,,protection ,it was mentioned above that hexamethylenetetramine 7urotropine7 was used in the early pads 7black veil and similar masks7 and flannel helmets4 ,this was found to be satisfactory against chlorine and phosgene1 in the concentrations usually found during a cylinder attack4 ,the mixture used consisted of urotropine1 sodium thiosulfate 78hypo071 sodium carbonate and glycerine4 ,the glycerine tended to keep the pads moist1 while the other chemicals acted as protective agents against the mixture of phosgene and chlorine4 ,the introduction of the ,standard ,box ,respirator with its charcoal-soda lime filling increased very materially the protection against phosgene4 ,in this filling1 the charcoal both absorbs the phosgene and catalyzes the reaction with the moisture of the air with which the phosgene is mixed1 to form hydrochloric acid and carbon dioxide4 ,soda-lime absorbs phosgene but does not catalyze its decomposition4 ,this shows the advantage of the mixture1 since the hydrochloric acid1 which is formed through the action of the charcoal1 is absorbed by the soda-lime4 ,experiments seem to indicate that it does not matter which material is placed in the bottom of the canister1 but that an intimate mixture is the best arrangement4 ,using a concentration of #e1jjj parts per million 7#bj4b mg4 per liter7 a type ,h canister 7see page #bag7 will give complete protection for about #dj minutes2 when the air-gas mixture passes at the rate of #af liters per minute the efficiency or life of a canister increases with a decrease in temperature1 as is seen in the following table 7the concentration was #e1jjj parts per million1 the rate of flow #af liters per minute7 ,temperature ,efficiency ,c4 7,time in minutes7 -#aj #bbc #j #agb #aj #adf #bj #acj #cj #abe #dj #ii ,from these figures it is seen that at -#aj ,c4 the life is about #ej per cent greater than at summer temperature4 ,as would be expected the life of a canister is shortened by increasing the concentration of phosgene in the phosgene air mixture4 ,this is illustrated by the following figures3 ,concentration ,life p4p4m4 7,time in minutes7 #e1jjj #agg #aj1jjj #aab #ae1jjj #gb #bj1jjj #eh #be1jjj #be 7#be1jjj p4p4m4 is equal to #aja4a mg4 per liter47 ,there is rather a definite relation between the concentration of the gas and the life of a canister at any given rate of flow4 ,many of these relations have been expressed by formulas of which the following is typical4 ,at #cb liters per minute flow1 ,c ,tb #aja1hdj1 in which ,c is the concentration and ,t the time4 ,,shell ,,filling ,the empty shell1 after inspection1 are loaded on trucks1 together with the appropriate number of 8boosters10 which screw into the top of the shell and thereby close them4 ,the trucks are run by an electric storage battery locomotive to the filling unit4 ,the shell are transferred by hand to a conveyor1 which carries the shell slowly through a cold room4 ,during this passage of about #cj minutes1 the shell are cooled to about #j ,f4 ,the cooled shell are transferred to shell trucks1 each truck carrying #f shell4 ,these trucks are drawn through the filling tunnel by means of a chain haul operated by an air motor to the filling machine4 ,here the liquid phosgene is run into the shell by automatic machines1 so arranged that the #f shell are at the same time automatically filled to a constant void4 ,the truck then carries the filled shell forward a few feet to a small window1 at which point the boosters are inserted into the nose of the shell by hand4 ,the final closing of the shell is then effected by motors operated by compressed air4 ,the filling and closing machines are all operated by workmen on the outside of the filling tunnel4 ,illustration3 ,,fig4 #be4--;,filling ,livens' ,drums with ,phosgene4 ,the filled shell are conveyed to the shell dump1 where they are stored for #bd hours1 nose down on skids1 in order to test for leaks4 ,,tactical ,,use ,phosgene was first used in cloud attacks in ,december1 #aiae4 ,these attacks continued for about nine months and were then gradually replaced1 to a large extent1 by gas shell attacks4 ,phosgene was first found in ,german projectiles in ,november1 #aiaf4 ,these shell were known as the ,d-shell4 ,besides pure phosgene1 mixtures of phosgene and chloropicrin1 phosgene and superpalite1 and phosgene and diphenylchloroarsine have been found4 ,illustration3 ,,fig4 #bf4--;,interior of a ,shell ,dump4 ,the ,english introduced the use of projectors in the ,spring of #aiag4 ,they have a decided advantage over shell in that they hold a larger volume of gas and readily lend themselves to surprise attacks4 ,as the ,germans say1 8the projector combines the advantages of gas clouds and gas shell4 ,the density is equal to that of gas clouds and the surprise effect of shell fire is also obtained40 ,toward the close of the war1 the ,germans made use of a mixture of phosgene and pumice stone4 ,a captured projector contained about #ac pounds of phosgene and #e pounds of pumice4 ,there seems to be some question as to the value of such a procedure4 ,lower initial concentrations are secured2 this is due1 in part of course1 to the smaller volume of phosgene in the shell containing pumice4 ,pumice does seem to keep the booster from scattering the phosgene so high into the air1 and at the same time does not prevent the phosgene from being liberated in a gaseous condition4 ,this would indicate that pumice gives a more even and uniform dispersion and a more economical use of the gas actually used4 ,owing to its non-persistent nature 7the odor disappears in from one and a half to two hours7 and to its general properties1 phosgene really forms an ideal gas to produce casualties4 ,,action ,,on ,,man ,phosgene acts both as a direct poison and as a strong lung irritant1 causing rapid filling of the lungs with liquid4 ,the majority of deaths are ascribed to the filling up of the lungs and consequently to the suffocation of the patients through lack of air4 ,this filling up of the lungs is greatly hastened by exercise4 ,accordingly1 all rules for the treatment of patients gassed with phosgene require that they immediately lie down and remain in that position4 ,they are not even allowed to walk to a dressing station4 ,the necessity of absolute quiet for gassed patients undoubtedly partly accounts for the later habit of carrying out a prolonged bombardment after a heavy phosgene gas attack4 ,the high explosive causes confusion1 forcing the men to move about more or less and practically prevents the evacuation of the gassed4 ,in the early days of phosgene the death rate was unduly high because of lack of knowledge of this action of the gas4 ,due to the decreased lung area for oxygenizing the air1 a fearful burden is thrown on the heart1 and accordingly1 those with a heart at all weak are apt to expire suddenly when exercising after being gassed4 ,as an illustration of the delayed action of phosgene1 a large scale raid made by one of the ,american divisions during its training is highly illuminating4 ,this division decided to make a raid on enemy trenches which were situated on the opposite slope of a hill across a small valley4 ,up stream from both of the lines of trenches was a ,french village in the hands of the ,germans4 ,when the attack was launched the wind was blowing probably six or seven miles per hour directly down stream from the village1 i4e41 directly toward the trenches to be attacked4 ,the usual high explosive box barrage was put around the trenches it was intended to capture4 ,three hundred ,americans made the attack4 ,during the attack a little more than three tons of liquid phosgene was thrown into the village in #ge- and #aee-millimeter shells4 ,the nearest edge of the village shelled with phosgene was less than #gjj yards from the nearest attacking troops4 ,none of the troops noticed the smell of phosgene1 although the fumes from high explosive were so bad that a few of the men adjusted their respirators4 ,the attack was made about #c ,a4,m41 the men remaining about #de minutes in the vicinity of the ,german trenches4 ,the men then returned to their billets1 some five or six kilometers back of the line4 ,soon after arriving there1 that is in the neighborhood of #i ,a4,m41 the men began to drop1 and it was soon discovered that they were suffering from gas poisoning4 ,out of the #cjj men making the attack #bcf were gassed1 four or five of whom died4 ,the ,medical ,department was exceedingly prompt and vigorous in the treatment of these cases1 which probably accounted for the very low mortality4 ,this is one of the most interesting cases of the delayed action that may occur in gassing from phosgene4 ,here the concentration was slight and there is no doubt its effectiveness was largely due to the severe exercise taken by the men during and after the gassing4 ,it should be remarked in closing that while gas officers were not consulted in the planning of this attack1 a general order was shortly thereafter issued requiring that gas officers be consulted whenever gas was to be used4 ,,chapter ,,vii ,,lachrymators ,without question the eyes are the most sensitive part of the body so far as chemical warfare is concerned4 ,lachrymators are substances which affect the eyes1 causing involuntary weeping4 ,these substances can produce an intolerable atmosphere in concentrations one thousand times as dilute as that required for the most effective lethal agent4 ,the great military value of these gases has already been mentioned and will be discussed more fully later4 ,there are a number of compounds which have some value as lachrymators1 though a few are very much better than all the others4 ,practically all of them have no lethal properties in the concentrations in which they are efficient lachrymators1 though we must not lose sight of the fact that many of them have a high lethal value if the concentration is of the order of the usual poison gas4 ,the lachrymators are used alone when it is desired to neutralize a given territory or simply to harrass the enemy4 ,at other times they are used with lethal gases to force the immediate or to prolong the wearing of the mask4 ,a large number of the lachrymators contain bromine4 ,in order to maintain the gas warfare requirements1 it was early decided that the bromine supply would have to be considerably increased4 ,the most favorable source of bromine is the subterranean basin found in the vicinity of ,midland1 ,michigan4 ,because of the extensive experience of the ,dow ,chemical ,co4 in all matters pertaining to the production of bromine1 they were given charge of the sinking of seventeen government wells1 capable of producing #fej1jjj pounds of bromine per year4 ,while the plant was not operated during the ,war1 it was later operated to complete a contract for #ejj1jjj pounds of bromine salts4 ,they will be held as a future war asset of the ,united ,states4 ,the principal lachrymators used during the ,war were3 ,bromoacetone1 ,bromomethylethylketone1 ,benzyl bromide1 ,ethyl iodoacetate1 ,bromobenzyl cyanide1 ,phenyl carbylamine chloride4 ,chloropicrin is something of a lachrymator1 but it has greater value as a toxic gas4 ,,halogenated ,,ketones ,one of the earliest lachrymators used was bromoacetone4 ,because of the difficulty of obtaining pure material1 the commercial product1 containing considerable dibromoacetone and probably higher halogenated bodies1 was used4 ,the presence of these higher bromine derivatives considerably decreased its efficiency as a lachrymator4 ,the preparation of bromoacetone involved the loss of considerable bromine in the form of hydrobromic acid4 ,this led the ,french to study various methods of preparation1 and they finally obtained a product containing #hj per cent bromoacetone and #bj per cent chloroacetone1 which they called 8martonite40 ,as the war progressed1 acetone became scarce1 and the ,germans substituted methylethylketone1 for which there was little use in other war activities4 ,this led to the ,french 8homomartonite40 ,various other halogen derivatives of ketones have been studied in the laboratory1 but none have proven of as great value as bromoacetone1 either from the standpoint of toxicity or lachrymatory power4 ,bromoacetone may be prepared by the action of bromine 7liquid or vapor7 upon acetone 7with or without a solvent74 ,aqueous solutions of acetone1 or potassium bromide solutions of bromine1 have also been used4 ,pure bromoacetone is a water clear liquid4 ,there are great differences in the properties ascribed to this body by different investigators4 ,this probably is due to the fact that the monobromo derivative is mixed with those containing two or more atoms of bromine4 ,a sample boiling at #abf-abg and melting at -#ed1 had a specific gravity of #a4fca at #j4 ,it has a vapor pressure of #i mm4 of mercury at #bj4 ,while bromoacetone is a good lachrymator1 it possesses the disadvantage that it is not very stable4 ,special shell linings are necessary1 and even then the material may be decomposed before the shell is fired4 ,the ,germans used a lead-lined shell1 while considerable work has been carried out in this country with enamel lined shell4 ,glass lined shell may also be used4 ,it is interesting to note that1 while bromoacetone decomposes upon standing in the shell1 it is stable upon detonation4 ,no decomposition products are found after the explosion1 and even unchanged liquid is found in the shell4 ,it may be considered as having a low persistency1 since the odor entirely disappears from the surface of the ground in twenty-four hours4 ,bromoacetone was also used by the ,germans in glass hand grenades 7,hand-a-,stink ,kugel7 and later in metal grenades4 ,the metal grenades weighed about two pounds and contained about a pound and a half of the liquid4 ,martonite was prepared by the ,french in an attempt more completely to utilize the bromine in the preparation of bromoacetone4 ,they regenerated the bromine by the use of sodium chlorate3 ,na,cl,o #f;,h,br ,na,cl #c;,br #c;,h,o ,in practice sulfuric acid is used with the sodium chlorate1 so that the final products are sodium acid sulfate and a mixture of #bj per cent chloroacetone and #hj per cent bromoacetone1 according to the reaction3 #e7;,,ch7,,co #d;,br ,h,,so ,na,cl,o #d;,,ch,br,c,o,c,h ,,ch,cl,c,o ,,ch ,na,h,s,o #c;,h,o4 ,this product is equally as effective as bromoacetone alone and is very much cheaper to manufacture4 ,in general its properties resemble very closely those of bromoacetone4 ,,german ,,manufacture ,,of ,,bromoacetone ,,and ,,bromomethylethyl ,,ketone#ag ,these two products were prepared by identical methods4 ,about two-thirds of the product produced by the factory was prepared from methylethyl ketone which was obtained from the product resulting from the distillation of wood4 ,the method employed was to treat an aqueous solution of potassium or sodium chlorate with acetone or methylethyl ketone1 and then add slowly the required amount of bromine4 ,the equation for the reaction in the case of acetone is as follows3 ,,ch,,coch ,br ,,ch,br,c,o,c,h ,h,br ,ten kg4-mols of acetone or methylethyl ketone were used in a single operation4 ,about #aj per cent excess of chlorate over that required to oxidize the hydrobromic acid formed in the reaction was used4 ,the relation between the water and the ketone was in the proportion of #b parts by weight of the former to #a part by weight of the latter4 ,for #a kg4-mol4 wt4 of the ketone1 #aj per cent excess over #a kg4 atomic-weight of bromine was used4 ,footnote #ag3 ,norris1 ,j4 ,ind4 ,eng4 ,chem41 #aa1 #hbh 7#aiai74 ,the reaction was carried out either in earthenware vessels or in iron kettles lined with earthenware4 ,the kettles were furnished with a stirrer made of wood1 and varied in capacity from #d1jjj to #e1jjj liters4 ,they were set in wooden tanks and cooled by circulating water4 ,the chlorate was first dissolved in the water and then the ketone added4 ,into this mixture the bromine was allowed to run slowly while the solution was stirred and kept at a temperature of from #cj to #dj ,c4 ,the time required for the addition of the bromine was about #dh hrs4 ,when the reaction was complete1 the oil was drawn off into an iron vessel and stirred with magnesium oxide in the presence of a small amount of water in order to neutralize the free acid4 ,it was then separated and dried with calcium chloride4 ,at this point a sample of the material was taken and tested4 ,the product was distilled to tell how much of it boiled over below #acj when methylethyl ketone had been used4 ,if less than #aj per cent distilled over1 the bromination was considered to be satisfactory4 ,if1 however1 a larger percentage of low boiling material was obtained1 the product was submitted to further bromination4 ,the material obtained in this way was found on analysis to contain slightly less than the theoretical amount of monobromoketone4 ,it was finally transferred by suction or by pressure into tank-wagons4 ,at first lead-lined tanks were used1 but later it was found that tanks made of iron could be substituted4 ,in order to take care of the small amount of hydrobromic acid1 which is slowly formed1 a small amount of magnesium oxide was added to the material4 ,the amount of the oxide used was approximately in the proportion of #a part to #ajjj parts of ketone4 ,when the magnesium oxide was used1 it was found that the bromoketone kept without appreciable decomposition for about #b months4 ,the yield of the product from #ehj kg4 of acetone 7#aj kg4-mol4 wts47 was #a1ajj kg4 ,the yield from #gbj kg4 of methylethyl ketone 7#aj kg4-mol4 wts47 was #a1bej kg4 ,,halogenated ,,esters ,the use of ethyl iodoacetate was advocated at a time when the price of bromine seemed prohibitive4 ,because of the relative price of bromine and iodine under ordinary conditions1 it is not likely that it would be commonly used4 ,however1 it is an efficient lachrymator and is more stable than the halogenated ketones1 so that on a smaller scale it might be advisable to use it4 ,it is prepared by the reaction of sodium iodide upon an alcoholic solution of ethyl chloroacetate4 ,it is a colorless oil1 boiling at #agh-ahj ,c4 7#fi ,c4 at #ab mm47 and having a density of about #a4h4 ,it is very much less volatile than bromoacetone1 having a vapor pressure of #j4ed mm4 of mercury at #bj ,c4 ,ethyl iodoacetate is about one-third as toxic as bromoacetone1 but has about the same lachrymatory value4 ,,aromatic ,,halides 8,benzyl bromide0 was also used during the early part of the war1 usually mixed with bromoacetone4 ,the material was not pure benzyl bromide1 but the reaction product of bromine upon xylene1 and should perhaps be referred to as 8xylyl bromide40 ,pure benzyl bromide is a colorless liquid1 boiling at #aih-aii ,c41 and having an odor reminiscent of water cress and then of mustard oil4 ,the war gas is probably a mixture of mono- and dibromo derivatives1 boiling at #baj-bbj ,c41 and having a density at #bj ,c4 of #a4c4 ,the mixture of benzyl and xylyl bromides used by the ,germans was known as 8,t-,stoff10 while the mixture of #hh per cent xylyl bromide and #ab per cent bromoacetone was called 8,green ,t-,stoff40 ,as in the case of the halogenated acetones1 it is necessary to use lead lined shell for these compounds4 ,enamel and glass lined shell may be used and give good results4 ,while they are difficult of manufacture1 satisfactory methods were being developed at the close of the war4 8,t-,stoff0 may be detected by the nose in concentrations of one part in one hundred million of air1 and will cause profuse lachrymation with one part in a million4 ,it is a highly persistent material and may last1 under favorable circumstances1 for several days4 ,while it is relatively non-toxic1 ,french troops were rendered unconscious by it during certain bombardments in the ,argonne in the summer of #aiae4 ,a number of derivatives of the benzyl halides have been tested and some have proven to be very good lachrymators4 ,the difficulty of their preparation on a commercial scale has made it inadvisable to use them1 and especially inasmuch as bromobenzyl cyanide has proven to be such a valuable compound4 ,,bromobenzyl ,,cyanide ,bromobenzyl cyanide is1 chemically1 -bromo--tolunitrile1 or phenyl-bromo-acetonitrile1 ,c,h,c,h,br,c,n4 ,it is prepared by the action of bromine upon benzyl cyanide4 ,benzyl cyanide is prepared by the action of sodium cyanide upon a mixture of equal parts of #ie per cent alcohol and benzyl chloride4 ,the benzyl chloride in turn is obtained by the chlorination of toluene at #ajj4 ,the material must be fairly pure in order that the benzyl cyanide reaction may proceed smoothly4 ,the cyanide is subjected to a fractional distillation and that part boiling within #c degrees 7the pure product boils at #bca4g ,c47 is treated with bromine vapor mixed with air4 ,it has been found necessary to catalyze the reaction by sunlight1 artificial light or the addition of a small amount of bromobenzyl cyanide4 ,the product obtained from this reaction1 if the hydrobromic acid which is formed is carefully removed by a stream of air1 is sufficiently pure for use as a lachrymator4 ,it melts from #af to #bb ,c41 while the pure product melts at #bi ,c4 ,it cannot be distilled1 even in a high vacuum4 ,it has a low vapor pressure and thus is a highly persistent lachrymator4 ,bromobenzyl cyanide is about as toxic as chlorine1 but is many times as effective a lachrymator as any of the halogenated ketones or aromatic halides studied4 ,it has a pleasant odor and produces a burning sensation on the mucous membrane4 ,like the other halogen containing compounds1 lead or enamel lined shell are necessary for preserving the material any length of time4 ,in all of this work the ,united ,states was at a very marked disadvantage4 ,while the ,allies and the ,germans could prepare substances of this nature and use them in shell within a month1 the ,united ,states was sure that shell filled at ,edgewood ,arsenal probably would not be fired within three months4 ,this means that much greater precautions were necessary1 both as to the nature of the shell lining and as to the purity of the 8war gas40 ,the question of protection against lachrymatory gases was never a serious one4 ,during the first part of the war this was amply supplied by goggles4 ,later1 when the ,standard ,respirator was introduced1 it was found that ample protection was afforded against all the lachrymators4 ,their principal value is against unprotected troops and in causing men to wear their masks for long periods of time4 ,the comparative value of the various lachrymators mentioned above is shown in the following table3 ,bromobenzyl cyanide #j4jjjc ,martonite #j4jjab ,ethyl iodoacetate #j4jjad ,bromoacetone #j4jjae ,xylyl bromide #j4jjah ,benzyl bromide #j4jjdj ,bromo ketone #j4jaa ,choroacetone #j4jah ,chloropicrin #j4jai ,the figures give the concentration 7milligram per liter of air7 necessary to produce lachrymation4 ,the method used in obtaining these figures is given in ,chapter ,,xxi4 ,,chapter ,,viii ,,chloropicrin ,during the spring of #aiag1 strange reports came from the ,italian front that the ,germans were using a new war gas4 ,this gas1 while it did not seem to be very poisonous1 had the combined property of being a lachrymator and also of causing vomiting4 ,large number of casualties resulted through the men being forced to remove their masks in an atmosphere filled with lethal gases4 ,the gas had the additional and serious disadvantage of being a very difficult one to remove completely in the gas mask4 ,the first ,american masks were very good when chlorine or phosgene was considered but were of no value when chloropicrin was used4 ,one of the interesting facts of chemical warfare is that few if any new substances were discovered and utilized during the three years of this form of fighting4 ,chlorine and phosgene were well known compounds4 ,and likewise1 chloropicrin was an old friend of the organic chemist4 ,so much so1 indeed1 that several organic laboratories prepared the compound in their elementary courses4 ,chloropicrin was first prepared by the ,english chemist1 ,stenhouse1 in #ahdh1 by the action of bleaching powder upon a solution of picric acid4 ,this was followed by a careful study of its physical and chemical properties1 few of which have any connection with its use as a poison gas4 ,the use of picric acid as an explosive made it very desirable that other raw materials should be used4 ,chloroform1 which is the ideal source theoretically 7since chloropicrin is nitro-chloroform1 ,cl,,cno71 gave very poor yields4 ,while it may be prepared from acetone1 in fair yields1 acetone was about as valuable during the war as was picric acid4 ,practically all the chloropicrin used was prepared from this acid as the raw material4 ,,manufacture ,in the manufacture of chloropicrin the laboratory method was adopted4 ,this consisted simply in passing live steam through a mixture of picric acid and bleaching powder4 ,the resulting chloropicrin passes out of the still with the steam4 ,there was a question at first whether a steam jacketed reaction vessel should be used1 and whether stirrers should be introduced4 ,both types were tested1 of which the simpler form1 without steam jacket or stirrer1 proved the more efficient4 ,illustration3 ,,fig4 #bg4--;,interior of ,chloropicrin ,plant4 ,the early work was undertaken at the plant of the ,american ,synthetic ,color ,company at ,stamford1 ,connecticut4 ,later a large plant was constructed at ,edgewood ,arsenal4 ,at the latter place ten stills1 #h by #ah feet1 were erected1 together with the necessary accessory equipment4 ,the following method of operation was used3 ,the bleach is mixed with water and stirred until a cream is formed4 ,this cream is then pumped into the still along with a solution of calcium picrate 7picric acid neutralized with lime74 ,when the current of live steam is admitted at the bottom of the still1 the temperature gradually rises1 until at #he ,c4 the reaction begins4 ,the chloropicrin passes over with the steam and is condensed4 ,upon standing1 the chloropicrin settles out1 and may be drawn off and is then ready for filling into the shell4 ,the yield was about #a4f times the weight of picric acid used4 ,,properties ,chloropicrin is a colorless oil1 which is insoluble in water1 and which can be removed from the reaction by distillation with steam4 ,it boils at #aab ,c4 and will solidify at -#fi ,c4 ,at room temperature it has a density of #a4fi and is thus higher than chloroform 7#a4e7 or carbon tetrachloride 7#a4ei74 ,at room temperature it has a vapor pressure of #bd mm4 of mercury4 ,it thus lies1 in persistency1 between such gases as phosgene on the one hand1 and mustard gas on the other1 but so much closer to phosgene that it is placed in the phosgene group4 ,chloropicrin is a very stable compound and is not decomposed by water1 acids or dilute alkalies4 ,the reaction with potassium or sodium sulfite1 in which all the chlorine is found as potassium or sodium chloride1 has been used as an analytical method for its quantitative determination4 ,the qualitative test usually used consists in passing the gas-air mixture through a heated quartz tube1 which liberates free chlorine4 ,the chlorine may be detected by passing through a potassium iodide solution containing starch1 or by the use of a heated copper wire gauze1 when the characteristic green color is obtained4 ,an interesting physiological test has also been developed4 ,the eye has been found to be very sensitive to chloropicrin4 ,the gas affects the eye in such a way that its closing is practically involuntary4 ,a measurable time elapses between the instant of exposure and the time when the eye closes4 ,below #a or #b parts per million1 the average eye withstands the gas without being closed1 though considerable blinking may be caused4 ,above #be parts1 the reaction is so rapid as to render proper timing out of the question4 ,but with concentrations between #b and #be parts1 the subject will have an overpowering impulse to close his eye within #c to #cj seconds4 ,the time may be recorded by a stop watch and from the values thus determined a calibration curve may be plotted1 using the concentration in parts per million and the time to zero eye reaction4 ,typical figures are given below4 ,it will be noted that different individuals will vary in their sensitivity1 though the order is the same4 -------------------------- ,conc4 ,a ,b p4p4m4 ,seconds ,seconds -------------------------- #bj4j #d4j #e4j #ae4j #e4d #e4d #aj4j #g4e #g4e #g4e #i4j #aj4j #e4j #ac4j #ae4j #b4e #ah4j #cj4j -------------------------- ,illustration3 ,,fig4 #bh4--;,calibration ,curve of ,eyes for ,chloropicrin4 ,,protection ,because of the stability of chloropicrin1 the question of protection resolves itself into finding an absorbent which is very efficient in removing the gas from air mixtures4 ,fortunately such an agent was found in the activated charcoal used in the ,american gas mask4 ,the removal of the gas appears to take place in two stages4 ,in the first1 the gas is adsorbed in such a way that the long-continued passage of air does not remove it4 ,in the second1 the gas is absorbed1 and this1 really excess gas1 is removed by pure air passing over the charcoal4 ,the relation of these two factors has an important bearing on the quality of charcoal to be used in gas masks4 ,it appears that up to a certain point an increase of the quality is desirable3 beyond this1 it is of doubtful value4 ,unlike phosgene1 chloropicrin is absorbed equally well at all temperatures4 ,moisture on the other hand has a very decided effect4 ,it appears that charcoal absorbs roughly equivalent weights of chloropicrin and of water2 the presence of water in the charcoal thus displaces an approximately equal amount of chloropicrin4 ,in the study of canisters it has been found that the efficiency time is approximately inversely proportional to the concentration4 ,formulas have been calculated to express the relation existing between concentration and life of the canister1 and also between the rate of flow of the gas and the life4 ,while water seems to have a decidedly marked effect upon the life of a canister1 this is not true of other gases1 and the efficiency of the canister for each gas is not decreased when used in a binary mixture4 ,,tactical ,,uses ,because of the high boiling point of chloropicrin it can only be used in shell4 ,the ,german shell usually contained a mixture of superpalite 7trichloromethyl chloroformate7 and chloropicrin1 the relative proportions being about #ge to #be4 ,these were called ,green ,cross ,shell1 from the peculiar marking on the outside of the shell4 ,mixtures of phosgene and chloropicrin 7#ej-ej7 have also been used4 ,the ,allies have used a mixture of #hj per cent chloropicrin and #bj per cent stannic chloride 7so-called ,n4 ,c474 ,this mixture combines the advantages of a gas shell with those of a smoke shell1 since the percentage of stannic chloride is sufficiently high to form a very good cloud4 ,in addition to this1 it is believed that the presence of the chloride increases the rate of evaporation of the chloropicrin4 ,it has been claimed that the chloride decreases the amount of decomposition of the chloropicrin upon the bursting of the shell1 but careful experiments appear to show that this decomposition is negligible and that the stannic chloride plays no part in it4 ,this mixture was being abandoned at the close of the war4 ,this ,n4 ,c4 mixture has also been used in ,liven's projectors and in hand grenades4 ,the material is particularly fitted for hand grenades1 owing to the low vapor pressure of the chloropicrin1 and the consequent absence of pressures even on warm days4 ,as a matter of fact1 it was the only filling used for this purpose1 though later the stannic chloride was changed1 owing to the shortage of tin1 to a mixture of silicon and titanium chlorides4 ,while chloropicrin is sufficiently volatile to keep the strata of air above it thoroughly poisonous1 it is still persistent enough to be dangerous after five or six hours4 ,,chapter ,,ix ,,dichloroethylsulfide 8,,mustard ,,gas0 ,the early idea of gas warfare was that a material1 to be of value as a war gas1 should have a relatively high vapor pressure4 ,this would1 of course1 provide a concentration sufficiently high to cause casualties through inhalation of the gas-ladened air4 ,the introduction of 8mustard gas0 7dichloroethylsulfide7 was probably the greatest single development of gas warfare1 in that it marked a departure from this early idea1 for mustard gas is a liquid boiling at about #bbj ,c41 and having a very low vapor pressure4 ,but mustard gas has1 in addition1 a characteristic property which1 combined with its high persistency1 makes it the most valuable war gas known at the present time4 ,this peculiar property is its blistering effect upon the skin4 ,very low concentrations of vapor are capable of 8burning0 the skin and of producing casualties which require from three weeks to three months for recovery4 ,the combination of these properties removed the necessity for a surprise attack1 or the building up of a high concentration in the first few bursts of fire4 ,a few shell1 fired over a given area1 were sufficient to produce casualties hours and even days afterwards4 ,mustard gas1 chemically1 is dichloroethylsulfide 7,cl,c,h,,ch7,s4 ,the name originated with the ,british ,tommy because the crude material first used by the ,germans was suggestive of mustard or garlic4 ,various other names were given the compound1 such as 8,yellow ,cross10 from the shell markings of the ,germans2 8,yperite10 a name used by the ,french1 because the compound was first used at ,ypres2 and 8blistering gas10 because of its peculiar effect upon the skin4 ,,historical ,it seems probable that an impure form of mustard gas was obtained by ,richie 7#ahed7 by the action of chlorine upon ethyl sulfide4 ,the substance was first described by ,guthrie 7#ahfj71 who recognized its peculiar and powerful physiological effects4 ,it is interesting in this connection to note that ,guthrie studied the effect of ethylene upon the sulfur chlorides1 since this reaction was the basis of the method finally adopted by the ,allies4 ,the first careful investigation of mustard gas1 which was then only known as dichloroethylsulfide1 was carried out by ,victor ,meyer 7#ahhf74 ,meyer used the reaction between ethylene chlorhydrin and sodium sulfide1 with the subsequent treatment with hydrochloric acid4 ,all the ,german mustard gas used during #aiag and #aiah was apparently made by the use of these reactions1 and all the early experimental work of the ,allies was in this direction4 ,mustard gas was first used as an offensive agent by the ,germans on ,july #ab-ac1 #aiag1 at ,ypres4 ,according to an ,english report1 the physiological properties of mustard gas had been tested by them during the summer of #aiaf4 ,the ,anti-,gas ,department put forward the suggestion that it should be used for chemical warfare1 but at that time its adoption was not approved4 ,this fact enabled the ,english to quickly and correctly identify the contents of the first ,yellow ,cross dud received4 ,it is not true1 as reported by the ,germans1 that the material was first diagnosed as diethylsulfide4 ,the tactical value of mustard gas was immediately recognized by the ,germans and they used tremendous quantities of it4 ,during ten days of the ,fall of #aiag1 it is calculated that over #a1jjj1jjj shell were fired1 containing about #b1ejj tons of mustard gas4 ,zanetti states that the ,british gas casualties during the month following the introduction of mustard gas were almost as numerous as all gas casualties incurred during the previous years of the war4 ,pope says that the effects of mustard gas as a military weapon were indeed so devastating that by the early autumn of #aiag the technical advisers of the ,british1 ,french1 and ,american ,governments were occupied upon large scale installations for the manufacture of this material4 ,,preparation ,,and ,,manufacture ,the analysis of the first ,german shell indicated that the mustard gas contained therein had been prepared by the method published by ,victor ,meyer 7#ahhf7 and later used by ,clark 7#aiab7 in ,england4 ,it was natural1 therefore1 that attention should be turned to the large scale operation of this method4 ,the following operations are involved3 ,ethylene is prepared by the dehydration of ethyl alcohol4 ,the interaction of hypochlorous acid 7,h,cl,o7 and ethylene yields ethylene chlorhydrin1 ,cl,c,h,,ch,,oh4 ,when this is treated with sodium sulfide1 dihydroxyethyl sulfide forms1 which1 heated with hydrochloric acid1 yields dichloroethyl sulfide4 ,chemically1 the reactions may be written as follows3 ,,ch,,ch,,oh ,,ch 3 ,,ch ,h,o ,,ch 3 ,,ch ,h,cl,o ,,hoch,,ch,cl #b;,,hoch,,ch,cl ,na,s 7,,hoch,,ch7,s #b,na,cl 7,,hoch,,ch7,s #b;,h,cl 7,cl,c,h,,ch7,s #b;,h,o ,without going into the chemistry of this reaction1 which is thoroughly discussed by ,gomberg#ah 7see also ,german ,manufacture71 it may be said that this 8procedure proved to be unsuitable for large scale production0 7,dorsey74 ,as ,pope remarks1 8,that he 7the ,german7 should have been able to produce three hundred tons of mustard gas per month by the large scale installation of the purely academic method 7of ,meyer7 constitutes indeed #8a significant tribute to the potentialities represented by the large ,german fine chemical factories4'0 ,it is true that a great deal of experimental work was carried out by the ,allies on this method1 but further study was dropped as soon as the ,pope method was discovered4 ,footnote #ah3 ,j4 ,am4 ,chem4 ,soc4 #da1 #adad 7#aiai74 ,the first step in advance in the manufacture of mustard gas was the discovery that ethylene would react with sulfur dichloride4 ,while ,american chemists were not very successful in their application of this reaction1 either in the laboratory or the plant1 it was apparently1 according to ,zanetti1 the only method used by the ,french 7the only one of the ,allies that manufactured and fired mustard gas74 ,the plant was that of the ,socit ,chimique des ,usines du ,rhone and was started early in ,march1 #aiah1 with a production of two to three tons a day4 ,in ,july it was producing close to twenty tons a day4 ,the plant was being duplicated at the time of the ,armistice1 so that probably in ,december1 #aiah1 the production of mustard gas by the dichloride process would have reached about #dj tons4 ,zanetti points out1 however1 that the process involved complicated and costly apparatus and required considerable quantities of carbon tetrachloride as a solvent4 ,it is for this reason that the ,levinstein process would have been a tremendous gain1 had the war continued4 ,about the end of ,january1 #aiah1 ,pope and ,gibson1 in a study of the reaction originally used by ,guthrie1 found that the action of ethylene upon sulfur chloride 7,s,cl7 at #fj yielded mustard gas and sulfur3 #b;,,ch 3 ,,ch ,s,cl 7,,ch,cl,c,h7,s ,s ,the reaction at this temperature caused the separation of sulfur2 this occurred after the product stood for some time or immediately if it was treated with moist ammonia gas4 ,while this process was put into commercial operation1 both in ,england and ,america1 it offered considerable difficulty from an operating standpoint4 ,the sulfur would often separate out and block the inlet tubes 7ethylene74 ,while it is comparatively easy to remove the mustard gas from the separated sulfur by decantation1 a certain amount always remains with the sulfur4 ,it is almost impossible to economically remove this1 and its presence adds to the difficulty of removing the sulfur from the reactors2 the men engaged in this operation almost always become casualties4 ,illustration3 ,,fig4 #bi4--,the ,levinstein ,reactor as ,installed at ,edgewood ,arsenal4 ,it was especially important1 therefore1 when ,green discovered that1 if the reaction was carried out at #cj1 the sulfur did not settle out but remained in 8pseudo solution0 in the mustard gas 7,pope7 or as a loose chemical combination of the monosulfide 7mustard gas7 with an atom of sulfur 7,green74 ,this material has all the physiological activity of the pure monosulfide1 while the enormous technical difficulties of handling separated sulfur are entirely obviated by this method of manufacture4 ,to carry out the reaction ,levinstein1 ,ltd41 devised the ,levinstein 8reactor40 ,the apparatus is shown in ,fig4 #bi4 ,the process consists essentially in bringing together sulfur chloride and very pure ethylene gas in the presence of crude mustard gas as a solvent at a temperature ranging between #cj-ce ,c4 ,a supply of unchanged monochloride is constantly maintained in the reacting liquid until a sufficiently large batch is built up4 ,then the sulfur monochloride feed is discontinued and the ethylene feed continued until further absorption ceases4 ,by controlling the ratio of mustard gas to uncombined monochloride1 the reaction velocity is so increased that the lower temperature may be used4 ,the product thus obtained is a pale yellow liquid which deposits no sulfur and requires no further treatment4 ,it is ready for the shell filling plant at once4 ,the obvious advantage of this method led to its adoption in all ,american plants started for the manufacture of mustard gas 7,edgewood1 ,cleveland and ,buffalo74 ,,ethylene ,it was known from the work of certain ,french chemists that in the presence of such a catalyst as kaolin1 ethyl alcohol is dehydrated at an elevated temperature to ethylene4 ,the process as finally developed by ,american chemists consisted essentially in introducing mixtures of alcohol vapor and steam1 in the ratio of one to one by weight1 into an #h-;inch iron tube with a #c-;inch core1 in contact with clay at #ejj-fjj ,c4 ,the use of steam rendered the temperature control more uniform and thus each unit had a greater capacity of a higher grade product4 ,the gaseous products were removed through a water-cooled surface condenser4 ,one unit of this type had a demonstrated capacity of #djj cubic feet per hour of ethylene1 between #ib and #ie per cent pure1 while the conversion efficiency 7alcohol to ethylene7 was about #he per cent4 ,the ,edgewood plant consisted of #dj such units4 ,this would have yielded sufficient ethylene to make #dj tons of mustard gas per #bd-;hour day4 ,the ,english procedure consisted in the use of phosphoric acid1 absorbed onto coke4 ,an ,american furnace was designed and built which gave #b1jjj cubic feet per hour of ethylene1 with a purity of #ih to #ii per cent4 ,this furnace was not used on a large scale1 because of the satisfactory nature of the kaolin furnaces4 ,illustration3 ,,fig4 #cj4--;,experimental ,installation for the ,production of ,ethylene by ,kaolin ,procedure4 ,capacity #djj-fjj cu4 ft4 ,ethylene per hr4 ,,sulfur ,,chloride ,since chlorine was prepared at ,edgewood1 it was logical that some of this chlorine should be utilized in the preparation of sulfur chloride4 ,the plant constructed consisted of #cj tanks 7#gh inches in diameter and #ce feet long71 each capable of producing #bj1jjj pounds of monochloride per day4 ,the tanks are partially filled with sulfur and chlorine passed in4 ,the reaction proceeds rapidly with sufficient heat to keep the sulfur in a molten condition4 ,if the chlorine is passed in too rapidly1 the heat generated may be sufficient to boil off the sulfur chloride formed4 ,hence water pipes are provided so that a supply of cold water may be sprayed upon the tanks1 keeping the temperature within the proper limits4 ,illustration3 ,,fig4 #ca4--,row of ,furnaces for the ,preparation of ,ethylene4 ,in the manufacture of one ton of mustard gas1 about one ton of sulfur chloride and a little less than half a ton of ethylene 7#ab1fdj cubic feet7 are required4 ,,german ,,method ,,of ,,manufacture#ai ,illustration3 ,,fig4 #cb4--,preparation of ,ethylene at ,badische ,anilin und ,soda ,fabrik4 #fj units4 ,footnote #ai3 ,norris1 ,j4 ,ind4 ,eng4 ,chem41 #aa1 #hba 7,sept41 #aiai74 8,,preparation ,,of ,,ethylene--,the gas was prepared by passing alcohol vapor over aluminum oxide at a temperature of #chj to #djj4 ,the details of the construction of one of the furnaces are given in ,figs4 #cb and #cc4 ,the furnaces were very small and sixty units were needed to furnish the amount of gas required4 ,the tubes containing the catalyzer were made of copper and were heated in a bath of molten potassium nitrate4 ,it was stated that the catalyzer was made according to the directions of ,ipatieff1 and that its life was from #aj to #bj days4 ,the gas produced was washed in the usual form of scrubber4 ,the yield of ethylene was stated to be about #ij per cent of the theoretical4 ,illustration3 ,,fig4 #cc4--;,ethylene ,production at ,badische ,anilin und ,soda ,fabrik4 #a unit4 ,illustration3 ,,fig4 #cd4--;,chlorhydrin reaction kettle at ,badische ,anilin und ,soda ,fabrik4 #af units4 8,,preparation ,,of ,,ethylene ,,chlorhydrin--,the reaction was carried out in a cylindrical tank resting on its side4 ,the tank was furnished with a stirrer and was insulated by means of cork in order to prevent the transfer of heat from the atmosphere to the inside4 ,enough chloride of lime was introduced into the tank to furnish #ejj kg4 of available chlorine1 together with #e cu4 m4 of water4 ,at first1 about #bj cu4 m4 of carbon dioxide were led into the mixture1 next ethylene1 and later carbon dioxide and ethylene simultaneously4 ,the rate of absorption of ethylene was noted and when it slackened1 more carbon dioxide was added4 ,fuller details as to the addition of the two gases were not given as it was stated that it was a matter of judgment on the part of the workman who was carrying out the operation4 ,the reaction should be carried out at as low a temperature as possible1 but it was found impossible to work below #e with the apparatus employed in this factory4 ,the temperature during the reaction varied between #e and #aj4 ,in order to maintain this temperature1 the solution was constantly pumped from the apparatus through a coil which was cooled by brine4 ,when ethylene was no longer absorbed and there was an excess of carbon dioxide present1 the solution was tested for hypochlorous acid4 ,the time required for the introduction of ethylene was between #b and #c hrs4 8,the contents of the apparatus were passed through a filter press by means of which the calcium carbonate was removed4 ,the solution thus obtained contained from #aj to #ab per cent of ethylene chlorhydrin4 ,it was next distilled with steam and a distillate collected which contained between #ah and #bj per cent of chlorhydrin4 ,the yield of chlorhydrin was from #fj to #hj per cent of that calculated from the ethylene used4 ,illustration3 ,,fig4 #ce4--,mustard ,gas ,manufacture at ,leverkusen4 ,layout for ,chlorination of ,thiodiglycol4 8,,preparation ,,of ,,dihydroxyethylsulfide--,to prepare the hydroxysulfide1 the theoretical quantity of sodium sulfide1 either in the form of the anhydrous salt or as crystals1 was added to the #ah to #bj per cent solution of chlorhydrin4 ,after the addition of the sulfide1 the mixture was heated to about #ij to #ajj4 ,it was then pumped to an evaporator1 and heated until all the water was driven off4 ,the glycol was next filtered from the salt which separated1 and distilled in a vacuum4 ,the yield of glycol was about #ij per cent of the theoretical1 calculated from the chlorhydrin4 8,,preparation ,,of ,,dichlorethylsulfide--,the thiodiglycol was taken from the rail to two large storage tanks and thence drawn by vacuum direct to the reaction vessel4 ,each reaction vessel was placed in a separate cubicle ventilated both from above and below and fitted with glass windows for inspection4 ,the vessels themselves were made of #a in4 cast iron and lined with #aj mm4 lead4 ,they were #b4e m4 high and #b4h m4 in diameter4 ,these tanks were jacketed so that they could be heated by water and steam1 and the reaction was carried out at #ej4 ,the hydrochloric acid coming from the main pipe was passed through sulfuric acid so that the rate could be observed1 and passed in by means of #ab glass tubes of about #b cm4 diameter4 ,the rate of flow was maintained at as high a rate as possible to procure absorption4 ,the vapors from the reaction were led from the vessel through a pipe into a collecting room1 and then through a scrubber containing charcoal and water1 through a separator1 and then1 finally1 into the chimney4 ,these exhaust gases were drawn off by means of a fan which was also connected with the lower part of the chamber in which the reaction vessels were set1 so that all the gases had to pass through the scrubber before going to the chimney4 ,when the reaction was completed1 the oil was removed by means of a vacuum1 induced by a water pump1 into a cast iron washing vessel4 8,the hydrochloric acid layer was removed to a stoneware receiver1 also by vacuum4 ,a glass enabled the operator to avoid drawing oil over with the acid4 ,the pan was fitted with a thermometer to the interior as well as to the jacket4 ,for testing the material during reaction1 provision was made for drawing some up by vacuum to a hydrometer contained in a glass funnel4 ,the final test at this point read #abf ,tw4 ,another portion could be drawn up to a test glass and hydrochloric acid passed through it in full view4 ,a float contained in a glass outer tube served to show the level of the liquid in the vessel4 ,the pans in which the operation is carried on1 as well as those employed for washing and distilling the product1 were of a standard pattern employed in many other operations in the works4 8,the washer consisted of a cast iron vessel1 lead lined1 and was #b4e m4 in diameter1 #b m4 deep1 and fitted with a dome cover and stirring gear4 ,lead pipes served for the introduction of sodium carbonate solution and water4 ,similar pipes were fitted for drawing these off by means of a vacuum4 ,a manhole on the cover1 with a flat top1 was fitted with light and sight glasses to which were fitted a small steam coil for keeping them clear4 ,the washed oil is drawn off to a distillation still1 which is a cast iron vessel homogeneously lead coated1 #a4e m4 in diameter and #b m4 deep1 fitted with a lead heating coil and connected through a spiral lead condenser and receiver to a vacuum pump4 ,the water is distilled from the oil at a pressure of from #fb to #gj mm4 absolute pressure4 ,when dried1 the oil is sent by vacuum to a mixing vessel1 similar in most respects to the washing vessel1 in which it is mixed with an appointed quantity of solvent1 which1 in this factory1 was usually chlorobenzene but occasionally carbon tetrachloride4 ,the relative quantities varied with the time of year1 and instructions were sent from ,berlin on this point4 ,thence the mixture was passed to a storage tank and into tank-wagons40 ,,american ,,method ,,of ,,manufacture ,the ,chemical ,warfare ,service investigated carefully the three methods 7,german1 ,french1 and ,english7 and finally adopted the ,levinstein process4 ,the following discussion is taken from a report originally made during construction1 ,sept41 #aiah4 ,the ,levinstein reactor consisted of a jacketed and lead-lined vessel or steel tank1 #h feet #e inches in diameter and #ad feet tall4 ,the reactor contained #a1djj feet of lead pipe 7outside diameter #b inches71 made up into five coils1 giving a total cooling surface of #a1bjj square feet4 ,the finished charge of such a reactor is #ab tons4 ,ethylene was introduced through lead injectors1 of which there were #af1 each suspended from its own opening in the top and hanging so that the end of the injector tube was #ab inches from the bottom of the reactor4 ,the nozzle of the injector was _/ inch outside diameter and ethylene was introduced through it at #dj pounds pressure4 ,in starting the reaction1 enough sulfur chloride was introduced into the reactor to cover the central nozzles4 ,ethylene was now introduced1 and as the reaction proceeded sulfur chloride was added in sufficient quantities to give a high rate of reaction4 ,brine or cold water was introduced through the cooling coils and jacket to keep the reacting temperature at #ce ,c4 ,when the charge was completed1 the ethylene was turned off so that only a small amount bubbled through the nozzles and the charge syphoned off to the settling tank4 ,these were constructed of iron1 #h feet in diameter and #ai feet tall4 ,they were provided with iron coils by which the liquid may be cooled down1 or the sulfur1 which precipitates in the bottom1 melted4 ,the tank was large enough to hold six complete charges of mustard gas and all the sulfur from these charges was allowed to accumulate before removal of the sulfur4 ,the supernatant mustard gas was drawn off from above this sulfur to storage tanks4 ,among the factors which influence the reaction are the following3 ,a temperature of over #fj ,c4 in lead will decompose the product slowly when sulfur chloride is present4 ,the presence of iron decomposes the product rapidly at a temperature of #ej ,c4 and probably at a considerably lower temperature4 ,the purity of the product is dependent upon the time of reaction4 ,there is always a slow reaction between the mustard gas and sulfur chloride1 and because of this the charge should be completed in #h hours4 ,in general the more sulfur that comes out of the solution1 the better is the product4 ,temperature has a marked effect on the separation of sulfur4 ,in order to entirely remove the sulfur from the product it was the custom to increase the temperature at the close of the reaction from #ee to #gj ,c4 ,this1 however1 caused plugging of the lines and the reactor4 ,,properties ,dichloroethylsulfide 7mustard gas7 is a colorless1 oily liquid1 which has a faint mustard odor4 ,the pure material is said to have an odor very suggestive of that of water cress4 ,while the odor is more or less characteristic1 it is possible to have extremely dangerous amounts of the gas in a neighborhood without being detected through its odors4 ,it still seems to be an open question whether mustard gas paralyzes the sense of smell4 ,one can find opinions on both sides4 ,mustard gas boils at #bae-bag ,c4 at atmospheric pressure1 so that it is at once seen to be a very persistent gas4 ,it distills without decomposition at this temperature but is best purified by vacuum distillation1 or by distillation with steam4 ,a still for the vacuum distillation of mustard gas has been described by ,streeter4#bj ,footnote #bj3 ,j4 ,ind4 ,eng4 ,chem41 #aa1 #bib 7#aiai74 ,mustard gas melts1 when pure1 at #ac to #ad ,c4 7,the ordinary summer temperature is #bj-be ,c474 ,the ordinary product1 as obtained from the 8reactor10 melts from #i-aj ,c4 ,in order that the product in the shell might be liquid at all temperatures1 winter as well as summer1 the ,germans added from #aj to #cj per cent of chlorobenzene1 later using a mixture of chlorobenzene and nitrobenzene and still later pure nitrobenzene4 ,carbon tetrachloride has also been used as a means of lowering the melting point4 ,many other mixtures1 such as chloropicrin1 hydrocyanic acid1 bromoacetone1 etc41 were tested1 but were not used4 ,the effect on the melting point of mustard gas is shown in the following table3 ,,melting ,,point ,,of ,,mustard ,,gas ,,mixtures ---------------------------------------- ------------- ,per ,cent ,chloropicrin ,chlorobenzene ,carbon ,added ,tetrachloride ---------------------------------------- ------------- #j #ac4d ,c4 #ac4d ,c4 #ac4d ,c4 #aj #i4h #h4d #i4h #bj #f4c #f4d #f4f #cj #b4f -#a4j #c4a ---------------------------------------- ------------- ,the mustard gas as finally made by the ,united ,states contained about #ag to #ah per cent sulfur in solution4 ,the gas was then put in shell and fired without the addition of any solvent4 ,in actual practice this impure product seemed even more powerful in causing casualties than equal quantities of the pure mustard gas4 ,accordingly no redistilling as originally contemplated was actually carried out4 ,the specific gravity of mustard gas at #bj is #a4bgda4 ,the solid material has a slightly higher value1 being #a4cch at #ac4 ,its vapor pressure at room temperature is very low2 at #bj this value has been found to be about #j4jf mm4 of mercury4 ,mustard gas is practically insoluble in water1 less than #j4a per cent forming a saturated solution4 ,the reports that a #a per cent solution could be obtained did not consider the question of hydrolysis4 ,mustard gas is freely soluble in all the ordinary organic solvents1 such as ligroin1 alcohol1 ether1 chloroform1 acetic acid1 chlorobenzene1 etc4 ,in case the solvent is miscible with water1 dilution throws out the product as an oil4 ,,chemical ,,properties ,mustard gas is very slowly decomposed by water1 owing to its very slight solubility4 ,the products are dihydroxyethylsulfide and hydrochloric acid3 7,cl,c,h,,ch7,s #b;,h,o 7,,hoch,,ch7,s #b;,h,cl ,certain sulfonated oils accelerate the rate of hydrolysis1 both by increasing the rate of solution and the solubility of the mustard gas4 ,alkalies also increase the rate of hydrolysis4 ,oxidizing agents destroy mustard gas4 ,this reaction was made use of practically in that solid bleaching powder was early introduced as a means of destroying mustard gas in the field4 7,fig4 #i47 ,chlorinating agents 7chlorine1 sulfur dichloride1 etc47 rapidly transform mustard gas into an inactive 7non-blistering7 substance4 ,sulfur dichloride was a valuable reagent in both laboratory and works in 8cleaning up0 mustard gas4 ,this reaction also explains why the early attempts to prepare mustard gas by the interaction of ethylene and sulfur dichloride were unsuccessful4 ,mustard gas is probably formed1 but is almost immediately chlorinated by the excess of sulfur dichloride4 ,sulfur chloride on the other hand has no effect on mustard gas4 ,chloramine-,t and ,dichloramine-,t 7the valuable therapeutic agents introduced by ,dakin and ,carrel for treatment of wounds7 also react with mustard gas4 ,for this reason they were advocated as treatment for mustard gas burns4 ,but as we will see later1 they were not altogether successful4 ,,detection ,at first the only method of detecting mustard gas was through the sense of smell4 ,it was then believed that concentrations which could not be detected in this way were harmless4 ,later this proved not to be the case1 and more delicate methods had to be devised4 ,in the laboratory and in the field these tests were not very satisfactory1 because most of them depended upon the presence of chlorine1 and the majority of the war gases contained chlorine or one of the other halogens4 ,the ,lantern ,test depended upon the accumulation of the halogen upon a copper gauze and the subsequent heating of the gauze in a ,bunsen flame4 ,this test could be made to detect one part of mustard gas in ten million parts of air4 ,another field detector devised by the ,chemical ,warfare ,service consisted in the use of selenious acid4 ,here again the lack of specificity is apparent1 for while certain halogen compounds did not give the test1 arsine and organic arsenicals gave a positive reaction and often in a shorter time than mustard gas4 ,illustration3 ,,fig4 #cf4--;,field ,detector for ,mustard ,gas4 ,the ,germans are said to have had plates covered with a yellow composition which had the property of turning black in the presence of mustard gas4 ,these plates were lowered into the bottom of recently captured trenches and if1 after a few minutes1 they turned black1 the presence of mustard gas was suspected4 ,it is also stated that the characteristic yellow paint on the olive of the mustard gas shell had the same composition1 and was useful in detecting leaky shell4 ,according to a deserter's statement1 however1 reliance upon this test resulted in casualties in several instances4 ,a white paint has also been reported which turned red in the presence of mustard gas4 ,this color change was not characteristic1 for tests made by our ,army showed that other oils 7aniline1 turpentine1 linseed7 were found to produce the same effect4 ,the ,chemical ,warfare ,service was able to develop an enamel and an oil paint which were very sensitive detectors of mustard gas4 ,both of these were yellow and became dark red in contact with mustard gas4 ,the change was practically instantaneous4 ,the enamel consisted of chrome yellow as pigment mixed with oil scarlet and another dye1 and a lacquer vehicle1 which is essentially a solution of nitrocellulose in amyl acetate4 ,one gallon of this enamel will cover #idf1ejj sq4 cm41 or a surface equivalent to a band #c cm4 wide on #ab1ejj seven cm4 shell4 ,the paint was composed of a mixture of #ej per cent raw linseed oil and #ej per cent ,japan drier1 with the above dye mixture added to the required consistency4 ,in contact with liquid mustard gas1 this changes to a deep crimson in #d seconds4 ,furthermore1 in contact with arsenicals1 this paint changes to a color varying from deep purple to dark green1 the color change being almost instantaneous and very sensitive1 even to the vapors of these compounds4 ,other substances have no effect upon the paint4 ,for field work1 however1 nothing was found equal to the trained nose1 and it is questionable if any of the mechanical means described will be used in the field4 ,,physiological ,,action ,one of the most interesting phases of mustard gas is its peculiar physiological action4 ,this has been studied extensively1 both as relates to the toxicity and to the skin or blistering effect4 ,,toxicity ,when one considers the high boiling point of mustard gas1 and its consequent low vapor pressure1 he is likely to conclude that such a substance would be of comparatively little value as a toxic or poison gas4 ,while it is true that an important part of the military value of mustard gas has been because of its vesicant properties1 the fact still remains that it is one of our most toxic war gases4 ,the following comparison with a few of the other gases indicates this3 --------------------------------------- ,mg4 per ,liter --------------------- ,mice ,dogs -------------------------------------- ,mustard gas #j4b #j4je ,phosgene #j4c ,hydrocyanic acid #j4b #j4a ,chloropicrin #a4e #j4h ,chlorine #c4j -------------------------------------- ,when an animal is exposed to the vapors of mustard gas in high concentration1 it subsequently shows a complexity of symptoms1 which may be divided into two classes3 7#a7 ,the local effects on the eyes1 skin and respiratory tract4 ,these are well recognized and consist mainly of conjunctivitis and superficial necrosis of the cornea2 hyperemia1 dema and later1 necrosis of the skin1 leading to a skin lesion of great chronicity2 and congestion and necrosis of the epithelial lining of the trachea and bronchi4 7#b7 ,the systemic effects due to the absorption of the substance into the blood stream1 and its distribution to the various tissues of the body4 ,the most striking observation about the symptoms of mustard gas poisoning is the latent period which elapses after exposure before any serious objective or subjective effects are noted4 ,the developments of the effects are then quite slow1 unless very high superlethal doses have been inhaled4 ,at first it was a very serious question whether or not the temporary blindness resulting from mustard gas would not be permanent4 ,later1 as the depth and seriousness of some of the body burns became well known1 it was a seven-day wonder that no permanent blindness occurred4 ,the reason seems to be largely a mechanical one4 ,the constant winking of the eyelids apparently washes the mustard gas off the eyeball and carries it away so that not enough remains to burn to the depth necessary to cause permanent blindness4 ,due to the very slight concentrations ordinarily encountered in the field1 resulting from a very slow rate of evaporation1 the death rate is very low1 probably under #a per cent among the ,americans gassed with mustard during the war4 ,if1 on the other hand1 the gas be widely and very finely dispersed by a heavy charge of explosive in the shell1 the gas is very deadly4 ,in such cases the injured breathe in minute particles of the liquid and thus get hundreds of times the amount of gas that would be inhaled as vapor4 ,this so-called 8high explosive mustard gas shell0 was a ,german development in the very last months of the war4 ,its effects were great enough to make it certain that in the future large numbers of these shell will be used4 ,the similarity of the symptoms and pathological effects after the inhalation of large amounts of the vapor and those following an injection of an olive oil or water solution of mustard gas led ,marshall and his associates to conclude that in high concentrations mustard gas is absorbed through the lungs4 ,a further bit of evidence consists in the isolation of the hydrolysis product1 dihydroxyethylsulfide1 in the urine of animals poisoned by inhalation of mustard gas4 ,this product is not toxic and is not responsible for the effects of mustard gas4 ,hydrochloric acid1 however1 does produce very definite effects upon the animal and may cause death4 ,from these facts ,marshall#ba has proposed the following mechanism of the action of mustard gas3 ,footnote #ba3 ,marshall1 ,lynch and ,smith1 ,j4 ,pharmacal1 #ab1 #bia-cja 7#aiah74 8,dichlorethylsulphide is very slightly soluble in water and very freely soluble in organic solvents1 or has a high lipoid solubility or partition coefficient4 ,it would1 therefore1 be expected to penetrate cells very readily4 ,its rapid powers of penetration are practically proven by its effects upon the skin4 ,having penetrated within the living cell1 it would undoubtedly hydrolyze4 ,the liberation of free hydrochloric acid within the cell would produce serious effects and might account for the actions of dichlorethylsulphide4 ,to summarize1 then1 the mechanism of the action of dichlorethylsulphide appears to be as follows3 8#a4 ,rapid penetration of the substance into the cell by virtue of its high lipoid solubility4 #b4 ,hydrolysis by the water within the cell1 to form hydrochloric acid and dihydroxyethylsulphide4 #c4 ,the destructive effect of hydrochloric acid upon some part or mechanism of the cell4 8,although hydrochloric acid does not penetrate cells readily and is easily neutralized by the buffer action of the fluids of the body1 we might expect by flooding the body with large quantities of acid to produce some of the characteristic effects of mustard gas4 ,stimulation of the respiratory center is a well known effect of acid4 ,convulsions and salivation may be produced by injection of hydrochloric acid and we have been able to produce slowing of the heart by rapid injection of this acid4 8,the delayed action of mustard gas might be explained by the formation of some compound with some constituent of the blood4 ,however1 blood taken from dogs which had been poisoned with mustard gas and were exhibiting typical symptoms at the time1 injected into normal dogs produced no effect4 ,serum treated in vitro with mustard gas and allowed to stand and then injected into a dog1 produced no effect4 ,the fluid which is formed in the vesicle and blebs produced by the application of mustard gas to the skin produces no mustard gas effects40 ,in studying the toxicity of mustard gas for dogs1 it was observed that a concentration of #j4ja mg4 per liter could be tolerated indefinitely4 ,if this value is considered as a threshold value1 and subtracted from the toxicity values for varying periods of time1 it is found that there is a definite relation between the toxic concentration and the time of exposure4 ,this is expressed by the formula 7,c - #j4ja7t ,k where ,c is the concentration observed for a given time t4 ,k has the approximate value of #a4g1 where t varies between #g4e and #dhj minutes4 ,,vesicant ,,action ,in addition to its toxicity mustard gas is highly important because of its peculiar irritating effect upon the skin4 ,its value is seen when we realize that one part in #ad1jjj1jjj is capable of causing conjunctivitis of the eye and that one part in #c1jjj1jjj and possibly one part in #e1jjj1jjj will cause a skin burn in a sensitive person on prolonged exposure4 ,according to ,warthin1 the lesions produced by mustard gas are those of a chemical1 not unlike hydrochloric acid1 but of much greater intensity4 ,the pathology of these lesions has been carefully studied and fully described by ,warthin and ,weller in their book on ,the ,pathology of ,mustard ,gas4 ,our observations will therefore be confined to certain striking features of the vesicant action of this substance4 ,,variation ,,in ,,susceptibility ,,of ,,the ,,skin ,every worker who has worked with mustard gas has noticed that some individuals are much more susceptible to skin burns from this substance than are others4 ,marshall made a study of #abhb men at ,edgewood ,arsenal1 using a #a per cent and a #j4ja per cent solution of mustard gas in paraffin oil4 ,a small drop of these solutions was applied to the skin of the forearm of the subject and the arm allowed to remain uncovered for about #aj minutes4 ,the presence or absence of a positive reaction is indicated by the appearance or absence of erythema #bd hours later4 ,the results were as follows3 #a #j4ja of ,total ,positive ,positive #c4c ,positive ,negative #ee4c ,negative ,negative #da4d ,the test made on #hd negroes gave the following results3 #a #j4ja of ,total ,positive ,positive #j4j ,positive ,negative #ae4j ,negative ,negative #gh4j ,questionable ,negative #g4j 8,it is seen from the above tables that negroes as a race1 have a much more resistant skin than white men4 ,no negro of the #hd examined reacted to the #j4a per cent solution1 and of course none would react to a more dilute one4 ,about #aj per cent of white men react to the #j4a per cent solution1 while #b to #c per cent react to the #j4ja per cent solution or are hypersensitive4 ,about #gh per cent of the negroes fail to react to the #a per cent solution1 while only #bj to #dj per cent of the white race do not show a reaction40 ,illustration3 ,,fig4 #cg4 ,the same individual may also show variations in susceptibility and this has also been studied by ,marshall4 8,the effect of exercise and sweating was investigated4 ,a number of individuals were given vapor burns 7one to five minutes exposure7 and then exercised until in a profuse sweat1 and then the same exposure to vapors made4 ,in all cases the burn produced after exercising was more severe4 ,sweating produced by having the subjects place their feet in hot water1 produced the same increase in susceptibility4 ,that the moisture on the skin produced by sweating is at least partly1 if not entirely1 responsible for the increased susceptibility1 was shown in the following way3 ,an area of the forearm was kept moist for a few minutes with wet cotton4 ,the sponge was then removed and two vapor tests made1 one over the moist area and one over normal1 dry skin4 ,in all cases the moist burn was the more severe1 in one1 producing a blister where the control did not4 8,the skin of different areas of the body is undoubtedly somewhat different in its susceptibility4 ,all our tests have been applied to the forearm4 ,the hands are considerably more resistant than the forearm4 ,tests made by the oil method on the forearm1 chest1 and back1 however1 indicate very little difference in susceptibility of these areas4 ,the skin in the neighborhood of old burns has been shown to be more susceptible4 8,in general1 the same individual does not become more susceptible to skin burns from continued exposure to the vapor4 ,the great number of tests which have been made on the same individual at different times and under the same conditions1 indicate a remarkable constancy in reaction4 ,a series of men who were tested at various times during a period of four months1 revealed slight changes from time to time in some of the men4 ,no man who originally reacted to only the #a per cent solution ever reacted to the #j4ja1 and likewise1 no man who originally reacted to the #j4ja ever failed to react to the #j4a per cent4 8,susceptibility of skin of animals4 ,the paraffin oil test was used on a number of animals and indicated that differences in susceptibility exist in different species and in different individuals of the same species40 ---------------------------------------- ------- ,percentage ,positive to ,species ,number -------------------------- ,tested #a ,per #j4a ,per #j4ja ,per ,cent ,cent ,cent ---------------------------------------- ----- ,horse #a #ajj #ajj #ajj ,dog #ia #hc #ce #j ,goat #aa #ee #cf #j ,rat #aj #cj #bj #j ,mouse #g #gj #ad #j ,rabbit #b #ajj #j #j ,guinea-pig #ab #cc #j #j ,monkey #i #bb #j #j ---------------------------------------- ----- ,the horse appears to be the most sensitive and the monkey and guinea-pig the most resistant species1 while the dog would seem to have a sensitivity as near man as any of the species studied4 ,no animal has yet been found which will give a blister from the application of mustard gas4 ,smith1 ,clowes and ,marshall#bb have studied the mechanism of absorption by the skin4 ,they find that it is quite evident that the mustard gas is at first rapidly taken up by some element on1 or adjacent to1 the surface of the skin and for two to three minutes it may be completely removed1 and for ten to fifteen minutes partially removed by prolonged washing ,with an organic solvent1 and to a lesser extent with soap and water4 ,footnote #bb3 ,j4 ,pharmacol41 #ac1 #a 7#aiai74 ,an interesting phenomenon is observed when the untreated normal skin of one subject is impressed for five minutes upon an area of skin of another subject1 which has been exposed previously to the vapors of mustard gas4 ,under these circumstances both donor and recipient may develop burns 7due to the transposition of the poison from one skin to another71 the intensity of which will vary according to the circumstances and the respective sensitiveness of the participants4 ,the degree of transposition is most strikingly observed in the intensity of the burn on the donor's arm4 ,if two similar exposures are made on the arm of a sensitive man1 and one of these burns is treated1 so to speak1 by contact for five minutes1 with the skin of a resistant man1 the treated burn will be markedly less severe than the control1 in some cases being entirely prevented4 ,if1 however1 the recipient is equally sensitive to or more sensitive than the donor1 the burns on the latter will exhibit far less difference4 ,both treatments may be effected at once1 using two recipients1 one more1 and the other less1 resistant than the donor4 ,in such a case the burn brought into contact with the more resistant skin will be the less severe4 ,similarly1 if a sensitive individual impresses his arm alternately against burns of the same concentration and exposure on a resistant and sensitive man1 the recipient receives a more severe burn from the sensitive than from the resistant man4 ,this indicates that the skin of a resistant individual exhibits a greater affinity or capacity for mustard gas than that of a sensitive one4 ,there is an actual partition of the gas between the two skins1 with an evident tendency to establish an equilibrium in which the larger portion of the gas will remain in that skin which possesses the greater capacity for it4 8,a tentative explanation of this phenomenon can be made as follows4 ,a three phase system is involved--the air over the skin surface constitutes the outer phase2 some fatty or keratinous elements of the skin1 the central phase2 and a cellular portion of the skin the inner phase4 ,the central phase is rich in lipoids and poor in water1 while the inner phase is rich in water and poor in lipoids4 ,after exposure to the vapors of dichloroethylsulphide the central phase is the absorbing agent and tends to establish equilibrium with the other two phases4 ,on account of the lipoid nature of the central phase no damage is produced here because the compound is not hydrolyzed4 ,on its passage from the central to the inner phase hydrolysis takes place within the cell and damage results when a sufficient concentration of hydrochloric acid is attained4 ,the outer phase is constantly being freed from vapor by diffusion and convection currents1 so more and more can evaporate from the central phase4 ,the susceptibility of an individual depends on the relative power of the central phase to hold the poison in an inactive form 7not hydrolyzed7 and prevent its entry into the inner phase at a sufficient velocity to result in the formation of a toxic concentration4 ,we do not attempt to localize the central or inner phases with any definite structure of the skin4 ,as mustard is known to penetrate the sebaceous ducts the fat here might form one phase and the epithelial lining another40 ,,tactical ,,use ,,of ,,mustard ,,gas ,as before stated1 mustard gas1 like most other materials used in war1 was discovered in peace4 ,indeed1 ,victor ,meyer in #ahhf worked out fairly completely its dangerous characteristics4 ,like phosgene and chlorine used before it1 the materials for its production were available in considerable quantities through the manufacture of components either for dyes or photographic chemicals4 ,mustard gas1 besides being highly poisonous1 has so many other important qualities as to have given it the designation during the war of the 8king of gases40 ,that broad distinction it still holds4 ,its introduction at ,ypres1 on the night of ,july #ab1 #aiag1 changed completely the whole aspect of gas warfare and to a considerable extent the whole aspect of warfare of every kind4 ,it is highly poisonous1 being in that respect one of the most useful of all war gases4 ,it produces no immediate discomfort4 ,it has a considerable delay action4 ,it burns the body inside or out1 wherever there is moisture4 ,eyes1 lungs and soft parts of the body are readily attacked4 ,it lingers for two or three days in the warmest weather1 while in cold1 damp weather it is dangerous for a week or ten days1 and in still colder weather may be dangerous for a month or longer whenever the weather warms up sufficient to volatilize the liquid4 ,it is only slowly destroyed in the earth1 making digging around shell holes dangerous for weeks and months and in some cases possibly a year or more4 ,the ,germans first used it simply to get casualties and interfere with or break up the threatened heavy attacks by the ,british on the ,ypres salient4 ,while not stopping the inauguration of these attacks in the fall of #aiag1 the ,german use of mustard gas was so effective as to delay the beginning of those attacks for at least two weeks and thus gain valuable time for the ,germans1 besides causing serious casualties with consequent partial break up of companies1 regiments and divisions in the ,english ,army4 ,the ,german used his mustard gas throughout the fall of #aiag and the winter of #aiag and #aiah1 as above stated1 to produce casualties1 to destroy morale1 to break up units1 and to interfere with operations generally4 ,during that time1 however1 he developed a more scientific use and when he started his big offensives in ,march1 ,april1 ,may and ,june1 #aiah1 he used mustard gas before the battles to cause losses1 break up units and destroy morale1 and also during the progress of battles to completely neutralize strong points which he felt he did not want to attempt to take by direct assault4 ,perhaps the most noted case of this was at ,armentires in ,april1 when he deluged the city to such an extent that mustard gas is said to have actually run in the streets4 ,so effective was this gassing that not only did the ,british have to withdraw from the city but the ,germans could not enter it for more than two weeks4 ,it1 however1 enabled the ,germans to take the city with practically no loss of life4 ,there were numerous other cases on a smaller scale where mustard gas was used in the same way4 ,on account of its persistence it has been generally referred to as a defensive gas and for that purpose it is incomparable4 ,the use of sufficient quantities of mustard gas will almost certainly stop the occupation of areas by the enemy and probably even stop his crossing them4 ,it also enables strong points which it is not desired to attack to be completely neutralized1--that is1 made so unhabitable that the area must be evacuated4 ,a use that was proposed toward the end of the war1 and that will undoubtedly be made of the gas in the future1 is to have it planted in drums in the ground and exploded when an enemy is attempting to advance4 ,this would be a highly economic way to distribute great quantities of the material at the moment and in the place most heeded4 ,it has even been proposed1 and this would seem entirely feasible1 to sprinkle certain of these areas with mustard gas by means of sprinklers attached to drums or even tanks mounted on trucks4 ,just before the ,armistice the ,german made another development in the use of mustard gas4 ,instead of the ordinary amount of explosive1 which only fairly opened up the shell and allowed the liquid to escape1 he filled nearly #cj per cent of the total space of the shell with high explosive4 ,this completely broke up the shell and distributed the greater part of the liquid mustard gas in the form of a fine spray4 ,this spray1 when breathed1 proved extremely deadly1 as might be expected from the fact that when in the form of minute particles one can draw into the lungs in a single breath one hundred times or more the amount that he would get of pure gas4 ,since mustard gas has such a delay action and is effective in such small concentrations it can be used very effectively in small calibre guns1 as the #ge mm4 or #c-;inch4 ,furthermore1 since it lasts for two or three days at the very least1 a small number of guns can keep a very large area neutralized with the gas4 ,with phosgene and similar non-persistent gases that volatilize almost completely upon the burst of the shell it is necessary to build up a high concentration immediately4 ,the exact opposite is true of mustard gas4 ,mustard gas can be fired very slowly with the certain knowledge that all shells fired at one moment will be effective when the next is fired1 though twelve hours or more may intervene between the first and last firing4 ,thus1 while with phosgene a large number of guns are needed for a gas attack1 with mustard gas the number can be reduced to one-tenth or even less4 ,mustard gas may be in the future and has been in the past used safely in hand grenades because of its very low vapor tension1 whereby the pressure at ordinary temperatures is exceedingly low4 ,this has an important bearing on cylinders and other containers for shipping mustard gas1 that is1 they need be only strong enough to be safe against handling and not to withstand the high pressure encountered with phosgene or chlorine cylinders4 ,in the future1 mustard gas will be used in all the ways above stated and undoubtedly in many more4 ,it can be fired in large quantities upon strong points to force their evacuation4 ,it can be fired on the flank of attacking armies for protection against counter-attacks4 ,it can be fired against the enemy artillery at all times to silence them and stop their firing4 ,it was thus used by the ,americans in the ,argonne against the enemy on the east bank of the ,meuse ,river1 this river separating the ,american and ,german armies4 ,it was extremely effective in stopping the enemy's artillery4 ,the high explosive mustard gas shell1 not only because of its persistency but because of its quick deadliness1 can be fired singly and be depended upon to do its work wherever there be men or animals4 ,one of the greatest uses will be by simple sprinkling from aeroplanes4 ,the future will see mustard gas used at nearly all times with a certain quantity of a powerful lachrymator or tear gas4 ,this is for the reasons1 as stated in the beginning1 that mustard gas causes no immediate discomfort and has no objectionable smell4 ,accordingly1 if the battle be critical1 men may continue to fight from four to eight hours in a mustard gas atmosphere without masks4 ,it is true the casualties will be high with a high death rate4 ,nevertheless1 this period of time might enable the artillery to do such effective work as to completely stop an attack4 ,if1 however1 at the instant mustard gas firing is begun a number of powerful lachrymatory shells are sent over1 the immediate wearing of the mask is forced4 ,the enemy is then subject to all the burning effects of mustard gas as well as the discomfort of long wearing of the mask4 ,it may confidently be expected that further developments in the use of mustard gas will be made1 as well as further developments in methods of throwing it upon the enemy or of bursting shell containing it in his midst4 ,,chapter ,x ,,arsenic ,,derivatives ,since arsenic is well known as an insecticide in the form of lead arsenate1 arsenic acid etc41 and in pharmacy1 specially in the form of salvarsan and neosalvarsan1 it is not surprising that the ,germans should have endeavored to discover an arsenic derivative which would be of value from the point of view of chemical warfare4 ,very early in the war persistent rumors were circulated that the ,germans were to use arsine4 ,these rumors led to the use of sodium permanganate in the canister1 but as far as is known1 no arsine was actually used4 ,another suggestion which received considerable attention from ,american workers was the use of arsenides1 which might decompose under the influence of the atmospheric moisture with the liberation of arsine4 ,calculation of the amount of arsenide necessary to establish a lethal concentration of arsine showed1 however1 that there was no possibility of using the material on the field4 ,because of the use of arsenic trichloride in the manufacture of organic arsenic compounds1 a method of preparation was developed from arsenic trioxide and sulfur chloride or hydrogen chloride4 ,it was also shown experimentally that the phosgene of the tail gas of phosgene plants might be converted into arsenic trichloride by reaction with arsenic trioxide4 ,charcoal is the catalyzer of this reaction4 ,arsenic trichloride is also of interest because it was one of the constituents of the mixture vincennite1 early used by the ,french4 ,this was a mixture of hydrocyanic acid1 stannic chloride1 arsenic trichloride and chloroform4 ,while extensively used at first1 it was gradually replaced by phosgene4 ,arsenic triflouride was also prepared by the action of sulfuric acid upon a mixture of calcium flouride and arsenic trioxide4 ,the compound is very easily decomposed by the moisture of the air1 and furthermore is not very toxic4 ,organic arsenic derivatives are the most important compounds from the military point of view4 ,the first substance used was diphylchloroarsine1 a white solid1 which readily penetrated the canister and caused sneezing4 ,this was used alone1 and in solution in phenyl dichloroarsine4 ,later methyl and ethyl dichloroarsines were introduced4 ,illustration3 ,,fig4 #ch4--;,apparatus for the ,manufacture of ,methyldichloroarsine4 ,,methyldichloroarsine ,the ,germans apparently used ethyldichloroarsine because they had no suitable method for the preparation of methyl dichloroarsine1 which is a more satisfactory material4 ,the ,chemical ,warfare ,service developed the following method of preparation of the methyl derivative4 ,sodium arsenite 7,na,as,o7 is prepared by dissolving arsenic trioxide in sodium hydroxide solution4 ,the action of methyl sulfate at #hej ,c4 gives disodium methyl arsenite1 ,na,,ch,as,o4 ,sulfur dioxide reduces the arsenite to methyl arsine oxide1 ,,ch,as,o1 which is then reacted with hydrochloric acid to give methyl dichloroarsine4 ,the final product is distilled from the mixture and condensed4 ,this material costs from two to two and a half dollars per pound for chemicals 7war prices74 ,methyldichloroarsine is a colorless liquid of powerful burning odor1 which boils at #acb ,c4 ,it is somewhat soluble in water and is soluble in organic solvents4 ,the specific gravity is #a4hch at #bj ,c4 ,the vapor pressure at #be was found to be #aj4hc mm4 mercury4 ,not only is the material toxic but it has remarkable vesicant properties1 comparing favorably with mustard gas in this respect4 ,ethyldichloroarsine1 which was used by the ,germans1 was prepared by the method given above1 using ethyl sulfate1 but the yield was never over #bj per cent4 ,in general this has properties similar to the methyl derivative4 ,,diphenylchloroarsine ,the best known of the arsenicals1 however1 is diphenylchloroarsine or sneezing gas4 ,although this is an old compound 7having been prepared by ,german chemists in #ahhe71 there was no method for its preparation on a large scale when1 first introduced into chemical warfare4 ,it was finally discovered that the interaction of triphenyl arsine with arsenic trichloride was fairly satisfactory and a plant was erected for its manufacture4 ,when pure1 diphenylchloroarsine is a colorless solid1 melting at #dd4 ,because of this1 it was always used in solution in a toxic gas or in a shell which contained a large amount of explosive so that on the opening of the shell the material would be finely divided and scattered over a wide territory4 ,its value lay in the fact that the fine particles readily penetrated the ordinary mask and caused the irritation of the nose and throat1 which resulted in sneezing4 ,this necessitated the perfection of special smoke filters to remove the particles1 after which the other toxic materials were removed by the absorbent in the canister4 ,it causes sneezing and severe burning sensations in the nose1 throat and lungs in concentrations as slight as #a part in #aj million4 ,in higher concentrations1 say #a in #bjj to #ejj thousand it causes severe vomiting4 ,while neither of these effects are dangerous or very lasting1 still higher concentrations are serious1 as in equal concentrations diphenylchloroarsine is more poisonous than phosgene4 ,various other arsenical chemicals were developed in the laboratory1 but with one or two exceptions they were not as valuable as diphenylchloroarsine and methyldichloroarsine and were therefore discarded4 ,,german ,,methods ,,for ,,manufacturing ,,arsenicals#bc ,,diphenylchloroarsine ,footnote #bc3 ,norris1 ,j4 ,ind4 ,eng4 ,chem41 #aa1 #hbe 7#aiai74 8,this substance 7,blue ,cross7 was a famous gas of the ,germans and was made in large quantities4 ,the method used by the ,germans was different from the one worked out by the ,allies1 and on account of the fact that the ,german method could be carried out without specially designed apparatus and required as raw materials substances readily obtainable1 it was probably preferable4 ,it is doubtful1 however1 whether the ,allies would have made this gas1 for as the result of its use no fatalities were reported4 ,the ,german process consisted in preparing phenylarsenic acid by condensing benzene diazonium chloride with sodium arsenite4 ,the acid was next reduced by sulfur dioxide to phenylarsenous acid1 which was1 in turn1 condensed with the diazonium compound to form diphenylarsenic acid4 ,this acid was reduced to diphenylarsenous oxide1 which with hydrochloric acid yielded diphenylchloroarsine4 ,the chemical equations for the reactions will make clearer the steps involved4 ,c,h,n,cl ,na,as,o ,c,h,as,o,na ,na,cl ,n ,c,h,as,o,na #b;,h,cl ,c,h,as,o,h #b,na,cl ,c,h,as,o,h ,,so,h,o ,c,h,as,o,h ,h,,so ,c,h,n,cl ,c,h,as,o,na 7,c,h7,as,o,na ,na,cl ,n 7,c,h7,as,o,na ,h,cl 7,c,h7,as,o,h ,na,cl #b7;,c,h7,as,o,h #b,,so ,h,o 7,c,h7,as,o #b;,h,,so 7,c,h7,as,o #b;,h,cl #b7;,c,h7,as,cl ,h,o4 8,the entire process was carried out at ,hchst4 ,the method used at ,hchst was as follows3 ,in preparing the diazonium solution1 #c kg4-mols of aniline were dissolved in #cjjj liters of water and the theoretical quantity of hydrochloric acid4 ,the temperature of the solution was reduced to between #j and #e and the theoretical amount of sodium nitrite added4 ,the reaction was carried out in a wooden tank of the usual form for the preparation of diazonium compounds4 ,a solution of sodium arsenite was prepared which contained #bj per cent excess of oxide over that required to react with the aniline used4 ,the arsenous oxide was dissolved in sodium carbonate1 care being taken to have enough of the alkali present to neutralize all of the acid present in the solution of the diazonium salt4 ,to the solution of the sodium arsenite were added #bj kg4 of copper sulfate dissolved in water1 this being the amount required when #c kg4-mols of aniline are used4 ,the solution of the diazonium compound was allowed to flow slowly into the solution of the arsenite while the temperature was maintained at #ae4 ,the mixture was constantly stirred during the addition which requires about #c hrs4 ,after the reaction was complete1 the material was passed through a filter press in order to remove the coupling agent and the tar which had been formed4 ,hydrochloric acid was next added to the clear solution to precipitate phenylarsenic acid1 the last portions of which were removed by the addition of salt4 8,the phenylarsenic acid was next reduced to phenylarsenous acid by means of a solution of sodium bisulfite1 about #bj per cent excess of the latter over the theoretical amount being used4 ,for #ajj parts of arsenic acid1 #djj parts of solution were used4 ,the reaction was carried out in a wooden vessel and the mixture stirred during the entire operation4 ,a temperature of #hj was maintained by means of a steam coil4 ,phenylarsenous acid separated as an oil4 ,the aqueous solution was decanted from the oil1 which was dissolved in a solution of sodium hydroxide1 #dj ,b4 ,the solution of the sodium salt of phenylarsenous acid was treated with water so that the resulting solution had a volume of #f cu4 m4 when #c kg4-mols of the salt were present4 ,ice was next added to reduce the temperature to #ae and a solution of benzene diazonium chloride1 prepared in the manner described for the first operation1 was slowly added4 ,after the coupling1 diphenylarsenic acid was precipitated by means of hydrochloric acid4 ,the acid was removed by means of a filter press and dissolved in hydrochloric acid1 #bj ,b4 ,for one part of diphenylarsenic acid1 #c parts of hydrochloric acid were used4 ,into this solution was passed #e per cent excess of sulfur dioxide over that required for the reduction4 ,the sulfur dioxide used was obtained from cylinders which contained it in liquid condition4 8,the reduction was carried out in an iron tank lined with tiles and a temperature of #hj was maintained4 ,about #h hrs4 were required for the reaction4 ,the diphenylarsenic acid on reduction by the sulfur dioxide was converted into diphenylarsenous oxide which1 in the presence of the hydrochloric acid1 was converted into diphenylchloroarsine1 which separated as an oil4 ,the oil was next removed and heated in the best vacuum obtainable until it was dry and free from hydrochloric acid4 ,the compound melted at #cd4 ,it was placed in iron tanks for shipment4 ,the yield of diphenylchloroarsine calculated from the aniline used was from #be to #cj per cent of the theoretical4 ,no marked trouble was observed in handling the materials and no serious poisoning cases were reported4 ,,diphenylcyanoarsine 8,this compound was prepared by treating diphenylchloroarsine with a saturated aqueous solution of potassium or sodium cyanide4 7,c,h7,as,cl ,na,c,n 7,c,h7,as,c,n ,na,cl4 ,five per cent excess of the alkaline cyanide was used4 ,the reaction was carried out at #fj with vigorous stirring4 ,the yield was nearly theoretical4 ,,ethyldichloroarsine 8,this compound was prepared at ,hchst from ethylarsenous oxide which was obtained from the ,badische ,anilin und ,soda ,fabrik4 8,,preparation ,,of ,,ethylarsenous ,,oxide--,the compound was prepared by treating sodium arsenite with ethyl chloride under pressure4 ,the resulting sodium salt of ethylarsenic acid was converted into the free acid and reduced by sulfur dioxide4 ,the ethylarsenous acid formed in this way lost water and was thereby transformed into ethylarsenous oxide4 ,the reactions involved are as follows3 ,c,h,cl ,na,as,o ,c,h,as,o,na ,na,cl ,c,h,as,o,na #b ,h,cl ,c,h,as,o,h #b ,na,cl ,c,h,as,o,h ,,so ,h,o ,c,h,as,o,h ,h,,so #b;,c,h,as,o,h 7,c,h,as7,o ,h,o4 8,the ethyl chloride used in the preparation was in part made in this factory1 and in part received from other sources4 ,as ethyl chloride is an important product used in peace time1 it is not1 therefore1 essentially a war product and its preparation was not described4 8,in preparing the solution of sodium arsenite1 one molecular weight of arsenous oxide was dissolved in a solution containing #h molecular weights of sodium hydroxide4 ,the solution of the base was prepared from a #ej per cent solution of sodium hydroxide to which enough solid alkali was added to make the solution a #ee per cent one4 ,in one operation #ffj kg4 of arsenous oxide were used4 ,for #ajj parts of arsenous oxide1 #acj parts of ethyl chloride were used1 this being the theoretical amount of the latter4 8,the reaction was carried out in a steel autoclave of about #cjj liters capacity4 ,the temperature was maintained at between #ij and #ie4 ,the ethyl chloride was pumped in1 in #c or #d portions1 and the pressure in the autoclave was kept at from #aj to #ae atmospheres4 ,the several portions of ethyl chloride were introduced at intervals of about #a hrs4 ,during the entire reaction1 the contents of the autoclave were vigorously stirred4 ,after all the ethyl chloride had been added1 the material was stirred from #ab to #af hrs41 at the end of which time the pressure had fallen to about #f atmospheres4 ,the excess of ethyl chloride and the alcohol formed in the reaction were next distilled off4 ,at this point a sample of the solution was drawn off for testing4 ,this was done by determining the amount of arsenite present in the solution4 ,if not more than #bj per cent of sodium arsenite had not reacted1 the preparation was considered satisfactory4 ,water was then added to the contents of the autoclave in sufficient amount to dissolve the solid material4 ,the product was next drawn over into a tank and neutralized with sulfuric acid4 ,it was then treated with sulfur dioxide gas until there was an excess of the latter present4 ,the mixture was then heated to about #gj when the ethylarsenous oxide precipitated as a heavy oil4 ,this was readily separated and shipped without further purification4 ,the yield of ethylarsenous oxide1 from arsenic oxide1 was from #hj to #hb per cent of a product which contained about #ic per cent of pure ethylarsenous oxide4 8,,preparation ,,of ,,ethyldichloroarsine--,the compound was prepared by treating ethylarsenous oxide with hydrochloric acid4 ,the reaction is as follows3 ,c,h,as,o #b;,h,cl ,c,h,as,cl ,h,o4 ,the operation was carried out in an iron kettle lined with lead1 which was cooled externally by means of water and which was furnished with a lead covered stirrer4 ,to the kettle1 which contained from #ejj to #ajjj kg4 of hydrochloric acid left over from the previous operation1 were added #djjj kg4 of ethylarsenous oxide4 ,the gaseous hydrochloric acid was next led in4 ,the kettle was kept under slightly diminished pressure in order to assist in the introduction of hydrochloric acid4 ,the temperature during the reaction must not rise above #ie4 ,when the hydrochloric acid was no longer absorbed and was contained in appreciable quantities in the issuing gases1 the operation was stopped4 ,this usually occurred at the end of from one to two days4 ,the product of the reaction was drawn off by means of a water pump and heated in a vacuum until drops of oil passed over4 ,the residue was passed over to a measuring tank and finally to tank-wagons made of iron4 ,the yield of the product was practically the theoretical4 ,on account of the volatility of the compound and its poisonous character1 the apparatus in which it was prepared was surrounded by an octagonal box1 the sides of which were fitted with glass windows4 ,through this chamber a constant supply of air was drawn4 ,this was led into a chimney where the poisonous vapors were burned4 ,the gases given off during the distillation of the product were passed through a water scrubber40 8,,lewisite0 ,the one arsenical which created the most discussion during the ,war1 and about which many wild stories were circulated1 was 8,lewisite10 or as the press called it1 8,methyl40 ,its discovery and perfection illustrate the possibilities of research as applied to ,chemical ,warfare1 and points to the need of a permanent organization to carry on such work when the pressure of the situation does not demand such immediate results4 ,the reaction of ethylene and sulfur chloride1 which led to the preparation of mustard gas1 naturally led the organic chemists to investigate the reaction of this gas and other unsaturated hydrocarbons1 such as acetylene1 upon other inorganic chlorides1 such as arsenic1 antimony and tin4 ,there was little absorption of the gas1 either at atmospheric or higher pressures1 and upon distilling the reaction product1 most of the gas was evolved1 showing that no chemical reaction had taken place4 ,however1 when a catalyser1 in the form of aluminium chloride1 was added1 ,capt4 ,lewis found that there was a vigorous reaction and that a highly vesicant product was formed4 ,the possibilities of this compound were immediately recognized and the greatest secrecy was maintained regarding all the details of preparation and of the properties of this new product4 ,at the close of the ,war1 this was considered one of the most valuable of ,chemical ,warfare secrets1 and therefore publication of the reactions involved were withheld4 ,unfortunately or otherwise1 the ,british later decided to release the material for publication1 and details may be found in an article by ,green and ,price in the ,journal of the ,chemical ,society for ,april1 #aiba4 ,it must be emphasized that the credit for this work belongs1 not to these authors1 but to ,capt4 ,w4 ,lee ,lewis and the men who worked with him at the ,catholic ,university branch of the ,american ,university ,division 7the ,research ,division of the ,c4 ,w4 ,s474 ,on a laboratory scale1 acetylene is bubbled through a mixture of #ddj grams of anhydrous arsenic trichloride and #cjj grams of anhydrous aluminium chloride4 ,absorption is rapid and much heat is developed4 ,after six hours1 about #ajj grams of acetylene is absorbed4 ,the reaction product was dark colored and viscid1 and had developed a very powerful odor1 suggestive of pelargoniums4 ,attempts to distill this product always led to violent explosions4 7,it may be stated here that ,lewis was able to perfect a method of distillation and separation of the products formed1 so that pure materials could be obtained1 with little or no danger of explosion47 ,the ,english chemists therefore decomposed the product with ice-cold hydrochloric acid solution of constant boiling point 7this suggestion was the result of work done by ,lewis74 ,the resulting oil was then distilled in a current of vapor obtained from constant boiling hydrochloric acid and finally fractionated into three parts4 ,the first product obtained consist in the addition of one acetylene to the arsenic trichloride molecule1 and1 chemically1 is chlorovinyldichloroarsine1 ,c,h,cl3 ,,ch,as,cl1 a colorless or faintly yellow liquid1 boiling at #ic at a pressure of #bf mm4 ,a small quantity1 even in very dilute solution1 applied to the skin causes painful blistering1 its virulence in this respect approaching that of mustard gas4 ,it is more valuable than mustard gas1 however1 in that it is absorbed through the skin1 and as stated on page #bc1 three drops1 placed on the abdomen of a rat1 will cause death in from one to three hours4 ,it is also a very powerful respiratory irritant1 the mucous membrane of the nose being attacked and violent sneezing induced4 ,more prolonged exposure leads to severe pain in the throat and chest4 ,the second fraction 71 -dichlorodivinylchloroarsine7 is a product resulting from the addition of two acetylene molecules to one arsenic trichloride1 and boils at #acj to #acc at #bf mm4 ,it is much less powerful as a vesicant than chlorovinyldichloroarsine1 but its irritant properties on the respiratory system are much more intense4 ,the third fraction1 1 1 -trichlorotrivinylarsine1 7,c,h,cl3 ,,ch7,as1 is a colorless liquid1 boiling at #aea to #aee at #bh mm41 which solidifies at #c to #d4 ,it is neither a strong vesicating agent nor a powerful respiratory irritant4 ,at the same time1 its odor is pungent and most unpleasant and it induces violent sneezing4 ,,chapter ,,xi ,,carbon ,,monoxide ,carbon monoxide1 because of its cheapness1 accessibility and ease of manufacture1 has been frequently considered as a possible war gas4 ,actually1 it appears never to have been used intentionally for such purposes4 ,there are several reasons for this4 ,first1 its temperature of liquefaction at atmospheric pressure is -#aci ,c4 ,this means too high a pressure in the bomb or shell at ordinary temperatures4 ,secondly1 the weight of carbon monoxide is only slightly less than that of air1 which keeps it from rolling into depressions1 dugouts and trenches1 as in the case of ordinary gases1 and also permits of its rather rapid rise and dissipation into the surrounding atmosphere4 ,a third reason is its comparatively low toxic value1 which is only about one-fifth that of phosgene4 ,however1 as it can be breathed without any discomfort1 and as it has some delay action1 its lack of poisonous properties would not seriously militate against its use were it not for the other reasons given4 ,it is1 nevertheless1 a source of serious danger both in marine and land warfare4 ,defective ventilation in the boiler rooms of ships and fires below decks1 both in and out of action1 are especially dangerous because of the carbon monoxide which is produced4 ,in one of the naval engagements between the ,germans and the ,english1 defective high explosive shell1 after penetrating into enclosed portions of the ship1 evolved large quantities of carbon monoxide and thus killed some hundreds of men4 ,on shore1 machine gun fire in enclosed spaces1 such as pill boxes1 and in tanks1 liberates relatively large quantities of carbon monoxide4 ,similarly1 in mining and sapping work1 the carbon monoxide liberated by the detonation of high explosives constitutes one of the most serious of the difficulties connected with this work and necessitated elaborate equipment and extensive military training in mine rescue work4 ,the removal of carbon monoxide from the air is difficult because of its physical and chemical properties4 ,its low boiling point and critical temperature makes adequate adsorption at ordinary temperatures by the use of an active absorbent out of the question4 ,its known insolubility in all solvents similarly precludes its removal by physical absorption4 ,after extensive investigation two absorbents have been found4#bd ,the first of these consists in a mixture of iodine pentoxide and fuming sulfuric acid1 with pumice stone as a carrier4 ,using a layer #aj cm4 deep and passing a #a per cent carbon monoxide air mixture at the rate of #ejj cc4 per minute per sq4 cm4 cross section1 a #ajj-ij removal of the gas could be secured for two hours at room temperature and almost as long at #j ,c4 ,the reaction is not instantaneous1 and a brief induction period always occurs4 ,this may be reduced to a minimum by the addition of a little iodine to the original mixture4 ,footnote #bd3 ,complete details of this work may be found in ,j4 ,ind4 ,eng4 ,chem41 #ab1 #bac 7#aibj74 ,the sulfur trioxide given off is very irritating to the lungs1 but by the use of a layer of active charcoal beyond the carbon monoxide absorbent1 this disadvantage was almost completely eliminated4 ,however1 sulfur dioxide is slowly formed as a result of this adsorption and after prolonged standing or long-continued use of the canister at a high rate of gas flow gives serious trouble4 ,considerable heat is given off in the reaction and a cooling attachment was required4 ,the most satisfactory device was a metal box filled with fused sodium thiosulfate pentahydrate1 which absorbed a very considerable amount of the heat4 ,still a further disadvantage was the fact that the adsorbents became spent by use1 even in the absence of carbon monoxide1 since it absorbed enough moisture from the air of average humidity in several hours1 to destroy its activity4 ,the difficulties mentioned were so troublesome that this absorbent was finally supplanted by the more satisfactory oxide absorbent described below4 ,illustration3 ,,fig4 #ci4--;,diagram of ,carbon ,monoxide ,canister1 ,,cma#c4 ,the metallic oxide mixture was the direct result of an observation that specially precipitated copper oxide with #a per cent silver oxide was an efficient catalyst for the oxidation of arsine by oxygen4 ,after a study of various oxide mixtures1 it was found that a mixture of manganese dioxide and silver oxide1 or a three component system containing cobaltic oxide1 manganese dioxide and silver oxide in the proportion of #bj3cd3df catalyzed the reaction of carbon monoxide at room temperature4 ,the studies were extended and it was soon found that the best catalysts contained active manganese dioxide as the chief constituent4 ,this was prepared by the reaction between potassium permanganate and anhydrous manganese sulfate in the presence of fairly concentrated sulfuric acid4 ,it also developed that the minimum silver oxide content decreased progressively as the number of components increased from #b to #d4 ,the standard catalyst 7,hopcalite7 finally adopted for production consisted of #ej per cent manganese dioxide1 #cj per cent copper oxide1 #ae per cent cobaltic oxide and #e per cent silver oxide4 ,the mixture was prepared by precipitating and washing the first three oxides separately1 and then precipitating the silver oxide in the mixed sludge4 ,after washing1 this sludge was run through a filter press1 kneaded in a machine1 the cake dried and ground to size4 ,while it is not difficult to obtain a product which is catalytically active1 it requires a vigorous control of all the conditions and operations to assure a product at once active1 hard1 dense and resistant as possible to the deleterious action of water vapor4 ,illustration3 ,,fig4 #dj4--,tanks and ,press for ,small ,scale ,manufacture of ,carbon ,monoxide ,absorbent4 ,hopcalite acts catalytically and therefore only a layer sufficiently deep to insure close contact of all the air with the catalyst is needed4 ,one and a half inches 7#caj gm47 were found ample for this purpose4 ,the normal activity of ,hopcalite requires a dry gas mixture4 ,this was secured by placing a three-inch layer of dry granular calcium chloride at the inlet side of the canister4 ,because of the evolution of heat1 a cooling arrangement was also used in the ,hopcalite canisters4 ,the life of this canister was the same irrespective of whether its use was continuous or intermittent4 ,the higher the temperature the longer the life because ,hopcalite is less sensitive to water vapors at higher temperatures4 ,since1 if the effluent air was sufficiently dried1 the ,hopcalite should function indefinitely against any concentration of carbon monoxide1 the life of the canister is limited solely by the life of the drier4 ,therefore the net gain in weight is a sure criterion of its condition4 ,after many tests it was determined that any canister which had gained more than #ce grams above its original weight should be withdrawn4 ,the canisters1 at the time of breakdown1 showed a gain in weight varying between #db and #ga grams1 with a average of #ed grams4 ,it is really1 therefore1 the actual humidity of the air in which the canister is used that determines its life4 ,illustration3 ,,fig4 #da4--,navy ,head ,mask and ,canister4 ,,chapter ,,xii ,,development ,,of ,,the ,,gas ,,mask ,while in ordinary warfare the best defense against any implement of war is a vigorous offense with the same weapon1 ,chemical ,warfare presents a new point of view4 ,here it is very important to make use of all defensive measures against attack4 ,because of the nature of the materials used1 it has been found possible to furnish1 not only general protection1 but also continuous protection during the time the gas is present4 ,the first consideration in the protection of troops against a gas attack is the provision of an efficient individual protective appliance for each soldier4 ,the gas attack of ,april #bb1 #aiae found the ,allies entirely unprepared and unprotected against poisonous gas4 ,while a few of the men had the presence of mind to protect themselves by covering their faces with wet cloths1 the majority of them became casualties4 ,immediately steps were taken to improvise protective devices among which were gags1 made with rags soaked in water or washing soda solution1 handkerchiefs filled with moist earth1 etc4 ,one suggestion was to use bottles with the bottom knocked off and filled with moist earth4 ,the breath was to be taken in through the bottle and let out through the nose2 but as bottles were scarce and few of them survived the attempt to get the bottom broken off1 the idea was of no value4 ,the first masks were made by the women of ,england in response to the appeal by ,lord ,kitchener2 they consisted of cotton wool wrapped in muslin or veiling and were to be kept moist with water1 soda solution or hypo4 ,,english ,,masks ,the ,black ,veiling ,respirator4 ,the first form of the ,english mask is known as the ,black ,veiling respirator and consisted of cotton waste enclosed in a length of black veiling4 ,the waste was soaked in a solution of3 ,sodium thiosulphate #aj lbs4 ,washing soda #b4e lbs4 ,glycerine #b lbs4 ,water #b gals4 ,the glycerine was put in to keep the respirator moist1 thus obviating the need for dipping before use4 ,illustration3 ,,fig4 #db4--;,early ,gas ,protection4 ,the respirator was adjusted over the mouth and nose1 the cotton waste being molded to the shape of the face and the upper edge of the veiling pulled up so as to protect the eyes4 ,these respirators were used in the attacks of ,may #ajth and #abth1 #aiae and were reasonably efficient against the low concentration of chlorine then used2 they were difficult to fit exactly to the face1 which resulted in leakage4 ,the cotton waste often became lumpy and had to be shredded out or discarded4 ,the ,hypo ,helmet4 ,the next development of the ,british protection was the so-called ,hypo helmet4 ,this is said to have resulted from the suggestion of a ,canadian sergeant that he had seen a ,german pulling a bag over his head during a gas attack4 ,it consisted of a flannel bag soaked in the same solution as was used for the veiling respirator and was fitted with a pane of mica as a window4 ,the helmet was tucked down inside the jacket which was then buttoned up tightly around the neck4 ,as may be seen from ,figure #dc1 this would not prove very satisfactory with the ,american type of uniform4 ,this helmet had many advantages over the veiling respirator but the window often became cracked or broken from the rough treatment in the trenches4 ,later the mica was replaced by celluloid and still later by glass eyepieces set in metal rings4 ,these were very effective against chlorine in the field4 ,the ,p and ,,ph ,helmets4 ,during the summer of #aiae it became evident that phosgene-chlorine mixtures would be used in gas attacks and it was therefore necessary to provide protection against this4 ,the hypo helmet1 which offered no protection against phosgene1 was soaked in an alkaline solution of sodium phenolate 7carbolic acid7 containing glycerine1 and with this new form of impregnation was called the ,p helmet4 ,it protected against #cjj parts of phosgene in a million of air4 ,since this solution attacks flannel1 two layers of flannelette were used4 ,the helmet was further improved by the addition of an expiratory valve1 partly to prevent the man from breathing any of his own breath over again and partly to prevent the deterioration of the alkali of the mask by the carbon dioxide of the expired air4 ,the protection was later further increased by the addition of hexamethylenetetramine1 and this mask is known as the ,,ph helmet4 ,this increased the protection to #a1jjj p4p4m4 ,the early types of helmet offered no protection against lachrymators4 ,for this purpose goggles were used1 the later types of which had glass eyepieces and were fitted around the eyes by means of rubber sponge4 ,while intended for use only after a lachrymatory bombardment1 the troops frequently used them during and after an ordinary gas attack when the mask should have been worn4 ,consequently they were withdrawn4 ,the ,,ph helmet was unsatisfactory because of the following reasons3 7#a7 ,it was warm and stuffy in summer2 7#b7 ,it deteriorated upon exposure to air2 7#c7 ,it was incapable of further development2 7#d7 ,it had a peculiar odor and1 when wet1 frequently burned the foreheads of the men2 7#e7 ,it offered practically no protection against lachrymators4 ,illustration3 ,,fig4 #dc4--,method of ,wearing the ,p4 ,h4 ,helmet4 ,illustration3 ,,fig4 #dd4--;,early ,type of ,standard 7,british7 ,box ,respirator 7,s4 ,b4 ,r47 ,box ,respirator4 ,the increasing concentration of gas from cylinder attacks and the introduction of shell1 with such gases as chloropicrin and superpalite1 led1 early in #aiaf1 to very definite and constructive efforts on the part of the ,british to increase the protection offered by the mask4 ,the result was a 8polyvalent0 respirator of the canister type 7the ,standard ,box ,respirator74 ,this mask was probably the result of experience with oxygen apparatus in mine rescue work4 ,the lines on which this canister was modeled involved the use of a canister filled with highly sensitive absorbent charcoal mixed with or alternating in layers with oxidizing granules of alkaline permanganate4 ,it was the result of innumerable experiments1 partly conducted in ,france but mostly in ,england under the direction of the late ,lieut4 ,col4 ,harrison1 who was almost entirely responsible for the wonderful production of this respirator4 ,the respirator 7,figure #dd7 consisted of the canister mentioned above1 which is attached by a flexible tube to a facepiece or mask4 ,the facepiece is made of rubberized fabric and fits the face so that there is little or no leakage4 ,this is secured by means of tape and elastic bands which fit over the head4 ,the nose is closed by means of clips1 which are wire springs with rubbered jaws covered with gauze 7,fig4 #de74 ,breathing is done through a mouthpiece of rubber2 the teeth close on the rubber tabs and the rubber flange lies between the teeth and the lips4 ,the expired air finds exit through a rubber flutter valve in an angle tube just outside the mask4 ,this arrangement furnishes a double line of protection2 if the face piece is punctured or torn1 gas-containing air cannot be breathed as long as the noseclip and mouthpiece are in position4 ,the early ,english canister was packed with #fge cc4 of #h-ad mesh war gas mixture1 #dj per cent of which was wood charcoal and #fj per cent reddish brown soda-lime granules4 ,the metal dome at the bottom of the can was covered with a thin film of cotton4 ,at two-thirds of the distance to the top was placed a paper filter and a heavy wire screen which differs from our heavy screen in that it is more loosely woven4 ,the mixture was covered with a cotton filter pad and a wire screen1 over which was placed the wire spring4 ,the use of this mask ensures that all the air breathed must enter the lungs through the canister4 ,this air passage is entirely independent of leaks in the facepiece1 due either to a poor fit about the face or to actual leakage 7from a cut or tear7 of the fabric itself4 ,the facepiece is readily cleared of poison gases which may leak in4 ,this is accomplished by taking a full inspiration1 releasing the noseclip1 and exhaling through the nose1 which forces the air out around the edges of the facepiece4 ,on the other hand1 this type of mask possesses a number of very obvious disadvantages1 particularly from a military point of view3 ,the extreme discomfort of the facepiece4 ,this discomfort arises from a number of causes certain of which are inherent in this type of mask1 among them being3 7a7 the noseclip1 7b7 the mouthpiece1 and 7c7 the lack of ventilation within the facepiece chamber4 ,aside from the actual physical discomfort of the noseclip and mouthpiece1 which becomes intense after long periods of wearing1 this combination forces upon the wearer an unnatural method of respiration to which it is not only difficult to become accustomed1 but which also causes extreme dryness of the throat4 ,the mouthpiece greatly increases salivation and as swallowing is rather more difficult with the nose closed1 this adds another extremely objectionable feature4 ,illustration3 ,,fig4 #de4--;,interior of ,s4 ,b4 ,r41 ,showing ,cotton ,wrapped ,noseclips4 ,illustration3 ,,fig4 #df4--;,french ,m-#b ,mask4 ,the lack of ventilation in the facepiece chamber entraps the heat radiating from the face and retains the moisture which is constantly evaporating from the skin4 ,this moisture condenses on the eyepieces1 and even if cleared away by the use of a so-called anti-dimming paste1 usually makes vision nearly impossible4 ,,french ,,masks ,m-#b ,mask4 ,the early protection of the ,french ,army was obtained from a mask of the type ,m-#b 7,fig4 #df74 ,this mask consists of a number of layers of muslin impregnated with various absorbent chemicals4 ,a typical mask was made up of #bj layers of cheesecloth impregnated with ,greasene and #bj layers impregnated with ,complexene4 ,these solutions were made up as follows3 ,complexene3 #ci4j lbs4 ,hexamethylenetetramine #cg4e lbs4 ,glycerine #bg4e lbs4 ,nickel sulfate 7,ni,s,o4#g ,h,o7 #aa4h lbs4 ,sodium carbonate 7,na,,co7 ,water ,greasene3 #ajg4j lbs4 ,castor oil #ha4j lbs4 ,alcohol 7#ie7 #aj4g lbs4 ,glycerine 7#ij7 #c4a lbs4 ,sodium hydroxide 7,na,o,h7 ,this mask fits the face tightly and as a consequence the inhaled air can be obtained only by drawing it through the pores of the impregnated fabric4 ,there is no outlet valve4 ,the exhaled air makes its escape through the fabric4 ,the eyepieces are made of a special non-dimming celluloid4 ,the mask is protected from rain by a flap of weather proof fabric1 which also protects the absorbent chemicals from deterioration4 ,at the beginning of the war the ,united ,states experimented considerably with the ,french mask4 ,several modifications of the impregnating solutions were suggested1 as well as methods of application4 ,one of these was to separate the components of the complexene solution and impregnate two separate layers of cloth2 this would make a three-layer mask4 ,in view of the phosgene which was in use at that time1 the following arrangement was suggested3 #bj layers of hexamethylenetetramine1 #aj layers of nickel sulfate-sodium carbonate1 #aj layers of greasene4 ,this arrangement was more effective than the original ,french mask and offered the following protection when tested against the following gases 7concentration #a to #a1jjj1 rate #cj liters per minute73 ,phosgene #fe minutes ,hydrocyanic acid #fj minutes ,chlorine #fj minutes ,illustration3 ,,fig4 #dg4--;,interior ,view of ,m-#b ,mask4 ,illustration3 ,,fig4 #dh4--;,french ,artillery ,mask1 ,tissot ,type4 ,tissot ,mask4 ,the ,french deserve great credit for their development of the ,tissot type mask4 ,this was first issued to artillerymen1 stretcher bearers1 and certain other special classes of soldiers to furnish them with protection and yet enable them to work with greater efficiency because of the decrease in resistance to breathing4 ,the mask 7,fig4 #dh7 resembles the ,british box respirator in that it consists of a canister and rubber facepiece1 but differs in that the mouthpiece and noseclip are lacking4 ,the inhaled air enters the mask from two tubes which open directly under the eyepieces and allow the air to sweep across them4 ,this removes1 by evaporation1 the condensed moisture of the breath from the eyepieces1 which otherwise would obstruct the vision4 ,the circulation of the fresh air in the mask also removes and dilutes lachrymatory gases which may filter through the mask4 ,the exhaled air escapes through a simple outlet valve4 ,this type of mask is advantageous because3 7#a7 ,the facepiece is tight and comfortable4 7#b7 ,the eyepieces do not become dimmed4 7#c7 ,there is no difficulty in speaking4 7#d7 ,salivation is eliminated because of the absence of the mouthpiece4 7#e7 ,it is generally more comfortable than the box respirator4 ,this mask1 however1 was made of thin rubber of great flexibility which1 while affording a perfect fit1 did not possess sufficient durability to recommend it as the sole defense of the wearer4 ,the canister is markedly different from all other canisters described in this chapter in that a highly hygroscopic chemical absorbent is used4 ,an approximate determination showed about #gj per cent sodium hydroxide4 ,the use of caustic soda in the canister is made possible by the intermixing of steel wool with the granules of caustic4 ,a layer of absorbent having the appearance of vegetable charcoal is placed at the top of the canister4 ,the canister has the shape of a rectangular prism #h #f #b inches2 and1 owing to the use of steel wool1 is large in proportion to the weight of absorbent contained4 ,valves are supplied which prevent exhalation through the canister4 ,when not in use the opening in the bottom of the canister is plugged with a rubber stopper to protect the absorbents from moisture4 ,the canister is carried against the body and is connected to the facepiece with a flexible rubber-fabric tube4 ,a4 ,r4 ,s4 ,mask 7,appareil ,respiratoire ,special74 ,one of the latest types of ,french mask is the so-called ,a4 ,r4 ,s4 mask1 which is based upon1 or at least resembles closely1 the ,german mask4 ,this is a frame mask made from well rubberized balloon material1 provided on the inside with a lining of oiled or waxed linen and fitted with a drum which is screwed on4 ,the mask is provided with eyepieces of cellophane1 fastened by metal rings into rubber goggles1 which are sewed in the mask4 ,a metal mouth-ring is tied in the mask with tape4 ,this ring is placed somewhat higher than in the ,german mask1 in this way reducing the harmful space under the mask4 ,an inlet and outlet valve is placed in the mouth-ring2 the first is of mica while the other1 which is in direct communication with the interior of the mask1 is of rubber4 ,on the inside of the mask1 in front of the valves1 a baffle is sewed in1 whereby the inhaled air is forced to pass in front of the eyepieces to prevent dimming and1 at the same time1 condensed vapor is prevented from entering the valves4 ,illustration3 ,,fig4 #di4--;,french ,a4 ,r4 ,s4 ,mask4 ,the mask or head straps are arranged in the same way as on the latest ,m-#b mask1 i4e41 one elastic band is placed across the top of the head and the other across the back2 the two are joined by an elastic4 ,below these two straps is an adjustable elastic neck band4 ,the drum is made of metal similar in shape to the ,german drum and fits in the mouth-ring by means of a thread4 ,it is made tight by a rubber ring as in the ,german mask4 ,the thread differs from that on the ,german mask1 making an interchange of canisters impossible4 ,the canister or drum includes a bottom screen1 springs and wire screens between the layers4 ,it is closed by a perforated bottom4 ,there are three layers4 ,on the top is a thin layer of absorbent cotton4 ,beneath this is a central layer of charcoal1 which is a little finer than the ,german charcoal4 ,the lower layer consists of soda-lime1 mixed with charcoal and zinc oxide and moistened with glycerine4 ,,german ,,mask ,the early type of ,german mask probably served as the model for the ,french ,a4 ,r4 ,s4 mask4 ,the facepiece was made of rubber1 which was later replaced by leather because of the shortage of rubber4 ,the following is a good description of a typical ,german facepiece3 8,the facepiece of the ,german mask was made of one piece of leather1 with seams at the chin and at the temples1 giving it roughly the shape of the face4 ,the leather was treated with oil to make it soft and pliable1 also to render it impervious to gases4 ,the dressed surface was toward the inside of the mask4 ,a circular steel plate1 #c inches in diameter1 was set into the facepiece just opposite the wearer's nose and mouth1 with a threaded socket into which the drum containing the absorbents screwed4 ,a rubber gasket 7synthetic87 held in place by a sort of pitch cement1 secured a gas-tight joint between the drum and the facepiece4 ,there were no valves1 both inhaled and exhaled air passing through the canister4 ,the eyepieces were inserted by means of metal rims with leather washers1 and were in two parts3 7a7 a permanent exterior sheet of transparent material 7#8cellon'7 resembling celluloid1 and 7b7 an inner removable disc which functioned as an anti-dimming device4 ,this latter appeared to be of #8cellon' coated on the side toward the eye with gelatin1 and was held in position by a #8wheel' stamped from thin sheet metal1 which screwed into the metal rim of the eyepiece from the inside4 ,the gelatin prevented dimming by absorbing the moisture1 but wrinkled and blistered and became opaque after a few hours' use1 and could not be changed without removing the mask4 ,the edge of the facepiece all around was provided with a bearing surface consisting of a welt of finely woven cloth about one inch wide sewed to the leather4 ,in some instances this welt was of leather of an inferior grade4 ,the edge of the facepiece was smoothed over by a coat of flexible transparent gum1 probably a synthetic compound40 ,illustration3 ,,fig4 #ej4--;,german ,respirator4 ,illustration3 ,,fig4 #ea4--,the ,german ,respirator4 #a4 ,smoke ,filter ,extension4 #b4 ,canister4 #c4 ,ring for ,protecting ,eye ,piece4 #d4 ,anti-dimming ,disc ,envelope4 #e4 ,carrying ,case4 #f4 ,cloth ,wallet for ,extra ,canister 7#aiah74 #g4 ,can for ,extra ,canister 7#aiaf74 #h4 ,assembled ,respirator4 #i4 ,face ,piece4 #aj4 ,anti-dimming disc4 ,german ,canister4 ,the general appearance of the canister 7,sept41 #aiaf ,type7 is that of a short thick cylinder slightly tapered and having at the smaller end a threaded protrusion or neck by which it is screwed onto the facepiece4 ,the cylinder is about #aj cm4 in diameter and about #e cm4 in length4 ,in the canister are three layers of absorbents of unequal thickness separated by disks of fine mesh metal screen4 ,the canister is shipped in a light sheet iron can #aj cm4 in diameter and #h cm4 high4 ,the can is shellacked and is lined with paper packing board4 ,the container is made air-tight by sealing with a strip of adhesive tape4 ,illustration3 ,,fig4 #eb4--;,cross ,section of #aiag and #aiah ,german ,canisters4 ,,absorbents4 ,absorbent4 ,composition4 ,weight4 ,volume4 #aiag4 ,no4 #a4 ,chemical ,absorbent4 #ff gr4 #aje cc4 ,no4 #b4 ,impregnated ,charcoal4 #cf gr4 #he cc4 ,no4 #c4 ,chemical ,absorbent4 #ae gr4 #de cc4 #aiah4 ,no4 #a4 ,impregnated ,charcoal4 #eh gr4 #ahe cc4 ,no4 #b4 ,chemical ,absorbent4 #bi gr4 #de cc4 ,total ,volume of ,absorbents1 #aiag1 #bce cc4 #ad4c cu4 in4 #aiah1 #bcj cc4 #ad4j cu4 in4 ,total ,weight of ,absorbents1 #aiag1 #aag gr4 #aiah1 #hg gr4 ,volume of ,air ,space above ,absorbents #ej cc4 #c4a cu4 in4 ,body4 ,the body of the canister is made of sheet metal 7probably iron71 which is protected on the outside with a coat of dark gray paint and on the inside with a japan varnish4 ,for ease in assembling the sides of the canister have a gentle taper1 and are formed so as to supply a seat for each of the follower rings4 ,the protrusion or neck has about six threads to the inch1 the pitch of the screw being #d mm4 ,the lower part of the body is rolled so as to give a finished edge1 and the upper part of the cylinder is grooved to receive the top support4 ,the first screen is double1 consisting of a coarse top screen five to six mesh1 per linear inch1 and immediately below1 a finer screen of #cj-dj mesh1 per linear inch4 ,the top support is a rigid ring of metal with two cross arms1 which give added1 strength to the ring and support to the screens4 ,it springs into a groove at the top of the body and forms the support for the contents of the canister4 ,both screens are made of iron wire and the top support is made of iron 7probably lightly tinned74 ,the second screen1 which separates the second and third absorbents1 is double1 consisting of two disks of #cj-dj mesh iron screen4 ,both screens are held in place by a follower ring4 ,the third screen is single1 but otherwise it is exactly similar to the second screen4 ,it serves to keep separate the layers of absorbents ,no4 #a and ,no4 #b4 ,the fourth screen 7#cj-dj mesh7 is made of iron wire and is held to the bottom support by six cleats which are punched from the body of the support4 ,the bottom support is simply a flanged iron cover for the bottom of the canister4 ,it is punched with #gi circular holes each #d mm4 in diameter and is painted on the outside to match the body of the canister4 ,the screen and the inside of the bottom support or cover are coated with a red paint4 ,,american ,,mask ,at the entrance of the ,united ,states into the war1 three types of masks were available3 the ,,ph helmet1 the ,british ,s4 ,b4 ,r4 and the ,french ,m-#b masks4 ,experiments were made on all three of these types1 and it was soon found that the ,s4 ,b4 ,r4 offered the greatest possibilities1 both as regards immediate protection and future development4 ,during the eighteen months which were devoted to improvement of the ,american mask1 the facepiece underwent a gradual evolution and the canister passed through types ,a to ,l1 with many special modifications for experimental purposes4 ,the latest development consisted in an adaptation of the fighting mask to industrial purposes4 ,for this reason a rather detailed description of the construction of the facepiece and of the canister of the respirator in use at the close of the war 7,r4 ,f4 ,k4 type7 may not be out of place4 ,the mask now adopted as standard for the ,u4 ,s4 ,army and ,navy is known as the ,model #aiai ,american mask1 with #aibj model carrier1 and will be described on page #bbe4 ,illustration3 ,,fig4 #ec4--;,diagrammatic ,sketch of ,box ,respirator ,type ,mask4 ,facepiece4 ,the facepiece of the ,r4 ,f4 ,k4 type ,box ,respirator is made from a light weight cotton fabric coated with pure gum rubber1 the finished fabric having a total thickness of approximately _/ inch4 ,the fit of the facepiece is along two lines--first1 across the forehead1 approximately from temple to temple2 second1 from the same temporal points down the sides of the face just in front of the ears and under the chin as far back as does not interfere with the ,adam's apple4 ,in securing this fit1 the piece of stock for the facepiece is died out of the felt and pleated up around the edges to conform to this line4 ,after this pleating operation1 the edges of the fabric are stitched to a binding frame similar to a hat-band made up of felt or velveteen covered with rubberized fabric4 ,all the stitching and joints in the facepiece are rendered gas-tight by cementing with rubber cement4 ,this facepiece is made in five sizes ranging from ,no4 #a to ,no4 #e1 with a large majority of faces fitted by the three intermediate sizes1 #b1 #c1 #d4 ,harness4 ,the function of the harness is to hold the mask on the face in such a way as to insure a gas-tight fit at all points4 ,because of the great variations in the conformation of different heads1 this problem is not a simple one4 ,probably1 the simplest type of harness1 as well as the one which is theoretically correct1 consists of a harness in which the line of fit across the forehead is extended into an elastic band passing around the back of the head1 while the line of fit around the side of the face and chin is similarly extended into another elastic tape passing over the top of the head2 these should be held in place by a third tape1 preferably non-elastic1 attached to the mask at the middle of the forehead and to the middle points of the other tapes at a suitable distance to hold them in their proper positions4 ,the discomfort of the earlier types of harness has been remedied1 in a large measure1 by the development of a specially woven elastic web which1 for a given change in tension1 allowed more than double the stretch of the commercial weaves4 ,there is still much room for valuable work in developing a harness which will combine greater comfort and safety4 ,the following points should always be observed in harness design3 7#a7 ,the straps should pull in such a direction that as large a component as possible of the tension of the strap should be available in actually holding the mask against the face4 7#b7 ,the number of straps should be kept to a minimum in order to avoid tangling and improper positioning when put on in a hurry by an inexperienced wearer4 ,eyepieces4 ,one of the most important parts of the gas mask1 from the military point of view1 is the eyepiece4 ,the primary requirement of a good eyepiece is that it shall provide a minimum reduction in clarity of vision with a maximum degree of safety to the wearer4 ,the clarity of vision may be affected in one of several ways3 7#a7 by abrasion of the eyepieces under service conditions2 7#b7 irregularities in the surface and thickness of the eyepiece1 causing optical dispersion2 7#c7 absorption of light by the eyepiece itself2 7#d7 dimming of the eyepieces due to condensation of moisture radiating from the face or in the exhaled air4 ,three types of eyepieces were used but by the end of the war the first two types had been abandoned4 7#a7 ,ordinary celluloid4 7#b7 ,various hygroscopic forms of celluloid1 known as non-dimming eyepieces4 7#c7 ,various combinations of glass and celluloid1 known as non-breakable eyepieces4 ,celluloid was used first1 due to its freedom from breakage4 ,it is not satisfactory because it is rapidly abraded in use1 turns yellow1 thus increasing its light absorption1 has relatively uneven optical surfaces and becomes brittle after service4 ,the various forms of non-dimming lenses function by absorbing the water which condenses on their surfaces1 either by combining individual drops into a film which does not seriously impair vision1 by transmitting it through the surface and giving it off on the exterior or by a combination of these mechanisms4 ,with the exception that they are non-dimming1 they are open to all the objections of the celluloid eyepiece and1 as a matter of fact1 were never tried out in the field4 ,the so-called non-breakable eyepieces are formed by cementing together a layer of celluloid between two layers of glass4#be ,this results in an almost perfect eyepiece4 ,any ordinary blow falling upon such an eyepiece does no more than crack the glass1 which remains attached to the celluloid coating4 ,except in extreme cases1 the celluloid remains unbroken and there is relatively slight danger of a cracked eyepiece of this sort leaking gas4 ,footnote #be3 ,so-called 8,triplex0 glass4 ,in the matter of flying fragments1 the type of eyepiece consisting of a single layer of celluloid and glass with the celluloid placed next to the eye1 has probably a slight advantage over the type in which there is glass on both sides4 ,however1 the superior optical surface of the latter type1 coupled with its greater freedom from abrasion of the surface led to the adoption of this type known as 8triplexin0 in the mask produced in the later part of the ,american manufacturing program4 ,it should be pointed out in connection with this type of eyepiece that it is possible to make it as perfect optically as desired by using the better grades of glass4 ,while the optical properties of these eyepieces undoubtedly suffer somewhat with age1 due to the discoloration of the celluloid1 it can be safely said that this material1 located as it is between the layers of glass and relatively little exposed to atmospheric conditions1 will probably be far less affected in this way than is the ordinary celluloid eyepiece4 ,illustration3 ,,fig4 #ed4--;,american ,box ,respirator1 ,showing ,improved ,rubber ,noseclip4 ,the position of the eyepiece is very important2 the total and the binocular fields of vision should be kept at a maximum4 noseclip4 ,the noseclip is probably the most uncomfortable feature of the types of mask used during the ,war4 ,while a really comfortable nose pad is probably impossible1 the comfort of the clip was greatly improved by using pads of soft rubber and springs giving the minimum tension necessary to close the nostrils4 ,mouthpiece4 ,the design of the mouthpiece should consider the size and shape of the flange which goes between the lips and teeth2 this should be such as to prevent leakage of gas into the mouth and should reduce to a minimum any chafing of the gums4 ,the opening through the mouthpiece is held distended at its inner end by a metallic bushing to prevent its collapse1 if1 under stress of excitement1 the jaws are forced over the flange and closed4 ,rubber has proved a very satisfactory material for this part of the facepiece4 ,flexible ,hose4 ,the flexible hose leads from the angle tube to the canister4 ,this should combine flexibility1 freedom from collapse1 and extreme physical ruggedness4 ,these specifications are met successfully by the stockinette-covered corrugated rubber hose4 ,the angular corrugations not only give a high degree of flexibility but are extremely effective in preventing collapse4 ,the flexibility gained by this construction is not only lateral but also longitudinal2 a hose having a nominal length of #aj inches functions successfully between lengths of #h and #ab inches4 ,the covering of stockinette1 which is vulcanized to the rubber in the manufacturing process1 adds materially to the mechanical strength by preventing incipient tears and breaks4 ,exhalation ,valve4 ,the exhalation valve allows the exhaled air to pass directly to the outside atmosphere4 7,this valve is not found on the ,german mask47 ,this valve has the following advantages3 7#a7 ,it tends to reduce very materially the dead air space in the mask4 7#b7 ,it prevents deterioration of the absorbent on account of moisture and carbon dioxide of the expired air4 7#c7 ,it reduces the back pressure against expiration1 since it is unnecessary to breathe out against the resistance of the canister4 ,the disadvantage1 which may under certain conditions be very serious1 is that1 if for any reason the valve fails to function properly1 inspiration will take place through the valve4 ,it can be readily seen that any failure of this nature will allow the poisonous atmosphere to be drawn directly into the lungs of the wearer4 ,the type of valve generally used is shown in ,fig4 #ee1 which shows one of these valves mounted and unmounted4 ,while it is rather difficult to give a clear description of its construction1 the valve may be considered as a flattened triangular sack of rubber1 whose altitude is two or three times the base and from which all three corners have been clipped1 each giving openings into the interior of the sack4 ,the opening at the top is slipped over the exhalation passage of the angle tube1 and the air passes out through the other two corners4 ,closure is obtained by the combination of two factors1--first1 the difference in atmospheric pressure1 and second1 the tension due to mounting a section which has been cured in the flat over an elliptical opening4 ,illustration3 ,,fig4 #ee4--;,american ,type ,exhale ,valve1 ,mounted and ,unmounted4 ,in order to protect the flutter valve from injury and from contact with objects which might interfere with its proper functioning1 the later types of valve were provided with a guard of stamped sheet metal4 ,,canisters ,during the development of the facepiece1 as discussed above1 the ,american canister underwent changes in design which have been designated as ,a to ,l4 ,these changes were noted by the different colored paints applied to the exterior of the canister4 ,type ,a canister was exactly like the ,british model then in use1 except that it was made one inch longer because it was realized that the early absorbents were of poor quality4 ,the canister was made of beaded tin plate and was #ah cm4 high4 ,the area of the flattened oval section was #fe sq4 cm4 ,in the bottom was a fine wire dome #c4d cm4 high4 ,the valve in the bottom was integral with the bottom of the container1 there being no removable plug for the insertion of the check valve4 ,the absorbents were held in place by a heavy wire screen on top and by two rectangular springs4 ,illustration3 ,,fig4 #ef4--;,american ,canister1 ,type ,a4 ,inhaled air entered through the circular valve at the bottom of the canister1 passed through the absorbents and through a small nipple at the top4 ,the filling consisted of #fj per cent by volume of wood charcoal1 developed by the ,national ,carbon ,co41 and #dj per cent of green soda lime1 developed and manufactured by the ,general ,chemical ,company1 ,easton1 ,pa4 ,the entire volume amounted to #ffj cc4 ,the early experiments with this volume of absorbent showed that soda-lime was the minimum amount that could be used and still furnish adequate protection against the then known war gases4 ,it was1 therefore1 decided to use soda-lime and charcoal by volume and this proportion has been adhered to in all of the later types of canisters4 ,it is interesting to note that these figures have been fully substantiated by the later experimental work on canister filling4 ,the charcoal and soda-lime were not mixed but arranged in five layers of equal volume1 each layer1 therefore1 containing #bj per cent of the total volume4 ,the layers were separated by screens of crinoline4 ,at the top was inserted a layer of terry cloth1 a layer of gray flannel1 and two steel wire screens4 ,the cloth kept the fine particles of chemicals from being drawn into the throat of the person wearing the mask4 ,this canister furnished very good protection against chlorine and hydrocyanic acid and was fairly efficient against phosgene1 but it was useless against chloropicrin4 ,these canisters were never used at the front1 but served a very useful purpose as experimental canisters and in training troops4 ,it was soon found that better protection was obtained if the absorbents were mixed before packing in the canister4 ,this procedure also simplified the method of packing and was used in canister ,b and following types4 ,among other changes introduced in later types were3 ,the integral valve was replaced by a removable check valve plug which enabled the men in the field to adjust the valve in case it did not function properly4 ,the mixture of charcoal and soda-lime was divided into three separate layers and these separated by cotton pads4 ,the pads offered protection against stannic chloride smokes but not against smokes of the type of sneezing gas4 ,the green soda-lime was replaced by the pink granules4 ,in ,april1 #aiah1 the mesh of the absorbent was changed to #h to #ad in place of #f to #ad4 ,about ,july #a1 #aiah1 the authorities were convinced by the field forces of the ,chemical ,warfare ,service that the length of life of the chemical protection of the standard ,h canister 7the type then in use7 was excessive and that the resistance was much too high4 ,type ,j was therefore adopted1 ,july #bg1 #aiah4 ,in this the volume of the absorbent was reduced from #dej cc4 to #cjj cc4 ,it was packed in two layers1 in the bottom and in the top4 ,one pad was placed between the layers and one on top4 ,this change gave a lowering of the resistance of #bg per cent 7to #b4e inches7 at a sacrifice of #ej per cent of the length of life of the canister1 but not of protection during the shortened life4 ,type ,l differed from this only in having #cbe cc4 of absorbent1 a change made to decrease leakage about the top cotton pad4 ,illustration3 ,,fig4 #eg4--,u4 ,s4 ,army ,canister1 ,type ,j4 ,the following table shows the relative efficiency of various canisters3 ---------------------------------------- ----------------------- ,u4 ,s41 ,british1 ,french1 ,german p4 p4 m4 ,type ,h ,s4 ,b4 ,r4 ,a4 ,r4 ,s4 ---------------------------------------- ----------------------- ,chloropicrin #ajjj #ggj #ag #b #dc ,phosgene #bejj #he #ed #e #af ,hydrocyanic acid #ejj #gj #ij #aj ,mustard gas #ajj #ahjj #ce #aie ---------------------------------------- ----------------------- ,the figures represent time in minutes till the first traces of gas begin to come through4 ,illustration3 ,,fig4 #eh4--,type ,j ,canister and ,contents ,,manufacture ,the following description of the manufacture of the gas mask at the ,long ,island plant is taken from an article by ,col4 ,bradley ,dewey#bf3 ,footnote #bf3 ,j4 ,ind4 ,eng4 ,chem41 #aa1 #ahe 7#aiai74 8,,incoming ,,inspection--,a thorough #ajj per cent inspection was made of each part before sending it to the ,assembly ,department4 ,the inspectors were carefully chosen and were sent to a school for training before they were assigned to this important work4 ,every feature found to be essential to the manufacture of a perfect gas mask was carefully checked4 8,the incoming inspection of the flexible rubber hose leading from the canister to the facepiece can be taken as an illustration4 ,each piece of hose was given a visual inspection for buckles or blisters in the ends or in the corrugations2 for cuts1 air pockets1 or other defects on the interior2 for loose seams where fabric covering was cemented to the rubber tube2 for weaving defects in the fabric itself2 and for careless application of the cement4 ,special tests were conducted for flexibility1 as a stiff hose would produce a strain on the soldier's mouth2 for permanent set to insure that the hose was properly cured2 for the adhesion of the fabric covering to the hose2 and for kinking when the hose was doubled on the fingers4 ,finally each piece was subjected to a test for leaks under water with a pressure of #e lbs4 per sq in4 8,each eyepiece and the three-way metal connection to the facepiece were subjected to a vacuum test for leakage4 ,the delicate exhalation valve was carefully examined for defects which would be liable to cause leakage4 ,fabric for the facepiece was given a high-tension electrical test on a special machine developed at the plant to overcome the difficulty met in the inspection of this most important material4 ,it was of course necessary that the facepiece fabric be free from defects but just what constituted a defect was the source of much discussion4 ,the electrical test eliminated all personal views and gave an impartial test of the fabric4 ,the machine consisted of two steel rolls between which a potential difference of #d1jjj volts was maintained2 the fabric was led through the rolls and wherever there was a pinhole or flaw the current arced through and burned a clearly visible hole4 8,,preliminary ,,facepiece ,,operations--,blanks were died out from the facepiece fabric in hydraulic presses4 ,each face blank was swabbed to remove bloom and the eye washers were cemented about the eyeholes4 ,the pockets for holding the noseclips were also cemented to the blanks4 ,the bands which formed a gas-tight seal of the mask about the face were died out from rubberized fabric to which a felt backing was attached4 ,the harness consisting of elastic and cotton tapes was also sewed together at this point4 8,,facepiece ,,operations--,the sewing machine operations were next performed4 ,first the died out blanks were pleated to form the facepiece4 ,the operator had to register the various notches in the blank to an accuracy of _/ in4 and to locate the stitches in some cases as closely as _/ in4 ,the band was next sewed to the periphery of the facepiece after which the harness was attached4 ,the stitches on the outside of the facepiece were covered with liquid dope1 which filled the needle holes and made the seams gas-tight4 8,in addition to the inspection of each operation1 the completed facepiece was submitted to a control inspection to discover any defects that might escape the attention of the inspectors on the various operations4 8,,assembly ,,operations--,the facepieces were now ready for assembly and were sent for insertion of the eyepieces1 which was done in specially designed automatic presses4 ,the eyepieces had to be carefully inserted so that the facepiece fabric extended evenly around the entire circumference4 8,before manufacture began on a large scale1 the most satisfactory method of conducting each assembly operation was worked out and the details standardized1 so that operators could be quickly and efficiently trained4 ,no detail was considered too small if it improved the quality of the mask4 ,the assembly operations proceeded as follows3 8,the exhalation valve was first joined to the three-way metal tube which formed the connection between the facepiece1 flexible hose1 and mouthpiece4 ,each valve was then tested for leakage under a pressure difference of a one inch head of water4 ,no valve was accepted which showed leakage in excess of #aj cc4 per min4 under these conditions4 8,the metal guard to protect the exhalation valve was next assembled1 followed by the flexible hose4 ,the three-way tube was then assembled to the facepiece by means of a threaded connection and the rubber mouthpiece attached4 ,to illustrate the attention to details the following operation may be cited3 8,the contact surfaces between each rubber and metal part were coated with rubber cement before the parts were assembled4 ,the connection was then tightly wired1 care being taken that none of the turns of wire should cross and finally the wire was covered with adhesive tape so that no sharp edges would be exposed4 8,the masks1 completely assembled except for the canisters1 were inspected and hung on racks on specially designed trucks which prevented injury in transit1 and were delivered to the ,finishing ,department4 8,,canister ,,filling--,meanwhile the canisters were being filled1 in another building4 8,the chemicals were first screened in such a way that the fine and coarse materials were separated from the correctly sized materials4 ,they were then carried on a belt conveyor to the storage bins1 whence they were fed by gravity through pipes to various mixing machines4 ,a special mixing machine was developed to mix the carbon and granules in the proper proportions for use in the canister4 ,the mixed chemicals were then led to the canister-filling machines4 ,there was a separate mixing machine for each filling machine1 of which there were eighteen in all4 8,the can-filling department was laid out in six units4 ,each unit had a capacity of #bj1jjj cans per day4 ,a system of double belt conveyors was installed to conduct empty canisters to the machines and carry away the filled ones4 8,each filling operation was carefully inspected and special stops were placed on the belt conveyors so that a canister could not go to the next operation without having been inspected4 ,operators and inspectors were stationed on opposite sides of the belt4 ,the chemicals were placed in the canister in three equal layers which were separated by pads of cotton wadding4 ,the first layer was introduced from the filling machine 7which delivered automatically the proper volume of chemicals71 the canister was shaken to pack the chemicals tightly1 the cotton baffle inserted1 the second layer of chemicals introduced and so forth4 ,on top of the top layer of chemicals were placed a wire screen and a specially designed spring which held the contents of the canister securely in place4 ,the metal top was then fitted and securely soldered4 8,each canister was tested under water for possible leaks in joints or soldering1 with an air pressure of #e lbs4 per sq4 in4 ,a test was also made for the resistance which it offered to breathing1 a rate of flow of air through the canister of #he liters per min4 being maintained and the resistance being measured in inches of water4 8,the filled canisters were then painted a distinctive color to indicate the type of filling4 8,,finishing ,,department--,in the finishing department1 the filled canisters1 were conducted down the middle of the finishing tables and assembled to masks4 ,illustration3 ,,fig4 #ei4 8,the finished masks were then inspected1 placed in unit boxes1 ten to a box1 and returned for the final inspection4 8,,final ,,inspection--,final inspection of the completely assembled masks was as rigid as could be devised1 and was closely supervised by army representatives4 ,only the most painstaking1 and careful women were selected for this work and the masks were examined in every detail to discover any defect that might have escaped previous inspection4 ,finally1 each mask was inspected over a bright light in a dark booth for small pinholes which the ordinary visual inspection might not have detected4 8,as a check on the quality on the final inspectors' work a reinspection of #e per cent of the passed masks was conducted4 ,where it was found that a particular inspector was making numerous mistakes1 her eyes were examined to see whether it was due to faulty eyesight or careless work4 ,masks containing known defects were purposely sent to these inspectors to determine whether they were capable of continuing the inspection work4 ,in this way the desired standard was maintained4 8,a daily report of the final inspection was sent back to each of the assembly departments involved so that defects might be eliminated immediately and the percentage of rejects kept as low as possible4 8,after the final inspection the masks were numbered1 packed in knapsacks1 and the filled knapsacks placed in packing cases1 twenty-four to a case40 ,,tissot ,,mask ,the ,french1 as has already been pointed out1 early recognized that certain classes of fighting men1 as the artillerymen1 needed the maximum of protection with the minimum decrease in efficiency4 ,the result of this was the ,tissot ,mask4 ,before the ,united ,states entered the war1 the ,british standard box respirator had reached a greater degree of perfection1 with far greater ruggedness and portability4 ,it was therefore adopted as the ,american standard4 ,at the time of the invention of the ,british box respirator and practically up to the time the ,united ,states entered the war1 masks were worn only during the sporadic gas attacks then occurring and only for a brief period at a time4 ,as the war progressed1 the men were compelled to wear their masks for much longer periods 7eight hours was not uncommon74 ,it was then seen that more comfort was needed1 even at the expense of a little safety4 ,the principle of the ,tissot mask was correct so far as comfort was concerned1 since it did away with the irritating mouthpiece and noseclip1 but the chief danger in the ,french mask arose from the fact that the facepiece was made of thin1 pure gum rubber4 ,the ,research ,division1 together with the ,gas ,defense ,division1 developed two distinct types of ,tissot masks4 ,the first of these was the ,akron ,tissot1 the second the ,kops ,tissot4 ,the best features of these have been combined in the #aiai ,model4 ,illustration3 ,,fig4 #fj4--;,american ,tissot ,mask1 ,early ,type4 ,illustration3 ,,fig4 #fa4--;,american ,tissot ,mask1 ,interior ,view4 #aiai ,,model ,,american ,,mask ,facepiece4 ,this facepiece is made of rubberized stockinet about one-tenth inch in thickness4 ,the stockinet is on the outside only and is for the purpose of strengthening and protecting the rubber which is of very high grade4 ,the facepiece is died out as a single flat piece from the stockinet which is furnished in long rolls4 ,the die is of such shape that when the facepiece is sewed there is but one seam1 and that between the angle tube opening and the edge under the chin4 ,this seam is sewed with a zigzag stitch with the stockinet sides flat together4 ,the seam is then stretched over a jig1 so as to form a flat butt joint4 ,this seam is then cemented with rubber cement and taped1 inside and out1 to make it thoroughly gas-proof4 ,the eyepiece openings are of oval shape with the longer axes horizontal and considerably smaller than the finished eyepieces4 ,the eyepieces being circular1 the cloth is stretched to accommodate them1 giving the necessary bulge to keep the cloth and metal of the eyepieces away from the face4 ,the harness has three straps on each side4 ,instead of the single strap over the top of the head1 two straps lead from directly over the eyes1 both being made of elastic the same as the other straps4 ,all six straps are brought together around a pad of felt and cloth about #b #c inches at the back of the head4 ,this pad makes the harness much more comfortable4 ,the rubberized stockinet is reinforced on the inner or rubber side with thin bits of cloth at all points where the straps are sewed on4 ,the strap across the temples just above the ears is sewed at two points1 one about one-half inch from the edge and the other about two inches from the edge4 ,this is for the purpose of helping press the cloth against the temples1 thereby adding to the gas-tightness for those heads that have a tendency to be hollow at the temples4 ,the lower strap is just above the chin and is for the purpose of giving gas-tightness in that vicinity4 ,all of the straps except the two over the top of the head are attached to the pad with buckles1 and are thus capable of exact adjustment4 ,the eyepieces are of triplex glass in metal rings with rubber gaskets4 ,in pressing the rings home1 the rubberized stockinet is turned and held securely so that there is no possibility of pulling them out4 ,the angle tube containing the outlet valve and the connection to the corrugated tube connecting with the canister is the same as with the latest model ,r4 ,f4 ,k4 mask4 ,the only difference as regards the corrugated tube is that a greater length is needed with the new carrier under the left shoulder4 ,the total length of the tube for this model is about #bd inches4 ,on the inside of the facepiece and connected to the angle tube inlet is a butterfly baffle of rubber1 so arranged that the incoming air is thrown upward and over the eyepieces1 thus keeping them clear no matter how much the exertion or what the temperature1 except in certain rare cases when the temperature is down at zero ,f4 or below4 ,illustration3 ,,fig4 #fb4--aiai ,model ,american ,mask4 ,,canister ,the canister is radically different from the canisters used in the ,r4 ,f4 ,k4 and earlier types4 ,in the first place1 it is longer1 the total length finished being #h inches4 ,it has two inlet valves at the top end protected by a tin cover instead of the single inlet valve at the bottom of the earlier types4 ,the two inlet valves are each inch in diameter and are made up of square flat valves on the end of a short rubber tube4 ,the rubber tube is fitted over a short metal tube4 ,gas-tightness is obtained both by the pressing of the valve against the round edge of the metal tube and by the pressure of the edges against each other4 ,these valves1 while delicate1 are proving very satisfactory1 and being simply check valves to prevent the air going back through the canister1 they are not vital4 ,in case of failure1 the eyepieces would fog somewhat and the dead air space be increased by that held in the inlet tube4 ,the canister consists really of two parts--an outer casing that is solid and an inner perforated tin casing4 ,around the perforated tin is fitted a filter of wool felt _/ of an inch in thickness4 ,this wool felt is very securely fastened by turning operations to solid pieces of tin1 top and bottom1 so that no air can get into the chemicals without passing through the filter4 ,thus the air coming through the inlet valves at the top circulates around the loosely fitting outside corrugated case to all parts of the filter and after passing through the filter continues through the perforations of the tin into the charcoal and soda-lime granules4 ,the chemicals are packed around a central wedge-shaped tube extending about two-thirds the length of the can4 ,the wedge is enlarged at the top and made circular where it passes through the top of the can to connect with the corrugated tube4 ,the wedge-shaped inner piece is made of perforated tin and is covered with thin cloth to prevent dust from the chemicals passing into the tube and thus into the lungs4 ,the cans are filled from the bottom and are subjected to two mechanical jarring operations in order to settle the chemicals thoroughly before the spring which holds them in place is added4 ,the outer tin cap protecting the inlet valves has two openings on each side but none at the ends of the canister4 ,illustration3 ,,fig4 #fc4--aiai ,model ,american ,mask after ,adjustment4 ,the carrier is a simple canvas case nearly rectangular1 about one foot wide and #ae inches in length4 ,the width is just sufficient at the back to hold the canister and the front part to hold the extra length of corrugated tube and the facepiece4 ,there are two straps1 one passing over the right shoulder and the other around the body4 ,the one passing over the right shoulder has two 8,v0 shaped seams at the top so as to change the direction of the strap over the shoulder in order that it will pull directly downward instead of against the neck4 ,the flap closing the case opens outward4 ,it has the usual automobile curtain fasteners4 ,a secondary fastener at the top of the opening is arranged so that when the tube is adjusted to the proper length and the mask is adjusted to the face of the wearer1 the flap can be buttoned tightly over the corrugated tube and held tightly4 ,this prevents water from entering the case4 ,figures #fb and #fc show the position of the carrier both with the facepiece in the carrier and after adjustment4 ,it will be noted that the carrier does not interfere with the pack nor with anything on the front of the body4 ,the left arm hangs almost entirely natural over the case4 ,it has been thoroughly tried out by the ,infantry1 ,cavalry1 ,artillery and ,special ,gas ,troops and adopted as eminently satisfactory4 ,,special ,,canisters ,navy4 ,the early ,navy canister is a drum much like the ,german canister4 ,the container is a slightly tapered metal cylinder1 #i cm4 in diameter at the bottom4 ,the most satisfactory filling for this drum consists of two layers1 #ih cc4 in each1 of a standard mixture of charcoal and soda-lime1 separated by cotton wadding pad4 ,the filling is #f-bj mesh1 instead of #h-ad mesh4 ,a later type is shown in ,figure #da4 ,carbon ,monoxide4 ,this canister is discussed in ,chapter ,,xi4 ,ammonia4 ,ammonia respirators were needed by the ,navy and also by the workmen in refrigeration plants4 ,early protection was obtained by the use of pumice stone impregnated with sulfuric acid4 ,this had many disadvantages1 such as the amount of heat evolved1 the caustic fumes produced1 high resistance and corrosion of the canister4 ,to overcome these1 the 8,kupramite0 canister was developed4 ,the filling consists of pumice stone impregnated with copper sulfate4 ,pumice stone1 #h to #ad mesh1 and technical copper sulfate are placed in an evaporating pan in the ratio of one part by weight ,cu,s,o#e;,h,o to #a4e parts pumice1 and the whole is covered with sufficient water to dissolve the salt at boiling temperature4 ,the mixture is then boiled down with constant stirring until crystallization takes place on the pumice and the crystals are nearly dry4 ,the pumice thus treated is then removed from the dish1 spread out and allowed to dry in the air4 ,the fines are then screened out on a #ad-mesh sieve4 ,care must be taken in the evaporating process that the absorbent is still slightly moist when taken from the pan4 ,illustration3 ,,fig4 #fd4--;,early ,type ,navy ,mask4 ,contains noseclip and mouthpiece4 ,in packing the standard ,army canister with kupramite a layer of toweling is placed on top of the absorbent to filter out any fine particles which might be drawn up from the absorbent1 and the whole is held in place by the usual heavy wire screen and spring4 ,this method of packing is to be used with the present mouthpiece type of army mask4 ,if the new ,tissot type mask is used1 a modification of the packing is desirable in order to eliminate the trouble due to moisture given off by the absorbent during service condensing on the eyepieces of the mask and thus impairing the vision of the wearer4 ,to remedy this defect a #a-;in4 layer of kupramite at the top of the canister is replaced by activated charcoal or silica gel1 preferably silica gel4 ,this decreases the humidity of the effluent air sufficiently to prevent dimming of the eyepieces4 ,if charcoal is used1 a #b-h cotton pad 7,eastern ,star ,furrier ,co41 ,pawtucket1 ,r4 ,i47 is substituted for the toweling in order to remove charcoal dust4 ,the canister complete weighs about #a4g lbs4 ,illustration3 ,,fig4 #fe4--;,ammonia ,canister--8,kupramite40 ,a canister containing #de cu4 in4 of this material will protect a man breathing at rest for at least #e hours against #b per cent ammonia and for #b hours against #e per cent ammonia4 ,its advantages are large capacity and activity1 negligible heat of absorption1 and cheapness4 ,,physiological ,,features ,,of ,,the ,,mask ,for some time after the introduction of gas warfare1 the gases used were of the so-called non-persistent type4 ,under these conditions it was necessary to wear the mask for only relatively short periods1 after which the cloud dissipated4 ,with the increasing use of gas and the introduction of the more persistent gases1 particularly mustard gas1 it not only became necessary to wear the mask for long periods of time but also to do relatively heavy physical work1 such as serving artillery1 when wearing the mask4 ,illustration3 ,,fig4 #ff4--;,ammonia ,mask1 ,showing ,relative ,size of ,canister4 ,under these conditions1 it became evident that the wearing of the mask caused a very great reduction in the military efficiency of the soldier4 ,the reasons for this reduction in efficiency have been made the subject of extensive research by a group of the foremost physiologists and psychologists of the country4 ,as a result of their work1 the causes contributing to this reduction in efficiency may be grouped about the following main factors3 7#a7 ,the physical discomfort of the mask arising from causes such as pressure on the head and face1 due to improperly fitting facepieces and harness1 the noseclip1 and the mouthpiece4 7#b7 ,abnormal conditions of vision1 due to poor optical qualities in eye pieces and restrictions of vision1 both as to total field and binocular field4 7#c7 ,abnormal conditions of respiration1 among them being 7a7 the unnatural channels of respiration caused by wearing the box respirator1 7b7 increase in dead air space in respiratory circuit1 and 7c7 the increase in resistance to both inhalation and exhalation1 the last two mentioned being present to a greater or less degree in all types of mask4 ,of these general subdivisions the various phases of the first two are so evident that no further discussion will be given4 ,the effects of the changed conditions of respiration are1 however1 less obvious1 and it may be of interest to present in a general way the results of the research along this line1 particularly as regards the harmful effects of increasing the resistance and dead air space in the respiratory tract above the normal4 ,the function of respiration is to supply oxygen to and remove carbon dioxide from the blood as it passes through the lungs4 ,this interchange of gases takes place in the alveoli1 a myriad of thin-walled air sacs at the end of the respiratory tract where the air is separated by a very thin membrane through which the gases readily pass4 ,the volume and rate1 or in other words1 the minute-volume1 of respiration is automatically controlled by the nerve centers in such a way that a sufficient amount of air is supplied to the lungs to maintain by means of this interchange a uniform percentage of its various constituents as it leaves the lungs4 ,it will be readily seen therefore1 that anything which causes a change in the composition of the air presented to the blood in the alveoli will bring about abnormal conditions of respiration4 ,inasmuch as the gaseous interchange between the lungs and the blood takes place only in the terminal air sacs it follows that1 at the end of each respiration1 the rest of the respiratory tract is filled with air low in oxygen and high in carbon dioxide1 which on inspiration is drawn back into the lungs1 diluting the fresh air4 ,the volume of these passages holding air which must be re-breathed is known as the anatomical dead air space4 ,similarly1 when a mask is worn the facepiece chamber and any other parts of the air passage common to inspiration and expiration become additional dead air space contributing a further dilution of oxygen content and contamination by carbon dioxide of the inspired air in addition to that occasioned by the anatomical dead space1 which of course1 is always present and is taken care of by the functions normally controlling respiration4 ,major ,r4 ,g4 ,pearce who directed a large amount of the research along this line1 sums up the harmful effects of thus increasing the dead air space as follows3 #a4 ,interpretation from the physiological standpoint3 7a7 ,a larger minute-volume of air is required when breathing through dead air space4 ,this1 interpreted on physiological grounds1 means that the carbon dioxide content of the arterial blood is higher than normal4 ,the level to which the content of carbon dioxide in the arterial blood may rise is limited4 ,anything which wastefully increases the carbon dioxide level of the blood decreases the reserve so necessary to a soldier when he is asked to respond to the demand for exercise which is a part of his daily life4 7b7 ,a larger minute-volume of air must be pulled through the canister1 which offers resistance proportional to the volume of air passing through it4 ,if resistance is a factor of harm1 dead air space increases that harm1 since dead air space increases the volume of air passing through the canister4 7c7 ,as will be noted below1 the effect of resistance is a tendency to decrease the minute-volume of air breathed4 ,dead air space increases the minute-volume4 ,accordingly1 if breathing is accomplished against resistance and through a large volume of dead air space1 the volume of air breathed is reduced more in proportion to the actual needs of the body than when breathing against resistance without the additional factor of dead space2 this1 again1 causes the level of carbon dioxide in the blood and tissues to be raised to a higher level than normal1 and thus again there is some reserve power wasted4 #b4 ,interpretation from the standpoint of the canister4 ,the life of the canister depends on the volume of the gas-laden air passed through it4 ,the dead space increases the minute-volume of air passed through the canister and1 therefore1 shortens its life4 ,physiologically1 the reason for the harmful effects of breathing resistance is more involved3 8,the importance of resistance to breathing lies in3 7#a7 the effect on the circulation of the blood1 and 7#b7 the changes in the lung tissue1 which seriously interfere with the gas exchange between the outside air and the blood4 ,data have been presented to draw attention to the seriousness of resistance to inspiration4 ,in these reports1 it was suggested that the deleterious effects on the body consist in changes in the blood pressure1 increased work of the right side of the heart1 and an increase in the blood and lymph content of the lungs4 ,resistance also decreases the minute-volume of air breathed and thereby increases the percentage of carbon dioxide in the expired air4 ,the foregoing changes are all deleterious4 8,although the chief problem of resistance in gas mask design concerns inspiration1 nevertheless resistance to expiration is an important factor4 ,the expired air of the lungs contains carbon dioxide for which means of escape must be provided4 ,the expiratory act is more passive than the inspiratory act1 and resistance to expiration is1 therefore1 more keenly felt than resistance to inspiration4 ,it is then imperative that the exhale valve be so arranged as to allow for the escape of the entire amount of air during the time of expiration with the least possible resistance4 ,the data of the laboratory indicate that seldom1 if ever1 do expiratory rates rise above a velocity of #aej to #age per minute4 ,the effect of resistance to exhalation upon the vital organs of the body is not dissimilar to that of inspiration40 ,,chapter ,,xiii ,,absorbents#bg ,the absorbents used in both the ,british and ,american gas mask canister1 which afforded a degree of protection far superior to that of any other allied or enemy nation except ,germany1 consisted of a mixture of charcoal and soda-lime1 as described in the preceding chapter4 ,in general1 a gas mask absorbent must have certain requirements4 ,these are3 absorptive activity1 absorptive capacity1 versatility1 mechanical strength1 chemical stability1 low breathing resistance1 ease of manufacture and availability of raw materials4 ,footnote #bg3 ,the basis of this chapter is the series of articles by ,lamb and co-workers which appeared in the ,j4 ,ind4 ,eng4 ,chem4 for #aiai4 ,absorptive activity1 or a very high rate of absorption1 is one of the more important properties of a satisfactory absorbent4 ,a normal man when exercising violently breathes about #fj liters of air per minute1 and since inhalation occupies but slightly more than half of the breathing cycle1 the actual rate at which gas passes through the canister during inhalation is about #ajj liters per minute4 ,calculated on the basis of the regular army canister1 this corresponds to an average linear air velocity of about #hj cm4 per second4 ,on the average1 therefore1 a given small portion of the air remains in contact with the gas absorbent for only about #j4a second4 ,besides this1 the removal of the toxic material must be surprisingly complete4 ,though the concentration entering the canister may occasionally be as high as one half per cent1 even the momentary leakage of #j4jja per cent 7ten parts per million7 would cause serious discomfort and the prolonged leakage of smaller amounts would have serious results in the case of some gases4 ,the activity of the present gas mask charcoal is shown by the fact that it will reduce a concentration of #gjjj parts per million of chloropicrin to less than #j4e part per million in less than #j4jc second4 ,of equal importance is the absorptive capacity4 ,that is1 the absorbent must be able to absorb and hold large amounts of gas per unit weight of absorbent4 ,its life must be measured in days against ordinary concentrations of gas4 ,it is further necessary that the gas be held firmly and not in any loose combination which might give up minute traces of gas when air is1 for long periods of time1 breathed in through a canister which has previously been exposed to gas4 ,the absorbents used must be of a type which can be relied upon to give adequate protection against practically any kind of toxic gas 7versatility74 ,the need of this is apparent when the difficulty of having separate canisters for various gases is considered1 as well as the difficulty in rapidly and accurately identifying the gases and the possible introduction of new and unknown gases4 ,fortunately1 practically all of the toxic gases are very reactive chemically or have relatively high boiling points and can therefore be absorbed in large amounts by charcoal4 ,absorbents must be mechanically strong in order to retain their structure and porosity under conditions of transport and field use4 ,further1 they must not be subject to abrasion for the production of a relatively small amount of fines would tend to plug the canister or to cause channels through which the gas would pass without being absorbed4 ,since the canister is filled several months before it is first used in the trenches1 and since the canister may be used over a period of months before it is discarded1 it is obviously the ultimate activity and capacity 7not the initial efficiency7 which determines the value of an absorbent4 ,it must therefore have a very considerable degree of chemical stability4 ,by this is meant that the absorbent itself is not subject to chemical deterioration1 that it does not react with carbon dioxide1 that it does not disintegrate or become deliquescent even after being used and that it has no corrosive action on the metal container4 ,in a good general absorbent there must be a proper balance between its various essential qualities1 and hence the most suitable mixture will probably always be a compromise4 ,,charcoal ,the fact that charcoal would condense in its pores or adsorb certain gases1 holding them firmly1 had been known for a long time4#bh ,in general1 it was known that so-called animal charcoal was the best for decolorizing sugar solutions1 that wood charcoal was the best for adsorbing gases and that coke had very little adsorbing or decolorizing power4 ,no one knew the reason for these facts and no one could write a specification for charcoal4 ,the ordinary charcoal used in the scientific laboratory was cocoanut charcoal1 since ,hunter had discovered more than fifty years ago that this was the best charcoal for adsorbing gases4 ,,raw ,,materials#bi ,the first charcoal designed to offer protection against chlorine and phosgene was made by carbonizing red cedar4 ,since this had little value against chloropicrin1 attention was turned to cocoanut shell as the source of raw material4 ,this charcoal fulfilled the above conditions for a satisfactory absorbent better than any other form tested4 ,it must not be supposed1 however1 that investigation of carbon stopped with these experiments4 ,in the search for the ideal carbon1 practically almost every hard vegetable substance known was tested4 ,next to cocoanut shells1 the fruit pits1 several common varieties of nuts abundant in the ,united ,states1 and several tropical nuts 7especially cohune nuts71 were found to make the best carbon4 ,pecan nuts1 and all woods ranging in hardness from iron wood down to ordinary pine and fir1 were found to be in the second class of efficiency4 ,among other substances tested were almonds1 ,arabian acorns1 grape seeds1 ,brazil nut husks1 balsa1 osage orange1 ,chinese velvet bean1 synthetic carbons 7from coal1 lamp-black1 etc471 cocoa bean shell1 coffee grounds1 flint corn1 corn cobs1 cotton seed husks1 peanut shells and oil shale4 ,while many of these substances might have been used in an emergency1 none of them would produce carbon as efficient1 volume for volume1 as that of the cocoanut shell and other hard nuts4 ,footnote #bh3 ,bancroft 7,j4 ,phys4 ,chem4 #bd1 #abg1 #bja1 #cdb #aibj7 gives a comprehensive review of 8,charcoal before the ,war40 ,footnote #bi3 ,part of this section is quoted from 8,armies of ,industry10 by ,crowell and ,wilson1 ,yale ,univ4 ,press4 ,some idea of the scale of charcoal production may be seen from the requirement for cocoanut shells4 ,when we first began to build masks our demands for carboniferous materials ranged from #dj to #ej tons a day of raw material2 by the end of the war1 we were in need of a supply of #djj tons of cocoanut shells per day4 ,this demand would absorb the entire cocoanut production of tropical ,america five times over4 7,the total production of cocoanuts in ,central ,america1 the ,west ,indies and the ,caribbean ,coast of ,south ,america amounted to #aca1jjj1jjj nuts annually1 equal to a supply of #ge tons of shells daily47 ,it was equal to one-tenth of the total production of the ,orient1 which amounted to #g1dej1bjj1jjj nuts annually4 ,this large demand always made a reserve supply of charcoal material practically impossible4 ,the 8,eat ,more ,cocoanut0 campaign started by the ,gas ,defense more than doubled the ,american consumption of cocoanut in a brief space of time and in ,october1 #aiah1 with the help of importation of shell1 we averaged about #aej tons of shells per day1 exclusive of the ,orient4 ,the first heating of cocoanut shells to make charcoal reduces their weight #ge per cent4 ,it was evident1 therefore1 that we could more economically ship our oriental supply in the form of charcoal produced on the other side of the ,pacific ,ocean4 ,a charcoal plant was established in the ,philippine ,islands and agents were sent to all parts of the ,oriental countries to purchase enormous supplies of shells4 ,while the work was only gaining momentum when the ,armistice was signed1 the plant actually shipped #cjj tons of cocoanut shell carbon to the ,united ,states and had over #ajjj tons on hand ,november #aa1 #aiah4 ,in the search for other tropical nuts1 it was found that the cohune or corozo nut was the best4 ,these nuts are the fruit of the manaca palm tree4 ,they grow in clusters1 like bananas or dates1 one to four clusters to a tree1 each cluster yielding from #fj to #ge pounds of nuts4 ,they grow principally on the west coast of ,central ,america in low1 swampy regions from ,mexico to ,panama but are also found along the ,caribbean coast4 ,the chief virtue of the cohune nut from the charcoal point of view was its extreme thickness of shell2 this nut is #c inches or more in length and nearly #b inches in diameter but the kernel is very small4 ,four thousand tons per month were being imported at the time of the ,armistice4 ,a disadvantage in the use of cohune nuts was that their husks contained a considerable amount of acid which rotted the jute bags and also caused the heaps of nuts to heat in storage4 ,a third source of tropical material was in the ivory nuts used in considerable quantities in this country by the makers of buttons4 ,there is a waste of #djj-ejj tons per month of this material1 which was used after screening out the dust4 ,this material is rather expensive1 because it is normally used in the manufacture of lactic acid4 ,another great branch of activity in securing carbon supplies was concerned with the apricot1 peach and cherry pits and walnut shells of the ,pacific ,coast4 ,a nation-wide campaign on the part of the ,american ,red ,cross was started on ,september #ac1 #aiah4 ,between this time and the ,armistice some #d1jjj tons of material were collected4 ,thus the slogan 8,help us to give him the best gas mask0 made its appeal to every person in the ,united ,states4 ,a ,,theory ,,of ,,charcoal ,,action ,it has been pointed out that the first charcoal was made from red cedar4 ,while this was very satisfactory when tested against chlorine1 it was of no value against chloropicrin4 ,in order to improve the charcoal still further it was desirable to have some theory as to the way charcoal acted4 ,it was generally agreed that fine pores were essential4 ,the functioning of charcoal depends upon its adsorptive power and this in turn upon its porosity4 ,the greater the ratio of its surface to its mass1 that is1 the more highly developed and fine grained its porosity1 the greater its value4 ,another factor1 however1 seemed to play a rle4 ,as a pure hypothesis1 at first1 ,chaney assumed that an active charcoal could only be secured by removing the hydrocarbon which he assumed to be present after carbonization4 ,being difficultly volatile1 these hydrocarbons prevent the adsorption of other gases or vapors on the active material4 ,to prove this1 red cedar charcoal was heated in a bomb connected with a pump which drew air through the bomb4 ,although the charcoal had been carbonized at #hjj1 various gases and vapor began to come off at #cjj1 and when cooled1 condensed to crystalline plates4 ,this experiment not only proved the existence of components containing hydrogen in the charcoal1 but also showed that one way of removing the hydrocarbon film on the active carbon was to treat with an oxidizing agent4 ,in the light of the later experimental work ,chaney feels that there are two forms of elementary carbon--8active0 and 8inactive02 the active form is characterized by a high specific adsorptive capacity for gas while the inactive form lacks this property4 ,in general the temperature of formation of the active form is below #ejj-fjj ,c4 ,the form is easily attacked by oxidizing agents--while the latter is relatively stable4 ,the combination of active carbon with an adsorbed layer or layers of hydrocarbon is known as 8primary0 carbon4 ,anthracite and bituminous coal are native primary carbons1 while coke contains a considerable amount of inactive carbon1 resulting from the decomposition of hydrocarbon during its preparation4 ,,preparation ,,of ,,active ,,charcoal 8,on the basis of the above discussion1 the preparation of active charcoal will evidently involve two steps3 8,first4--,the formation of a porous1 amorphous base carbon at a relatively low temperature4 8,second4--,the removal of the adsorbed hydrocarbons from the primary carbon1 and the increase of its porosity4 8,the first step presents no very serious difficulties4 ,it involves1 in the case of woods and similar materials1 a process of destructive distillation at relatively low temperatures4 ,the deposition of inactive carbon1 resulting from the cracking of hydrocarbons at high temperatures1 must be avoided4 ,the material is therefore charged into the retorts in thin layers1 so that the contact of the hydrocarbon vapors with hot charcoal is avoided as much as possible4 ,furthermore1 most of the hydrocarbon is removed before dangerous temperatures are reached4 ,a slight suction is maintained to prevent outward leaks1 but no activation by oxidation is attempted1 as this can be carried on under better control and with less loss of material in a separate treatment4 ,illustration3 ,,fig4 #fg4 ,dorsey ,reactor for ,activating ,cocoanut ,charcoal with ,steam4 8,the second step1 that is1 the removal of the absorbed hydrocarbons from the primary carbon1 is a much more difficult matter4 ,prolonged heating1 at sufficiently high temperatures1 is required to remove or break up the hydrocarbon residues4 ,on the other hand1 volatilization and cracking of the hydrocarbons at high temperatures is certain to produce an inactive form of carbon more or less like graphite in its visible characteristics1 which is not only inert and non-adsorbent1 but is also highly resistant to oxidation4 ,the general method of procedure which has yielded the best results1 is to remove the adsorbed hydrocarbons by various processes of combined oxidation and distillation1 whereby the hydrocarbons of high boiling points are broken down into more volatile substances and removed at lower temperatures1 or under conditions less likely to result in subsequent deposition of inactive carbon4 ,thin layers of charcoal and rapid gas currents are used so that contact between the volatilized hydrocarbons and the hot active charcoal may be as brief as possible4 ,in this way cracking of the hydrocarbons at high temperature1 with consequent deposition of inactive carbon1 is largely avoided4 8,while the removal of the hydrocarbons by oxidation and distillation is the main object of the activation process1 another important action goes on at the same time1 namely1 the oxidation of the primary carbon itself4 ,this oxidation is doubtless advantageous1 up to a certain point1 for it probably at first enlarges1 at the expense of the walls of solid carbon1 cavities already present in the charcoal1 thus increasing the total surface exposed4 ,moreover1 the outer ends of the capillary pores and fissures must be somewhat enlarged by this action and a readier access thus provided to the inner portions of the charcoal4 ,however1 as soon as the eating away of the carbon wall begins to unite cavities1 it decreases1 rather than increases1 the surface of the charcoal1 and a consequent drop in volume activity1 that is in the service time1 of the charcoal1 is found to result4 8,it is obvious1 therefore1 that conditions of activation must be so chosen and regulated as to oxidize the hydrocarbons rapidly and the primary carbon slowly4 ,such a differential oxidation is not easy to secure since the hydrocarbons involved have a very low hydrogen content1 and are not much more easily oxidized than the primary carbon itself4 ,furthermore1 most of the hydrocarbons to be removed are shut up in the interior of the granule4 ,on the one hand1 a high enough temperature must be maintained to oxidize the hydrocarbons with reasonable speed2 on the other hand1 too high a temperature must not be employed1 else the primary carbon will be unduly consumed4 ,the permissible range is a relatively narrow one1 only about #ej to #ge4 ,the location of the optimum activating temperature depends upon the oxidizing agent employed and upon other variables as well2 for air1 it has been found to lie somewhere between #cej and #dej1 and for steam between #hjj and #ajjj4 8,the air activation process has the advantage of operating at a conveniently low temperature4 ,it has the disadvantage1 that local heating and an excessive consumption of primary carbon occur1 so that a drop in volume activity results from that cause before the hydrocarbons have been completely eliminated4 ,as a consequence1 charcoal of the highest activity cannot be obtained by the air activation process40 ,the steam activation process has the disadvantage that it operates at so high a temperature that the regulation of temperature becomes difficult and other technical difficulties are introduced4 ,it has the advantage that local heating is eliminated4 ,the hydrocarbons can1 therefore1 be largely removed without a disproportionate consumption of primary carbon4 ,this permits the production of a very active charcoal4 ,it has the further advantage that it worked well with all kinds of charcoal4 ,inferior material1 when treated with steam1 gave charcoal nearly as good as the best steam-treated cocoanut charcoal4 ,because of the shortage of cocoanut1 this was a very important consideration4 ,illustration3 ,,fig4 #fh4--,section of ,raw ,cocoanut ,shell4 ,magnified #adf diameters4 ,the air1 steam and also carbon dioxide-steam activation processes have all been employed on a large scale by the ,chemical ,warfare ,service for the manufacture of gas mask carbon4 ,illustration3 ,,fig4 #fi4--,section of ,carbonized ,cocoanut ,charcoal4 ,magnified #adf ,diameters4 ,illustration3 ,,fig4 #gj4--,two-,minute ,charcoal not ,activated4 ,magnified #gcb ,diameters4 8,the above considerations are illustrated fairly well by the photo-micrographs shown in ,figs4 #fh to #ga4 ,fig4 #fh shows a section of the original untreated cocoanut shell crosswise to the long axis of the shell4 ,in it can be seen the closely packed1 thick-walled so-called #8stone-cells' characteristic of all hard and dense nut shells4 ,fig4 #fi is a photograph of a similar section through the same cocoanut shell after it has been carbonized4 ,as these photographs are all taken with vertical illumination against a dark background1 the cavities1 or voids1 and depressions all appear black1 while the charcoal itself appears white4 ,it is clear from this photograph that much of the original grosser structure of the shell persists in the carbonized products4 ,figs4 #gj and #ga are more highly magnified photographs of a carbonized charcoal before and after activation1 respectively4 ,as before1 all the dark areas represent voids of little or no importance in the adsorptive activity of the charcoal1 while the white areas represent the charcoal itself4 ,in ,fig4 #gj 7unactivated7 the charcoal itself between the voids it seen to be relatively compact1 while in ,fig4 #ga 7activated7 it is decidedly granular4 ,this granular structure1 just visible at this high magnification 7#ajjj diameters71 probably represents the grosser porous structure on which the adsorption really depends4 ,these photographs1 therefore1 show how the porosity is increased by activation40 ,illustration3 ,,fig4 #ga4--ca-,minute ,steam ,activated ,charcoal4 ,magnified #gcb ,diameters4 ,the great demand for charcoal1 and the need for activating other than cocoanut charcoal led to the development of the ,dressler tunnel kiln1 which seemed to offer many advantages over the ,dorsey type of treater4 ,illustration3 ,,fig4 #gb4--,sectional ,view of ,dressler ,tunnel ,kiln1 ,adapted to ,activation of ,charcoal4 8,the ,dressler tunnel kiln is a type used in general ceramic work4 ,the furnace consists essentially of a brick kiln about #aij ft4 long1 #ab ft4 broad1 and #i ft4 high1 lined with fire brick4 ,charcoal is loaded in shallow1 refractory trays in small tram cars1 about #abj trays to the car4 ,the cars enter the kiln through a double door and the charcoal remains in the hot zone at a temperature of about #hej ,c4 for about #d hrs41 depending upon the nature of the material charged4 ,water is atomized into this kiln1 and a positive pressure maintained in order to exclude entrance of air4 ,the kiln is gas-fired and the charcoal is activated by the steam in the presence of the combustion gases4 8,under such treatment the charcoal is given a high degree of activation without the usual accompanying high losses4 ,seemingly the oxidizing medium used1 together with the operating conditions1 produce a deep penetration of the charcoal particles without increasing the extensive surface combustion experienced in the steam activators4 ,the capacity of such a type furnace is limited only by the size of the installation4 8,the advantages of this type furnace may be tabulated as follows3 #a--;,high quality of product4 #b--,small weight and volume losses4 #c--,large capacity per unit4 #d--,minimum initial cost and maintenance of installation4 #e--,simplicity and cheapness of operation4 #f--;,adaptability to activation of all carbon materials4 #g--;,availability of furnaces of this general type already constructed40 ,,substitutes ,,for ,,nut ,,charcoal ,the first experiments were made with a special anthracite coal 7non-laminated and having conchoidal fracture74 ,this had a life of #efj minutes as against #cfj minutes for air treated cocoanut charcoal and #hjj-ijj minutes for steam-treated charcoal4 ,when the ,gas ,defense ,service tried to activate anthracite on a large scale in vertical gas retorts at ,derby1 ,connecticut1 the attempt was a failure4 ,they carbonized at #ijj and then turned on the steam with the result that the steam-treated coal had a slightly greater density than the untreated1 which was wrong1 and had a shiny appearance in parts with roughened deposits in other parts4 ,when the hydrocarbons are decomposed at high temperatures1 the resulting carbon is somewhat graphitic1 is itself inactive1 is not readily oxidized1 and impairs or prevents the activation of the normal carbon upon which it is deposited4 ,this discovery made it possible to treat anthracite successfully4 ,the conditions must be such as to minimize high temperature cracking1 to carry off or oxidize the hydrocarbons as fast as formed1 and especially to prevent the gases from cooler portions of the treater coming in contact with carbon at a much higher temperature4 ,with these facts in mind1 a plant was built at ,springfield which produced #aj tons a day of #aej-cjj minute charcoal from raw anthracite4 ,this was one-third of the total production at that time and was mixed with the nut charcoal made at ,astoria1 thereby preventing an absolute shortage of canister-filling material in ,october1 #aiah4 ,it was next shown that the cocoanut charcoal fines resulting from grinding and screening losses and amounting to #ej per cent of the product1 could be very finely ground1 mixed with a binder1 and baked like ordinary carbon products4 ,by avoiding gas-treating in the bake1 the resulting charcoal is nearly as good as that from the original shell4 ,a recovery plant for treating the cocoanut fines was built at ,astoria4 ,the product was called 8,coalite40 ,the great advantage of cocoanut shell as a source of charcoal is that it is very dense and consequently it is possible to convert it into a mass having a large number of fine pores1 whereas a less dense wood1 like cedar1 will necessarily give more larger pores1 which are of relatively little value4 ,the cocoanut charcoal is also pretty resistant to oxidation which seems to make selective oxidation a more simple matter4 ,by briquetting different woods1 it is possible to make charcoal from them which is nearly equal to that from cocoanut shell4 ,by heating lamp-black with sulfur and briquetting1 it was possible to make a charcoal having approximately the same service time as cocoanut charcoal4 ,a charcoal was made by emulsifying carbon black with soft pitch1 which gave the equivalent of #djj minutes against chloropicrin before it had been steam-treated4 ,this looked so good that the plans were drawn for making a thousand pounds or more of this product at ,washington to give it a thorough test4 ,this was not done on account of the cessation of all research work4 ,the possible advantage of this product was the more uniform distribution of binder4 ,instead of steam-treating anthracite coal direct1 it was also pulverized1 mixed with a binder1 and baked into rods which were then ground and activated with steam4 ,the resulting material1 which was known as ,carbonite1 had somewhat less activity than the lamp-black mixes but was very much cheaper4 ,a plant was built to bake #dj tons a day of this material1 which would yield #aj tons a day of active carbon after allowing for grinding losses and steam treatment4 ,the plant was guaranteed to furnish an absorbent having a life of #fjj minutes against chloropicrin4 ,,german ,,charcoal ,after the ,armistice was signed1 ,chaney took up the question of how the ,germans made their charcoal4 ,the ,german charcoal was made from coniferous wood and was reported to be as good as ours1 in spite of the fact that they were using inferior materials4 ,inside of a month ,chaney had found out how the ,german charcoal was made1 had duplicated their material1 and had shown that it was nothing like as good as our charcoal4 ,the ,germans impregnated the wood with zinc chloride1 carbonized at red heat1 and washed out most of the zinc chloride4 ,when this zinc chloride was found in the ,german charcoal1 it was assumed that it had been added after the charcoal had been made4 ,it was therefore dissolved out with hydrochloric acid1 thereby improving the charcoal against chloropicrin4 ,the ,german charcoal was then tested as it stood1 including the fines1 against ,american charcoal1 #h to #ad mesh4 ,the most serious error1 however1 was in testing only against a high concentration of chloropicrin4 ,the ,german charcoal contains relatively coarse pores which condense gases at high concentrations very well but which do not absorb gases strongly at low concentrations4 ,the result was that the ,german charcoal was rated as being four or five times as good as it really was4 ,illustration3 ,german ,charcoal4 #bjj4 ,illustration3 ,,fig4 #gc4--;,charcoal from ,spruce ,wood4 ,,comparison ,,of ,,charcoal ,the following table shows a comparison of charcoals from different sources4 ,the method of activation was identical and the times of treatment were those approximately giving the highest service time4 ,the results against chloropicrin1 therefore1 represent roughly the relative excellence of the charcoal obtainable from various raw materials1 using this method of activation3 ,,comparison ,,of ,,various ,,active ,,charcoals ,,activated ,,in ,,laboratory ---------------------------------------- ------------------------- ,accelerated ,apparent ,steam ,treatment ,chloropicrin ,density at #ijj ,test ,results ,base ,material ---------------------------------------- ----- ,primary,activated,time ,weight ,weight ,service ,carbon ,carbon ,min4 ,loss ,absorbed ,time ,per ,cent ,per ,cent ,min4 ---------------------------------------- ---------------------- ,sycamore #j4aeh #j4jhj #ah #ec #da #g4c ,cedar #j4bbc #j4jig #fj #hh #gh #af4j ,mountain mahogany #j4dbj #j4bcf #fj #dd #cb #af4c ,ironwood #j4dfe #j4cca #fj #dd #ca #bj4h ,brazil nut #j4ebj #j4caf #abj #ga #df #cb4b ,ivory nut #j4gjj #j4dfj #abj #gj #dh #dg4j ,cohune nut #j4fei #j4ejb #abj #dh #ea #ec4d ,babassu nut #j4edj #j4cbb #baj #fh #he #eh4g ,cocoanut #j4gaj #j4dde #abj #fj #fa #eh4d ,cocoanut #j4gaj #j4dag #ahj #ge #gb #fd4d ---------------------------------------- ---------------------- ,,briquetted ,,materials ---------------------------------------- ---------------------- ,sawdust #j4edb #j4cfe #abj #ff #ec #dj4j ,carbon black #j4gfi #j4ddd #bdj #fd4c #ec #ej4e ,bituminous coal #j4ghi #j4dcj #afe #fa #eh4c #df4h ,anthracite coal #j4hcj #j4cga #dhj #ha #ec #dj4g ---------------------------------------- ---------------------- 8,in conclusion1 it will be of interest to compare the charcoals manufactured and used by the principal belligerent nations1 both with one another and with the above mentioned laboratory preparations4 ,data on these charcoals are given in the following table3 ,,comparison ,,of ,,typical ,,production ,,charcoals ,,of ,,the ,,principal ,,belligerent ,,nations ---------------------------------------- ----------------------- ,apparent,service ,country ,date ,raw ,material ,density ,time ,remarks ,corr4 to #h-ad ,mesh ---------------------------------------- ----------------------- ,u4 ,s4 ,a4,nov4 #aiag ,cocoanut #j4fj #aj ,air activated ,u4 ,s4 ,a4,june1 #aiah,mixed nuts1 #j4eh #ah ,steam activated etc4 ,u4 ,s4 ,a4,nov4 #aiah ,cocoanut #j4ea #cd ,steam activated ,england #aiag ,wood #j4bg #f ,long distillation ,england ,aug4 #aiah ,peach stones1 #j4ed #af etc4 ,france #aiag-ah ,wood #j4bc #b ,germany ,early ,wood 8 #c ,chemical and steam treatment ,germany ,june1 #aiag,wood #j4be #cc ,chemical and steam treatment ,germany ,june1 #aiah,wood #j4bd #db ,chemical and steam treatment ---------------------------------------- ----------------------- 8,it is at once evident that the service time of most of these charcoals is very much less than was obtained with the laboratory samples4 ,however1 in the emergency production of this material on a large scale1 quantity and speed were far more important than the absolute excellence of the product4 ,it will be noted1 for instance1 that the cocoanut charcoal manufactured by the ,united ,states1 even in ,november1 #aiah1 was still very much inferior to the laboratory samples made from the same raw material4 ,this was not because a very active charcoal could not be produced on a large scale1 for even in ,may1 #aiah1 the possibility of manufacturing a #ej-min4 charcoal on a large scale had been conclusively demonstrated1 but this activation would have required two or three times as much raw material and five times as much apparatus as was then available1 due to the much longer time of heating1 and the greater losses of carbon occasioned thereby4 8,it should furthermore be pointed out that the increase in the chloropicrin service time of charcoal from #ah to #ej min4 does not represent anything like a proportionate increase in its value under field service conditions4 ,this is partly due to the fact that the increased absorption on the high concentration tests is in reality due to condensation in the capillaries1 which1 as has been pointed out1 is not of much real value4 ,more important than this1 however1 is the fact that most of the important gases used in warfare are not held by adsorption only1 but by combined adsorption and chemical reaction1 for which purpose an #ah-min4 charcoal is1 in general1 almost as good as a #ej-min4 charcoal40 ,,typical ,,absorptive ,,values ,,of ,,different ,,charcoals ,,against ,,various ,,gases ,,legend3 7,a7 ,h,o ,content1 77 7,b7 ,accel4 ,chloropicrin ,service ,time1 7,min47 7,c7 ,chloropicrin 7,d7 ,phosgene 7,e7 ,hydrocyanic ,acid 7,f7 ,arsine 7,g7 ,cyanogen ,chloride 7,h7 ,trichloromethylchloroformate 7,i7 ,chlorine ---------------------------------------- ----------------------- ,service ,time1 ,minutes ,standard ,conditions ,no4 ,charcoal ,nation --------------------- 7,a7 7,b7 7,c77,d77,e77,f77,g77,h77,i7 ---------------------------------------- ----------------- #a ,poor cocoanut ,u4 ,s4 ,a4 #j #aj #abjage #bj #ah #ee #ejbgj #b ,medium cocoanut ,u4 ,s4 ,a4 #j #cj #cejbfj #be #be #fe #fecgj #c ,good cocoanut ,u4 ,s4 ,a4 #j #fj #fbjcaj #bg #cj #ge #gjdbj #d ,same as ,no4 #b but wet ,u4 ,s4 ,a4#ab #ah #cbjccj #ce #af #ce #ie #e ,no4 #b impregnated,u4 ,s4 ,a4 #j #ce #djjgjj #gjdjj #gjaijeaj #f ,wood ,french #j #b4e #be #ge #i #j #a #bj #g ,wood ,british #j #f #gj #ij #ah #d #e #cj #h ,peach stone ,british #j #af #aijace #cj #be #fe #fj #i ,treated wood ,german #j #db #bcjaje #bj #bj #bb #be #aj ,no4 #i impregnated,german #cj #i #ijcbj #af #aaajabj ---------------------------------------- ----------------- ,,standard ,,conditions ,,of ,,tests ,mesh of absorbent #h-ad ,depth of absorbent layer #aj cm4 ,rate of flow per sq4 cm4 per min4 #ejj cc4 ,concentration of toxic gas #j4a per cent ,relative humidity #ej per cent ,temperature #bj ,results expressed in minutes to the #ii per cent efficiency points4 ,results corrected to uniform concentrations and size of particles4 ,,soda-,,lime ,charcoal is not a satisfactory all-round absorbent because it has too little capacity for certain highly volatile acid gases1 such as phosgene and hydrocyanic acid1 and because oxidizing agents are needed for certain gases4 ,to overcome these deficiencies the use of an alkali oxidizing agent in combination with the charcoal has been found advisable4 ,the material actually used for this purpose has been granules of soda-lime containing sodium permanganate4 ,its principal function may be said to be to act as a reservoir of large capacity for the permanent fixation of the more volatile acid and oxidizable gases4 ,the development of a satisfactory soda-lime was a difficult problem4 ,the principal requirements follow3 ,its activity is not of vital importance1 as the charcoal is able to take up gas with extreme rapidity and then later give it off more slowly to the soda-lime4 ,absorptive capacity is of the greatest importance1 since the soda-lime is relied upon to hold in chemical combination a very large amount of toxic gas4 ,both chemical stability and mechanical strength are difficult to attain4 ,the latter had never been solved until the war made some solution absolutely imperative4 ,,composition ,,of ,,regular ,,army ,,soda-,,lime ,the exact composition of the army soda-lime has undergone considerable modification from time to time as it has been found desirable to change the raw materials or the method of manufacture4 ,a rough average formula which will serve to bring out the interrelation between the different constituents is as follows3 ,,composition ,,of ,,wet ,,mix ,per ,cent ,hydrated lime #de ,cement #ad ,kieselguhr #f ,sodium hydroxide #a ,water #cc 7approx47 ,,after ,,drying ,moisture content #h 7approx47 ,,after ,,spraying ,moisture content #ac 7approx47 ,sodium permanganate content #c 7approx47 ,within limits1 the method of manufacture is more important than the composition or other variables1 and has been the subject of a great deal of research work even on apparently minor details4 ,the process finally adopted consists essentially in making a plastic mass of lime1 cement1 kieselguhr1 caustic soda1 and water1 spreading in slabs on wire-bottomed trays1 allowing to set for #b or #c days under carefully controlled conditions1 drying1 grinding1 and screening to #h-ad mesh1 and finally spraying with a strong solution of sodium permanganate with a specially designed spray nozzle4 ,the spraying process is a recent development1 most of the soda-lime having been made by putting the sodium permanganate into the original wet mix4 ,many difficulties had to be overcome in developing the spraying process1 but it eventually gave a better final product1 and resulted in a large saving of permanganate which was formerly lost during drying1 in fines1 etc4 ,,function ,,of ,,different ,,components ,lime4 ,the hydrated lime furnishes the backbone of the absorptive properties of the soda-lime4 ,it constitutes over #ej per cent of the finished dry granule and is responsible in a chemical sense for practically all the gas absorption4 ,cement4 ,cement furnishes a degree of hardness adequate to withstand service conditions4 ,it interferes somewhat with the absorptive properties of the soda-lime and it is an open question whether the gain in hardness produced by its use is valuable enough to compensate for the decreased absorption which results4 ,kieselguhr4 ,the loss in absorptive capacity due to the presence of cement is in part counterbalanced by the simultaneous introduction of a relatively small weight though considerable bulk1 of kieselguhr4 ,in some cases1 there seems to be a reaction between the lime and the kieselguhr1 which results in some increase in hardness4 ,sodium ,hydroxide4 ,sodium hydroxide has two primary functions in the soda-lime granule4 ,in the first place1 a small amount serves to give the granule considerable more activity4 ,the second function is to maintain roughly the proper moisture content4 ,this water content 7roughly #ac-ad per cent after spraying7 is very important1 in order that the maximum gas absorption may be secured4 ,sodium ,permanganate4 ,the function of the sodium permanganate is to oxidize certain gases1 such as arsine1#cj and to act as an assurance of protection against possible new gases4 ,the purity of the sodium permanganate solution used was found to be one of the most important factors in making stable soda-lime4 ,it was1 therefore1 necessary to work out special methods for its manufacture4 ,two such methods were developed1 and successfully put into operation4 ,footnote #cj3 ,which1 however1 was never used on the battlefield4 ,careful selection of other material is also necessary1 and this phase of the work contributed greatly to the final development of the form of soda-lime4 ,,chapter ,,xiv ,,testing ,,absorbents ,,and ,,gas ,,masks ,one of the first necessities in the development of absorbents and gas masks was a method of testing them and comparing their deficiencies4 ,while the ultimate test of the value of an absorbent1 canister or facepiece is1 of course1 the actual man test of the complete mask1 the time consumed in these tests is so great that more rapid tests were devised for the control of these factors and the man test used as a check of the purely mechanical methods4 ,,testing ,,of ,,absorbents#ca ,absorbents should be tested for moisture1 hardness1 uniformity of sample and efficiency against various gases4 ,footnote #ca3 ,see ,fieldner and others1 ,j4 ,ind4 ,eng4 ,chem41 #aa1 #eai 7#aiai74 ,moisture is simply determined by drying for two hours at #aej4 ,the loss in weight is called moisture4 ,the hardness or resistance to abrasion is determined by shaking a #ej-;gram sample with steel ball bearings for #cj minutes on a ,ro-tap shaking machine4 ,the material is then screened and the hardness number is determined by multiplying the weight of absorbent remaining on the screen by two4 ,the efficiency of an absorbent against various gases depends upon a variety of factors4 ,because of this1 it is necessary to select standard conditions for the test4 ,these were chosen as follows3 ,the absorbent under test is filled into a sample tube of specified diameter 7#b cm47 to a depth of #aj cm4 by the standard method for filling tubes1 and a standard concentration 7usually #a1jjj or #aj1jjj p4p4m4 by volume7 of the gas in air of definite 7#ej per cent7 humidity is passed through the absorbent at a rate of #ejj cc4 per sq4 cm4 per min4 ,the concentration of the entering gas is determined by analysis4 ,the length of time is noted from the instant the gas-air mixture is started through the absorbent to the time the gas or some toxic or irritating reaction product of the gas begins to come through the absorbent1 as determined by some qualitative test4 ,quantitative samples of the outflowing gas are then taken at known intervals and from the amount of gas found in the sample the per cent efficiency of the absorbent at the corresponding time is calculated4 ,per cent efficiency p4p4m4 entering gas - p4p4m4 effluent gas ---------------------------------------- - #ajj4 p4p4m4 entering gas ,these efficiencies are plotted against the minutes elapsed from the beginning of the test to the middle of the sampling period corresponding to that efficiency point4 ,a smooth curve is drawn through these points and the efficiency of the absorbent is reported as so many minutes to the #ajj1 #ii1 #ie1 #ij1 #hj1 etc41 per cent efficiency points4 ,the apparatus used in carrying out this test is shown in ,fig4 #gd4 ,descriptive details may be found in the article by ,fieldner in ,the ,journal of ,industrial and ,engineering ,chemistry for ,june1 #aiai4 ,with modifications for high and low boiling materials1 the apparatus is adapted to such a variety of gases as chlorine1 phosgene1 carbon dioxide1 sulfur dioxide1 hydrocyanic acid1 benzyl bromide1 chloropicrin1 superpalite1 etc4 ,as the quality of the charcoal increased1 the so-called standard test required so long a period that an accelerated test was devised4 ,in this the rate was increased to #a1jjj cc4 per minute1 the relative humidity of the gas-air mixture was decreased to zero1 and the concentration was about #g1jjj p4p4m4 ,the rate is obtained by using a tube with an internal diameter of #a4da cm4 instead of #b4j cm4 ,,canisters ,after an absorbent has been developed to a given point1 and is considered of sufficient value to be used in a canister1 the materials are assembled as described in ,chapter ,,xii4 ,while the final test is the actual use of the canister1 machine tests have been devised which give valuable information regarding the value of the absorbent in the canister and the method of filling4 ,illustration3 ,,fig4 #gd4--,standard ,two-tube ,apparatus for ,testing ,absorbents1 ,showing ,arrangement for ,gases ,stored in ,cylinders4 ,the first test must be that for leakage4 ,the canister must show no signs of leaking when submitted to an air pressure of #ae inches of mercury 7about half of the normal atmospheric pressure74 ,the second factor tested is the resistance to air flow4 ,this is determined at a flow of #he liters per minute and should not exceed #c inches4 ,the latest canister design has a much lower resistance 7from #b to #b inches74 ,the third test is the efficiency of the canister against various gases4 ,for routine work1 phosgene1 chloropicrin and hydrocyanic acid are used against the standard mixture of charcoal and soda-lime3 ,chloropicrin is usually used against straight charcoal fillings1 while phosgene and hydrocyanic acid are used against soda-lime4 ,illustration3 ,,fig4 #ge4--;,apparatus for ,testing ,canisters ,against ,chloropicrin4 ,different types of apparatus are required for these gases4 ,they are very complicated1 as may be seen from the sketch in ,fig4 #ge1 and yet a man very quickly learns the procedure necessary to carry out a test of this kind4 ,the gas is passed through the canister under given conditions1 until at the end of the apparatus a test paper or solution indicates that the gas is no longer absorbed but is passing through unchanged4 ,this point is called the 8break point10 and the time required to reach this point is known as the life of the canister4 ,this time is also the time to #ajj per cent efficiency4 ,other points1 such as #ii1 #ie1 #ij and #hj per cent efficiency are determined4 ,these are used in comparing canisters4 ,the canister tests were of two general classes3 continuous and intermittent4 ,in the first the air-gas mixture was drawn through continuously until the break point was reached4 ,the results obtained in this way1 however1 did not give the time measure of the value of a canister in actual use4 ,the intermittent test differs only in that the flow of air-gas mixture is intermittent1 corresponding to regular breathing4 ,special valves were adapted to this work4 ,canisters must also be tested as to the protection they offer against smoke4 ,these methods are discussed in ,chapter ,,xviii4 ,,man ,,tests ,the final test of the canister is always carried out by means of the so-called 8man test40 ,special man-test laboratories were built at ,washington1 ,philadelphia and ,long ,island4 ,these are so constructed that1 if necessary1 a man may enter the chamber containing the gas and thus test the efficiency of the completed gas mask4 ,in most cases1 however1 the canister is placed inside or outside the gas-chamber and the men breathe through the canister1 detecting the break point by throat and lung irritation4 ,the following brief description of the man test laboratory at the ,american ,university will give a good idea of the plan and procedure4#cb ,footnote #cb3 ,taken from ,fieldner's article mentioned above4 ,the man test laboratory is a one-story building1 #ef ft4 in length and #be ft4 in width4 ,the main part is occupied by three gas chambers1 laboratory tables1 and various devices for putting up and controlling gas concentrations in the chambers4 ,a small part at one end is used as an office and storeroom4 ,good ventilation is of great importance in a laboratory of this nature4 ,this is secured by means of a #f ft4 fan connected to suitable ducts4 ,the fan is mounted on a heavy framework outside and at one end of the building4 ,the fan is driven at a speed of about #bej r4p4m4 by a #aj h4p4 motor4 ,the main duct is #cc in4 square1 extending to all parts of the building4 ,a connection is also made to a small hood used when making chemical analyses4 ,the gases1 fumes1 etc41 drawn out by the fan1 are forced up and out of a stack #cj in4 in diameter1 extending upward #ee ft4 above the ground level4 ,the main features of each of the three gas chambers are identical4 ,auxiliary pieces of apparatus are used with each chamber1 the type of apparatus being determined by the characteristics of the gas employed4 ,illustration3 ,,fig4 #gf4--,man ,test ,laboratory1 ,american ,university4 ,each chamber is #aj ft4 long1 #h ft4 wide and #h ft4 high1 having1 therefore1 a capacity of #fhj cu4 ft4 or #ai1beg liters4 ,the floor is concrete1 and the walls and ceiling are constructed on a framework of #b #d in4 scantling1 finished on the outside with wainscoting and on the inside with two layers of ,upson board 7laid with the joints lapped7 covered with a in4 layer of special cement plaster laid upon expanded metal lath4 ,the interior finish is completed by two coats of acid-proof white paint4 ,the single entrance to the chamber is from outside the laboratory1 and is closed by two doors1 with a #cf #dj in4 lock between them4 ,these doors are solid1 of #c-ply construction1 #b in4 thick1 with refrigerator handles1 which may be operated from either inside or outside the chamber4 ,the door jambs are lined with _/ in4 heavy rubber tubing to secure a tight seal4 ,at the end of the chamber opposite the doors1 a pane of in4 wire plate glass1 #cf #dh in41 is set into the wall1 and additional illumination may be secured by #b headlights1 #ab in4 square1 set into the ceiling of the chamber and of the air-lock1 respectively1 and provided with #bjj watt ,mazda lamps and ,holophane reflectors4 ,openings into the chamber1 five in number1 are spaced across this end beneath the window and #i in4 above the table top4 ,fans are installed for keeping the concentration uniform4 ,illustration3 ,,fig4 #gg4--;,details of ,canister ,holder4 ,various devices have been installed for attaching the canister to be tested 7,fig4 #gg74 ,this arrangement allows the canister to be changed at will without any necessity for disturbing the concentration of gas by entering the chamber4 ,arrangements for removing the gas from the chamber consist of a small 8bleeder0 which allows a continuous escape of small amounts and a large blower for rapidly exhausting the entire contents of the chamber4 ,other general features of the equipment deal with the determination of the physical condition surrounding the tests1 often a matter of considerable importance4 ,the temperature of the gas inside the chamber is easily ascertained by means of a thermometer suspended inside the window in such a position as to be read from the outside4 ,the relative humidity of the mixture of air and gas in the chamber is determined by means of a somewhat modified ,regnault dew point apparatus mounted on the built-in table4 ,,pressure ,,drop ,,and ,,leak ,,detecting ,,apparatus ,another piece of apparatus consists of a combined pressure drop machine and leak tester 7,fig4 #gh7 for measuring the resistance of canisters and testing them for faulty construction4 ,this is mounted on a small table1 with the motor and air pump installed on a shelf underneath4 ,the resistance1 or pressure drop1 of canisters is measured by the flow meter ,a and the water manometer ,b4 ,air is drawn through the canister and the flow meter ,a at the rate of #he liters per min41 the flow being adjusted by the needle valve4 ,the pressure drop across the canister is read on the water manometer ,b1 one end of which is connected to the suction line1 the other open to the air4 ,the reading is generally made in inches1 correction being made for the resistance of the connecting hose and the apparatus itself4 ,canisters are tested for leaks by the apparatus shown at ,d in ,fig4 #gh4 ,the canister is clamped down tightly by wing nuts against a piece of heavy -in4 sheet rubber large enough to cover completely the bottom of the canister and prevent any inflow of air through the valve4 ,suction is then applied1 and a leak is indicated by a steady flow of air bubbles through the liquid in the gas-washing cylinder ,e4 ,a second gas-washing cylinder1 empty1 is inserted in the line between ,e and the canister as a trap for any liquid drawn back when the suction is shut off4 ,if a leak is shown1 it can be located by applying air pressure to the canister and then immersing it in water4 ,illustration3 ,,fig4 #gh4--;,apparatus for ,determining ,pressure ,drop and for ,detecting ,leaks in ,canisters4 ,,methods ,,of ,,conducting ,,tests ,three general methods of conducting man tests are followed3 7#a7 ,canisters are placed in the brackets outside the chamber or fastened to the wall tubes within the chamber4 ,the subjects of the test remain outside the chamber1 and the facepieces of the masks are connected directly to the canisters1 in the first case1 and to the wall tubes connecting with the canisters1 in the second case4 ,the concentration is established and the time noted4 ,then the men put on the masks and breathe until they can detect the gas coming through the canisters4 ,reading matter is provided for the men during the test period4 ,when gas is detected1 the time is again noted and the time required for the gas to penetrate the canister is reported as the 8time to break down0 or 8service time0 of the canister4 ,ten canisters are tested at one time1 and the average of the results for the #aj canisters is taken for that type of canister4 ,much less accurate results are obtained when the final figure is based on a small number of canisters4 ,this is largely due to the various breathing rates and sensitiveness of different men4 7#b7 ,the canisters are placed as in 7#a71 but it is only necessary to know if they will give perfect protection for a given length of time4 ,the procedure is the same as in 7#a71 except that the test is arbitrarily stopped at the end of the indicated time1 and the number of canisters and the service times of the same noted4 7#c7 ,when the canisters are of such a type that they cannot be properly tested as in 7#a71 or when it is desired to test the penetrability of the facepiece1 the men wear the complete mask and enter the chamber4 ,they remain until gas penetrates the canister or the facepiece1 as the case may be1 or until it is determined that the desired degree of protection is afforded4 ,the service time is computed as in 7#a74 7#d7 ,maximum-breathing-rate tests are made either by men in the chamber or by the men outside1 in which they do vigorous work on a bicycle ergometer4 ,in this test the average man will run his breathing rate up to #fj or #gj liters per min4 ,the concentration of the gas is followed throughout the test by aspirating samples and analyzing them4 ,type of ,masks ,used4 ,in the future the #aiai model will be used for all tests4 ,in general1 during the ,war1 the following procedure held1 although variations occurred in special cases3 ,when men entered a gas-chamber1 the full facepiece was1 of course1 required4 ,the type of facepiece was determined by the nature of the gas4 ,if the gas was most easily detected by odor or eye irritation1 a modified ,tissot mask was used4 ,if it was most easily detected by throat irritation1 a mouth-breathing mask was employed4 ,when men were outside the chamber1 the choice was made in the same manner1 except in the case of detection of the gas by throat irritation4 ,in this case the mouthpiece was attached to two or three lengths of breathing tubes and a separate noseclip was used4 ,the facepiece was not needed and the men were much more comfortable without it4 ,disinfection of ,masks4 ,mouthpieces are disinfected after use by first holding them under a stream of running water and brushing out thoroughly with a test tube brush2 then the latter is dipped into a #b per cent solution of lysol1 and the inner parts of the mouthpiece are brushed out well2 finally the mouthpiece and exhaling valve are dipped bodily into the lysol solution and allowed to dry without rinsing4 ,tissot masks are wiped out with a cloth moistened in alcohol1 followed by another cloth moistened in #b per cent lysol solution4 ,the flexible tubes are given periodic rinsings with #ie per cent alcohol4 ,applicability of ,man ,tests4 ,man tests are applicable to all gases which can be detected by the subject of the test before he breathes a dangerous amount4 ,the man test laboratory described above provides facilities for obtaining information concerning the efficiency of canisters1 facepieces1 etc41 within very short periods of time1 without waiting for the construction of special apparatus required for machine tests4 ,to get satisfactory results from machine tests1 a delicate qualitative chemical test for the gas is essential4 ,man tests can be made when such a qualitative test is not known4 ,further1 man tests can be made with higher concentrations of some gases than is practicable with machines4 ,evolution of excessive amounts of moisture when high concentrations of some gases are used causes much more trouble with machine tests than with man tests4 ,on the other hand1 man tests are adversely affected by the varying sensitiveness and lung capacities of the men1 and the humidity of the air-gas mixture is not subject to as exact control as is the case with machine tests4 ,,field ,,tests ,it will be observed that all of the above tests are concerned only with the efficiency of the absorbent and its packing in the canister4 ,no attempt was made to determine the comfort and general 8feel0 of the mask4 ,for this purpose field tests were devised1 covering periods from two to five hours4 ,the first test was a five-hour continuous wearing test4 ,it was assumed that any mask which could be worn for five hours without developing any marked features of discomfort could1 if the occasion demanded it1 be worn for a much longer period of time4 ,a typical test follows3 #h3jj to #h3cj ,instruction and adjustment of gas mask4 ,gas-chamber tests #h3cj to #i3cj ,games involving mental and physical activity #i3cj to #aa3cj ,cross-country hike with suitable periods of rest #aa3cj to #ab3jj ,tests of vision #ab3jj to #ab3cj ,games to test mental condition of subjects #ab3cj to #a3jj ,gas-chamber fit test ,illustration3 ,,fig4 #gi4--;,hemispherical ,vision ,chart4 ,vision was tested by means of a hemispherical chart 7,fig4 #gi74 ,this chart was #f ft4 in diameter and was constructed of heavy paper laid over a wire frame4 ,a hinged head rest was provided for holding the subject's head firmly in position with the center directly between the eyes4 ,the subject wearing the mask took up his position1 and with one eye closed at a time1 indicated how far along the meridian of longitude he could see with the other eye4 ,the observer sketched in the limit of vision by outlining the perimeter of the roughly circular field allowed by each eyepiece4 ,the intersection of the two fields gave the extent of binocular vision possible with the mask4 ,various other tests were also used1 in order that the extent and nature of the vision could be accurately determined4 ,aside from the problems of comfort1 protection1 vision and other important features of gas mask efficiency1 the question arose as to whether certain designs of masks or canisters were mechanically able to withstand the rough treatment they were certain to receive in actual field service4 ,a test was1 therefore1 developed to simulate such service as transportation of masks from base depots to the front1 carrying of supplies and munitions by men wearing masks in the 8alert0 position1 exposure to rain and mud1 hasty adjustment of masks during gas alarms and typical mistreatment of masks by the soldiers4 ,all these tests were of great value in the development of a good gas mask4 ,,chapter ,,xv ,,other ,,defensive ,,measures ,,protective ,,clothing ,protective clothing was an additional feature of the general program of protection4 ,as far as factory protection is concerned1 the use of protective garments was more or less of a temporary expedient and they were abandoned as fast as automatic machinery and standard practice made their use less necessary4 ,it is likewise a question regarding their value at the front4 ,it is very certain that the garments developed needed to be made lighter and more comfortable to be of much value to the fighting unit4 ,the first development of protective clothing was along the lines of factory protection4 ,the large number of casualties in connection with the manufacture of mustard gas made it imperative that the workmen be protected not only from splashes of the liquid mustard gas1 but also from its vapors4 ,the first suit developed provided protection to the entire body4 ,the ordinary clothing materials and even rubberized fabrics offered little protection but it was found that certain oilcloths were practically impermeable to mustard gas4 ,the suit was a single garment1 buttoning in the back1 with no openings in the front1 no pockets and with tie-strings at wrists and ankles4 ,the head was protected by means of an aluminium helmet1 supported by means of a head band resting on the head like a cap and slung from the inside of the helmet2 this permitted slight head motions independent of the helmet4 ,in order to provide cooling and ventilating and pure air breathing1 the suit was inflated by pumping a considerable volume of air into the suit through a flexible hose long enough to permit considerable freedom of movement4 ,this suit had the very great disadvantage of limiting the range of motion to the length of the hose4 ,because of this1 a ,tissot type mask was used in place of the helmet and hose connections4 ,the hood was made of the same special oilcloth as the suit1 enveloped the head and neck and extended a short distance down the back and over the chest4 ,the canister was slung on the left hip by an oilcloth harness and was kept from swinging by an oilcloth belt around the waist4 ,the canister was much larger than the standard box respirator1 had a much longer life with lower resistance and weighed about #c4e lbs4 ,illustration3 ,,fig4 #hj4--;,impervious ,overall ,suit for ,mustard ,gas4 ,another type of impervious overall suit was developed which protected against mustard gas for over #ajj minutes4 ,the material was a cotton sheeting which was impregnated with linseed oil containing a suitable non-drying material1 which was thoroughly oxidized in the fabric4 ,these suits proved to be very uncomfortable1 especially in warm weather1 because they entirely prevented the escape of perspiration from the body4 ,semi-permeable suits were then prepared1 in which the cotton sheeting was impregnated or coated with a solution of gelatin and glycerine4 ,the fabric was then 8tanned0 to render the gelatin insoluble in water4 ,such a suit is valuable for factory wear1 but the impregnating material is easily leached out and the suit is therefore not recommended for field service4 ,this was built with an inside layer of dry cloth together with an outside layer of treated cloth to afford the necessary chemical protection against mustard gas4 ,work of fabrication consisted in treating the cloth with simplexene1 cutting the suits to design and size1 and sewing them together4 ,treatment consisted in passing the fabric through a dye machine1 then through the wringer rolls where the excess oil was expressed4 ,the inner layer of dry cloth was found necessary1 since the cloth was cut as soon as treated4 ,simplexene does not attain the maximum degree of 8tackiness0 for two or three days1 owing to the presence in the oil of a small amount of volatile spirits4 ,however1 by allowing the cloth to air for #dh hours before cutting1 the inner lining could probably be dispensed with4 ,the fighting suits were distributed among various detachments using mustard gas in field tests1 and in other places where protection against vapor was needed and where field conditions were approximated4 ,the tests showed that the suit gave satisfactory protection for considerable periods against mustard gas vapors4 ,no other suit1 equal both in porosity and protection1 has yet been submitted1 although samples furnishing better protection with much higher resistance have been examined4 ,the protection of the simplexene suit is about #cj minutes against saturated gas4 ,a large number of these suits were made and taken abroad for field tests at the front4 ,,protective ,,gloves ,protective gloves have been made with a variety of impregnating agents4 ,the one which was selected for large scale production was impregnated with a solution of cellulose nitrate because of the availability of materials and the protection offered by the finished product4 ,the material is impregnated after being made up4 ,the one finger type of glove is used4 ,the gloves are placed on wooden forms and dipped into the impregnating solution4 ,after draining a few minutes1 the gloves are turned upside down on racks and run through a drying oven4 ,finally they are removed from the forms and conditioned by drying at a moderate temperature for several hours4 ,after being properly cured they are fitted with two straps on the gauntlet of each glove4 ,they should offer protection to chloropicrin 7standard method of test7 for #cj minutes4 ,when subjected to rough work they will last from one to two weeks4 ,illustration3 ,,fig4 #ha4--;,coated ,gloves for ,protection against ,mustard ,gas4 ,,protective ,,ointments ,the extensive use of mustard gas on the field caused the men to be exposed to low concentrations of the vapors for extended periods of time4 ,since it did not seem feasible to furnish the men with special fighting suits1 which would protect them against these vapors1 it was desirable to provide protection in the form of an ointment which could be applied to the body4 ,in order to be satisfactory an ointment should have the following properties3 7a7 ,it should protect against saturated mustard gas during the longest possible exposure4 7b7 ,its protective action should last as long as possible after the application of the ointment4 ,it was felt that the ointment should give protection for #bd hours after it is applied1 even if the body is perspiring freely4 7c7 ,the material should not be easily rubbed off under the clothing4 7d7 ,it should be non-irritating to the membranes of the body4 7e7 ,there should be no likelihood of toxic after-effects on long use4 7f7 ,it should be of a good consistency under a fairly wide temperature range and give a good coating at the temperature of the body4 7g7 ,its method of manufacture should be simple and rapid1 and the raw materials required should be abundant4 7h7 ,the cost should not be excessive4 ,an extensive study of this question was made both in the laboratories and on the field4 ,at first it was believed that successful results could be obtained by the use of such ointments4 ,careful investigation showed1 however1 that while these ointments really did protect against rather high concentrations of vapor for short times of exposure1 they were probably not so valuable when used against low concentrations over an extended period of time4 ,it was further demonstrated that the protection furnished by a coating of linseed oil is practically equal to the best ointment which has been developed4 ,about #aej ointments were prepared and tested4 ,these consisted of two parts or components1 the metallic soap or other solid material and the oil or liquid part which bound and held the solid4 ,the latter is called the base4 ,the best base is lanolin1 containing #cj per cent of water4 ,a solution of wax in olive oil was next best4 ,of the metallic soaps the oleates and linoleates are better than the stearates4 ,a satisfactory ointment has the following composition3 ,zinc oxide #dj ,linseed oil 7raw7 #bj ,lard #bj ,lanolin #bj ,a modification of this formula is3 ,zinc oxide #de ,linseed oil #cj ,lard #aj ,lanolin #ae ,the physical properties of this ointment are very good4 ,it forms a smooth1 even coating on the skin1 sticks well enough not to rub off easily on the clothing and yet is not sticky4 ,its consistency is such that it can be readily pressed from an ointment tube4 ,a4 ,e4 ,f4 reports indicate that sag paste 7zinc stearate and vegetable oil7 is as satisfactory as any of the preparations tried4 ,the great difficulties of such preparation from a field point of view are3 ,extra weight to be carried by the soldiers1 necessity for keeping in tight boxes or tubes1 thereby adding to the difficulty of carrying1 and finally1 the difficulty encountered when applying it properly to the body in the field1 where gas contaminated hands may cause harm4 ,the paste was too late a development for thorough field trial4 ,it was used just enough to cause severe partisan controversies between its advocates and those opposed to it4 ,unquestionably1 it proved of decided value in preventing mustard gas burns when properly applied4 ,there are many authentic cases where men alongside each other were similarly gassed except as to burns4 ,the difference in burns arose from the use or non-use of the paste1 and in some cases of poor application4 ,fries is of the opinion that had the war lasted another year the use of pastes would have become universal unless some thoroughly successful substance for impregnating the uniform or underclothing had been developed4 ,this is likewise his belief for the future4 ,,protection ,,of ,,animals ,horse ,mask4 ,the need of protection for animals 7horses and dogs71 although not as great as in the case of men1 was of sufficient importance so that masks and boots were developed for the horse and a mask for the dog4 ,the ,german horse mask was the first produced4 ,it was of the nose bag type1 enveloping the mouth and nose of the animal4 ,it was fitted with a complicated drawstring and with snap hooks fastening it to the harness4 ,the interior contains a plate of stiff material to prevent the collapse of the bag4 ,the mask itself was apparently not impregnated1 but was used wet or with a filling of wet straw or rags to act as the absorbent4 ,illustration3 ,,fig4 #hb4--;,german ,respirator for ,horses4 ,the ,french had two types of horse masks impregnated with a glycerine-nickel hydroxide mixture4 ,one type had a closed bottom1 while in the other1 the bottom was open4 ,the ,british horse mask has a two-layer flannelette bag1 with a canvas mouth pad and elastic drawstring4 ,it was impregnated with a mixture of phenol1 formaldehyde1 ammonia1 canister soda and glycerine4 ,the first type of ,american horse mask was modelled after the ,british and was impregnated with the ,komplexene mixture 7hexamethylenetetramine1 glycerine1 nickel sulfate mixture74 ,this mask had too high a resistance and caused complete exhaustion in running horses4 ,the second mask was made of a large number of layers of very open cheesecloth4 ,it consists of two bags1 impregnated with different mixtures 7,komplexene and ,simplexene74 ,horses can run two miles with this mask without showing evidences of exhaustion4 ,dewey gives the following method of manufacture3 ,the chemical employed consisted of a mixture of hexamethylenetetramine 7to give protection against phosgene71 nickel sulfate 7to protect against the possible use of hydrocyanic acid71 sodium carbonate and glycerine4 ,this solution was mixed in a heavy steam jacketed mixing kettle with heavy geared stirrers4 ,the mixture was conducted by pipes to the impregnating apparatus which consisted of a rotary laundry washing machine4 ,the masks were treated in this machine for #ae minutes1 and then placed in a power operated wringer and the solution driven off to a given weight4 ,following this operation1 they were suspended on wire supports and conducted through a hot air drying machine and dried to a definite weight4 #cgh1jjj horse masks were produced at the rate of #e1jjj per day4 ,illustration3 ,,fig4 #hc4--;,horse ,mask--,american ,type4 ,theoretically1 horse masks and horse boots are very valuable1--practically1 they did very little actual good in the field1 not that they would not protect or that animals would not wear them4 ,the trouble was with the riders and drivers4 ,gas attacks1 coming usually at night1 made adjustment of horse masks difficult at best1 while in the confusion of bursting shell and smoke1 the drivers absolutely forgot the horse masks or after putting on their own masks feared to try putting masks on the animals4 ,this last was natural as most animals fight the adjustment of the mask and in so doing there is great risk that the man's mask may be torn off and the man gassed4 ,in the future1 such masks will have even more importance than in the past1 for the present methods of manufacture of mustard gas coupled with its all-round effectiveness will cause a use of it ten-fold greater than at any time in the ,world ,war4 ,in such cases1 operations will necessarily be frequently carried on over large areas thoroughly poisoned with mustard gas4 ,here the animals will be masked and booted before entering the gassed area1 and remain so until they leave it4 ,in the torn and broken ground around the front line there will always be need for animal transportation1--wagon1 cart and horse--as in such places it is far better in nearly all cases than motor transport4 ,dog ,mask4 ,the use of dogs in messenger service and in ,red ,cross work1 in which gassed areas must be passed1 led to the designing of a mask to give the animals suitable protection4 ,the same materials and method of impregnation were used as in the horse mask4 ,with eight layers of cheesecloth1 adequate protection against mustard gas was secured with practically no pressure drop4 ,the eyepieces were made of thin sheets of cellulose acetate bound around the edge with adhesive tape and sewed directly over openings cut through the mask fabric4 ,the ear pockets were made round and full enough to fit pointed or lop-eared animals4 ,the mask is continued to form a wide neck band which may be drawn up by two adjustable straps4 ,it is made sufficiently full to allow a free movement of the dog's jaws and yet tight enough around the neck to avoid the possibility of being pawed off4 ,the dog apparently soon became accustomed to wearing the mask4 ,horse ,boots4 ,the increasing amount of mustard gas used on the ,western front made it seem necessary to develop some form of protection for the horse's hoof and fore-leg4 ,it has been found that mustard gas vapors attack the fleshy portion of the leg1 especially around the coronary band and causes inflammation of the frog of the foot4 ,the problem was solved by devising a special hoof pad and a boot4 ,the pad was made of sheet iron imbedded in a hoof protector 7composition rubber7 to which the shoe is applied4 ,the shoe just overlaps the metal plate on the inside and provides a solid metal surface for the bottom of the foot4 ,such a pad not only offers protection against gas but against shell splinters1 barbed wire1 etc41 and would be useful at all times on the front4 ,illustration3 ,,fig4 #hd4--;,impervious ,boots and ,pads to ,protect ,horses' ,legs and ,hoofs against ,mustard ,gas4 ,illustration3 ,,fig4 #he4--,protective ,gas ,outfit--,gas ,mask1 ,gas ,suit1 ,gloves1 ,boots1 ,horse ,mask1 ,horse ,boots1 ,horse ,pads4 ,the boot was made of satin1 treated so as to be impervious to mustard gas4 ,it covers all of the foot except the bottom and extends to just below the knee4 ,the boot is held in contact with the hoof by a sewed cloth strap1 which passes around the bottom of the hoof and is held in position by projections extending from the spur or toe clip4 ,special care is taken to insure a perfect joint at the rear of the boot since the small cavity in the back of the hoof is one of the most sensitive parts4 ,the boot is wrapped about one and a half times around the leg and is clipped with five loops through which passes a -inch strap4 ,dugout ,blankets4 ,dugout protection is intended to prevent entrance of any gases1 lethal1 lachrymatory or irritant1 into the enclosed space4 ,this has been most efficiently accomplished by means of curtains hung upon wooden frames and fitting closely against all edges of the opening to be closed4 ,these curtains have usually been of heavy material and have generally been spoken of as dugout blankets4 ,since they were designed to exclude all toxic gases1 they had to be devised upon general mechanical principles rather than upon principles of chemical action with specific gases4 ,permeability to air has not been considered a necessity1 it being held that sufficient ventilation is secured by means of the air entering through the soil4 ,for large dugouts and extended use large air filters were designed to draw pure air into the dugout with a fan4 ,the qualities aimed at1 to which both fabric and treatment should contribute1 are the following3 7a7 ,impermeability to gas4 7b7 ,flexibility1 especially at low temperatures4 7c7 ,non-inflammability4 7d7 ,freedom from stickiness and from tendency to lose material by drainage under action of gravity4 7e7 ,mechanical strength4 7f7 ,simplicity of manufacture and treatment4 7g7 ,low cost4 ,army blankets1 both those for men and those for horses1 proved suitable materials for curtains1 but the scarcity of wool made it desirable to select an all cotton fabric4 ,a large number of oils were studied as impregnating agents4 ,the most satisfactory mixture consisted of #he per cent of a heavy steam refined cylinder oil and #ae per cent of linseed oil4 ,this is taken up to the extent of about #cjj per cent increase in weight of the blanket during impregnation4 ,it becomes oxidized to some extent upon the surface of the blanket1 which becomes less oily than the soft1 central core4 ,the finished blanket possessed the following properties3 ,it resists penetration of #djj-fjj p4p4m4 of chloropicrin for #h hours 7dugout test7 and mustard gas for #ajj-djj minutes 7machine test74 ,it is sufficiently flexible after standing for #b hours at #ah ,f4 to unroll of its own weight1 and may be unrolled by applying a slight force at #f ,f42 it is not ignited by lighted matches and shows but little loss by drainage4 ,two types of machines were designed for impregnation1 one for use on large scale behind the line1 and a field apparatus for use at the front4 ,,chapter ,,xvi ,,screening ,,smokes ,the intelligent use of screening smokes in modern infantry tactics offers innumerable advantages through concealment and deception4 ,it confers upon daylight operations many of the advantages which were gained by conducting operations at night with few of the disadvantages of the latter4 ,smoke screens have been frequently used by the ,navy and by ,merchantmen2 a common method of escape was to shut off the air from the fire with consequent incomplete combustion of the fuel1 thus causing a cloud of dense black smoke4 ,this is often mentioned in the blockade runners of the days in the ,civil ,war1 where wood1 high in pitch and rosin1 was freely introduced into the furnaces1 in order that they might escape under cover of this smoke4 ,early in the present war it was found that black smoke had a low obscuring power1 showed frequent rents or holes and were difficult to standardize4 ,their production also caused a considerable loss in the speed of the vessel4 ,they therefore fell into disuse except for emergency purposes and today the standard smoke for screening purposes of all kinds is1 without exception1 white4#cc ,footnote #cc3 ,while it is a well known fact that black smoke is not as efficient as white smoke for screening purposes1 the reason for this fact is not clear4 ,,properties ,,of ,,smoke ,,cloud ,the properties most desired in a screening smoke1 apart from low cost1 are3 7a7 ,maximum screening power1 which refers to the question of density1 i4e41 a relatively thin layer must completely obscure any object behind it1 and 7b7 ,stability1 which implies1 among other things1 a low rate of settling or dissipation4 ,there is little reason to doubt that1 within limits1 the smaller the particles of a smoke cloud1 the more completely will the smoke possess these qualities4 ,the screening power of a smoke cloud depends very largely upon the scattering of the light coming through it1 and by analogy with those peculiar solutions which we call colloidal1 we should expect the scattering to increase as the degree of subdivision increases1 within limits4 ,the rate of settling is unquestionably an inverse function of the size of the particles4 ,the chief aim1 therefore1 in smoke production is to attain as high a degree of subdivision as possible4 ,methods may be classified as good or bad1 in so far as they satisfy or fail to satisfy this criterion4 ,,raw ,,materials ,,for ,,smoke ,,clouds ,it is obvious that only gases or substances capable of being brought into the vapor state or into a very fine state of subdivision can be used for producing smoke clouds4 ,the reaction product1 of which the smoke particles consist1 should preferably be3 7a7 ,solid4 ,otherwise the particles will tend to grow in size by condensation of the liquid particles present in the cloud4 7b7 ,non-volatile4 ,if volatile1 the particles will disappear by evaporation as the cloud is diluted by air currents4 ,larger particles will also form at the expense of the smaller ones4 7c7 ,non-deliquescent4 ,if the particles are deliquescent1 they will tend to grow by condensation of water vapor upon them4 7d7 ,stable towards the usual components of the atmosphere1 especially moisture4 ,while it might seem that it would be difficult to fulfill these conditions1 there are several chemical compounds which have been successfully used as smoke producers4 ,this does not mean that they fulfill all the conditions1 but they represent a compromise between the various requirements4 ,phosphorus4 ,one of the earliest materials to be used in smoke clouds was phosphorus4 ,this is prepared on a commercial scale by heating phosphate rock 7which contains calcium phosphate7 with sand and coke in an electric furnace4 ,phosphorus occurs in two forms1 white and red4 ,white phosphorus1 which is formed when the vapor of the substance is quickly cooled1 is1 in the pure state1 almost colorless1 melts at #dd ,c41 boils at #bhg ,c41 is readily soluble in various solvents1 and is luminous in the air1 at the same time emitting fumes 7the oxidation product1 phosphorus pentoxide74 ,on gentle warming in the air1 it takes fire and burns with a brightly luminous flame4 ,red phosphorus is obtained by heating white phosphorus out of contact with the air1 to a temperature of #bej to #cjj ,c4 ,red crusts then separate out from the colorless liquid phosphorus1 and almost the entire amount is gradually converted into a red1 solid mass4 ,if this is freed by suitable solvents from the small amounts of unchanged white phosphorus1 a dark red powder is obtained1 which remains unchanged for a long time in the air1 does not appreciably dissolve in the solvents for white phosphorus1 does not become luminous1 and can be heated to a fairly high temperature without igniting4 ,further1 red phosphorus is not poisonous1 while white phosphorus is highly so4 ,either form burns to phosphorus pentoxide1 which is converted by the moisture of the air to phosphoric acid1 #d,p #e,o #b ,p,o #b,p,o #f;,h,o #d;,h,,po ,since one pound of phosphorus takes up #a4cc pounds of oxygen and #j4i pound of water1 it is not surprising that phosphorus is one of the best smoke producers per pound of material4 ,comparison of the value of the two forms for shell purposes have invariably pointed to the superiority of the white variety4 ,in addition to its use as a smoke producer1 it is used in incendiary shell and in tracer bullets4 ,for incendiary purposes a mixture of red and white phosphorus is superior4 ,chlorosulfonic ,acid4 ,chlorosulfonic acid1 ,cl,s,o,,oh1 was first employed by the ,germans to produce white clouds1 both on land and on sea4 ,for this purpose1 they sprayed or dropped it onto quicklime1 the reaction between it and the lime furnishing the heat necessary for volatilization1 though in this way about #cj per cent of the acid is wasted4 ,chlorosulfonic acid is obtained from sulfur trioxide and hydrogen chloride1 which combine when gently heated3 ,,so ,h,cl ,cl,s,o,,oh ,illustration3 ,,fig4 #hf4--ge mm4 ,white ,phosphorus ,shell4 #b seconds after bursting4 ,on a commercial scale1 hydrogen chloride is passed into #bj per cent oleum1 until saturation is reached4 ,this is heated in a nitric acid still1 when the chlorosulfonic acid distills over between #aej-afj ,c4 ,with #cj per cent oleum1 the conversion factor is about #db per cent4 ,the residue in the still is about #ih per cent sulfuric acid4 ,it forms a colorless liquid1 boiling at #aeb ,c41 and having a density of #a4g4 ,chlorosulfonic acid fumes in the air1 because reaction with water forms sulfuric acid and hydrochloric acid4 ,cl,s,o,,oh ,h,o ,h,,so ,h,cl ,this material was not used by the ,united ,states since oleum was found superior4 ,oleum4 ,oleum is a solution of #bj to #cj per cent sulfur trioxide 7,,so7 in concentrated sulfuric acid4 ,it has been used by the ,germans to produce clouds on land and sea1 by its contact with quicklime1 and by the ,americans for screening tanks and aeroplanes4 ,sulfur trioxide has been found to be superior as a shell filling4 ,it is believed that the smoke producing power of oleum is due solely to its sulfur trioxide content1 the sulfuric acid itself acting only as a solvent4 ,the rather high freezing point of the oleum containing high percentages of sulfur trioxide is a disadvantage4 ,sulfur ,trioxide4 ,sulfur trioxide1 ,,so1 is a colorless mobile liquid1 which boils at #df ,c4 and solidifies to a transparent ice-like mass1 melting at #ae ,c4 ,it is prepared by passing a mixture of sulfur dioxide and oxygen over finely divided platinum or other catalysts at a temperature between #djj and #dej ,c4 ,sulfur trioxide can only be used as a filler for shell and bombs1 and is probably the best substitute for phosphorus4 ,tin ,tetrachloride4 ,tin tetrachloride1 ,sn,cl1 is obtained by the action of chlorine on metallic tin4 ,it is a liquid1 boiling at #aad ,c41 and having a density of #b4b4 ,it fumes in the air1 because it hydrolyzes to stannic hydroxide3 ,sn,cl ,h,o ,sn7,,oh7 #d ,h,cl ,it makes a better and more irritating smoke for shell and hand grenades1 than either silicon or titanium tetrachlorides4 ,since there is practically no tin in this country1 the other tetrachlorides were developed as substitutes4 ,silicon ,tetrachloride4 ,silicon tetrachloride1 ,si,cl1 is prepared from silicon or from impure silicon carbide by heating it with chlorine in an electric furnace4 ,the raw material 7silicon carbide7 is a by-product in the manufacture of carborundum4 ,it is a colorless liquid1 boiling at about #eh ,c41 and fumes in moist air1 owing to hydrolysis3 ,si,cl #d ,h,o ,si7,,oh7 #d ,h,cl ,it is not very valuable in shell1 though it is more effective on moist1 cool days than on warm1 dry ones4 ,its greatest use is found in the smoke cylinder1 combined with ammonia4 ,by the action of the moisture of the air1 the following reaction takes place3 ,si,cl #d ,,nh #d ,h,o ,si7,,oh7 #d,,nh,cl ,the addition of a lachrymator gives a mixture which works well in hand grenades for mopping up trenches4 ,titanium ,tetrachloride4 ,titanium tetrachloride1 ,ti,cl1 is made from rutile1 ,ti,o1 by mixing with #cj per cent carbon and heating in an electric furnace4 ,a carbonitride is formed1 which is said to have the composition ,ti,c,n1 but the actual composition may vary from this to the carbide ,ti,c4 ,this product is heated to #fjj-fej ,c41 and chlorine passed through1 giving the tetrachloride4 ,it is a colorless1 highly refractive liquid1 which boils at about #acf ,c41 is stable in dry air and fumes in moist air4 ,the best smoke is produced by using #e parts of water to one of the tetrachloride1 instead of the theoretical #d parts which would form ,ti7,,oh74 ,since it is more expensive to manufacture and not as effective as silicon or tin tetrachloride1 it is used only as an emergency material4 ,berger ,mixture4 ,one of the most important smoke materials was the zinc-containing mixture1 which was used in the smoke box1 the smoke candle1 certain of the smoke grenades and in various forms of colored smokes4 ,the basis of this was the ,berger ,mixture1 which had the composition3 ,zinc #be ,carbon tetrachloride #ej ,zinc oxide #bj ,kieselguhr #e ,this formula produced a light gray carbon smoke1 with much carbon in the residue4 ,in this mixture the zinc and carbon tetrachloride react to form zinc chloride and carbon2 the kieselguhr keeps the mixture solid by absorbing the tetrachloride1 while the zinc oxide is practically useless1 as its absorbing power is small4 ,in order to accelerate the reaction and to oxidize the carbon1 thereby changing the color of the smoke from gray to white1 an oxidizing agent was added4 ,sodium chlorate was chosen for economic reasons4 ,the reaction now proved to be too violent1 and the zinc oxide was replaced by ammonium chloride4 ,this cooled the smoke1 retarded the rate of burning and added to the density of the smoke1 since the obscuring power of the ammonium chloride is high4 ,the kieselguhr was replaced by precipitated magnesium carbonate1 which is as good an absorbent1 gives a much smoother burning mixture1 and also adds somewhat to the density of the smoke by virtue of the magnesium mechanically expelled4 ,the mixture then had the composition3 ,zinc #cd4f ,carbon tetrachloride #dj4h ,sodium chlorate #i4c ,ammonium chloride #g4j ,magnesium carbonate #h4c ,,size ,,of ,,smoke ,,particles ,in the problem of smoke production1 the size of the particle is of great importance4 ,being a physical quantity it can easily be correlated with such physical properties as settling1 diffusion1 coagulation1 and evaporation4 ,these factors are more important in connection with toxic smokes1 since there the penetration factor must be considered4 ,smoke appears to consist of particles of all sizes from #aj cm41 which may just be resolved by the unaided eye1 to molecular dimensions1 #aj cm4 ,the larger particles settle out most rapidly and so do not remain long in suspension4 ,,measurement ,wells and ,gerke have developed a form of ultra-microscope which is well adapted to the measurement of the size of smoke particles4 ,the ultra-microscope is a low power microscope using intense dark ground illumination for viewing particles which are too small to be seen by transmitted light4 ,they are rendered visible in this way1 since any object1 no matter how small1 which emits enough light to affect the retina is visible1 provided the background is sufficiently dark4 ,thus stars are visible at night and dust particles are easily seen in a sunbeam in a darkened room4 ,the larger particles1 viewed in this way1 do not appear larger but brighter4 ,the apparent size of the particles is determined by the diffraction pattern and is thus dependent only on the optical system used to view them4 ,the more intense the incident light1 the brighter the particles appear4 ,in the ultra-microscope described1 the image of an intense source1 such as a concentrated filament lamp1 or an arc1 is focused upon the particles in the microscopic field1 but the axis of the illuminating beam1 instead of coinciding with the axis of the microscope1 as ordinarily used1 is perpendicular to it4 ,the beam itself1 therefore1 never enters the microscope at all1 but passes under the objective into a blackened chamber where it is absorbed4 ,the field of the microscope is made dark by placing underneath the objective another 8black hole0 or blackened chamber with an opening just a little larger than the field4#cd ,footnote #cd3 ,this ultra-microscope is described in ,j4 ,am4 ,chem4 ,soc4 #da1 #cab 7#aiai74 ,the method used for measuring the velocity consisted in causing the particle to describe a definite stroke many times in succession in an electric field4 ,this was accomplished by reversing the direction of the field with a rotating commutator4 ,the convection due to the source of light is perpendicular to this motion so that a zigzag line is obtained 7see ,fig4 #hh74 ,the amplitude of this oscillation is an accurate measure of the distance traversed by the particle under the electric force for a definite small interval of time4 ,the speed of the rotating commutator and the electric field are both susceptible of precise measurement1 so that the size of a single particle is precisely determined4 ,illustration3 ,,fig4 #hg4--,ultramicroscope for ,measuring ,size of ,smoke ,particles4 ,illustration3 ,,fig4 #hh4--,measurement of ,smoke ,particles by ,use of ,ultramicroscope4 ,when a sample of smoke is viewed in the ultra-microscope1 it appears like the starry heavens1 except that the stars are dancing violently about4 ,at first little distinction is made between the particles1 as there seems to be no order in their motion1 but soon it becomes evident that the brighter particles are more sluggish than the dim ones4 ,this is due to the greater mass of the bright particles1 for they are larger4 ,the particles are all moving slowly away from the source of light and eventually diffuse to the walls of the cell4 ,when the electric field is turned on1 about one-third of the particles immediately migrate1 about equally in both directions1 to the two electrodes4 ,if the field is reversed1 the direction of migration is reversed and if the commutator is used the particles oscillate regularly4 ,sometimes the particles may be seen to combine and become neutral1 in which case oscillation ceases4 ,,concentration ,,of ,,smoke ,in measuring the concentration of smokes1 the following terms are useful3 ,density4 ,the density of a smoke is defined as the reciprocal of the thickness of the smoke layer in feet necessary to obscure a given filament4 ,thus six inches of a smoke of density #b4j is required to obscure an electric light filament1 whereas one requiring four feet would have a density of #d4 ,another way to show the significance of this definition is to point out that if a definite weight of a stable smoke is diluted with air after it is formed1 the product of the volume by the density always remains constant4 ,any marked variation in this rule may be taken as evidence that the particles of smoke are undergoing a change1 in most cases due to evaporation4 ,total ,obscuring ,power4 ,the volume of smoke produced per unit weight of material used is the second factor in determining the value of a smoke4 ,the product of this volume per unit weight by the density of the smoke is the real measure of effectiveness1 and is called the total obscuring power 7,t4 ,o4 ,p47 of the smoke4 ,if the volume is expressed in cubic feet per pound and the density in reciprocal feet1 the unit of ,t4 ,o4 ,p4 is square feet per pound4 ,that is1 it expresses the square feet of a smoke wall1 thick enough to completely obscure a light filament behind it1 which could be produced from a pound of the reacting substances4 ,the total obscuring power of some typical smokes are as follows3 ,phosphorus #dfjj ,,nh,cl7,,nh ,h,cl7 #bejj ,sn,cl ,,nh ,h,o #aeij ,berger ,mixture #abej ,sn,cl ,,nh #ijj ,,so ,,nh #cge ,in all measurements of density1 and therefore of ,t4 ,o4 ,p41 the rate of burning must be considered4 ,if a slow burning material be compared with a rapid one1 the former will not reach its true maximum density1 as a great deal of the smoke may settle out during the time of burning4 ,comparisons of ,t4 ,o4 ,p4 are significant only when made on smoke mixtures of the same type and in about the same quantities4 ,,measurement ,two methods of measuring the effectiveness of a smoke cloud have been devised1 one1 the smoke box1 which measures the obscuring power directly by observing at what distance a lamp filament is obscured by intervening smoke1 the other1 the ,tyndall meter1 which measures the intensity of the scattering of the light4 ,the earliest measurements of smoke intensity are perhaps those of ,ringelmann 7,revue ,technique1 #ai1 #bhf71 who devised the well known chart of that name1 intended mainly for measuring intensities of black smoke issuing from a chimney at a distance4 ,the first measurements for military purposes are probably due to ,bertrand1 who made numerous comparative studies with his 8salle opacimetrique40 ,this was a room #bc #ad #c4f meters1 with #g windows4 ,two doors1 one provided with #c oculars #b cm4 in diameter1 gave access to the room4 ,on the other door1 opposite the first1 were hung several black signs4 ,six pairs of columns were spaced along the room at measured distances4 ,when a smoke is produced in the room1 the black paper signs first become invisible1 then the door itself1 and finally the columns1 pair by pair4 ,they reappear in the reverse order1 and as a measure of relative opacity ,bertrand took the time elapsing between the detonation and the reappearance of the farther door4 ,illustration3 ,,fig4 #hi4--,tyndall ,meter4 ,illustration3 ,,fig4 #ij4--;,cottrell ,precipitation ,tube4 ,smoke ,box4 ,the smoke box1 used by the ,c4 ,w4 ,s41 was constructed of wood with tight joints1 and had a moveable brass rod running through it to which was attached a small size #be-,watt ,mazda lamp4 ,the density of each smoke introduced in the box is determined by moving this lamp back and forth until a point is reached when the pattern of the filament can just be distinguished by the observer looking in at the glass window1 external light being excluded by a black cloth4 ,the thickness of the smoke layer between the glass window and the light is recorded as the measure of the smoke density4 ,for field tests1 a larger box1 #f #h #h feet 7#bhh cubic feet7 was constructed4 ,the observation light was moveable in a line connecting the mid-points of opposite sides of the box4 ,to insure uniform distribution of smoke1 a fan with #ah-;inch blade revolved at any desired speed between #fj and #bej r4p4m4 ,with this1 results are obtained indicating both the original density and its stability4 ,tyndall ,meter4 ,the ,tyndall meter was first devised for studying smokes and mists4 ,tolman and ,vliet adapted it to ,chemical ,warfare purposes1 and used it in studying the properties of smokes4 ,the apparatus 7,fig4 #hi7 consists eventually of an electric light bulb1 a condensing lens giving a beam of parallel light which passes through the diaphragm1 and a ,macbeth illuminometer for measuring the strength of the ,tyndall beam4 ,in case the material is a liquid suspension or solution1 it is introduced into a cylindrical glass tube1 while smokes and mists are premixed directly through the apparatus4 ,the long closed tubes are provided1 respectively1 for absorbing the beam after it has passed through the disperse system and for giving a dark background for observing the ,tyndall beam4 ,methods of standardization are given in the ,journal of the ,american ,chemical ,society1 #da1 #bii4 ,a third method for analyzing smokes consists in the use of an electrical precipitator4 ,this apparatus consists essentially of a modified ,cottrell ,precipitator1 with a central wire as cathode surrounded by a cylindrical foil as anode 7,fig4 #ij74 ,the smoke to be analyzed is drawn through the apparatus at a known rate1 and the particles of smoke precipitated on the foil by means of a high voltage1 direct current4 ,the determination of concentration is made by weighing the foil before and after precipitation4 ,,apparatus ,,for ,,smoke ,,production ,,smoke ,,box ,the smoke box was developed for the ,navy for use when it was desirable to have the smoke screen generated away from the ship4 7,the smoke funnel1 described later1 was operated on board ship74 ,the float consists of an iron container 7holding the smoke mixture7 surrounded by an iron float to support the apparatus when it is thrown into the water 7,fig4 #ia74 ,the iron container consists of a cylinder #bb inches high and #aj inches in diameter4 ,one inch holes are bored #a inches from the top of this cylinder1 from which the smoke is emitted4 ,the iron float is about #b feet in diameter and #h inches deep4 ,this box holds approximately #ajj pounds of smoke mixture1 and is so constructed that it will float one hour4 ,when ignited1 the mixture burns #i to #i minutes4 ,the smoke produced has a ,t4 ,o4 ,p4 of about #aijj4 ,fig4 #ib shows the ,navy ,smoke ,box in action4 ,illustration3 ,,fig4 #ia4--,navy ,smoke ,box4 ,illustration3 ,,fig4 #ib4--,navy ,smoke ,box in ,action4 ,,smoke ,,candle ,smoke candles are used for producing a cloud of smoke for screening purposes in or behind the lines4 ,they are made by packing about three pounds of the modified ,berger ,mixture in a container 7,fig4 #ic7 7galvanized can #e inches by #c inches7 and are lighted by means of the match head type of ignition4 ,smoke is given off at a uniform rate for about #d minutes1 forming a dense1 fog-like cloud which hangs low 7,fig4 #id74 ,this smoke is absolutely harmless1 and can be breathed without discomfort4 ,the obscuring power is high and1 with a favorable wind1 a small number of the candles will produce a screen sufficiently dense to allow operations to be carried out unseen by the enemy4 ,illustration3 ,,fig4 #ic4--;,b4 ,m4 ,smoke ,candle4 ,,smoke ,,grenade ,the smoke grenade is also designed for use in trench and field warfare1 where it is desired to produce a dense smoke screen4 ,it is made by packing #cdj grams of the standard smoke mixture in an ordinary light metal gas grenade4 ,around the top of the grenade are vents closed by a zinc strip4 ,the ignition is caused by the standard bouchon when the grenade is thrown4 ,the heat of the reaction burns through the zinc strip and a dense cloud of smoke is evolved for #de seconds4 ,illustration3 ,,fig4 #id4--,smoke ,cloud from ,b4 ,m4 ,candle4 ,stannic chloride has also been used extensively in hand grenades1 as it gives a very disagreeable cloud of smoke upon detonation4 ,due to the high prices and urgent need of tin for other purposes1 silicon tetrachloride was substituted for tin tetrachloride towards the close of the war4 ,a mixture of silicon tetrachloride and chloropicrin was also used4 ,this not only gives a very good smoke cloud1 but combines with it the toxic properties of the chloropicrin cloud4 ,the method of firing the smoke grenade is the same as that of any grenade using the same type of bouchon4 ,usually the grenade is grasped in the hand for throwing in such a manner that the handle of the bouchon is under the fingers4 ,the safety clip is pulled out with the other hand and the grenade is thrown with an overhand motion4 ,when the grenade leaves the hand1 the handle of the bouchon flies off1 allowing the trigger to hit the cap which ignites the fuse4 ,the white phosphorus combined hand and rifle grenade became the standard smoke grenade by the end of the war4 ,stannic chloride was used to clear out dugouts1 but not as a smoke producer4 ,,stokes' ,,smoke ,,shell ,illustration3 ,,fig4 #ie4--,stokes' ,smoke ,shell4 ,the ,stokes' smoke shell was perfected to furnish a means of maintaining the best possible smoke screen at long ranges by means of an easily portable gun4 ,the #c-;inch ,stokes shell1 as adapted for combustion smokes1 weighs about #ac pounds and contains about #d pounds of standard smoke mixture4 ,this shell is designed to produce a continuous screen over a period of #c to #d minutes4 ,,livens ,,smoke ,,drum ,the ,livens smoke drum was designed for use with the #h-;inch ,livens projector1 so as to produce a smoke screen of large volume and long duration at long ranges4 ,the drum1 as adapted for combustion smokes1 weighs #ag4e pounds empty and #di pounds loaded4 ,the smoke-gas mixture was specially adapted for use in the ,livens drum4 ,illustration3 ,,fig4 #if4--,livens ,smoke ,bomb4 ,smoke mixtures in ,livens were never used to any considerable extent in the war and it is questionable if they ever will be4 ,a ,livens can usually only be fired once before resetting1 hence ,stokes mortars are used whenever possible4 ,,smoke ,,funnel ,the smoke funnel was developed for the production of a white smoke cloud from the stern of a vessel4 ,the smoke producing materials are liquid ammonia and silicon tetrachloride1 with carbon dioxide as a compressing medium4 ,this is the most satisfactory compressing medium1 because3 7#a7 ,the silicon tetrachloride is forced out at nearly constant pressure4 7#b7 ,the carbon dioxide is easily compressed to a liquid and can be handled in this form4 ,further1 it has a vapor pressure of #hjj pounds at #fj ,f41 and a cylinder can be nearly emptied without loss in efficiency4 7#c7 ,carbon dioxide is sufficiently soluble in silicon tetrachloride to cause the latter to effervesce and thus materially aid in its evaporation on spraying4 7#d7 ,liquid carbon dioxide1 behaving in a manner similar to liquid ammonia1 affords a means for the silicon tetrachloride to 8keep pace0 with the ammonia1 under changes in temperature1 and thus ensures a more nearly neutral1 and therefore the most effective1 smoke4 ,illustration3 ,,fig4 #ig4--,navy ,smoke ,funnel4 ,the smoke funnel proper consists of an open end cylinder1 about #b feet in diameter and #g feet long1 mounted in a horizontal position on an angle iron frame4 ,at one end is an #ah-;inch fan securely fastened to the cross supports4 ,this fan is operated by hand1 through gears giving a ratio of about #cj to #a4 ,the silicon tetrachloride enters the cylinder through a pipe1 which terminates in four spray nozzles1 while the ammonia enters through a single nozzle4 ,the air forced into the funnel serves to hydrolyze the silicon tetrachloride and mixes the vapors4 ,the resulting reaction evolves a dense white cloud of very large volume and high obscuring power4 ,one set of cylinders is capable of maintaining this cloud for over #cj minutes4 ,under normal conditions the discharge is at the rate of #b pounds of silicon tetrachloride to #a pound of ammonia4 ,to stop the smoke1 the silicon tetrachloride is closed first1 the ammonia allowed to run about half a minute1 and the fan is shut off last4 ,illustration3 ,,fig4 #ih4--,navy ,smoke ,funnel in ,operation4 ,,smoke ,,knapsack ,the smoke knapsack furnishes a portable apparatus for smoke production4 ,the gross weight is about #gj pounds2 when in operation it gives a dense white smoke for about #ae minutes4 ,the operation may be intermittent or continuous and the quantity of smoke is sufficient to completely hide one platoon of men in skirmish formation with a #e-mile per hour enfilade wind4 ,the apparatus consists of two steel tanks about #bf inches in height and #f inches in diameter4 ,from the side of each tank1 but near the bottom1 extends a short pipe on which is placed a suitable valve4 ,a flexible armored hose connects the valve to a short length of pipe which is equipped with spray nozzle4 ,the cylinders are charged with silicon tetrachloride and ammonia under pressure4 ,the valves may be operated with the left hand1 while the sprayer apparatus is held in the right4 ,the release buckles are within easy reach of both hands4 ,,shell ,while many special devices have been developed by means of which the gas troops and infantry are able to set up smoke clouds on short notice1 the smoke shell1 fired by the artillery1 always played an important part in this work4 ,in the same way that a large number of the poison gases were adapted to artillery use1 so were most of the smoke producing substances4 ,as a filler for smoke shell1 phosphorus easily ranks first1 and is approached only by sulfur trioxide in very humid weather4 ,a rough approximation to the relative values of some of its rivals is given in the following table3 ,white phosphorus #ajj ,sulfur trioxide #fj-ge ,stannic chloride #dj ,titanium chloride #be-ce ,arsenic chloride #aj ,comparison of the value of different forms of phosphorus for shell purposes has invariably pointed to the superiority of the white variety4 ,mixtures of white and red 7#b to #a7 have also proved effective4 ,a complete barrage over a front of #bjj yards can be established in from #dj seconds to #a minute and maintained by firing a salvo followed by battery fire of #c seconds4 ,four #d4e-;inch howitzers could maintain an effective barrage over a front of #ajjj yards4 ,the influence of sunshine is very marked1 as in moist1 cool weather one shell every #ae seconds is sufficient4 ,illustration3 ,,fig4 #ii4--,smoke ,screen for ,tanks4 ,,screening ,,tanks ,tests have demonstrated 7see ,fig4 #ii7 that successful smoke screens for tanks may be produced by spraying oleum into the exhaust4 ,on a #g-ton tank of the ,renault type 7#dj ,h4 ,p47 #aaj cc4 per minute produced a large volume of smoke1 which had excellent covering power1 and which could be made intermittent or continuous at will4 ,the same method may be applied to aeroplanes1 and to ships4 ,it is calculated that a cylinder containing #cjj pounds of #bj per cent oleum will maintain a smoke screen on a ship for a period of #ae minutes1 if oleum is used at the rate of #bc4f pounds per minute4 ,since the cylinders may be arranged in batteries1 the screen may be continued for any period of time4 ,the ,tank ,corps rather favor phosphorus rifle grenades for producing a smoke screen at a distance from the tank4 ,,purpose ,,of ,,smoke ,,screen ,smoke screens may be employed with one or more of the following objects in view3 7#a7 ,to mask known enemy observation posts and machine gun nests2 to conceal the front and flanks of attacking troops1 concentration of guns and tanks1 roads and concentration points2 to blind the flashes of batteries in action and to hamper aerial observations4 7#b7 ,as a feint to draw the enemy's attention to a front on which no attack is being made1 so as to hold his troops to their trenches1 or to induce him to expend ammunition needlessly and to put down a barrage in the wrong place4 7#c7 ,to simulate gas and force the enemy to wear his mask4 ,gas should occasionally be mixed with smoke1 to impress upon him the belief that it is never safe to remain in a smoke cloud without wearing his mask4 7#d7 ,in rolling or mountainous country1 to fill valleys with smoke and thereby conceal the advance from all observation1 including aerial4 7#e7 ,to cover the construction of bridges1 trenches1 etc41 in the face of the enemy4 ,,the ,,tactical ,,value ,,of ,,smoke ,the pall of smoke that hung over every battlefield of the ,civil ,war made a profound impression upon ,fries when1 as a boy1 he first read of those battles4 ,however1 practically every reference made to smoke treated it as a nuisance4 ,it obscured the field of vision and interfered with troop movements as well as with the aiming and firing of rifles and cannon1 though due to their short range this was not so serious as it would be nowadays4 ,nevertheless so deeply was this interference appreciated that the most earnest efforts were made to discover a smokeless powder4 ,this1 as the world well knows1 was developed with great efficiency during the latter part of the nineteenth century4 ,with the development of the smokeless powders came also a better understanding of the action of powder1 whereby the velocity of projectiles1 and consequently the range and accuracy1 were greatly increased4 ,this increased range and accuracy of guns forced a consideration of protection1--and concealment is one form of protection4 ,the ,navy would appear to have been the first branch of the ,american forces to realize how valuable a smoke screen may be4 ,thus ,fries1 in ,august1 #aiac1 had the interesting experience of witnessing a week's maneuvers at the eastern entrance to ,long ,island ,sound between the ,navy and the ,coast ,artillery4 ,during that week the ,navy carried out extensive experiments with smoke screens both by day and by night4 ,the smoke in all cases was generated by smothering the fires on destroyers or other ships1 thus causing dense clouds of black smoke to be given out from the funnels4 ,after the ,world ,war had been in progress some time and particularly about the time the ,united ,states entered it1 a determined search was begun for more efficient smokes and more efficient smoke producers4 ,in the ,navy1 smoke screens were expected to be established by small craft behind which larger vessels could maneuver for position and range4 ,these screens were also established for the purpose of cutting off the view of enemy submarines or other vessels1 thus allowing merchant ships or even warships when injured or outclassed to escape4 ,the ,army was much slower to appreciate the value of smoke4 ,in fact1 apparently no army really realized the value of a smoke screen until after gas warfare became an accomplished fact4 ,as is well known1 the evaporation of the large quantity of liquid used in wave attacks caused a cloud of condensed moisture4 ,this is what gave rise to the designation 8cloud attack40 ,english regulations for defense against gas in the early days called for every man and animal to stand fast upon the approach of a gas cloud and remain quiet until the cloud had passed4 ,thus casualties were reduced to a minimum and the ,english were fresh to receive the attack that was frequently launched immediately after the cloud had passed4 ,the ,germans finally thought of the plan of sending over a fake gas attack4 ,in that way they simply produced a smoke cloud that looked like a gas attack4 ,naturally the ,english stood fast as before4 ,the ,germans attacking in the fake cloud naturally caught the ,british at a complete disadvantage with consequent disastrous results to the latter4 ,but that was a game at which two could play4 ,about this time the value of white phosphorus for producing a smoke screen was taken up by the ,british and large numbers of #d-;inch ,stokes mortar shells were filled for that purpose4 ,all armies then began to experiment with smoke producing materials4 ,most of these were liquid4 ,of them all1 as has been stated before1 white phosphorus1 a solid1 proved the best4 ,toward the close of the war these smoke screens began to be used to a considerable extent for the purposes given above4 ,no one who has engaged in target practice and encountered a fog1 or who has hunted ducks and geese in a fog needs to be told of the difficulty of hitting an object he cannot see4 ,the ,first ,gas ,regiment proved its worth and won everlasting glory by using the ,stokes' mortars of the ,british with their phosphorus bombs for attacking machine gun nests4 ,the white phosphorus in that case had a double effect4 ,it made a perfect smoke screen1 thereby making the ,german machine gun shots simply shots in the dark1 while at the same time the burning phosphorus forced the gunners to abandon their guns and surrender4 ,thus phosphorus played and will play in the future the double rle of forming a defensive screen and of viciously attacking enemy troops4 ,this phosphorus1 which catches fire spontaneously1 burns wet or dry1 total immersion in water alone sufficing to put it out4 ,this means of extinguishing the flames being almost totally absent on the battlefield1 it can be truthfully said that burning phosphorus is unquenchable4 ,the burns are severe and difficult to heal4 ,for these reasons white phosphorus will be used in enormous quantities in any future war4 ,all armies have begun to realize this value of smoke4 ,in the future it will be the infantryman's defense against all forms of weapons and it will be used on every field of battle1 by every arm of the service and at all times1 day or night4 ,it is even more effective in shutting out the light from searchlights1 star bombs and similar illuminants for use in night attacks than it is in daylight4 ,with this straight use of smoke for protection will go its use along with poisonous gases4 ,every smoke cloud will be poisonous or non-poisonous at the will of the one producing the cloud1 and this will be true whether it is produced from artillery shell1 mortar bombs1 hand grenades1 smoke candles or other apparatus4 ,thus smoke and gas together will afford a field for the exercise of ingenuity greater than that of all other forms of warfare4 ,the only limitation to the use of smoke and gas will be the lack of vision of commanders and the ignorance of armies4 ,proper recognition and aid given to chemical warfare development and instruction in peace are the only methods of overcoming these limitations4 ,in this1 as in all other development work1 the most serious obstacle comes from the man who will not see1 whether it be from a lack of intelligence1 laziness or inbred opposition to all forms of advancement4 ,,chapter ,,xvii ,,toxic ,,smokes ,the introduction of diphenylchloroarsine as a poison gas really introduced the question of toxic smokes4 ,this material1 as has already been pointed out1 is a solid1 melting at about #cj4 ,in order to secure efficient distribution1 the material was mixed with a considerable amount of high explosive4 ,when the shell burst1 the diphenylchloroarsine was finely divided or atomized and produced a cloud of toxic particles4 ,since smoke particles are only slightly removed by the ordinary mask1 this formed a very effective means of chemical warfare4 ,an analogous result was obtained by the use of poison gases1 such as chloropicrin1 in a smoke cloud produced from silicon or stannic chloride4 ,here1 however1 the toxic material was a real gas1 and so the real result attained consisted in forcing the men to wear their masks in all kinds of clouds4 ,the true toxic smoke went further in that the ordinary mask offered little protection and thus compelled the warring nations to develop a special type of smoke filter4 ,these smoke clouds consist of very small particles1 which may be considered as a dispersed phase1 distributed in the air1 which we may call the dispersing medium4 ,the dispersed phase may be produced by mechanical1 thermal1 or chemical methods4 ,mechanical dispersion consists in the tearing apart of the material into a fine state of subdivision4 ,it may be called a hammer and anvil action4 ,the more powerful the mechanical force1 the smaller the resulting particles4 ,this may be accomplished by the use of a high explosive1 such as the ,germans used in the case of diphenylchloroarsine4 ,the production of smoke by thermal dispersion depends essentially upon the fact that when a substance of sufficiently low vapor pressure is volatilized1 and the vapors are passed into the air1 they recondense on the nuclei of the air to form a smoke4 ,vaporization from an open container1 permitting the vapors to pass directly to the air without being quickly carried away from the surface of evaporation1 produces smoke having larger particles1 because each particle formed remains for an appreciable period of time in contact with air saturated with vapor1 and hence grows very rapidly4 ,the easiest way to produce small smoke particles is to mix the toxic material directly with some fuel which will produce a large amount of heat and gas upon burning4 ,when this mixture is enclosed in a container having a small orifice1 upon burning1 the toxic vapor and gas will pass through this orifice at high velocity2 it has been demonstrated by ,lord ,rayleigh that the size of the particles depends upon the velocity of emission of the gas from a given orifice4 ,the product of chemical combination may include a super-saturated vapor1 which condenses into small particles4 ,explosive dispersion is really a combination of mechanical dispersion followed by thermal dispersion4 ,,penetration ,the fundamental idea underlying all the work on toxic smokes is to obtain a smoke that has marked penetrating power4 ,screening power is not important here4 ,in addition to penetration1 a smoke should be highly toxic and have a slow rate of settling4 ,penetration may be tested by the use of a standard filter2 a suitable filter for this purpose is one which does not remove the smoke to such an extent that measurement of its concentration becomes difficult1 and one which does not become clogged quickly by the smoke4 ,a filter consisting of two pads of felt1 placed side by side and arranged so that the smoke first comes in contact with the thinner and less dense pad has been found very satisfactory4 ,in testing penetration1 smoke is produced by dispersing one gram of the toxic substance in a sheet iron box of #ajjj liters capacity4 ,after #e minutes a steady concentration is usually attained and the smoke is then forced through a ,tyndall meter1 7see page #bii7 after dilution with air1 where the initial concentration is determined4 ,it then passes through the standard filter1 and through a second ,tyndall meter1 where the final concentration is measured4 ,the difference of the two readings gives the amount of smoke retained by the filter4 ,the penetration is ordinarily represented by a series of figures1 which decrease from a maximum value at the beginning of the test to a minimum at a point where the filter permits the passage of so little smoke that it cannot be measured4 ,this decrease is due to decrease in penetrating power and concentration of the smoke1 and to increase in filtering power of the filter as a result of plugging4 ,usually five degrees of penetration are recognized1 excellent1 good1 fair1 poor and very poor4 ,illustration3 ,,fig4 #ajj4--,penetration ,apparatus ,used to ,test ,toxic ,smokes4 ,a portable penetration apparatus is shown in ,fig4 #ajj4 ,in using the apparatus1 the smoke producing material is so placed with reference to the apparatus that the sample is taken about #bj feet down the wind1 so that the smoke is appreciably diluted4 ,one man is stationed at each ,tyndall meter and takes readings as fast as his recorder can write them1 so that the smoke density1 before and after the filter1 can be followed very closely4 ,,physiological ,,action ,in addition to a high penetrating power a smoke should also possess great toxic1 irritant1 sternutatory1 or lachrymatory power4 ,these properties are tested by exposing mice to the smoke in the chamber4 ,they are placed in the chamber at the beginning of the run1 and exposed for #aj minutes to the smoke from #a gram of the material4 ,while these tests are only qualitative in character1 they give a fairly good notion of the relative value of different materials4 ,,quantitative ,,relationships ,it has been found that1 if the optical readings from the ,tyndall meter are plotted as ordinates against the time t 7the time elapsed after detonation7 as abcissas1 and that portion of the curve between t #j and t #cj considered1 the curve generally descends sharply at first1 from a high point representing the density immediately after the production of the smoke1 to a point in the neighborhood of t #h1 where it flattens out and descends much more slowly with a slope that changes little4 ,the area under the significant portion of the curve1 that is1 the area circumscribed by the curve from the point t to t1 the vertical axis from this point to the origin1 the horizontal axis from the origin to t and the line perpendicular to this axis1 cutting the curve at t1 is a rough measure of the relative values of different smokes4 ,this area is calculated as the sum of two rectangles1 from t to t and from t to t4 ,some results are as follows3 ,area #cj ,phenyldichloroarsine #aha ,triphenyldichloroarsine #agh ,diphenylcyanoarsine #acg ,diphenylchloroarsine #aja ,cyanogen bromide #id ,methyl dichloroarsine #gj ,phenylimidophosgene #fi ,mustard gas #ch ,the curves in ,fig4 #aja show the way in which the readings fall off with time4 ,each substance of course has its characteristic curves4 ,illustration3 ,,fig4 #aja4--,typical ,curves ,showing the ,decrease in ,concentration of ,smoke ,cloud with ,time4 ,,toxic ,,materials ,the selection of materials for the production of toxic smokes can only be carried out experimentally4 ,a number of very toxic substances have been shown to be valueless as toxic smokes because of low penetration1 decomposition during the process of smoke production1 or for other reasons4 ,arsenic compounds produce smokes distinctly better than the average4 ,inorganic compounds which have high melting and boiling points are very poor smoke producers4 ,the only exception to this is magnesium arsenide1 which may suffer decomposition4 ,compounds like mercuric chloride and arsenic tribromide1 which boil or sublime at comparatively low temperatures1 produce good smokes4 ,most materials which boil below #acj ,c4 produce no smoke as they evaporate on dispersion4 ,it is difficult to set any upper limit for the boiling point beyond which materials do not produce good smokes1 but in all probability #ejj ,c4 is not far from the maximum4 ,liquids and solids are1 on the whole1 almost equally good as smoke producers4 ,the physical condition of the material has no great effect upon the amount of smoke which it will produce4 ,this seems to depend only upon the physical and chemical properties of the material4 ,,toxic ,,smoke ,,apparatus ,it has been mentioned above that the ,germans used a shell1 containing solid diphenylchloroarsine and a high explosive4 ,a #aj4e cm4 shell 7,blue ,cross7 was about two-thirds filled with cast trinitrotoluene and contained a glass bottle with #cjj-djj grams of toxic material4 ,diphenylchloroarsine was also used in shell1 in solution1 a mixture of phosgene and diphosgene 7superpalite7 being the ordinary solvent 7,green ,cross74 ,mixtures of diphenylchloroarsine and phenyldichloroarsine were also used4 ,in the case of high explosive shell1 the use of a separate container appears to be desirable1 because a mixture with the explosive seriously decreases its sensitiveness and even its destructive power4 ,there is also a question as to the stability of such a mixture4 ,however1 #ge mm4 shell containing #cj per cent diphenylchloroarsine mixed with ,t4 ,n4 ,t4 gave good clouds of toxic smoke4 ,,toxic ,,smoke ,,candle ,two toxic smoke candles were developed by the ,chemical ,warfare ,service1 known as the ,b-,m ,toxic ,smoke ,candle1 perfected by the ,pyrotechnic ,section of the ,research ,division1 and the ,dispersoid ,smoke ,candle1 developed by the ,dispersoid ,section4 ,the ,b-,m ,toxic ,smoke ,candle consists of a bottle-shaped sheet steel toxic container set into a can1 containing smoke mixture4 ,the heat from the burning mixture causes the distillation of the toxic material4 ,the toxic vapor is discharged through a nipple1 screwed into the neck of the container and extending over the top of the smoke can4 ,steel wool is used in the toxic container to reduce the violent boiling and spattering of the material4 ,a small amount of steel wool1 held in place by a wire screen1 is also used in the nipple for the same purpose4 ,the toxic container is sealed by a fusible metal plug1 melting at #ij ,c41 cast into a retainer at the base of the nipple4 ,the fusible plug melts upon the first application of heat and allows free passage of the vapor into the smoke cloud4 ,the ignition of the apparatus is effected by means of a simple match head and an accompanying scratcher4 ,illustration3 ,,fig4 #ajb4--,toxic ,smoke ,cloud from #ejj ,d4 ,m4 ,candles4 ,the candles were placed in #e parallel rows which were #b yards apart1 each row containing #ajj candles on a #ajj yard front4 ,the total time of active smoke emission was #bc minutes4 ,the first evolution of smoke occurs about #aj seconds after the first appearance of flame4 ,about one minute after ignition the toxic material will begin to distill into the smoke cloud and this will continue for about four minutes4 ,the burning of the candle should be complete in about six minutes4 ,illustration3 ,dispersoid ,candle ,british ,candle ,,fig4 #ajc4--;,comparison of ,dispersoid and ,british ,d4 ,m4 ,candles4 ,the ,dispersoid ,toxic ,smoke ,candle differs from the ,b-,m candle in that the toxic container is not used4 ,a mixture of smokeless powder and the toxic material 7diphenylchloroarsine or ,d4 ,m41 an arsenical obtained from arsenic trichloride and diphenylamine7 is filled directly into the container1 a cylindrical can #c4e inches in diameter and #i inches high made from #bg gauge sheet metal1 and packed under a total pressure of #b1ejj pounds4 ,the top of the candle is a metal cover1 containing the match head scratcher1 which is separated from the match head by a ,manila paper disc4 ,these are the same as those used in the ,b-,m candle4 ,the candle has a total weight of about #d4be pounds1 of which #c4f pounds are the smoke mixture1 containing about #a4c pounds of toxic material4 ,in operating the candles1 the cover is removed and the match head ignited by friction with the scratcher4 ,the match head burns through the cardboard and ignites the powder4 ,the heat and gas produced by the combustion of the powder vaporizes the particles of the toxic material and carries the vapors out through the orifices at a high velocity whereupon they recondense to form a smoke4 ,the rapid emission of the vapors through the orifice prevents any possibility of their ignition4 ,the time before good emission of smoke takes place after the ignition of the match tip of a candle is #cj seconds4 ,the average time of vigorous smoke emission is from four to five minutes4 ,the result of a field test with the dispersoid candle is shown in ,fig4 #ajb4 ,a comparison of a ,british and a ,dispersoid candle is shown in ,fig4 #ajc4 ,it should be stated that this may not have been a fair test as only one ,british candle was available for the comparative test4 ,,chapter ,,xviii ,,smoke ,,filters ,the first types of the ,standard ,box ,respirator contained cotton pads1 which sufficed to remove the ordinary smoke of the battlefield and even that from the earlier toxic materials4 ,improved methods of producing toxic smokes1 by means of which smaller particles were obtained1 led1 early in #aiah1 to the recognition of the need of improved protection against these smokes4 ,the first attempts to meet this need consisted in improving the filtering qualities of these pads4 ,it was soon found1 however1 that to make better filter pads would greatly increase the total resistance of the canister4 ,this was highly undesirable1 since the resistance of the ordinary canister was already so high as to be very uncomfortable4 ,to overcome this objection1 some of the early designs of filter canisters were provided with a mechanical valve1 which could be operated by hand1 to by-pass the air around the filter when the canister was used against gas alone1 or so set as to make the air pass through the filter when smoke was feared4 ,this introduced a factor of uncertainty among the men during a gas attack1 since each man must decide for himself whether smoke was present4 ,this reason alone was sufficient for discarding this design4 ,a preliminary study of the situation indicated that any filter for fine smoke particles must have a high resistance per unit of area1 but that the total resistance must be comparatively low4 ,in order to secure the large area necessary to bring the total resistance within reason1 the experimental work was developed along three lines3 ,the formation of a filter into a bag1 cup1 or jacket to surround the outside of the canister2 the use of an arrangement sufficiently compact to go inside the canister2 and the use of a filter as a separate unit1 to be attached to the canister by an air connection4 ,a survey of the possible filtering materials indicated that only two offered promise1 namely1 paper and felt4 ,,paper ,,filters ,reports that the ,british had developed thin1 creped1 sulfite-cellulose wood pulp paper for filters led to an intensive study of this material by the ,chemical ,warfare ,service4 ,illustration3 ,,fig4 #ajd4--;,crepe ,paper ,doughnut ,filter ,canister4 ,in general we may say that the development of paper filters 7in sheet form7 met with little success4 ,papers affording the required protection did not live up to the resistance specifications4 ,the reason for this probably is in the method of making paper4 ,the pulp is fed onto the screen of a ,fourdrinier machine under conditions that do not permit of uniformity in the distribution of the fibers and consequently there is no uniformity in the size of pores4 ,in order to eliminate the large holes1 which allow the smoke to pass readily1 the paper must be pressed to reduce these pores to the proper magnitude4 ,this naturally results in an approximately equal decrease in the size of the small pores1 with a consequent increase in the final resistance out of all proportion to the protection gained4 ,a very satisfactory paper was finally produced1 but the resistance was too high and it was necessary to increase the total available filtering area1 which resulted in the accordion type of filter4 ,this filter was incapable of development on a large scale because of the large amount of hand work required in assembling4 ,the lack of uniformity in a single sheet has been overcome with some success by making up a filter from #dj to #hj layers of tissue or crepe paper1 trusting that the law of chance would bring the large pores in some successive layer4 ,such a filter was adopted by the ,british1 but since it did not give protection comparable with that afforded by felt filters1 it was rejected in the ,united ,states4 ,in the so-called 8doughnut0 filter use was made of tissue paper4 ,instead of seeking for uniformity in a vertical direction through a block of tissues1 it was sought along the axis horizontal with the sheet4 ,the effectiveness of such a filter was less than that of felt4 ,in addition1 serious difficulty was met in cutting the pile of tissue paper into the proper shape so that eventually it was abandoned as a production possibility4 ,,felt ,,filters ,work on the felt filters started about ,june1 #aiah4 ,great difficulties were met in the beginning1 as a felt satisfactory for this purpose must be made under carefully controlled conditions and production conditions during the war did not readily lend themselves to such control4 ,however1 the opportunities afforded in felt making for uniform packing and arranging of the fibers 7the whole process of making a felt1 is one of gradual packing of fibers into a relatively small volume7 are such as to assure a greater degree of success than is the case in paper making4 ,very successful filters have been obtained with the use of felt4 ,there are two serious objections to its use1 however4 ,the first is the great cost of the filter 7this was above one dollar per filter at the close of the ,war72 the second is that felt is a valuable industrial commodity4 ,it is thus very desirable that a cheaper and a less important industrial material be found4 ,,the #aiai ,,canister ,just before the ,armistice1 the ,gas ,defense ,long ,island ,laboratory brought out the so-called 8#aiai ,canister10 which consisted of an oval section1 perforated metal1 war gas material container with a central1 flat1 perforated breathing tube connected to a nozzle at one end4 7,see also page #bbh47 ,after this inner container is packed with the war gas chemicals1 a filter jacket is slipped over it and the top edge sealed to the inner container4 ,illustration3 ,,fig4 #aje4--aiai ,felt ,filter ,canister4 ,attempts were made to put paper filters on this canister by wrapping it with layers of paper4 ,in some cases1 layers of coarse burlap or mosquito netting were applied between the layers of paper to give mechanical strength and air space4 ,the fact that many filters gave good protection showed that a filter of this type and material is possible1 but the operations of wrapping and sealing require careful work in production and inspection and even with the greatest skill and care1 imperfections are almost impossible to avoid4 ,this chance of defects1 together with the labor involved1 makes the process undesirable4 ,a ,,theory ,,of ,,smoke ,,filters ,tolman1 ,wells and ,gerke1 during the course of their work on toxic smokes1 developed the following theory of smoke filters4 ,the phenomena occurring in the filtration of smoke are exceedingly complicated1 but the general nature of the process may be simply described in terms of the kinetic properties of the small particles comprising the smoke4 ,a filter may be regarded as a series of minute capillaries through which the smoke slowly flows4 ,in order that filtration may take place1 it is not necessary to assume that the capillaries of the filter are smaller than the particle1 for the particles may diffuse to the walls of the capillaries and it is believed that with typical filters this is the actual method of smoke removal for particles less than #aj cm4 in diameter4 ,in accordance with this view as to the nature of smoke filtration1 the important factors involved are 7#a7 the ,brownian motion of the smoke particles1 7#b7 the area and arrangement of the internal surface presented by the filter1 7#c7 the flow of the smoke as a whole1 and 7#d7 the attractive forces between the filter surfaces and the smoke particles4 ,the first three of these factors determine how many particles come within the range of the mutual forces of the particle and filter surface1 and the fourth factor determines the chance or expectation that the particle will permanently adhere to the surface of the filter4 ,,testing ,,smoke ,,filters ,all the early tests made on smoke filters used diphenylchloroarsine1 because it was felt that the filter must be tested against a toxic smoke4 ,a man test was developed as representative as possible of actual conditions in the field1 and the time necessary for a man to detect diphenylchloroarsine smoke in the effluent stream when breathing at a normal rate1 using a carefully controlled concentration of smoke produced by detonation1 was used as the criterion of the protection offered by the canister4 ,this test was subject to extensive individual variations1 due to the varying physiological resistances of different men to diphenylchloroarsine smoke4 ,further1 it was quite inadequate for rapid testing on a large scale4 ,a testing machine was then developed1 which gave results comparable with those obtained in the man test4 ,the method used in detecting the gas was physiological1 that is1 by smell or by its irritating action towards the membranes of the eye4 ,while these are purely qualitative tests1 they are much more sensitive than any possible chemical tests4 ,because of the desirability of having a method which could be controlled chemically1 other methods were developed4 ,ammonium chloride is a solid smoke1 consisting of particles of quite variable sizes4 ,it is sensitive to dilution and clogs the pores of the filtering medium quite rapidly4 ,for this reason it was used in the study of the rate of plugging or clogging of the filter 7the closing of the pores of the fabric or other material to the passage of air74 ,the smoke is produced by the reaction of ammonia and hydrogen chloride-air streams4 ,the smoke thus generated is passed from the mixing chamber to a larger distribution box and from there through the filter1 at a standard rate4 ,the concentration of the smoke may be accurately determined by chemical means or photometrically1 using a ,hess-,ives ,tint ,photometer1 the ,marten ,photometer1 or a special photometer developed by the ,chemical ,warfare ,service4 ,a comparison of a large number of tests with those of other smokes would indicate that ammonium chloride smoke offers accurate information as to protection sought1 but is hardly a desirable smoke for testing on a large scale4 ,the third method developed was the sulfuric acid smoke4 ,this smoke was produced by passing dry air through a tower of solid pieces of sulfur trioxide and then mixing the vapor with a large volume of air at #ej per cent relative humidity4 ,it is not a clogging smoke and the filtering efficiency does not change materially in the time of exposure required for a test4 ,the smoke lends itself easily to chemical analysis and offers data as to exact particulate cloud concentrations which will penetrate canisters2 photometric measurements are also applicable4 ,illustration3 ,,fig4 #ajf4--,tobacco ,smoke ,apparatus for ,testing ,canisters4 ,the fourth method consists in the use of tobacco smoke4 ,this is generated by passing air over ignited sticks of a mixture of tobacco 7#fc per cent71 rosin 7#cj per cent7 and potassium nitrate 7#g per cent74 ,this smoke is composed of particles of extreme uniformity in size2 chemically it is relatively inert4 ,it is not a clogging smoke and is not sensitive to moisture and dilution4 ,the density of the effluent smoke is compared with that of the entering smoke in a ,tyndall beam1 and the filtering capacity of the material determined in terms of the amount of air necessary to dilute the entering air to the same concentration of the effluent air4 ,the method is simple in manipulation and the test is a rapid one 7#ej canisters per day74 ,because of the apparent superiority of tobacco smoke as a testing smoke1 the accompanying disadvantages are possibly outweighed4 ,from the standpoint of inherent chemical properties1 the general desirability of a suitable testing smoke would decrease in the following order3 tobacco1 sulfuric acid1 ammonium chloride4 ,,chapter ,,xix ,,signal ,,smokes ,the success of pyrotechnics in night signalling led1 during the ,world ,war1 to considerable attention being paid to the development of pyrotechnic signals for day use4 ,this was mainly directed to the production of distinctive smokes1 which should have the same long range visibility under varying light conditions4 ,since a gray or white smoke might be confused with the smoke produced accidentally by the explosion of shell1 it was necessary to use smoke of definite and unmistakable colors1 and red1 blue1 yellow1 green and purple smokes were developed4 ,during the early part of the war1 only a yellow smoke was in use1 though others were added later4 ,,production ,,of ,,colored ,,smokes ,there are three possible ways of obtaining signal smokes4 ,i4 ,mechanically dispersing solids4 ,,ii4 ,chemical ,reaction4 ,,iii4 ,volatilization of colored materials4 ,i4 ,the first method1 while possible1 can never be an efficient method of producing signals4 ,some success was met with in dispersing certain inorganic materials1 as rouge1 and ultramarine1 in projectiles fired from a #c-;inch mortar and exploded by a time fuse arrangement at the height of their flight4 ,various mixtures were also tried1 such as antimony oxysulfide and aluminum powder 7red71 arsenic and antimony trichlorides with sodium thiosulfate 7yellow71 etc41 but these compositions have the disadvantages of being liable to catch fire if dispersed by a black powder explosion4 ,,ii4 ,while colored smokes may be produced by chemical reaction1 such as the combination of hydrogen iodide 7,,hi71 chlorine and ammonia1 the clouds are not satisfactory as signals4 ,in this particular case1 the purple cloud 7to the operator in the aeroplane7 appeared white to the observers on the ground4 ,high temperature combustion smokes have also been studied4 ,these are used in the so-called smoke torches4 ,the yellow arsenic sulfide smoke is the most widely used4 ,most formulas call for some sulfide of arsenic 7usually the native realgar1 known commercially as 8,red ,saxony ,arsenic071 sulfur1 potassium nitrate1 and in some cases1 a diluent like ground glass or sand4 ,a typical mixture consists of3 ,red arsenic sulfide #ee ,sulfur #ae ,potassium nitrate #cj ,a very similar smoke may be obtained from the following mixture3 ,sulfur #bh4f ,white arsenic #cb4j ,potassium nitrate #cc4h ,powdered glass #f4f ,these smokes are not as satisfactory in color as the smoke produced by a dye smoke mixture1 especially when viewed from a distance1 with the sky as a background4 ,they fade out rather quickly to a very nearly white smoke4 ,a black smoke upon first thought might seem to be the easiest of all smokes to produce1 but actually the production of a black smoke that would be satisfactory for signalling purposes was rather a difficult matter4 ,starting with the standard smoke mixture1 which gives a white or gray smoke1 hexachloroethane1 which is solid1 was substituted for the carbon tetrachloride1 in order to avoid a liquid constituent4 ,naphthalene was first used1 until it was found that the mixture of naphthalene and hexachloroethane melted at temperatures below that of either of the constituents4 ,anthracene was then substituted4 ,the principal reaction is between the magnesium and the chlorine-containing compound1 whereby magnesium chloride and carbon are formed4 ,the reaction is very violent1 and a white smoke is produced4 ,the anthracene slows down the reaction and at the same time colors the smoke black4 ,the speed of the reaction may be controlled by varying the anthracene content4 ,in burning this type of smoke mixture in a cylinder1 it is essential that free burning be allowed4 ,it has been found that if combustion is at all smothered1 and the smoke forced to escape through a comparatively small opening1 it will be gray instead of dense black4 ,,iii4 ,various attempts have been made to utilize the heat evolved when the ,berger type smoke mixture reacts to volatilize or mechanically disperse various colored inorganic substances1 and especially iodine4 ,these were unsuccessful4 ,modifications1 such as ,strontium nitrate #a part ,powdered iron #b parts ,iodine #c parts were also tried1 but while such mixtures ignited easily1 burned freely and evenly1 and gave a continuous heavy purple cloud1 they were very sensitive to moisture and capable of spontaneous ignition4 ,the most satisfactory and successful colored smokes are those produced by the volatilization of organic dye materials4 ,this practice seems to have originated with the ,british1 who produced such smokes by volatilizing or vaporizing special dyes by igniting mixtures of the dye1 lactose and potassium chlorate and smothering the combustion4 ,in selecting dyestuffs for this purpose it was at once recognized that only those compounds can be used which are volatilized or vaporized without decomposition by the heat generated when the mixture is ignited and the combustion smothered4 ,it was also found that the boiling point and melting or volatilization point of the colored compound must be close enough together so that there is never much liquid dye present4 ,since all colored organic compounds are destroyed if subjected to sufficient heat1 the mixture must be so prepared and the ignition so arranged that the heat generated is not sufficient to cause this destruction4 ,the oxidizing agents used in the combustion mixture may be either potassium or sodium chlorate4 ,the nitrate is not satisfactory4 ,lactose has proven the best combustible4 ,powdered orange shellac is fairly satisfactory but offers no advantage over lactose4 ,the following dyes have been found to give the best smokes3 ,red 8,paratoner0 ,yellow ,chrysoidine ,auramine ,blue ,indigo ,purple ,indulin 787 ,green ,auramine ,yellow ,indigo ,at the beginning of the war1 the only colored smoke used by the ,united ,states ,army was a yellow smoke4 ,the smoke mixture used in all signals1 excepting the smoke torch1 was the old arsenic sulfide mixture4 ,the following smoke signals were adopted during the ,world ,war3 ,signal ,parachute ,rocket ,yellow and ,red ,v4 ,b4 ,parachute ,cartridge ,yellow #be mm4 ,very ,parachute ,cartridge ,yellow #ce mm4 ,signal ,cartridge ,yellow #ce mm4 ,signal ,cartridge ,red #ce mm4 ,signal ,pistol #be mm4 ,very ,signal ,pistol ,v4 ,b4 ,rifle ,discharger ,cut ,,the ,,tactical ,,use ,,of ,,signal ,,smokes ,from the days when ,horatius kept the bridge1 down through the centuries to the ,world ,war1 all leaders in battle were pictured at the front and with flaming sword1 mounted on magnificent chargers1 or otherwise so prominently dressed that all the world knew they were the leaders4 ,during all these hundreds of years commands on the field of battle were by the voice1 by the bugle1 or by short range signals with arms1 flags1 and swords4 ,even where quite large forces were involved they were massed close enough ordinarily so that signalling by such means sufficed to cover the front of battle4 ,in those cases where they did not1 reliance was put upon swift couriers on horseback or on foot4 ,with the invention of smokeless powder and the rifled gun battles were begun and carried on at greater and greater ranges4 ,artillery fired not only #b1jjj to #c1jjj yards but up to #e1jjj and #aj1jjj yards1 or even1 as in the ,world ,war1 at #bj1jjj yards and more4 ,it was then that other means of signalling became essential4 ,distant signalling with flags is known to have been practiced to a certain extent on land for a long time4 ,the extension of the telegraph and telephone through insulated wires laid by the ,signal ,service was the next great step in advance1 and in the ,world ,war there came in addition the wireless telephone both on land and in aeroplanes and balloons4 ,along with this development1 as mentioned under ,screening ,smokes1 came the development of the use of smoke for protection and for cutting off the view of observers1 thus making observation more and more difficult4 ,this use of smoke1 coupled with the deadly fire of machine guns and high explosives1 forced men to take shelter in deep shell holes1 in deep trenches and other places that were safe1 but which made it nearly impossible to see signals along the front of battle4 ,every man can readily be taught to read a few signals when clearly indicated by definite1 sharply defined colored smokes4 ,at first these were designed for use on the ground and will be used to a certain extent in the future for that purpose1 particularly when it is desired to attract the attention of observers in aeroplanes or balloons4 ,in such cases a considerable volume of smoke is desired4 ,for the man in the trench or shell hole some means of getting the signal above the dust and smoke of the battlefield is needed4 ,it is there that signal smokes carried by small parachutes1 contained in rockets or bombs1 have proven their worth4 ,these signals floating high above the battlefield for a minute or more1 giving off brilliantly colored smokes1 afford a means of sending signals to soldiers in the dust and smoke of battle not afforded by any other method so far invented4 ,as before stated1 every man can be taught these simple signals1 where but very few men can be taught to handle even the simplest of wireless telephones4 ,thus1 smoke has already begun to complicate1 and in the future will complicate still more1 every phase of fighting4 ,it will be used for deception1 for concealment1 for obscuring vision1 for signalling and to hide deadly gases4 ,the signal rocket will be used to start battles1 change fronts1 order up reserves1 and finally to stop fighting4 ,the signal smokes by day will be displaced at night by brilliantly colored lights which will have the same meaning as similarly colored smokes during the day4 ,thus1 literally1 smoke in the future will be the cloud by day and the pillar of fire by night to guide the bewildered soldier on the field of battle with all its terrors and amidst the confusion1 gas1 smoke and dust that will never be absent while battles last4 ,,chapter ,,xx ,,incendiary ,,materials ,since it is generally known that white phosphorus1 when exposed to the air1 takes fire spontaneously1 it logically follows that numerous suggestions should have been made for using this material in incendiary devices4 ,practice1 however1 has shown that1 while phosphorus is undoubtedly of value against very easily ignitable materials1 such as hydrogen in ,zeppelins1 or the gasoline tanks of aeroplanes and dry brush or grass1 it is of much less value when wood and other materials are considered4 ,this is partly because of the low temperature of burning1 and partly because the product of combustion 7phosphoric anhydride7 is really an excellent fireproofing substance4 ,in view of this1 phosphorus was used primarily for smoke production4 ,a superior incendiary material is found in thermit1 a mixture of aluminum and iron oxide4 ,when ignited1 it produces an enormous amount of heat very quickly1 and the molten slag that results from the reaction will prolong the incendiary action upon inflammable materials4 ,when used alone1 however1 it has the disadvantages that the incendiary action is confined to a small area and that the heat energy is wasted because of the fact that it is so rapid in its action4 ,for this reason it is customary to add a highly inflammable material1 which will become ignited by the thermit and will continue the conflagration4 ,petroleum oils1 carbon disulfide1 wood distillation products and other inflammable liquids were thoroughly tested for this purpose4 ,the final conclusion was reached that oil1 solidified with soap 7sodium salts of the higher fatty acids7 by a special method developed by the ,chemical ,warfare ,service1 was by far the best material to be used4 ,in certain tests1 using a combination of thermit and solid oil1 flames fifteen feet high were obtained1 which would be very useful against walls1 ceilings1 etc4 ,in addition to this type of incendiary material1 it was desirable to have a spontaneously inflammable mixture of oils1 which could be used in ,livens' shell1 ,stokes' shell or aeroplane bombs4 ,the basis of these mixtures is fuel oil and phosphorus4 ,by varying the proportions of the constituents it is possible to obtain a mixture that will ignite immediately upon exposure to the air1 or one that will have a delayed action of from #cj seconds to two minutes4 ,the incorporation of metallic sodium gives a mixture that will ignite when spread upon water surfaces4 ,,incendiary ,,devices ,the incendiary devices used during the late war included3 bombs1 shell1 tracer shell and bullets1 grenades1 and flame throwers4 ,,bombs ,incendiary bombs were used almost exclusively by aircraft4 ,the value of bombs which would cause destruction by starting conflagrations was early recognized but their development was rather slow4 ,while the designs were constantly changing1 two stand out as the most favored3 a small unit1 such as the ,baby ,incendiary ,bomb of the ,english1 and a large bomb1 such as the ,french ,chenard bomb or the ,american ,mark ,,ii bomb4 ,in general bombs which1 when they function upon impact1 scatter small burning units over a considerable area1 are not favored4 ,small unit bombs can be more effectively used because the scatter can be better regulated and the incendiary units can be more advantageously placed4 ,german ,bombs4 ,incendiary bombs were used by the ,germans in their airplane raids1 usually in connection with high explosive bombs4 ,a typical armament of the later series of ,german naval airships consisted of the following3 #b #ffj-pound bombs #aj #bbj-pound bombs #ae #aaj-pound bombs #bj ,incendiary bombs making a total weight of about #b tons4 ,illustration3 ,,fig4 #ajg4--;,incendiary ,devices4 7,from ,left to ,right74 ,mark ,,ii ,bomb1 ,b4 ,i4 ,bomb1 ,mark ,i ,dart1 ,mark ,,ii ,dart1 ,mark ,i ,dart1 ,grenade1 ,mark ,i ,bomb4 ,a typical ,german bomb is shown in ,fig4 #ajh4 ,it consists essentially of a receiver of white iron 7,r7 composed of a casing and a central tube of zinc1 joined together in such a fashion that1 when the whole was complete1 it had the appearance of an elongated vessel with a hollow center4 ,within this central hollow is placed a priming tube 7,t7 of thin sheet iron1 pierced by a number of circular openings4 ,the receiver is about #dde mm4 7#ag4e in47 high and #aaj mm4 7#d4c in47 at its maximum diameter4 ,it is wrapped with strands of tarred cord over nearly its entire length4 ,the empennage 7#bgj mm4 or #aj4f in4--in height7 consisted of three inclined balancing fins1 which assured the rotation of the projectile during its fall4 ,in the body of the bomb was a viscous mass of benzine hydrocarbons1 while the lower part of the receiver contained a mixture of potassium perchlorate and paraffin4 ,the central tube apparently contained a mixture of aluminum and sulfur4 ,illustration3 ,,fig4 #ajh4--;,aerial ,incendiary ,bomb1 ,november1 #aiaf4 ,illustration3 ,,fig4 #aji4--;,german ,incendiary ,bomb1 ,scatter ,type4 ,later the ,germans used a scatter type of bomb 7,fig4 #aji7 which was designed to give #df points of conflagration4 ,each of these #df small cylinders contained #ej grams of an air incendiary material4 ,they were arranged in layers1 packed in with very fine gun powder4 ,the bomb is ignited by a friction lighter which is pulled automatically when the bomb is released from the aeroplane4 ,the bomb is constructed to burst in the air and not on striking the ground4 ,the upper part of the projectile consists of a cast iron nose riveted to the sheet iron body of the bomb4 ,when the explosion occurs1 the nose is blown away and the small incendiary cylinders are scattered in the air4 ,the incendiary material appears to be a mixture of barium nitrate and tar4 ,its incendiary power is very low because combustion takes the form of a small flame of very short duration4 ,it should1 however1 be very valuable for firing inflammable materials4 ,british ,bombs4 ,the early ,british bombs were petrol bombs1 which were used without great success for crop burning4 ,phosphorus bombs were then used for attacking aircraft4 ,but the most successful incendiary is the so-called 8,baby ,incendiary ,bomb40 ,this is a #f4e-ounce bomb with an incendiary charge of special thermit4 ,these small bombs are carried in containers holding either #add or #bgb bombs4 ,the former container approximates in size and weight one #ej-pound ,h4,e4 bomb and the latter one #abj-pound ,h4,e4 bomb4 ,the bomb contains a cartridge very much like a shot gun shell which1 on impact1 sets down on the striker point in the base of the body1 and causes the ignition of the charge4 ,it is claimed that the cartridge of the ,b4,i4 bomb burns when totally immersed in any liquid 7water included7 and in depths up to two feet the flame breaks through the surface4 ,french ,bombs4 ,the ,french used three types of incendiary bombs1 a special thermit 7calonite71 the ,chenard and the ,davidsen4 ,the ,chenard bomb is a true intensive type and is thought to be very successful4 ,it functions by means of a time fuse operated by the unscrewing of a propeller1 before striking the ground1 and reaches its target in flames4 ,its chief disadvantage is the small amount of incendiary material which it carries4 ,the ,davidsen bomb expels its charge as a single unit and is not considered as valuable or as successful as the ,chenard4 ,american ,bombs4 ,the program of the ,chemical ,warfare ,service included three types of bombs3 ,mark ,,ii ,incendiary drop bomb ,mark ,,iii ,incendiary drop bomb ,mark ,i ,scatter bomb ,mark ,,ii ,bomb4 ,the incendiary ,mark ,,ii drop bomb is designed to be dropped from an aeroplane and is intended for use against buildings1 etc41 when penetrating effect followed by an intensive incendiary action is sought4 ,the bomb case consists of two parts3 a body and a nose4 ,the body is a tapering zinc shell which carries the firing mechanism and stabilizing tail fin at the small end and at the large end a threaded ring which screws into the nose4 ,the nose is of drawn steel of such shape as to have low end-on resistance and is sufficiently strong to penetrate frame structures4 ,illustration3 ,,fig4 #aaj4--,loading ,bombs with 8,solid0 ,oil4 ,the incendiary effect is produced by a thermit charge carried in the nose of the bomb4 ,this charge is ignited by a booster of 8,thermit ,igniter0 fired by black powder4 ,the latter is ignited by a flash from the discharge of a standard #j4cj caliber service cartridge contained in the body of the bomb1 and exploded by a firing mechanism of the impact type4 ,this method of firing has proven wholly unsatisfactory and will be superseded by some more direct-acting mechanism4 ,the body of the bomb is filled with solidified oil4 ,the molten thermit burns through the case of the bomb and liberates the oil which has been partially liquefied by the heat of the thermit reaction4 ,additional incendiary effect is afforded by the sodium nitrate contained in the nose below the thermit1 and by two sheet lead cylinders filled with sodium and imbedded in the solid oil4 ,the sodium increases the difficulty of extinguishing the fire with water4 ,mark ,,iii ,bomb4 ,this bomb is simply a larger size of the ,mark ,,ii bomb1 its weight being approximately #ajj pounds as compared with #dj pounds for the ,mark ,,ii bomb4 ,it is designed to be dropped from an aeroplane and is intended for use against buildings when marked penetrating effect is desired4 ,the method of functioning is the same as the ,mark ,,ii bomb and it has the same defects in the firing mechanism4 ,mark ,i ,bomb 7,scatter ,type74 ,the ,mark ,i incendiary drop bomb is also designed to be dropped from aeroplanes and is intended for use against grain fields1 ammunition dumps1 light structures or similar objectives when only a low degree of ignition is required4 ,it is of the so-called scatter type1 due to the action of the exploding charge which casts out incendiary material within a radius of #bj feet from the point of contact4 ,the incendiary action is due to the ejection of the various incendiary units in the bomb by the explosion of the black powder in the nose4 ,the flash of this explosion serves to ignite the units4 ,a powder charge in the rear of the bomb acts simultaneously with the nose charge1 opening the bomb casing1 and aiding materially in the scatter of the units4 ,the bomb is so arranged as to function close to the ground1 which is a further factor in the scatter of the units4 ,the incendiary units are waste balls about #b4e in4 in diameter and having an average weight of #b4e ounces1 tied securely with strong twine4 ,these are soaked in a special oil mixture4 ,carbon disulfide and crude turpentine1 or carbon disulfide1 benzene heads and crude kerosene gave satisfactory results4 ,a later development attempted to replace the waste balls by solid oil1 but the difficulties of manufacture and questions of transportation argued against its adoption4 ,these bombs were not used at the front4 ,nearly all of the ,american incendiary bombs proved too light on the nose and lower half1 generally resulting in deformation upon impact and very poor results4 ,new ones will be made stronger4 ,,incendiary ,,darts ,the ,british early recognized the value of a small bomb1 and consequently adopted their ,b4,i4,b4 7,baby ,incendiary ,bomb71 weighing about #f4e ounces4 ,these are capable of being dropped in lots of #ajj or more and thus literally shower a given territory with fire4 ,the intensity of fire at any given point is much less than that obtained with the larger bombs1 but the increased area under bombardment more than counter balances this disadvantage4 ,while the ,british aimed at the perfection of a universal bomb1 the ,american service felt that two classes should be developed1 one to be used against grain fields and forests1 the other against buildings4 ,the first class was called the ,mark ,i ,dart4 ,this consisted of an elongated #ab-;gauge shot gun shell1 filled with incendiary material and provided with a firing mechanism to ignite the primer as the dart strikes the ground4 ,the flash of the primer sets fire to the booster1 which1 in turn1 ignites the main incendiary charge4 ,the latter burns several minutes1 with a long flame4 ,a retarding stabilizer attached to the tail of the dart serves the two-fold purpose of insuring the functioning of the firing mechanism and1 by retarding the final velocity of the dart1 preventing the collapse of the dart body when dropped from very high altitudes4 ,the incendiary mixture is one which gives a long hot flame1 burns for several minutes and leaves very little ash4 ,in general it consists of an oxidizing agent 7barium or sodium chlorate71 a reducing agent 7aluminum1 or a mixture of iron1 aluminum and magnesium71 a filler 7rosin1 powdered asphaltum or naphthalene7 and in some cases a binder 7asphaltum1 varnish or boiled linseed oil74 ,the ,mark ,,ii ,dart was developed to furnish a small size penetrating agent4 ,it consists of a two-inch 7diameter7 zinc case filled with thermit and solid oil as the incendiary materials and provided with a cast iron nose for penetration4 ,during the first half minute after firing1 a pool of molten iron is formed by the thermit1 which is very penetrating and affords a good combustible surface for the oil1 which burns for an additional ten minutes4 ,it has an advantage over the ,mark ,i dart in that it penetrates1 and over the ,mark ,,ii bomb in that it is smaller and lighter in weight4 ,,incendiary ,,shell ,incendiary shell have been successfully used against aircraft and to some extent in bombardments of inflammable ground targets4 ,anti-aircraft shell are of small caliber and are usually tracer-incendiary4 ,such shell are filled with pyrotechnic mixtures which ignite at the moment of firing1 or by time fuse1 and are effective against highly inflammable material4 ,shell filled with thermit which explode and scatter the molten iron have been used against aircraft and ground targets1 but with rather poor results4 ,large shell1 which burst upon impact and scatter units of burning materials1 have been used with some success against ground targets4 ,tracer shell contain such mixtures as barium nitrate1 magnesium and shellac1 or red lead and magnesium4 ,,incendiary ,,bullets ,incendiary bullets are only effective against highly inflammable material1 and are therefore used principally in aerial warfare against aircraft1 either for the purpose of igniting the hydrogen of the gas bag1 or the gasoline4 ,the present tendency is towards the use of the large size 7#aa mm47 bullet1 because of its greater incendiary action4 ,the incendiary material is either white phosphorus or a special incendiary mixture consisting of an oxidizing agent and some combustible or mixture of combustibles4 ,the white tracer bullet contains a mixture of barium peroxide and magnesium4 ,a red bullet contained in addition1 strontium nitrate and chloride1 or peroxide4 ,,incendiary ,,hand ,,grenade ,while the use of incendiary grenades and other small incendiary devices is limited1 such armament is considered very valuable in trench warfare4 ,they can be used to set fire to inflammable material1 either in offensive or defensive operations4 ,phosphorus grenades1 while used principally for producing smoke 7see page #cjb71 have considerable value as an incendiary weapon4 ,thermit grenades are very useful in rendering unserviceable guns and other metallic equipment which must be abandoned4 ,they permit aviators to destroy planes which motor troubles oblige to land in enemy territory4 ,they are also used to ignite inflammable liquids1 thrown into a dugout1 or sprayed over an objective by a flame projector4 ,the ,mark ,i hand grenade was developed for burning enemy ammunition dumps1 for clearing away brush or other material in front of trenches and for use in dugouts4 ,the standard ,h4,e4 grenade body was half-filled with thermit and half with a celluloid container filled with a solidified fuel oil4 ,the grenade is fired by the spit of the fuse of the bouchon firing mechanism4 ,this1 through the booster1 lights the thermit igniter1 which in turn fires the main charge of thermit4 ,the resulting molten iron readily penetrates the grenade case1 at the same time igniting the celluloid case and its contents4 ,the oil burns for about #c4e minutes4 ,this grenade was never used since it was considered that an all thermit grenade would be of more value4 ,,trench ,,mortar ,,equipment ,special projectiles were designed for use with the ,stokes mortar and the ,livens' projector4 ,thermit was used only in ,stokes' projectiles4 ,the ,livens' projectile was filled with inflammable units 7chlorated jute7 immersed in a light oil mixture4 ,thrown from a projector into the enemy's trench1 it explodes1 giving a large flash and scattering the burning units over an area of forty yards4 ,the ,mark ,,ii projectile1 designed for general incendiary effect against readily inflammable material1 consists of an altered #h-;inch ,livens' gas projectile filled with chlorated jute units impregnated with solid oil and immersed in a spontaneously inflammable oil4 ,after a short delay1 these units burst into flame and burn vigorously for several minutes4 ,it is almost impossible to extinguish them without large quantities of water4 ,such bombs have only a very limited use1 so that it is questionable if they are really worth while4 ,illustration3 ,,fig4 #aaa4--;,german #h ,incendiary ,bullet4 ,illustration3 ,,fig4 #aab4--;,german ,incendiary ,blue ,pencil4 ,,german ,,blue ,,pencil ,a very interesting and curious device was developed by the ,germans in the form of an incendiary pencil4 ,similar in appearance to a common blue pencil1 sharpened at one end1 they are distinguished only by a small1 almost imperceptible1 point placed on the outside #aa mm4 from the unsharpened end4 ,they are #age mm4 long1 #aa4a mm4 in diameter and weigh #ab to #ac grams4 ,the interior of the pencil contains a glass bulb1 with two compartments filled with sulfuric acid and a celluloid tube filled with potassium chlorate4 ,the glass bulb ends in a slender point2 when this is broken the acid comes into contact with the chlorate and causes an explosion4 ,the two materials are separated by a layer of clay1 which causes a delayed action of about #cj minutes4 ,the operator breaks the point of bulb1 buries the pencil vertically in the inflammable material and then has half an hour in which to get away1 before any possibility of a fire4 ,he cuts the pencil with a knife #b cm4 from the point1 so that if caught he has the appearance of simply sharpening a pencil4 ,,flaming ,,gun ,among the unsuccessful weapons of the late war1 the liquid fire gun or ,flammenwerfer1 as the ,german called it1 is probably the most interesting4 ,its origin1 according to a ,german story1 was due to a mere accident4 ,a certain officer1 during peace maneuvers1 was ordered to hold a fort at all cost4 ,during the sham fight1 having employed all the means at his disposal1 he finally called out the fire brigade and directed streams of water upon the attacking force4 ,afterwards1 during the criticism of the operations in the presence of the ,kaiser1 he claimed that he had subjected the attackers to streams of burning oil4 ,the ,kaiser immediately inquired whether such a thing would be possible1 and was assured that it was entirely feasible4 ,illustration3 ,copyright by ,kadel and ,herbert1 ,n4 ,y4 ,,fig4 #aac4--,liquid ,fire ,attack4 ,long series of experiments were necessary before a satisfactory combination of oils was produced1 which could be projected as a flame on the enemy1 but they were finally successful4 ,unlike the use of poison gas1 however1 the flaming liquid gun did not prove to be a successful weapon of warfare4 ,true1 at first they were rather successful1 but this was before the men learned their real nature4 ,in the first attack1 the ,allies were completely surprised and the troops were routed by the flames4 ,auld tells of one of the early attacks 7,july #bi1 #aiae7 when1 without warning1 the front line troops were enveloped in flames4 ,where the flames came from could not be seen4 ,all that the men knew was that they seemed surrounded by fierce1 curling flames1 which were accompanied by a loud roaring noise1 and dense clouds of black smoke4 ,here and there a big blob of burning oil would fall into a trench or saphead4 ,shouts and yells rent the air as individual men1 rising up in the trenches or attempting to move in the open1 felt the force of the flames4 ,the only way to safety appeared to be to the rear4 ,this direction the men that were left took4 ,for a short space the flames pursued them and the local retirement became a local rout4 ,after the bombardment which followed1 only one man is known to have returned4 ,after a study of the pictures of the liquid fire gun in operation1 it is evident that the men could not be blamed for this retirement4 ,one has only to imagine being faced by a spread of flame similar to that used for the oil burners under the largest boiler1 but with a jet nearly #fj feet in length and capable of being sprayed round as one might spray water with a fire hose4 ,later1 when the device was better known it was different1 though even then it was a pretty good test of a man's nerve4 ,it was found that the flames could not follow one to the bottom of a trench as the gas did1 and that1 if a man crouched to the bottom of his trench1 his head might be very warm for a minute or so but that the danger was soon past and he then could pick off the man who had so recently made things uncomfortable for him4 ,while it is said that ,major ,r41 who invented the ,flammenwerfer1 enjoyed a great popularity among his men1 and is familiarly known as the ,prince of ,hades1 there is no doubt that this was not shared by the ,allies4 ,their rule was3 8,shoot the man carrying the apparatus before he gets in his shot1 if possible4 ,if this cannot be done1 take cover from the flames and shoot him afterwards40 ,the ,german had several types1 which may be grouped into the small or portable and the large ,flammenwerfers4 ,the portable ,flammenwerfer consisted of a sheet steel cylinder of two compartments1 one to hold compressed nitrogen1 the other to hold the oil4 ,the nitrogen furnished the pressure which forces the oil out through the flexible tube4 ,air cannot be used1 because the oxygen would form an explosive mixture with the vapors of the oil1 and any heating on compression1 or back flash from the flame or fuse might make things very unpleasant for the operator4 ,a pressure of about #bc atmospheres is reached when the cylinder is charged4 ,the nitrogen appeared to be carried on the field in large containers and the flame projectors actually charged in the trenches4 ,the oil used in the flame projectors varied from time to time1 but always contained a mixture of light or easily volatile and heavy and less volatile fractions of petroleum or mineral oil1 very carefully mixed4 ,in some cases even ordinary commercial ether has been found in the cylinders4 ,illustration3 ,,fig4 #aad4--,small ,flammenwerfer4 ,the most interesting part about the flame projector is the lighting device4 ,this is so made that the oil ignites spontaneously the minute the jet is turned on1 and is kept alight by a fiercely burning mixture which lasts throughout the discharge4 ,this mixture is composed of barium nitrate1 potassium nitrate1 metallic magnesium and charcoal1 with some resinous material4 ,the priming consists of black powder and metallic magnesium4 ,when the oil rushes out of the jet1 it forces up the plunger of a friction lighter and ignites this core of fiercely burning mixture4 ,the range of these small projectors is from #ad to #ag meters 7#ag to #bj yards7 but the duration of the flame is rather less than a minute4 ,in a later pattern1 it was designed that one nozzle should be issued to three reservoirs4 ,after the discharge of one1 the jet is attached to the others in succession4 ,this is called the 8,wx0 ,flammenwerfer 7interchangeable74 ,in this way a squad of three men could carry #eh pints of inflammable oil4 ,it is a question1 though1 whether the third man would live to use his reservoir4 ,illustration3 ,,fig4 #aae4--;,boyd ,flame ,projector4 ,the fact that the trenches were often very close together during the early part of the war1 made possible the use of large or stationary ,flammenwerfer4 ,these consisted of a steel reservoir #c feet in height and #a feet in diameter1 weighing about #bej pounds1 which could be connected to two steel cylinders1 containing nitrogen under pressure4 ,these carried #ahj liters 7#dj gallons7 of liquid and operated under a pressure of #ae atmospheres4 ,the discharge nozzle was at the end of a metal tube three feet long1 and its orifice was about _/ of an inch in diameter4 ,the range of this apparatus was from #cc to #dj yards and the duration of the flame from one to two minutes4 ,because of the comparatively short range of these guns and the ease with which they could be destroyed1 if located by the enemy1 their use was very limited4 ,even with the portable flammenwerfer1 the most difficult thing to do is to get near enough the target to make the shoot effective4 ,another serious disadvantage is its very short duration4 ,it is impossible to charge up again on the spot1 and the result is that once the flame stops1 the whole game is finished and the operators are at the mercy of the enemy4 ,with these facts in mind it is easy to see how service in the flaming gun regiments is apparently a form of punishment4 ,men convicted of offenses in other regiments were transferred either for a time or permanently and were forced under threat of death in the most hazardous enterprises and to carry out the most dangerous work4 ,taken all in all the flame thrower was one of the greatest failures among the many promising devices tried out on a large scale in the war4 ,,chapter ,,xxi ,,the ,,pharmacology ,,of ,,war ,,gases ,the pharmacology of war gases plays such an important part in chemical warfare that a brief discussion may well be given of the methods used in the testing of gases for toxicity and other pharmacological properties4 ,war gases may be divided into two groups3 persistent and non-persistent1 each of which may include several classes3 ,i4 ,lethal ,,ii4 ,lachrymatory ,,iii4 ,sternutatory ,,iv4 ,special ,each class necessitates special tests in order to determine whether or not it is suitable for further development4 ,,toxicity ,one of the first points which must be carefully determined in investigating a substance is its toxicity4 ,it is important that this be determined for numerous reasons3 #a4 ,to determine what concentrations are dangerous in the field4 #b4 ,to ascertain how effective protective devices have to be to furnish sufficient protection against the gas4 #c4 ,to furnish a basis for accurate experimental work on the treatment of gassed cases4 #d4 ,to decide whether or not the material is worthy of further development in the laboratory or in the plant4 ,these considerations necessitate the determination of the toxicity in the form of a vapor and not by the ordinary method of administration by mouth1 through the skin 7subcutaneously7 or through the blood 7intravenously74 ,the simplest method of determining the toxicity of a substance as a vapor would be to place animals in a gas-tight box and introduce a known amount of the substance in the form of vapor4 ,but by this method the concentration is not accurately known unless chemical analyses of the air are made1 and then it is found to be much less than that calculated from the amount of substance introduced1 because of condensation on the walls of the chamber1 or absorption of the substance by the skin and hair of the animal and in some cases1 of decomposition of the substance by moisture in the air4 ,moreover1 it is found that the concentration decreases markedly with time4 ,because of these factors1 the figures used for the concentration are more or less guess work4 ,to overcome these difficulties1 a chamber is used through which a continuous current of air1 containing a known and constant amount of the poisonous vapor1 is passed4 ,such an apparatus is shown in ,fig4 #aaf4 ,illustration3 ,,fig4 #aaf4--;,continuous ,flow ,gassing ,chamber for ,animals4 ,the flask ,e is a #cjj cc4 ,erlenmeyer flask1 with a ground glass stopper4 ,the liquid to be tested is placed in this flask together with a sufficient quantity of glass wool to prevent splashing and the carrying over mechanically of droplets of the liquid4 ,air is passed through ,a and ,c 7calcium chloride drying tubes7 and the rate measured by the flow meter ,d4 ,the air and gas are mixed in ,f before passing into the chamber ,g4 ,this chamber is made of plate glass1 is of about #ajj liters capacity1 and is air-tight4 ,the entire flow of air and gas through the box1 kept constant at #bej liters per minute1 is measured at ,h4 ,the gas is removed through ,k1 which is filled with charcoal and soda-lime1 in order that little gas may pass into the pump4 ,by weighing the flask ,e1 and its contents before and after passing air through it1 and knowing the total volume of the mixture passing through the chamber during the same period1 the concentration of the substance can readily be calculated4 ,this concentration1 as determined by the 8loss in weight0 method1 can be checked by chemical analysis 7samples taken at ,m--,m74 ,the method has been found to give accurate values4 ,the concentration in the chamber reaches its constant level within #cj to #dj seconds after the apparatus is started4 ,with the flow of #bej liters per minute1 the difficulties mentioned above are reduced to a point where they are practically negligible4 ,all toxicity tests on mice were made with an exposure of ten minutes1 while dogs were exposed for thirty minutes4 ,in case death did not occur during exposure1 the animals were kept under observation for several days4 ,toxicity and all other figures are expressed in milligrams per liter of air1 though parts per million 7p4p4m47 was frequently used during the early work4 ,another point of difficulty is the great individual variation in the susceptibility of animals4 ,this is probably greater than when the poison is administered subcutaneously or intravenously4 ,it necessitates the use of a large number of animals in making a determination of the toxicity of a gas4 ,again1 the toxicity for different species may vary1 and as the ultimate aim is a knowledge of the toxicity for man1 a great many different species must be used4 ,if the toxicity is widely different for different animal species1 it is hard to arrive at a definite conclusion as to the toxicity for man4 ,with longer exposures than thirty minutes the lethal concentration is usually less1 there being a cumulative effect4 ,this is not true for hydrocyanic acid4 ,if the concentration is not enough to kill at once1 an animal can stand it almost indefinitely4 ,whether the action is cumulative or not depends on the rate at which the system destroys or eliminates the poison4 ,if the poison is being eliminated as fast as received the concentration in the tissues cannot increase4 ,it is stated1 for example1 that the amount of nicotine in a cigar would kill a man if taken in one dose4 ,if it is spread over twenty minutes1 the destruction or elimination of the nicotine is so rapid that no obviously bad effects are noted4 ,another interesting thing about the work on poison gases is that in most cases a preliminary exposure to less than the lethal concentration does not seem to make the animal either more or less sensitive on a later exposure4 ,this is quite unexpected1 because we know that with irritating gases1 especially lachrymators1 men adapt themselves to much higher concentrations than they could stand at first4 ,in view of the experiences of arsenic eaters1 it is quite possible that the experiments1 which showed no accustoming to toxic gases1 were not continued long enough to give positive results4 ,not only does the susceptibility of different animals of the same species vary greatly for a particular gas1 but the susceptibility of different species varies greatly with different gases4 ,thus while the effects of certain gases on mice are quite comparable to the effects on man1 it is very far from being true with other gases4 ,,lachrymators ,while one cannot determine the lethal concentrations of poison gases for men1 it is possible to determine the concentration that will produce lachrymation4 ,the threshold value is that at which two-thirds of the observers experience irritation4 ,the lachrymatory value is considerably higher than the threshold value4 ,illustration3 ,,fig4 #aag4--;,aeration ,apparatus for ,testing ,lachrymators4 ,a very satisfactory method for determining lachrymatory values is shown in ,fig4 #aag4 ,air is measured at ,a and bubbled through the lachrymatory substance in ,b4 ,the air and gas are mixed in ,d and pass into ,e1 a gas-tight1 glass-walled chamber of about #aej liters capacity4 ,the gas is removed through ,ef1 by suction and the volume of the air-gas mixture measured by the flow meter1 ,f4 ,after the apparatus has run a few minutes1 and the concentration of the gas has become constant1 the subject is instructed to adjust the mask1 attached at ,h1 and to tell whatever he notices just as soon as he notices it4 ,the operator stands in such a position that he can manipulate the stopcock ,h without being observed by the subject4 ,after breathing air for a time 7,h is a two-way cock1 connected with the air through ,j1 and to the chamber through ,eg7 both to become accustomed to the mask and to eliminate1 as far as possible1 any 8psychological symptoms10 the subject is allowed to breathe the gas mixture for a maximum of three minutes4 ,if the expected symptoms are produced in less than this time1 the test is discontinued as soon as they develop4 ,illustration3 ,,fig4 #aah4--,type of ,spray ,nozzles4 ,for accurate work1 it is necessary to work with a pure sample which is at least fairly volatile4 ,mixtures cannot be run by this method4 ,in this case it is necessary to volatilize each separately1 passing the vapors simultaneously into the mixing chamber ,e4 ,a spray method may also be used with satisfactory results4 ,types of sprays are shown in ,fig4 #aah4 ,,odors ,because of the great value in detecting low concentrations of gases in the field1 it is important to know the smallest amount of a gas that can be detected by odor4 ,in some cases1 this test is more delicate than any chemical test yet devised4 ,odors may be divided into two classes1 true odors1 and mild irritation4 ,by true odor is meant a definite stimulation of the olfactory nerve1 giving rise to a sensation which is more or less characteristic for each substance producing the stimulation4 ,mild irritation defines the sensation which is confused with the sense of smell by untrained observers1 but which is really a gentle stimulation of the sensory nerve endings of the nose4 ,this so-called odor of substances producing this effect is not characteristic4 ,higher concentrations of these compounds almost invariably cause a definite irritation of the nose4 ,examples of true odors are the mercaptans1 mustard gas1 bromoacetone1 acrolein1 chlorine and ammonia4 ,substances which cause mild irritation are chloroacetone1 methyl dichloroarsine1 ethyl iodoacetate and chloropicrin4 ,in making the test for odor1 the same apparatus is used as for lachrymators4 ,the time of exposure is shortened to #cj seconds1 as the subject always detects the odor at the first or second inhalation4 ,in this connection the recent work of ,allison and ,katz 7,j4 ,ind4 ,eng4 ,chem4 #aa1 #ccf1 #aiai7 is of interest4 ,they have designed an instrument1 8the odorometer10 for measuring the intensity of odors in varying concentrations in air4 ,it is based on the principle given above4 ,a measured volume of air is passed through the liquid and then diluted to a given concentration4 ,the mixture is then passed through a rubber tube with a glass funnel at the open end4 ,only one inhalation of the mixture is used to determine the intensity of the odor4 ,the position of any strength of odor on the scale depends upon the sensitiveness and judgment of the operator1 but with one person conducting the entire test1 the results have been found quite satisfactory4 7,see tables on pages #cfj and #cfa47 ,,skin ,,irritants ,substances which seem useful for producing skin burns are studied both on animals and on man4 ,dichloroethyl sulfide 7mustard gas7 is used as a basis of comparison4 ,several methods are available4 ,direct ,application4 ,this method consists of the direct application of the compound itself to the skin1 using a definite quantity 7#j4jje cc4 or #j4jje mg47 over a definite area 7#e square centimeters7 of the skin4 ,with such a quantity of mustard gas a rather severe burn on animals is produced4 ,no precautions are taken to prevent evaporation from the skin since it is believed that in this way the test will approximate fairly closely the field conditions4 ,vapor ,tests4 ,preliminary tests with vapors of volatile compounds are best made by placing a small amount of the material on a plug of cotton in the bottom of a test tube enclosed in a larger test tube which acts as an air jacket4 ,after about an hour at room temperature the mouth of the test tube is applied to the skin4 ,the concentration is not known1 but one is dealing practically with saturated vapor4 ,if an exposure of from #cj to #fj minutes produces no effect1 one is safe to assume that the compound is not sufficiently active to be of value as a skin irritant4 ,if quantitative results are desired1 the apparatus shown in ,fig4 #aai is used4 ,dry air is blown through the bubbler1 which is connected with a series of glass skin applicators4 ,the concentration is determined in the usual way4 ,the skin applicator consists of a small cylinder about #a4e to #b cm4 in diameter and about #d cm4 long with a small glass handle attached on top4 ,the opening is #a cm4 in diameter4 ,when the concentration of the gas is constant1 the exposure to the skin is made directly for any desired length of time4 ,the skin irritant efficiency is judged by comparing the per cent of positive responses to approximately equal concentrations of the vapors1 using mustard gas as a standard4 ,,table ,i--,,physical ,,and ,,physiological ,,properties ,,of ,,chemicals ,,used ,,as ,,stenches ---------------------------------------- --------------------------------- ,boiling,freezing ,physiological ,chemical ,point1 ,point1 ,character ,properties ,remarks ,c4 ,c4 of ,odor of ,vapor ---------------------------------------- --------------------------------- ,amyl acetate #adh -#ge ,banana oil ,harmless ,pleasant to 7thick7 most people2 disagreeable to some ,ethyl acetate #gg4d -#hc4h ,fruity1 pleasant ,harmless ,amyl alcohol #acg4h ,alcoholic ,harmless ,butyric acid #afb4c -#g4i ,very disagreeable,harmless ,valeric acid #ahf4d -#eh4e ,very disagreeable,harmless ,ethyl ether #ce -#aab4f ,pungent ,soporific ,phenyl #afe ,very disagreeable,unknown isocyanide ,allyl #aea ,mustard oil1 ,lachrymatory isothiocyanate disagreeable and toxic ,methyl #aai #cd ,mustard oil1 ,lachrymatory isothiocyanate disagreeable and toxic ,amyl isovalerate #aij ,very disagreeable,harmless ,butyl mercaptan #ig ,very disagreeable,harmless ,isobutyl #hh ,very disagreeable,unknown ,probably mercaptan harmless ,ethyl mercaptan #cg -#add4d ,very disagreeable,harmless ,propyl mercaptan #fg ,very disagreeable,unknown ,probably harmless ,methyl #bbb4b -#h4c ,oil of ,harmless salicylate wintergreen1 pleasant ,amyl thioether #ie-ih ,very disagreeable,unknown ,probably harmless ,ethyl thioether #ib -#ii4e ,very disagreeable,unknown ,probably harmless ,carbon #gf4gd -#ai4e ,sweet1 unpleasant,harmless tetrachloride ,chloroform #fb -#fc4b ,sweet1 agreeable ,soporific ,iodoform ,decom- #aai ,unpleasant ,harmless poses ,artificial musk ,pleasant ,harmless ,unpleasant in higher concentration ,nitrobenzene #bji4d #e4ga;,almonds1 pleasant,toxic ,oil of ,pleasant ,harmless peppermint ,pyridine #aae4b -#db ,very disagreeable,toxic ---------------------------------------- ---------------------------------- ,,table ,,ii--,,results ,,of ,,measurement ,,of ,,the ,,intensity ,,of ,,various ,,stenches ---------------------------------------- -------------------------- ,volumes of the ,chemical1 as a ,perfect ,gas1 per ,million ,volumes of ,air1 ,intensity of ,odor ---------------------------------------- -- ,chemical ,quite ,very ,detectable ,faint ,noticeable ,strong ,strong ------------------------------- ------------------------------- ,amyl acetate #g #aj #ac #ij #bdf ,ethyl acetate #aij #cci #fae #abcf #agec ,amyl alcohol #fc #hc #abc #dci #fja ,butyric acid #b4d #f #ah #ia #afa ,valeric acid #g #bi #abe #ccb #ifb ,ethyl ether #aibc #cceb #dibg #ehbe #aiihb ,butyl mercaptan #f #ab #ah #ch #ef ,isobutyl mercaptan #c4e #e #g #aa #af ,ethyl mercaptan #ah #ce #gc #ada #aih ,propyl mercaptan #b #g #i #ad #ag ,amyl thioether #j4b #a #a4f #a4g #b4b ,ethyl thioether #c #ab #bi #fa #gd ,allyl isothiocyanate 8#b #c #f #h #ej ,methyl isothiocyanate #e #ac #bc #cf #dh ,amyl isovalerate #a4g #c #f #aj #ab ,carbon tetrachloride #gah #adfa #aehh #difd #fjia ,chloroform #fgd #achi #bfjj #ehhg #iebh ,iodoform #a4ace ,artificial musk ,nitrobenzene #bi #cf #dd #aad #bif ,phenyl isocyanide #j4e #a #c #aj #be ,pyridine #aj #de #ic #gjj #agfd ,methyl salicylate #af4a #bc #bi #bddcf ,oil of peppermint ---------------------------------------- ----------------------- ---------------------------------------- --------------------------- ,milligrams of ,chemical per ,cu4 ,ft4 of ,air1 ,intensity of ,odor ---------------------------------------- -- ,chemical ,quite ,very ,detectable ,faint ,noticeable ,strong ,strong ---------------------------------------- ----------------------- ,amyl acetate #a4a #a4e #b #ad #ch ,ethyl acetate #ai4d #cd4f #fc #abf #aia ,amyl alcohol #f4d #h4e #ac #de #fa ,butyric acid #j4c #j4f #b #i #af ,valeric acid #j4h #c4d #ae #ci #aad ,ethyl ether #afe4a #bhg4g #dbc #ejj #agae ,butyl mercaptan #j4e #a4j #b #c #e ,isobutyl mercaptan #j4b #j4e #j4g #a #b ,ethyl mercaptan #a4c #b4e #e #aj #ad ,propyl mercaptan #j4b #j4f #j4h #a4b #a4f ,amyl thioether #j4jd #j4b #j4c #j4d #j4e ,ethyl thioether #j4c #a4b #c #f #h ,allyl isothiocyanate #j4b #j4c #j4g #j4i #f ,methyl isothiocyanate #j4d #a4a #b #c #d ,amyl isovalerate #j4d #j4e #a #b #b4c ,carbon tetrachloride #abh #bfj #bhc #hhf #ajhg ,chloroform #ic #aib #cfj #haf #acba ,iodoform #j4ecg ,artificial musk #j4jjach ,nitrobenzene #d #e #f #af #db ,phenyl isocyanide #j4jf #j4a #j4d #a #c ,pyridine #j4i #d #i #fd #afb ,methyl salicylate #b4h #d #e #dcci ,oil of peppermint #j4fh #j4i #c #i4e #i4i ---------------------------------------- ------------------------ ---------------------------------------- ---------------------------- ,milligrams of ,chemical per ,liter of ,air1 ,intensity of ,odor ---------------------------------------- -- ,chemical ,quite ,very ,detectable ,faint,noticeable ,strong ,strong ---------------------------------------- ----------------------- ,amyl acetate #j4jci #j4jec #j4jfg #j4dgh #a4cbf ,ethyl acetate #j4fhf #a4bbd #b4bai #d4deg #f4gcc ,amyl alcohol #j4bbe #j4cjj #j4ddb #a4eha #b4afg ,butyric acid #j4jji #j4jba #j4jff #j4cbi #j4ehj ,valeric acid #j4jbi #j4aai #j4ebc #a4cid #d4jcf ,ethyl ether #e4hcc #aj4afg #ad4idd #ag4fffg #fj4fjj ,butyl mercaptan #j4jah #j4jcg #j4jee #j4abj #j4agg ,isobutyl mercaptan #j4jjh #j4jah #j4jbe #j4jda #j4jfj ,ethyl mercaptan #j4jdf #j4jhh #j4ahf #j4ceg #j4eja ,propyl mercaptan #j4jjf #j4jbj #j4jbh #j4jdc #j4jed ,amyl thioether #j4jja #j4jjg #j4jaae #j4jab #j4jae ,ethyl thioether #j4jab #j4jdb #j4ajg #j4bbc #j4bga ,allyl isothiocyanate #j4jjh #j4jab #j4jbd #j4jcj #j4bja ,methyl isothiocyanate #j4jae #j4jci #j4jfg #j4ajh #j4add ,amyl isovalerate #j4jab #j4jah #j4jci #j4jgb #j4jhb ,carbon tetrachloride #d4ecc #i4bbb #aj4jbd #ca4ccc #ch4ddd ,chloroform #c4cjj #f4hjj #ab4gcc #bh4hcc #df4fff ,iodoform #j4jahdj ,artificial musk #j4jjjjdda ,nitrobenzene #j4adf #j4agh #j4bbb #j4efc #a4dic ,phenyl isocyanide #j4jjb #j4jje #j4jac #j4jdb #j4aje ,pyridine #j4jcb #j4adf #j4cja #b4bfe #e4gaj ,methyl salicylate #j4ajj #j4ade #j4agi #a4ebfdb ,oil of peppermint #j4jbd #j4jcb #j4aji #j4ccb #j4cdh ---------------------------------------- ----------------------- ,footnote #ce3 ,maximum concentration obtainable4 ,footnote #cf3 ,maximum concentration obtainable4 ,footnote #cg3 ,maximum concentration obtainable4 ,footnote #ch3 ,maximum concentration obtainable4 ,footnote #ci3 ,maximum concentration obtainable4 ,footnote #dj3 ,maximum concentration obtainable4 ,footnote #da3 ,maximum concentration obtainable4 ,footnote #db3 ,maximum concentration obtainable4 ,touch ,method4 ,this method consists of dipping a small glass rod drawn to a needle-like end to the depth of #a mm4 in the compound and then quickly touching the skin4 ,the method is qualitative only4 ,illustration3 ,,fig4 #aai4--,skin ,irritant ,vapor ,apparatus4 ,use of ,solutions4 ,alcohol1 kerosene1 olive oil1 carbon tetrachloride and other solvents may be used for the purpose of determining the lowest effective concentration of a substance1 and for the determination of the relative skin irritant efficiencies of various compounds4 ,since the skin irritants were scarcely ever used in this form in the field1 that is1 in solution1 the method is not as satisfactory as the vapor method4 ,,chapter ,,xxii ,,chemical ,,warfare ,,in ,,relation ,,to ,,strategy ,,and ,,tactics#dc ,fundamentals of ,war4 ,the underlying fundamental principles of ,chemical ,warfare are the same as for all other arms4 ,because of this1 it is worth while1 and even necessary1 to understand the applications of ,chemical ,warfare1 for us to go back and study the work of the masters in war from the dawn of history down to the present4 ,when we do that we find that the underlying fundamental principles of war remain unchanged4 ,they are the same today as they were in the time of ,demosthenes1 and as they will be #aj1jjj years from now4 ,it is an axiom that the basis of success in war is the ability to have at the decisive point at the decisive moment a more effective force than that of the enemy4 ,this involves men and materials4 ,it involves courage1 fighting ability1 and the discrimination and energy of the opposing commanders4 ,footnote #dc3 ,this material is adapted from a lecture by ,gen4 ,fries before the students of the ,general ,staff ,college1 in ,washington1 ,may #aa1 #aiba4 ,another fundamental is that no success is achieved without positive action2 passive resistance never wins4 ,these are really unchanging fundamentals4 ,we may also say that the vigor of attack1 the speed of movement of men and supplies1 and the thorough training of men in the use of the weapons of war are unchanging requirements1 but outside of these everything is subject to the universal law of change4 ,grecian ,phalanx and ,roman ,legion4 ,the last word in the development of human strength as a battle weapon was illustrated by the ,grecian phalanx with its sixteen rows of men1 the spears of each row being so adjusted that all reached to the front line4 ,that phalanx could not be stopped by any other human formation that met it face to face4 ,to overcome it required a ,roman legion that could open up and take the phalanx in the flank and rear4 ,in the same way1 the elephants of the ,africans and the chariots of the ,romans with their great swords swept all in front of them1 until the ,roman ,legion1 opening up into smaller groups allowed the elephants and chariots to pass through only to close in on them from the rear4 ,then and then only did those engines of war disappear forever4 ,frederick the ,great4 ,frederick the ,great1 realizing that rapidity of fire would win on the fields of battle where he fought1 trained his men to a precision of movement in close order probably never achieved by any other troops in the world and then added to their efficiency by teaching them to load and fire muskets at double the rate of that of his adversaries4 ,he was thus enabled to concentrate at the decisive points a preponderance of power1 which swept all his enemies before him4 ,napoleon4 ,napoleon achieved the same decisive power in a different way4 ,realizing that his ,french troops could not stand the rigorous training that the ,prussians underwent1 he trained them to fight with great enthusiasm1 to travel long distances with unheard of swiftness1 and to strike the enemy where least expected4 ,he added to that a concentration of artillery until then not thought of as possible on the field of battle4 ,he1 of course1 had also a genius for organizing and keeping up his supply4 ,grant and ,jackson4 ,grant at ,vicksburg and ,stonewall ,jackson in the ,shenandoah ,valley and at ,chancellorsville1 achieved the same results in different ways4 ,in every case the fundamental principle of concentrating the greatest force at the decisive point at the vital moment in the battle remained the same4 ,the methods for achieving that end change with every age1 and every commander of world-wide renown developed something new or used an old method in a new way4 ,and that is the fundamental requirement for a successful general4 ,hannibal1 ,hasdrubal1 ,csar1 ,napoleon1 ,frederick the ,great1 ,scott1 ,grant1 and ,jackson were all independent thinkers4 ,each and every one dared to do something that every other general and statesman of his time told him could not be done or that would bring about disaster4 ,they had the courage of their convictions4 ,they had the courage to think out new ideas and to develop them1 and then they had the courage to carry through those convictions1 not alone against the opposition of the enemy1 but against the opposition of their own people1 both in the field and at home4 ,and we may be perfectly sure that in each case had these men not done the things they did1 they would have gone down to oblivion just as has been the case with millions of others who tried the usual methods in the usual way4 ,chemical ,warfare ,latest ,development4 ,chemical ,warfare is the latest development of war4 ,so far as the ,united ,states is concerned1 it is considerably less than four years old4 ,it is the most scientific of all methods of fighting and also the most universally applicable to all other methods of making war4 ,the use of poisonous and irritating gases in war is just as fundamental as the introduction of gunpowder4 ,in fact1 they have an even wider application to war than powder itself4 ,necessity for ,new ,methods4 ,the idea that has been expressed above is that the ,general ,staff and the ,army commander who sticks to old and tried methods and who is unwilling to try with all his might new developments1 will never achieve any first class success4 ,the ,general ,staffs and the generals of the future that win wars will be the ones who make the most vigorous and efficient use of ,chemical ,warfare materials4 ,they cannot confine this use to the artillery1 to ,aviation1 to ,special ,gas ,troops1 or to any other single branch of the war machine4 ,they must make use of it in every way4 ,what ,is ,meant by ,gas4 ,it must be understood that by gases we refer to materials that injure by being carried to the victim in the air4 ,the word 8gas0 has nothing whatever to do with the condition of the material when in the shell1 or the bombs1 or the cylinders before released4 ,in every case1 the gases are liquids or solids4 ,when the containers are broken open the liquids are volatilized either by the gas pressure or by the force of the explosion of the bomb4 ,groups of ,gases4 ,chemical ,warfare gases are divided into three great groups4 ,so far as their actual tactical use on the field of battle is concerned1 there are only two groups--persistent and non-persistent4 ,the third is the irritant group4 ,this group affects the eyes and the lungs so as to make the victim very uncomfortable if not completely incapable of action in quantities so small as to cause no injury that lasts more than a few hours4 ,the quantities of such gases needed to force the wearing of the mask is _/ that needed to cause the same discomfort by the really poisonous gases1 such as phosgene4 ,they1 therefore1 have a very great economic value in harassing the enemy by forcing him to wear masks and to take other precautions against gas4 ,and no matter how perfect gas masks and gas-proof clothing become1 their long-continued use will cut down physical vigor in an ever increasing ratio until in two or three days an army may be totally incapacitated4 ,smoke4 ,in ,chemical ,warfare materials we have another great group which will probably be equal in the future to the three groups just mentioned4 ,that is common smoke4 ,smoke has a variety of uses4 ,by the simple term 8smoke0 is meant smokes that are not poisonous or irritating4 ,such smokes offer a perfect screen against enemy vision1 whether it is the man who sights the machine gun1 the observer in the lookout station1 the cannoneer or even the aeroplane observer4 ,every shot through impenetrable smoke is a shot in the dark and has a tenth or even less chance of hitting its mark4 ,smoke affords a means of decreasing the accuracy of firing1 much the same as night decreases it1 without the inherent difficulties of night action4 ,peace ,strategy4 ,the strategy of successful war involves the strategy of peace4 ,this has been true from the days when ,david with his sling-shot slew ,goliath1 down to the present moment4 ,we don't always think of it in connection with war1 but back of every successful war has been preparation during peace4 ,it may have been incidental preparation such as the training of men in fighting ,indians1 and in creating public sentiment favorable to an independent nation that preceded the ,revolutionary ,war4 ,it may1 on the other hand1 have been a deeply studied policy such as that of the ,germans prior to the ,world ,war4 ,they tried and generally quite successfully1 to cordinate all peace activities toward the day when a war should come that would decide the future destiny of the ,german ,empire1 and it was only because of that study in peace that ,germany almost single-handed was able to stand out for more than four years against the world4 ,the ,allies came near losing that war because they did not appreciate that the strategy of efficient war had to be preceded by the strategy of peace4 ,chemical ,warfare an ,example4 ,chemical warfare is a particularly good example of this fact4 ,prior to the ,world ,war we had acknowledged1 and without any misgivings1 that ,germany led the world in chemistry1 that it produced most of the dyes in the world1 and to a large extent the medicines of the world4 ,we felt that when ,american needs showed it to be advisable we could take up chemistry and chemical production and soon excel the ,germans4 ,we had not reckoned on the suddenness of war4 ,we were just getting ready with chemicals1 and that included powders and high explosives1 when the war closed4 ,and yet we had had not only eighteen months' intensive preparation after our own entry into the ,world ,war1 but also the preparation of great steel institutions and powder factories for nearly three years in manufacturing supplies for the ,allies who preceded us in the war4 ,coal ,tar4 ,the ,world ,war opened the eyes of ,england1 ,france and ,japan as well as the ,united ,states4 ,each of them today is struggling to build up a great chemical industry as the very foundation of successful war4 ,few of us realized prior to the ,world ,war that in the black1 sticky mess called coal tar from the coking of coal or the manufacture of gas from coal and oil1 was stored up most of the high explosives used in war1 the majority of the poison gases1 a great deal of the medicines of the world1 and nearly all the dyes of the world4 ,the ,germans realized it and in their control over methods of using this material1 together with the great commercial plants developed to manufacture it1 as well as with the trained personnel that must go with such plants1 were enabled1 when blockaded on land and sea1 to furnish the munitions1 the clothing and the food needed for four and one-half years of war4 ,great ,chemical ,industries4 ,thus it is that our ,government today is giving most serious heed to the need of building up a great chemical industry in the ,united ,states4 ,we have the raw materials4 ,we need only the factories and the trained men that go with them4 ,we need1 of course1 in addition to the development of the coal tar industry1 a production of heavy chemicals such as chlorine1 sulfuric acid and the like1 all of which1 however1 are bound together by community interest in peace as well as in war4 ,reserves of ,chemists4 ,a part of the strategy of peace is the card-indexing of the manpower of a nation divided into special groups4 ,in one great group must come those who have a knowledge of chemistry and the chemical industries4 ,that must be so worked out that if war should come on a moment's notice1 within twenty-four hours thereafter every chemist could be given his job1 jobs extending from the firing line to the research laboratory4 ,and that is the task of the ,chemical ,warfare ,service4 ,and right here it is well to know that ,congress1 among the other features of its ,army ,reorganization ,act of ,june #d1 #aibj1 provided for a separate ,chemical ,warfare ,service with these powers3 ,,chemical ,,warfare ,,powers ,the ,chief of the ,chemical ,warfare ,service under the authority of the ,secretary of ,war shall be charged with the investigation1 development1 manufacture1 or procurement and supply to the ,army of all smoke and incendiary materials1 all toxic gases1 and all gas defense appliances2 the research1 design1 and experimentation connected with chemical warfare and its material2 and chemical projectile filling plants and proving grounds2 the supervision of the training of the ,army in chemical warfare1 both offensive and defensive1 including the necessary schools of instruction2 the organization1 equipment1 training1 and operation of special gas troops1 and such other duties as the ,president may from time to time prescribe4 ,why ,power ,is ,needed4 ,these rather broad powers indicate that ,congress realized the unity of effort that must be made from the research laboratory to the firing line if ,america was to keep pace with ,germany or any other nation in chemical warfare4 ,some have raised the question as to whether a service should be both supply and combat4 ,perhaps the best answer to that question is that so organized ,chemical ,warfare was a success in the ,world ,war4 ,it was a success notwithstanding it had to be developed in the field six months after our entry into the war and with no precedents1 no materials1 no literature and no personnel4 ,through its officers on the staffs of commanding generals of armies1 corps and divisions1 and through its fighting gas troops in the front line1 it was enabled to direct its research1 development and manufacture more quickly along lines shown to be necessary by every change in battle conditions1 than any other service4 ,chemical ,warfare ,troops4 ,and why should there not be fighting ,chemical ,warfare troops8 ,they fight under exactly the same orders as all other troops4 ,they conform to the same general plan of battle4 ,they bring1 however1 to that battle experts in a line that it takes a long time to master4 ,and where has there been any live commander in the world's history who refused aid from any class of troops that might help him win8 ,specialists in ,war4 ,the wars of the future will become more and more wars of the specialists4 ,your ,infantry may remain the backbone of the fighting force1 but if it has not the ,artillery1 the ,aviation1 the ,chemical ,warfare1 the ,engineers1 the tanks and other specialists to back it up1 it will be overcome by the army which has such specialists4 ,indeed the specialist goes into the very organization of the ,infantry itself with its machine gun battalions1 its tank battalions1 and as now proposed1 the ,infantry light howitzer companies4 ,duties of ,chemical ,warfare ,staff ,officers4 ,the ,chemical ,warfare officers on the staff of armies1 corps and divisions are there for the purpose of giving expert advice as to the quantities of chemical materials available1 the best conditions for using them1 and the best way of avoiding the effects of enemy gas upon our own troops4 ,the conditions that must be kept in mind are so many that no other officer can be expected to master and keep them if he does his own work well4 ,the general staff officers and commanding generals will not have the time to even try to remember the actual effects of clouds1 wind1 rain1 trees1 valleys1 villages and plains upon each and every gas4 ,they must depend upon the ,chemical ,warfare officer for accurate information along those lines1 and if he cannot furnish it they will have to secure some one who can4 ,the history of war is filled with the names of generals who failed because they could not forget how to command a company4 ,these ,chemical ,warfare officers will also furnish all data as to supply of chemical warfare materials1 and will furnish the best information along lines of training1 whether for defensive or offensive use of gas4 ,gas ,used by all ,arms4 ,as before stated1 we cannot confine the use of gas to any one arm4 ,we may then ask why1 if it is applicable to all arms1 it should need special gas troops4 ,special gas troops are for the purpose of putting off great quantities of chemical warfare materials by special methods that are not applicable to any other branch now organized or that any other branch has the time to master4 ,long-range firing of gas by the artillery can be done just as well by the artillery as by gas troops4 ,why8 ,because in the mechanics of firing chemical ammunition there is no difference whatever from the mechanics of firing high explosives or shrapnel4 ,the same will be true of gas rifle grenades and smoke candles in use by the ,infantry4 ,the same will be true of the dropping of gas bombs and the sprinkling of gas by the aeroplanes4 ,in this connection just remember that all of the army is trained in first aid1 but in addition we have our ambulance companies1 our hospitals1 and our trained medical personnel4 ,arguments ,against ,use of ,gas4 ,it has been many times suggested since the ,armistice that the use of poisonous gas in war may be done away with by agreement among nations4 ,the arguments against the use of gas are that it is inhumane and that it might be used against non-combatants1 especially women and children4 ,the inhumanity of it is absolutely disproven by the results of its use in the ,world ,war4 ,the death rate from gas alone was less than one-twelfth that from bullets1 high explosives and other methods of warfare4 ,the disability rate for gas patients discharged was only about one-fourth that for the wounded discharged for other causes4 ,the permanently injured is likewise apparently very much less than from other causes4 ,humanity4 ,no reliable statistics that we can get show that gas in any way causes tuberculosis any more than a severe attack of bronchitis or pneumonia causes tuberculosis4 ,since its principal effects are upon the lungs and1 therefore1 hidden from sight1 every impostor is beginning to claim gassing as the reason for his wanting ,war ,risk benefits from the ,government4 ,we do not claim there may not be some who are suffering permanent injuries from gas1 and we are trying very hard to find out from the manufacturers of poisonous gases and allied chemicals if they have any authentic records of such cases4 ,so far the results indicate that permanent after-effects are very rare4 ,as to non-combatants1 certainly we do not contemplate using poisonous gas against them1 no more at least than we propose to use high explosives in long-range guns or aeroplanes against them4 ,the use of the one against non-combatants is just as damnable as the other and it is just as easy to refrain from using one as the other4 ,gas ,cannot be ,abolished4 ,as to the abandonment of poison gas1 it must be remembered that no powerful weapon of war has ever been abandoned once it proved its power unless a more powerful weapon was discovered4 ,poisonous gas in the ,world ,war proved to be one of the most powerful of all weapons of war4 ,for that reason alone it will never be abandoned4 ,it cannot be stopped by agreement1 because if you can stop the use of any one powerful weapon of war by agreement you can stop all war by agreement4 ,to prepare to use it only in case it is used against you is on the same plane as an order that was once upon a time issued to troops in the ,philippine ,islands4 ,that order stated in substance that no officer or soldier should shoot a savage ,moro1 even were he approaching the said officer or soldier with drawn kriss 7sword71 unless actually first struck by such savage4 ,every officer preferred1 if necessary1 to face a court-martial for disobedience of such an order rather than allow a savage ,moro with a drawn kriss to get anywhere near1 let alone wait until actually struck4 ,let the world know that we propose to use gas against all troops that may be engaged against us1 and that we propose to use it to the fullest extent of our ability4 ,we believe that such a proposition will do more to head off war than all the peace propaganda since time began4 ,it has been said that we should not use gas against those not equipped with gas4 ,then why did we use repeating rifles and machine guns against ,negritos and ,moros armed only with bows and arrows or poor muskets and knives4 ,let us apply the same common sense to the use of gas that we apply to all other weapons of war4 ,effect on ,world ,war ,tactics4 ,a very brief study of the effects of chemical warfare materials on the strategy of the ,world ,war will indicate its future4 ,it began with clouds of chlorine let loose from heavy cylinders buried under the firing trench4 ,these took a long time to install and then a wait1 sometimes long1 sometimes brief1 for a favorable wind1 but even at that these cloud gas attacks created a new method of fighting and forced new methods of protection4 ,gas at once added a tremendous burden to supply in the field1 to manufacture1 and to transportation1 and in a short time even made some decided changes in the tactics of the battle field itself4 ,cloud ,gas4 ,the fact that the gas cloud looked like smoke is responsible for the name 8cloud gas40 ,really all gases are nearly or wholly invisible1 but those which volatilize suddenly from the liquid state so cool the air as to cause clouds of condensed water vapor4 ,the cloud obscured everything behind and in front of it4 ,it led the ,german to put off fake smoke clouds and attack through them1 thus taking the ,british at a tremendous disadvantage4 ,then and there began a realization of the value of smoke4 ,cloud gas was also the real cause of the highly organized raid that became common in every army during the ,world ,war4 ,the real purpose in the first raids1 carried out by means of the box barrage1 was to find out whether or not gas cylinders were being installed in trenches4 ,these raids finally became responsible1 in a large measure1 for driving the old cloud gas off the field of battle4 ,it did not1 however1 stop the ,british from putting off cloud gas attacks in #aiah by installing their gas cylinders on their light railway cars and then letting the gas loose from the cylinders while still on the cars4 ,this enabled them to move their materials to the front and put off gas attacks on a few hours' notice when the wind was right4 ,toxic ,smoke ,candles4 ,to-day we have poisonous smokes that exist in solid form and that are perfectly safe to handle until a fuse is lighted4 ,the so-called candles will be light enough so that one man can carry them4 ,with these1 cloud gas can be put off on an hour's notice when wind and weather conditions are right1 no matter how fast the army may be moving and whether on the advance or in retreat4 ,cloud gas will usually be put off at night because the cloud cannot be seen1 because then men are tired and sleepy1 and all but the most highly trained become panicky4 ,under those conditions the greatest casualties result4 ,the steadiness of wind currents also aids cloud gas attacks at night4 ,value of ,training in ,peace4 ,and this brings up the value of training in peace4 ,we are frequently asked1 8,why do you need training with masks in peace2 why do you need training with actual gas in peace2 cannot these things be taught on short notice in war80 ,the answer is1 8,no60 ,nothing will take the place of training in peace4 ,all of us recall that early in the war the ,germans spread broadcast charges that the ,allies were using unfair and inhumane methods of fighting because they brought the ,ghurka with his terrible knife from ,asia and the ,moroccan from ,africa4 ,and we all know that after a time the ,germans ceased saying anything about these troops4 ,what was the cause8 ,they were not efficient4 ,just as the ,negro will follow a white officer over the top in daylight and fight with as much energy and courage and many times as much efficiency as the white man1 he cannot stand the terrors of the night1 and the same was true of the ,ghurka and the ,moroccan4 ,all the ,allies soon recognized that fact as shown by their drawing those troops almost entirely away from the fighting lines4 ,in some cases dark-skinned troops were kept only as shock troops to be replaced by the more highly developed ,caucasian when the line had to be held for days under the deadly fire of the counter attack4 ,the ,german idea1 and our own idea prior to the ,world ,war1 was that semi-savages could stand the rigors and terrors of war better than the highly sensitive white man4 ,war proved that to be utterly false4 ,familiarity with ,gas ,necessary4 ,the same training that makes for advancement in science1 and success in manufacture in peace1 gives the control of the body that holds the white man to the firing line no matter what its terrors4 ,a great deal of this comes because the white man has had trained out of him nearly all superstition4 ,he has had drilled into him for hundreds of years that powder and high explosive can do certain things and no more4 ,if the soldier is not to be afraid of gas we must give him an equal knowledge of it1 its dangers1 and its limitations4 ,the old adage says1 8,familiarity breeds contempt40 ,perhaps that is not quite true1 but we all know that it breeds callousness and forgetfulness2 that the man manufacturing dynamite or other more dangerous explosives takes chances that we who do not engage in such manufacture shudder at4 ,edgewood ,chemists ,not ,afraid4 ,all of this has direct application to training with chemical warfare materials in peace4 ,we believe that all opposition to chemical warfare today can be divided into two classes--those who do not understand it and those who are afraid of it--ignorance and cowardice4 ,our chemists at ,edgewood ,arsenal are every day toying with the most powerful chemical compounds2 toying with mixtures they know nothing of1 not knowing what instant they may induce an explosion of some fearful poisonous gas4 ,but they have learned how to protect themselves4 ,they have learned that if they stop breathing and get out of that place and on the windward side they are safe4 ,they have been at that work long enough to do that automatically4 ,staff ,officers ,must ,think of ,gas in ,every ,problem4 ,the staff officer must train the army man in peace with all chemical warfare materials or he will lose his head in war and become a casualty4 ,the general staff officers and commanding generals must so familiarize themselves with these gases and their general use that they will think them in all their problems just exactly as they think of the ,infantry1 or of the ,cavalry1 or of the tanks or of the ,artillery in every problem4 ,on them rests the responsibility that these gases are used properly in battle4 ,if plans before the battle do not include these materials for every arm and in the proper quantities of the proper kinds they will not be used properly on the field of battle and on them will rest the responsibility4 ,they are not expected to know all the details of gases and their uses1 but they will be expected to consider the use of gas in every phase of preparing plans and orders and then to appeal to the chemical warfare officers for the details that will enable them to use the proper gases and the proper quantities4 ,they cannot go into those details any more than they can go into the details of each company of infantry4 ,if they try to do that they are a failure as staff officers4 ,effect of ,masks on ,troops4 ,the very best of masks cause a little decrease in vision1 a little increase in breathing resistance1 and a little added discomfort in warm weather1 and hence the soldier must learn to use them under all conditions4 ,but above all in the future he must be so accustomed to the use of the mask that he will put it on automatically--almost in his sleep as it were4 ,we have tear gases1 today1 so powerful and so sudden in their action that it is doubtful if one man out of five who has had only a little training can get his mask on if subject to the tear gas alone--that is1 with tear gas striking him with full force before he is aware of it4 ,effectiveness of ,gas in ,world ,war4 ,in the past war more than #bg out of every #ajj ,americans killed and wounded suffered from gas alone4 ,you may say that many of the wounds were light4 ,that is true2 but those men were put out of the battle line for from one to four months--divisions1 corps and armies almost broken up--and yet the use of gas in that war was a child's game compared to what it will be in the future4 ,it is even said that many of them were malingerers4 ,perhaps they were1 but do you not suppose that there were at least as many malingerers among the enemy as there were in our own ranks8 ,furthermore1 if you can induce malingering it is a proper method of waging war1 and unless our boasted ability is all a myth we should have fewer malingerers under conditions of battle than any other nation4 ,strategy of ,gas at ,picardy ,plains4 ,let us go back now to the strategy of gas in war4 ,following the cloud gas came tear gases and poisonous gases in shells and bombs4 ,a little advance in tactics here and a little there1 the idea1 though1 in the early days being only to produce casualties4 ,as usual the ,germans awoke first to the fact that gas might be used strategically and on a large scale4 ,and thus we find that ten days before he began the battle of ,picardy ,plains he deluged many sections of the front with mustard gas4 ,he secured casualties by the thousands1 but he secured something of greater importance4 ,he wore out the physical vigor and lowered the morale of division after division1 thus paving the way for the break in the ,british ,army which almost let him through to the sea4 ,he used non-persistent gases up to the very moment when his own men reached the ,british lines1 thereby reducing the efficiency of ,british rifle and artillery fire and saving his own men4 ,and this is just a guide to the future4 ,a recent writer in the ,field ,artillery ,journal states that gas will probably not be used in the barrage because of its probable interference with the movement of our own troops4 ,in making that statement he forgot the enemy and you cannot do that if you expect to win a war4 ,gas in ,barrages4 ,in the future we must expect the enemy to be in a measure as well prepared in chemical warfare as we are4 ,let us consider the special case of our own men advancing to the attack behind a rolling barrage4 ,we will consider also that the wind is blowing toward our own troops4 ,obviously under those conditions the wind will blow our own gas back onto our troops4 ,will we use gas in that barrage8 ,we certainly will6 ,because with the wind blowing toward our own troops we have the exact ideal condition that the enemy wants for his use of gas4 ,he will then be deluging our advancing troops with all the gas he can fire1 in addition to high explosives and shrapnel4 ,our men must wear masks and take every precaution against enemy gas4 ,how foolish it would be not to fire gas at the enemy under those conditions4 ,if we did not fire gas we would leave him entirely free from wearing masks1 and entirely free from taking every other precaution against gas while our own troops were subject to all the difficulties of gas4 ,no1 we will fire gas at him in just as great quantities as we consider efficient4 ,and that is just a sample of what is coming on every field of battle--gas used on both sides by every method of putting it over that can be devised4 ,world ,war ,lessons ,only ,guide ,posts4 ,example of ,book ,worms4 ,every lesson taught by the ,world ,war must be taken as a guide-post on the road to future success in war4 ,no use of gas or other materials in the past war must be taken as an exact pattern for use in any battle of the future4 ,too much study1 too much attention to the past1 may cause that very thing to happen4 ,a certain general commanding a brigade in the ,argonne told me just recently that while the battle was going on a general staff officer called him on the telephone and asked him what the situation was4 ,he gave it to him4 ,the staff officer then asked1 8,what are you doing80 and he told him4 ,the staff officer replied1 8,why1 the book doesn't say to do it that way under such conditions40 ,there you have the absurd side of too much study and too close reliance on details of the past4 ,the battle field is a perfect kaleidoscope4 ,the best we can hope to get out of books is a guide--something that we will keep in our minds to help us decide the best way to meet certain situations4 ,he who tries to remember a particular position taught in his school with the idea of applying that to actual use in battle is laying the foundation for absolute failure4 ,your expert rifleman never thinks back when he goes to fire a shot as to just what his instructor told him or what the book said4 ,he just concentrates his mind on the object to be attained1 using so far as comes to him facts he has learned from books or teachers4 ,your general and your staff must do the same4 ,infantry ,use of ,gas4 ,a few words about how we will use gas in the future4 ,we will start with the ,infantry4 ,the ,infantry as such will use gas in only two or three ways4 ,they will use some gas in rifle grenades1 and a great deal more smoke4 ,we speak of the rifle grenade because in our opinion the hand grenade is a thing of the past4 ,we do not believe there will ever be used in the future any grenade that is not applicable to the rifle4 ,the ,infantry will probably often carry large quantities of gas in the shape of the toxic smoke candle4 ,these materials being solids may be shot up by rifles or artillery fire1 run over by trucks or tractors1 or trampled and still be harmless4 ,it is only when the fuses are lighted and the material driven off by heat that they are dangerous4 ,in using these candles under these conditions you must have sufficient chemical warfare officers and soldiers to get the necessary control indicated by the sun1 wind1 woods1 fogs1 ravines and the like4 ,cavalry ,use of ,gas4 ,next consider the ,cavalry4 ,the ,cavalry will use gas practically the same as the ,infantry4 ,the chemical warfare troops will accompany the ,cavalry with ,stokes' mortars or other materials to fire gases into small enemy strongholds that may be encountered whether machine gun nests1 mountain tops1 woods or villages4 ,they will do this either against savages or civilized people4 ,methods of making these materials mobile for that purpose are already well under way4 ,if against savages and one does not want to kill them1 use tear gases--no better method of searching out hidden snipers in mountain tops1 among rocks1 or villages1 in ravines1 or in forests was ever invented4 ,use of ,gas by ,tanks4 ,the tanks will employ gas in the same way as the ,infantry with the possibility1 however1 that they may be used to carry large quantities of gas on caterpillar tractors where otherwise it would be difficult to move the gas4 ,this is not a certainty1 but is a situation promising enough to warrant further study4 ,artillery ,use of ,gas4 ,your ,artillery will fire gas and smoke in every caliber of gun4 ,there is a tendency now to limit gas to certain guns and howitzers and to limit smoke to even a smaller number of guns4 ,this is a mistake that we are going to recognize4 ,a very careful study of the records of the war show that more casualties were produced several times over by a thousand gas shells than by a thousand high explosive or shrapnel4 ,and that is because gas has an inherent permanence that no other weapon of war has4 ,permanency of ,gas4 ,the bullet whistles through the air and does its work or misses4 ,the high explosive shell bursts1 hurling its fragments that in a few seconds settle to earth1 and its work is done4 ,the shrapnel acts in the same way1 but when one turns loose a shell of gas it will kill and injure the same as the high explosive shell and in the same length of time and in addition for some minutes thereafter4 ,even with the non-persistent gases1 it will continue on its way1 causing death or injury to every unprotected animal1 man or beast in its path4 ,with the persistent gases1 the materials from each shell may persist for days4 ,variety of ,uses of ,gas4 ,this brings up the point of the great variety of uses to which gas can be put4 ,the non-persistent gas may be used at all times where one wants to get rid of it in a few moments--the persistent gas wherever one wants to keep the enemy under gas for days at a time4 ,we will use mustard gas on strong points in the advance1 on flanks1 on distant areas one will not expect to be reached1 and as our own protection of masks and clothing increases toward perfection we will use it on the very fields you expect to cross4 ,why8 ,because we will be firing it at the enemy for days before hand and we will cause him trouble all those days while we ourselves will encounter it for a few hours at the most4 ,so do not think that mustard gas is only going to be used in defense in the future4 ,solid ,mustard ,gas and ,long-,range ,guns4 ,we will come to use chemical warfare materials just as high explosives and bullets are used today1 even though at times we do suffer an occasional loss from our own weapons4 ,our ,artillery in long-range guns where we want destruction will fill each shell with say #ae per cent gas and #he per cent high explosive4 ,we have a solid mustard gas that may be so used4 ,we have tremendously powerful tear gases and irritating gases that may be so used4 ,being solids they do not affect the ballistic qualities of the shell4 ,and what an added danger will mustard gas from every shell bring against railroad centers1 rest villages1 cantonments1 cross-roads and the like4 ,the results will be too great for any force to overlook such use4 ,tear ,gases in ,shrapnel4 ,we will probably use tear gas in most1 if not all1 of our shrapnel4 ,the general idea now is that we should not put tear gas in all shrapnel because under certain conditions it will be blown back and harass our own troops4 ,but as was said before1 we must remember that the enemy will be using gas at all times as well as ourselves1 and hence if we limit ourselves in any line we give the enemy an advantage4 ,this use of gas by the ,artillery will extend to all classes of guns--seacoast1 field1 turret and what not4 ,use of ,gas by ,air ,service4 ,bombs4 ,let us next consider the ,air ,service4 ,we naturally think of dropping gas in bombs when we speak of the use of gas by the ,air ,service4 ,gas will so be used and it will be used in bombs of perhaps a thousand pounds or even a ton in weight1 at least #ej per cent of which will be gas4 ,such gases1 however1 will be of the non-persistent type--phosgene or similar ones4 ,they will be used against concentration camps and cross-roads1 on troops on the road in columns2 against railroad centers and rest areas2 in other words1 against groups of men or animals4 ,sprinkling4 ,but that is not even the beginning of the use of gas by aeroplanes4 ,mustard gas1 which is one-third again as heavy as water1 and which volatilizes far slower than water1 may be sprinkled through a small opening such as a bung hole in a tank that simply lets liquid float out4 ,the speed of the aeroplane will atomize it4 ,in this way1 gas can be sprinkled over whole areas that must be crossed in battle4 ,the ,lewisite1 of which we have heard considerable1 will be used4 ,it is less persistent than the mustard gas1 but like mustard gas it produces casualties by burning4 ,unlike mustard gas1 however1 the burns from a quantity equal to three drops will usually cause death4 ,the material can be made up by hundreds1 even thousands1 of tons per month4 ,we are working on clothing that will keep it out just as we have been and are working on clothing that will protect against mustard gas4 ,but these gases are so powerful that if any opening be left in the clothing the gas will get through1 so that even if we get clothing that will protect1 it must cover every inch of the skin from head to foot4 ,besides the mask must be worn at all times4 ,consider the burden put on any army in the field that would have to continually wear such complete protection4 ,what a strain on the mentality of the men6 ,as before said1 to endure it at all we must train our men to think of such conditions1 to face them in peace1 and in order to do so we must actually use gas4 ,just as in the ,world ,war the highly trained ,caucasian outdistanced the savage in endurance1 just so will the most highly trained men in the future outdistance all others in endurance4 ,navy4 ,we now come to the consideration of the ,navy4 ,the ,navy will use gas both in its guns and in smoke clouds1 and in some form of candle that will float4 ,the toxic smokes that in high enough concentrations will kill are extraordinarily irritating in minute quantities--so minute they cannot be seen or felt for a few moments4 ,every human being on a ship must breathe every minute just as every human being everywhere must breathe every minute or die4 ,a gas that gets into the ventilating system of a ship will go all through it and the ,navy realizes it4 ,the ,navy is studying how to keep the gas out of their own ships1 and how to get it into the enemy's ships4 ,the toxic smokes may be dropped from aeroplanes or turned loose from under water by submarines4 ,in either case they will give off smokes over wide areas through which ships must pass4 ,any defects will let these toxic smokes in and will force every man to wear a mask4 ,aeroplane bombs will come raining down on the ship or alongside of it either with toxic smokes or other terrible gases4 ,white phosphorus that burns and cannot be put out wet or dry will be rained on ships4 ,yes1 chemical warfare materials will be used by the ,navy4 ,gas ,against ,landing ,parties4 ,the use of gas against landing parties or to aid landing parties has come up in many ways4 ,our studies to date indicate that gas is a greater advantage to the defense against landing parties than to the offense4 ,mustard gas and the like may be sprinkled from aeroplanes1 and while it will not float long on the water1 it will float long enough to smear any small boats attempting to land4 ,it can be sprinkled over all the areas that landing parties must occupy4 ,mustard gas may be placed in bombs or drums around all areas that are apt to be used as landing places and exploded in the face of advancing troops4 ,storing ,reserve ,gases in ,peace4 ,and a word here about how long gases may be stored4 ,one of the statements made by opponents of chemical warfare was that gas is a purely war time project and could not be stored up in peace4 ,we have today at ,edgewood ,arsenal some #a1djj tons of poisonous gases not including chlorine4 ,those gases have been manufactured1 practically every ounce of them1 for three years1 and are yet in almost perfect condition4 ,our chemists believe they can be kept in the future for ten years and perhaps longer4 ,our gas shells then will have the life almost of a modern battleship1 while the cost of a million will be but a fraction of the cost of a battleship4 ,what ,i have just said applies particularly to liquid gases such as phosgene1 chlorpicrin1 and mustard gas4 ,we know that many of the solids may be kept for far longer periods4 ,storing ,gas ,masks4 ,our masks1 too1 we believe can be kept for at least ten years4 ,experience to date indicates that rubber deteriorates mainly through the action of sunlight and moisture that cause oxidation or other change in the crystalline structure of cured rubber4 ,accordingly1 we are putting up masks today in hermetically sealed boxes4 ,it is thus evident that we can store a reserve of masks and gases in peace the same as other war materials4 ,use of ,gas by ,gas ,troops4 ,now we come to the use of gas by special gas troops4 ,in the war1 ,gas ,troops used #d-;inch ,stokes' mortars and #h-;inch ,livens' projectors and in a very short time would have used a new portable cylinder for setting off cloud gas1 using liquid gases1 such as phosgene4 ,they will use these same weapons in future wars4 ,all of these are short-range weapons1 but since the ,livens' bomb or drum contains #ej per cent of its weight in gas while the artillery shell contains #aj per cent1 they have an efficiency away beyond that of artillery or any other method of discharging gas except cloud gas4 ,they will1 therefore1 produce more casualties than any other method known for the amount of material taken to the front4 ,these short-range weapons were developed by the ,british for trench use and not for open warfare1 and yet our troops developed methods with the ,stokes' mortars that enabled them to keep up with many of the ,infantry divisions4 ,phosphorus and ,thermit ,against ,machine ,gun ,nests4 ,the use of phosphorus and thermit against ,german machine gun nests by the ,gas ,troops is well known4 ,how effective it was is not known to so many4 ,phosphorus and thermit were so used from the early days of the ,marne fight in the latter part of ,july1 #aiah1 to the very close of the war4 ,there is no recorded instance where the ,gas ,troops failed to silence machine gun nests once the machine guns were located4 ,in the future ,gas ,troops will put off the majority of all cloud gas attacks even with toxic smoke candles4 ,necessity for ,training in ,peace4 ,this is an outline of the subject of chemical warfare4 ,as stated in the beginning1 the fundamental underlying principles for the successful use of poisonous gas is necessarily the same as for any other war materials4 ,the necessity for continuous training in peace is just the same with chemical warfare as with the rifle1 the machine gun1 with field artillery or any other weapon of war4 ,indeed it is more so because the use of gas is so perfectly adaptable to night work4 ,men must be taught to take precautionary measures when so sleepy1 tired and worn out that they will sleep through the roar of artillery4 ,how ,chemical ,warfare ,should be ,considered4 ,we ask you only to look at the use of chemical warfare materials as you look at the use of the artillery1 infantry1 cavalry1 tanks or aeroplanes4 ,measure its possible future use2 not simply by its use in the ,world ,war1 but by considering all possible developments of the future4 ,remember that its use was barely four years old when the war closed1 while the machine gun1 the latest type of infantry weapon1 had been known for more than one-third of a century4 ,chemical warfare developments are in the infant stage4 ,even those on the inside of chemical warfare when the ,armistice was signed can see today things that are certain to come that were undreamed of at that time4 ,this is bound to be so with a new weapon4 ,to sum up1 gas is a universal weapon1 applicable to every arm and every sort of action4 ,since we can choose gases that are either liquid or solid1 that are irritating only or highly poisonous1 that are visible or invisible1 that persist for days or that pass with the wind1 we have a weapon applicable to every act of war and for that matter1 to every act of peace4 ,but we must plan its use1 remembering there is no middle ground in war1 it is success or failure1 life or death4 ,remember also that training outruns production in a great war1 that #e1jjj1jjj men can be raised and trained before they can be equipped unless we with proper foresight build up our essential industries1 keep up our reserve of supplies1 and above all1 keep such perfect plans that we can turn all the wheels of peace into the wings of war on a moment's notice4 ,,chapter ,,xxiii ,,the ,,offensive ,,use ,,of ,,gas ,,what ,,chemical ,,warfare ,,includes ,chemical ,warfare includes all gas1 smoke and incendiary materials and all defensive appliances1 of which the mask is the principal item1 used by the ,army4 ,some of the items or materials in both offense and defense are used by the entire ,army1 while a few are used only by ,chemical ,warfare troops4 ,,the ,,term 8,,gas0 ,the term 8gas0 is now taken to include all materials that are carried to the enemy by the air1 after their liberation from cylinders1 bombs or shell4 ,it is necessary that this broad use of the term 8gas0 be thoroughly understood1 because some of these materials are solids1 while all others are liquids1 until liberated from the containers at the time of the attack4 ,these containers may be special cylinders for cloud gas attacks1 special bombs for ,livens' projectors and mortars1 or artillery shell1 and even aviation bombs4 ,some of the liquids which have a very low boiling point volatilize quickly upon exposure to air1 and hence require only enough explosive to open the shell and allow the liquid to escape4 ,practically all solids have to be pulverized by a large amount of high explosive1 or driven off as smoke by some heating mixture4 ,,technical ,,nature ,chemical warfare1 besides being the newest1 is the most technical and most highly specialized ,service under the ,war ,department4 ,there is no class of people in civil life1 and no officers or men in the ,war ,department1 who can take up chemical warfare successfully until they have received training in its use4 ,this applies not only to the use of materials in attack1 but to the use of materials for defense4 ,ten years from now perhaps this will not be true4 ,it is certainly hoped that it will not be4 ,by that time the entire ,army should be pretty thoroughly trained in the general principles and many of the special features of chemical warfare4 ,if not1 chemical warfare cannot be used in the field with the efficiency and success with which it deserves to be used4 ,furthermore1 it is believed that within ten years the knowledge of the gases used in chemical warfare will be so common through the development of the use of these same materials in civil life1 that it will not be so difficult1 as at the present date1 to get civilians who are acquainted with ,chemical ,warfare ,service materials4 ,,effectiveness ,,of ,,gas ,chemical warfare materials were used during the war by ,chemical ,warfare ,service troops1 by the ,artillery and by the ,infantry4 ,in the future the ,air ,service and ,navy will be added to the above list4 ,chemical warfare1 even under the inelastic methods of the ,germans1 proved one of the most powerful means of offense with which the ,american troops had to contend4 ,to realize its effectiveness we need only remember that more than #bg out of every #ajj casualties on the field of battle were from gas alone4 ,unquestionably many of those who died on the battlefield from other causes suffered also from gas4 ,no other single element of war1 unless you call powder a basic element1 accounted for so many casualties among the ,american troops4 ,indeed1 it is believed that a greater number of casualties was not inflicted by any other arm of the ,service1 unless possibly the ,infantry1 and even in that case it would be necessary to account for all injured by bullets1 the bayonet1 machine guns and hand grenades4 ,this is true1 in spite of the fact that the ,german was so nearly completely out of gas when the ,americans began their offensive at ,st4 ,mihiel and the ,argonne1 that practically no gas casualties occurred during the ,st4 ,mihiel offensive1 and only a very few until after a week of the ,argonne fighting4 ,furthermore1 the ,germans knew that an extensive use of mustard gas against the ,american lines on the day the attack was made1 and also on the line that marked the end of the first advance a few days later1 would have produced tremendous casualties4 ,judging from the results achieved at other times by an extensive use of mustard gas1 it is believed that had the ,german possessed this gas and used it as he had used it a few other times1 ,american casualties in the ,argonne would have been doubled4 ,in fact1 the advance might even have been entirely stopped1 thus prolonging the war into the year #aiai4 ,,humanity ,,of ,,gas ,a few words right here about the humanity of gas are not out of place1 notwithstanding the ,army and the general public have now so completely indorsed chemical warfare that it is believed the argument of inhumanity has no weight whatever4 ,there were three great reasons why chemical warfare was first widely advertised throughout the world as inhumane and horrible4 ,these reasons may be summed up as follows3 ,in the first place1 the original gas used at ,ypres in #aiae was chlorine1 and chlorine is one of a group of gases known as suffocants--gases that cause death generally by suffocating the patient through spasms of the epiglottis and throat4 ,that is the most agonizing effect produced by any gas4 ,the second reason was unpreparedness4 ,the ,english had no masks1 no gas-proof dugouts1 nor any of the other paraphernalia that was later employed to protect against poisonous gas4 ,consequently1 the death rate in the first gas attack at ,ypres was very high1 probably #ce per cent4 ,as a matter of fact1 every man who was close to the front line died4 ,the only ones who escaped were those on the edges of the cloud of gas or so far to the rear that the concentration had decreased below the deadly point4 ,the third great reason was simply propaganda4 ,it was good war propaganda to impress upon everybody the fact that the ,german was capable of using any means that he could develop in order to win a victory4 ,he had no respect for previous agreements or ideas concerning warfare4 ,this propaganda kept up the morale and fighting spirit of the ,allies1 and was thoroughly justifiable upon that score1 even when it led to wild exaggeration4 ,the chlorine used in the first attack by the ,german is the least poisonous of the gases now used4 ,those later introduced1 such as phosgene1 mustard gas and diphenylchloroarsine are from five to ten times as effective4 ,the measure of humanity for any form of warfare is the percentage of deaths to the total number injured by the particular method of warfare under consideration4 ,american ,gas ,casualties4 ,the official list of casualties in battle as compiled by the ,surgeon ,general's office covering all cases reported up to ,september #a1 #aiai1 is #beh1cch4 ,of these #gj1geb1 or #bg4d per cent1 were gas casualties4 ,also of the above casualties #df1eai resulted in death1 of whom about #a1djj only were due to gas4 ,from these figures it is readily deduced that while #bd4he per cent of all casualties from bullets and high explosives resulted in death1 only #b per cent of those wounded by gas resulted in death4 ,that is1 a man wounded on the battle field with gas had twelve times as many chances of recovery as the man who was wounded with bullets and high explosives4 ,,fundamentals ,,of ,,chemical ,,warfare ,before taking up in some detail the methods of projecting gas upon the enemy1 it is very desirable to understand the fundamentals of chemical warfare1 in so far as they pertain to poisonous gases4 ,following the first use of pure chlorine all the principal nations engaged in the war began investigations into a wide range of substances in the hope of finding others more poisonous1 more easily produced1 and more readily projected upon the enemy4 ,these investigations led to the use of a large number of gases which seriously complicated manufacture1 supply1 and the actual use of the gases in the field4 ,gradually a more rational conception of chemical warfare led both the ,allies and the enemy to restrict the numbers of gases to a comparative few1 and still later to divide all gases into three groups4 ,thus the ,german divided his into three groups known as 7#a7 ,green ,cross1 the highly poisonous non-persistent gases1 7#b7 ,blue ,cross1 or diphenylchloroarsine1 popularly known as sneezing gas1 and 7#c7 ,yellow ,cross1 highly persistent gases1 such as mustard gas4 ,in the ,american ,chemical ,warfare ,service we have finally divided all gases into two primary groups4 ,these groups are known as 8,non-persistent0 and 8,persistent40 ,the 8,non-persistent0 gases are those quickly volatilizing upon exposure to the air1 and hence those that are carried away at once by air currents1 or that in a dead calm will be completely dissipated into the surrounding air in a few hours4 ,if sufficient high explosive be used to pulverize solids1 they may be used in the same way1 and to a large extent certain highly persistent liquid gases may have their persistency greatly reduced by using a large amount of high explosive1 which divides the liquid into a fine spray4 ,the 8,persistent0 group constitutes those gases that are very slowly volatilized upon exposure to the atmosphere4 ,the principal ones of these now used or proposed are mustard gas and bromobenzylcyanide4 ,for purposes of economy1 and hence efficiency1 certain gases1 both persistent and non-persistent1 are placed in a third group known as the 8,irritant ,group40 ,these gases are effective in extremely low concentrations against the lungs and other air passages1 or the eyes4 ,diphenylchloroarsine1 and some other solids when divided into minute particles by high explosive or heat1 irritate the nose1 throat and lungs to such an extent in a concentration of one part in ten millions of air as to be unbearable in a few minutes4 ,the tear gases are equally powerful in their effects on the eyes4 ,the irritating gases are used to force the wearing of the mask1 which in turn reduces the physical vigor and efficiency of the troops4 ,this reduction in efficiency1 even with the best masks1 is probably #be per cent for short periods1 and much more if prolonged wearing of the mask is forced4 ,,efficiency ,,of ,,irritant ,,gases ,one pound of the irritant gases is equal to #ejj to #a1jjj pounds of other gases when forcing the wearing of the mask alone is desired4 ,the great economy resulting from their use is thus apparent4 ,due to the rapid evaporation of the non-persistent gases they are used generally only in dense clouds1 whether those clouds be produced from cylinders or from bombs4 ,these gases are used only for producing immediate casualties1 as the necessary amount of gas to force the enemy to constantly wear his mask by the use of non-persistent gases alone could not possibly be taken to the front4 ,mustard gas1 which is highly persistent and also attacks the lungs1 eyes and skin of the body1 may and will be used to force the wearing of the mask4 ,it has one disadvantage when it is desired to force immediately the wearing of the mask1 and that is its delayed action and the fact that it acts so slowly1 and is usually encountered in such slight concentrations that several hours' exposure are necessary to produce a severe casualty4 ,for these reasons the enemy may often take chances in the heat of battle with mustard gas1 and while himself becoming a casualty1 inflict quite heavy casualties upon opposing troops by continuing to operate his guns or rifles without masks4 ,a powerful tear gas on the other hand forces the immediate wearing of the mask4 ,,material ,,of ,,chemical ,,warfare ,,used ,,by ,c4 ,w4 ,s4 ,,troops ,chemical warfare troops1 in making gas attacks1 use cylinders for the cloud or wave attack1 and the ,livens' projector and the #d-;inch ,stokes' mortar for attacks with heavy concentrations of gas projected by bombs with ranges up to a mile4 ,this distance will in the future probably be increased to #a or #a miles4 ,the original cylinders used in wave attacks were heavy1 cumbersome and very laborious to install1 and notwithstanding the wave attack was known to be the deadliest form of gas attack used in the war1 fell into disrepute after the use of gas became general in artillery shells and in special bombs4 ,cloud ,gas4 ,the ,americans at once concluded that since cloud gas attacks were so effective1 efforts should be made to make these attacks of frequent occurrence by decreasing the weight of the cylinders1 and by increasing the portability and methods of discharging the cylinders4 ,as early as ,march1 #aiah1 specifications for cylinders weighing not more than #fe pounds1 filled and completely equipped for firing1 were cabled to the ,united ,states4 ,they would have been used in large numbers in the campaign of #aiai had the enemy not quit when he did4 ,toxic smoke candles that are filled with solids driven off by heat will probably be the actual method in the future for putting off cloud attacks4 ,the toxic smoke candle is perfectly safe under all conditions and can be made in any size desired4 ,cloud gas attacks will be common in the future1 and all plans of defense must be made accordingly4 ,they will usually be made at night1 when1 due to fatigue and the natural sleepiness which comes at that time1 men are careless1 lose their way1 or neglect their masks1 and are thus caught unprepared4 ,experience in the war proved that a wave attack always produced casualties even1 as several times occurred1 when the enemy or the ,allied troops knew some hours beforehand that the attack was coming4 ,the ,english estimated these casualties to be #aj or #aa per cent of the troops exposed4 ,livens' ,projectors4 ,the second most effective weapon for using gas by gas troops was and will be the ,livens' projector4 ,this projector is nothing less than the simplest form of mortar1 consisting of a straight drawn steel tube and a steel base plate4 ,as used during the ,world ,war by the ,allies it did not even have a firing pin or other mechanism in the base1 the electric wires for firing passing out through the muzzle and alongside the drum or projectile which was small enough to permit that method of firing4 ,these were set by the hundreds1 very close behind or even in front of the front line trenches4 ,they were all fired at the same instant1 or as nearly at the same instant as watches could be synchronized1 and firing batteries operated4 ,as discussed on page #ah these mortars were emplaced deep enough in the ground to bring their muzzles practically level with the surface4 ,it usually took several days to prepare the attack1 and consequently allowed an opportunity for the enemy to detect the work by aeroplane photographs or by raids1 and destroy the emplacements by artillery fire4 ,it should be added1 however1 that notwithstanding this apparent great difficulty1 very few attacks were broken up in that way4 ,nevertheless1 in line with the general policy of the ,american troops to get away from anything that savored of trench warfare1 and to make the fighting as nearly continuous as possible with every means available1 the ,american ,chemical ,warfare ,service set at work at once to develop an easy method of making projector attacks4 ,it was early found1 that1 if the excavation was made just deep enough so that the base plate could be set at the proper angle1 the drums or projectiles were fired as accurately as when the projectors or mortars were set so that the muzzles were level with the surface4 ,the time required to emplace a given number of mortars in this way was only about one-fifth of that required for digging them completely in4 ,coupled of course with these proposed improvements in methods1 studies were being made and are still being made to produce lighter mortars1 better powder charges1 and better gas checks in order to develop the full force of the powder4 ,many improvements along this line can be made1 all of which will result in greater mobility1 more frequent attacks1 and hence greater efficiency4 #d-;,inch ,stokes' ,mortar4 ,the ,stokes' mortar is not different from that used by the ,infantry1 except that it is #d-;inch1 while the ,infantry ,stokes' is #c-;inch4 ,the #d-;inch was chosen by the ,british for gas1 as it was the largest caliber that could be fired rapidly and yet be moderately mobile4 ,its range of only about #a1ajj yards handicapped it considerably4 ,the poor design of the bomb was partly responsible for this4 ,the powder charges also were neither well chosen nor well designed4 ,it is believed that great improvements can be made in the shape of the bomb and in the powder charge1 which will result in much longer range and high efficiency1 while in no way increasing the weight of the bomb or decreasing the rate of fire4 ,these last two weapons were used during the ,world ,war1 and will be very extensively used in the future for firing high explosive1 phosphorus1 thermit and similar materials that non-technical troops might handle4 ,since gas has proven without the shadow of a doubt1 that it will produce more casualties for an equal amount of material transported to the front than any other substance yet devised1 all troops using short range guns or mortars should be trained to fire gas whenever weather conditions are right4 ,when weather conditions are not right1 they should fire the other substances mentioned4 ,the ,livens' projector with its #fj pound bomb1 of which #cj pounds will be gas or high explosive1 is a wonderful gun up to the limit of its range4 ,the bomb1 not being pointed1 does not sink into the ground1 and hence upon exploding exerts the full force of high explosive upon the surroundings1 whether bombs1 pill boxes1 barbed wire or trenches1 to say nothing of personnel4 ,high ,explosive in ,projectors4 ,when these are burst by the hundreds on a small area everything movable is blotted out4 ,thus concrete machine gun emplacements1 lookout stations1 bomb-proofs and wire entanglements are destroyed1 trenches filled up1 and the personnel annihilated4 ,this was amply demonstrated on the few occasions when it was actually used at the front4 ,the ,american ,infantry1 wherever they saw it tried out1 were wild to have more of it used4 ,the ,german was apparently equally anxious to have the use stopped4 ,it is1 however1 one of the things that must be reckoned with in the future4 ,it means practically that ,no ,man's ,land in the future will be just as wide as the extreme range of these crude mortars--and here a word of caution4 ,while efforts have been made to increase the range of these mortars1 whether of the ,livens' projector or ,stokes' variety1 no further increase will be attempted when that increase reduces the speed of firing or the efficiency of the projectile4 ,in other words results depend upon large quantities of material delivered at the same instant on the point attacked1 and if this cannot be obtained the method is useless4 ,for this reason these mortars will never be a competitor of the artillery4 ,the artillery will have all that it can do to cover the field within its range--beyond that reached by the mortars4 ,phosphorus in #d-;,inch ,stokes4 ,phosphorus will be used largely by gas troops1 but only in the #d-;inch or other ,stokes' mortar that may be finally adopted as best4 ,the ,livens' projector carries too great a quantity1 and being essentially a single shot gun1 is not adapted to keeping up a smoke screen by slow and continued firing1 or of being transported so as to keep up with the ,infantry4 ,phosphorus has also very great value for attacking personnel itself4 ,any one who has been burned with phosphorus or has witnessed the ease with which it burns when exposed to air1 wet or dry1 has a most wholesome fear of it4 ,the result of it in the war showed that the enemy machine gunners or other troops would not stand up under a bombardment of phosphorus fired from the #d-;inch ,stokes' mortar--each bomb containing about seven pounds4 ,thermit4 ,thermit is used in the same way1 and while the idea of molten metal1 falling upon men and burning through clothing and even helmets1 is attractive in theory1 it proved absolutely worthless for those purposes on the field of battle4 ,it was found impossible to throw sufficiently large quantities of molten metal on a given spot to cause any considerable burn4 ,in other words1 the rapid spreading out and cooling of the metal almost entirely ruined its effectiveness1 except its effect on the morale4 ,this latter1 however1 was considerable1 as one might judge from seeing the thermit shells burst in air4 ,for this reason thermit may find a limited use in the future4 ,,the ,,spread ,,of ,,gas ,height of ,gas ,cloud4 ,the height to which gas rises in a gas cloud is not exactly known1 but it is believed to be not much more than fifty feet1 and then only at a considerable distance from the point of discharge4 ,moving pictures taken of gas clouds show this to be true4 ,it is also indicated by the fact that pigeons1 which are very susceptible to poisonous gas1 practically always return to their cages safely when liberated in a gas cloud4 ,this was a good deal of a mystery until it was realized that the pigeon escaped through his rising so quickly above the gas4 ,this of course would be expected when it is known that practically all gases successfully used were two or more times as heavy as air4 ,such gases rise only by slow diffusion1 or when carried upwards by rising currents4 ,the absence of these upward currents at night is one of the reasons why gas attacks are more effective at night than during the day4 ,horizontal ,spread of ,gas4 ,another important thing to know in regard to the behavior of the wave of gas is the horizontal spread of a cloud4 ,if gas be emitted from a cylinder the total spread in both directions from that point is from #bj to #cj or an average of #be4 ,this varies1 of course1 with the wind4 ,the higher the wind the less the angle1 though the variation due to wind is not as great as might be expected4 ,this horizontal spread of the gas cloud was measured experimentally1 and the results checked by aeroplane pictures of heavy wave attacks over the enemy line4 ,in the latter case the path of the gas was very closely indicated by the dead vegetation4 ,this vegetation was killed and bleached so that it readily showed up in aeroplane photographs4 ,the visibility of a gas cloud arises from the fact that when a large amount of liquid is suddenly evaporated1 the air is cooled and moisture condensed1 thereby creating a fog4 ,with gases such as mustard gas and others of slight volatility1 a visible cloud is not formed4 ,for purposes of identification of points struck by shell1 smoke substances are occasionally added1 or a few smoke shell fired with the gas shell4 ,as future battle fields will be dotted everywhere with smoke clouds1 a point that will be discussed more fully later1 the firing of smoke with gas shell will probably be the rule and not the exception4 ,,requirements ,,of ,,successful ,,gas ,if we succeed in getting a poisonous gas that has no odor it will be highly desirable to fire it so that it will not be visible4 ,in that case no smoke will be used4 ,carbon monoxide is such a gas1 but there are several important reasons why it has not been used in war4 7,see page #aij74 ,these considerations indicate the general requirements for a successful poisonous gas4 ,if non-persistent it must be quickly volatilized1 or must be capable of being driven off by heat or by other means1 which can be readily and safely produced in the field4 ,it must be highly poisonous1 producing deaths in high concentrations1 and more or less serious injuries when taken into the system in quantities as small as one-tenth of that necessary to produce death4 ,if it has a slightly delayed action with no intervening discomfort1 it is still better than one that produces immediate discomfort and more or less immediate action4 ,it must be readily compressed into a liquid and remain so at ordinary temperatures1 with the pressure not much above #be or #cj pounds per square inch4 ,as a persistent gas it must be effective in extremely low concentrations1 in addition to having the other qualities mentioned above4 ,these general characteristics concerning gases apply whether used by ,chemical ,warfare troops1 the ,artillery1 the ,air ,service1 the ,navy1 or the ,infantry4 ,in speaking of these substances being used by the ,infantry1 it is understood that an ample number of ,chemical ,warfare officers will be present to insure that the gases may not be turned loose when weather conditions are such that the gas might drift back and become a menace to our own troops4 ,this is absolutely essential since no troops who have as varied duties to perform as the ,infantry1 can be sufficiently trained in the technical side of chemical warfare to know when to put it off on a large scale with safety and efficiency4 ,,artillery ,,use ,,of ,,gas ,the ,artillery of the future will probably fire more gas than any other one branch of the ,army4 ,there are two reasons for this--first1 the large number of guns now accompanying every ,army1 and second1 the long range of many of these guns4 ,as before indicated1 the gases are adaptable to various uses1 and hence to guns differing both in caliber and range4 ,the gas will be fired by practically all guns--from the #ge mm4 to the very largest in use4 ,it is even possible that if guns smaller than the #ge mm4 become generally useful that certain gases will be fired by them4 ,efficiency of ,artillery ,gas ,shell4 ,it is well to remember in the beginning that all artillery shell so far designed and used1 contain only about #aj per cent gas1 i4e41 #aj per cent of the total weight of shell and gas4 ,it is hoped that gas shell may later be so designed that a somewhat greater proportion of the total weight of the shell will be gas than is now true4 ,this is very desirable from the point of efficiency4 ,as stated above the bombs used by ,chemical ,warfare troops contain nearly #ej per cent of their total weight in gas1 and hence are nearly five times as efficient as artillery shell within the limit of range of these bombs4 ,this fact alone is enough to warrant the use of gas troops to their full maximum capacity in order that the artillery may not fire gas at the ranges covered4 ,,guns ,,firing ,,persistent ,,and ,,non-,,persistent ,,gases ,considering the firing of non-persistent and persistent gases1 it may be said generally that non-persistent gases will be fired only by the medium caliber guns which are available in large numbers4 ,in fact1 the firing of non-persistent gases will be confined mainly to the #f-;inch or #aee mm4 ,howitzer and gun4 ,as our ,army was organized in ,france1 and as it is organized at present1 the number of #aee mm4 guns will be greater than all others put together1 except the #ge mm4 ,in order that a non-persistent gas may be most effective a high concentration must be built up very quickly4 ,this necessitates the use of the largest caliber shell that are available in large numbers4 ,of course1 a certain percentage of the gas shell of other calibers may consist of non-persistent gases in order to help out the #aee mm4 gun4 ,this is in accordance with the present program for loading gas shell and applies particularly to the #h-;inch and #bdj mm4 ,howitzer4 ,few ,ideally ,persistent or ,non-,persistent ,gases4 ,naturally there will be very few gases that are ideally non-persistent or ideally persistent4 ,the groups will merge into one another4 ,those on the border line will be arbitrarily assigned to one group or the other4 ,it might be said definitely1 however1 that a gas which will linger more than six or possibly eight hours under any conditions1 except great cold1 will not be considered non-persistent4 ,for reasons of efficiency and economy persistent gases will not be chosen unless they will persist under ordinary conditions for two or three days or more4 ,accordingly1 a gas which would persist for one day only would have to be extraordinarily useful to lead to its adoption4 ,firing ,non-,persistent ,gases4 ,of the non-persistent gases phosgene is the type and the one most used at present4 ,furthermore1 so far as can now be foreseen1 it will continue to be the non-persistent gas most used4 ,it volatilizes very quickly upon the bursting of the shell4 ,accordingly1 in order that the shell fired at the beginning of a gas 8shoot10 as they are generally referred to in the field1 shall still be effective when the last shell are fired1 it is necessary that the whole number be fired within two to three minutes4 ,the temperature and velocity of the wind both affect this4 ,if it be in a dead calm1 the time may be considerably extended2 if in a considerable wind1 it must be shortened4 ,another important consideration requiring the rapid firing of non-persistent gases is the fact that nearly all masks thoroughly protect against phosgene and similar gases4 ,it is accordingly necessary to take the enemy unawares and gas him before he can adjust his mask2 otherwise1 practically no harm will result4 ,from the considerations previously mentioned1 these 8gas shoots0 are usually made at night when1 as before stated1 carelessness1 sleepiness and the resulting confusion of battle conditions always insure more casualties than firing gas in the daytime4 ,firing ,persistent ,gases4 ,the persistent gases will be fired by all caliber guns1 but to a less extent by the #aee mm4 than by the other calibers4 ,persistent gases must be sufficiently effective in low concentrations to act more or less alone4 ,if it be desirable to fill an atmosphere over a given area with mustard gas1 the firing may extend for two or three1 or even five or six hours and all shell still act together4 ,the same is true of bromobenzylcyanide4 ,this1 then1 permits the minimum number of guns to be used in firing these persistent gases4 ,inasmuch as they persist and force the wearing of the mask1 they are available for use in long-range1 large-caliber guns for interdiction firing on cross-roads1 in villages1 and on woods that afford hiding places1 as well as on other similar concentration points4 ,firing ,irritant ,gases4 ,the irritant gases will be fired by the various caliber guns1 in the same manner as the persistent and non-persistent gases4 ,we will have non-persistent irritant gases and persistent irritant gases4 ,they are1 however1 considered as a group because they are used for harassing purposes1 due to their efficiency in forcing the wearing of the mask4 ,before the signing of the ,armistice1 the ,general ,staff1 ,a4 ,e4 ,f41 had authorized1 beginning ,january #a1 #aiai1 the filling of #be per cent of all shell with ,chemical ,warfare materials4 ,the interpretation there given to shell was that it included both shrapnel and high explosive4 ,of the field guns in use1 the #ge mm4 will be best1 up to the limit of its range1 for persistent gases such as mustard gas1 and the tear gas1 bromobenzylcyanide4 ,a considerable number1 however1 were filled with non-persistent gases and probably will continue to be so1 since1 due to the very large number of #ge mm4 guns available1 they can be used to add greatly at times to the amount of non-persistent gas that can be fired upon a given point4 ,,use ,,of ,,gas ,,by ,,the ,,aviation ,,service ,no gas was used by aeroplanes in the ,world ,war4 ,many rumors were spread during the latter part of the war to the effect that the ,germans had dropped gas here or there from aeroplanes4 ,every such report reaching the ,chemical ,warfare ,service ,headquarters was run down and in every case was found to be incorrect4 ,however1 there was absolutely no reason for not so using gas1 except that the ,german was afraid4 ,in the early days of the use of gas he did not have enough gas1 nor had he developed the use of aeroplanes to the point where it would have seemed advisable4 ,when1 however1 he had the aeroplanes the war had not only begun to go against him1 but he had become particularly fearful of gas and of aeroplane bombing4 ,it does not seem to be generally known1 but it is a fact1 that after three or four months' propaganda he made a direct appeal to the ,allies to stop the use of gas sometime during the month of ,march1 #aiah4 ,this propaganda took the form of an appeal by a ,professor of ,chemistry who had access to ,switzerland1 to prevent the annihilation of the ,allied forces by a ,german gas that was to make its appearance in #aiah4 ,this ,german professor claimed that1 while favoring the ,germans winning the war1 he had too much human sympathy to desire to see the slaughter that would be caused by the use of the new gas4 ,the ,allies in the field felt that this was simply an expression of fear and that he did not have such a gas4 ,the ,germans were accordingly informed that the ,allies would not give up the use of gas4 ,later events proved these conclusions to be absolutely correct4 ,the ,german evidently felt that the manufacturing possibilities of the ,allies would put them in a more predominant position with gas than with anything else4 ,in that he was exactly correct4 ,the use of gas by aeroplanes will not differ from its use in artillery or by ,chemical ,warfare ,troops4 ,non-persistent gases may be dropped on the field of battle1 upon concentration points1 in rest areas1 or other troop encampments to produce immediate casualties4 ,persistent gases will be dropped particularly around cross-roads1 railroad yards1 concentration points and encampments that cannot be reached by the artillery4 ,the sprinkling of persistent gases will be one of the best ways for aeroplanes to distribute gas4 ,it might be said here that the aviation gas bomb will be highly efficient1 inasmuch as it has to be only strong enough to withstand the low pressure of the gas and ordinary handling1 whereas artillery shell must be strong enough to withstand the shock of discharge in the gun4 ,,infantry ,,and ,,gas ,,warfare ,when one suggests the possibility of the infantry handling gas1 it is at once argued that the infantry is already overloaded4 ,that is true1 but in the future1 as in the past1 the infantryman will increase or decrease his load of a given material just as its efficiency warrants4 ,if he finds that gas will get casualties and help him win victories more readily than an equal weight of any other material1 he will carry gas material4 ,a study of the articles of equipment abandoned by #aj1jjj stragglers in the ,british ,army picked up during the great ,german drive towards ,amiens in ,march1 #aiah1 illustrates this very clearly4 ,of the equipment carried by these stragglers1 more than #f1jjj had discarded their rifles4 ,the helmets were thrown away to a somewhat less extent1 but the gas mask had been thrown away by only #hjj out of the #aj1jjj4 ,now the gas mask is not a particularly easy thing to carry1 nor was the ,english type comfortable to wear1 but the ,english soldier had learned that in a gas attack he had no chance whatever of escape if his gas mask failed him4 ,accordingly1 he hung on to the mask when he had discarded nearly everything else in his possession4 ,the same thing will be true of any gas equipment if it proves its worth4 ,,smoke ,,and ,,incendiary ,,materials ,so far nothing has been said in regard to smoke or incendiary materials4 ,this has been due to the fact that their use is not dependent upon weather conditions to anything near the extent that gas is4 ,second1 the smokes1 not being poisonous1 are not a danger to our own troops1 although they may hamper movements and add to the difficulty of taking a position1 if used improperly4 ,of the two classes of materials1 smoke and incendiary1 smoke materials may be said to be at least a thousand times as important as the incendiary materials4 ,a material that will burst into flame when a shell is opened or that will scatter balls of burning fire appeals to the popular imagination1 and yet actual results achieved by such materials on the field of battle have been almost nil4 ,about the only results worth while achieved by incendiary materials have been in occasionally firing ammunition dumps and more frequently1 setting fire to warehouses and other storage places4 ,this will undoubtedly continue in the future4 ,,flame ,,thrower ,of the incendiary materials the least valuable is the flame thrower4 ,in the ,chemical ,warfare ,service it has been the habit for a long while not to mention the flame thrower at all1 unless questions were asked about it4 ,it is mentioned here to forestall the questions4 ,even the ,german1 who invented it and who1 during the two years of trench warfare1 had full opportunity for developing its use1 finally came to using it largely as a means of executing people that he did not want to shoot himself4 ,men falling in that class were equipped with flame throwers and sent over the top4 ,the ,german knew1 as did the ,allies1 that each man with a flame thrower became a target for every rifle and machine gun nearby4 ,the flame thrower is very quickly exhausted and then the one equipped with it has no means of offensive action1 and in addition1 is saddled with a heavy load1 hampering all movements1 whether to escape or to advance4 ,,inflammable ,,materials ,there will probably be some use for materials such as metallic sodium1 spontaneously inflammable oils1 etc41 that will burst into flame and burn when exposed to the air1 though white phosphorus is probably equal1 and in most cases vastly superior to anything else so far suggested4 ,phosphorus burns with an unquenchable flame when exposed to the air1 whether wet or dry4 ,it is of great value for screening purposes1 and for use against the enemy's troops4 ,the ,german did not use phosphorus simply because he did not have it1 just as he did not use helium in his observation balloons because he did not have it4 ,the value of phosphorus was just beginning to be realized slightly when the ,americans entered the war1 while its full value was not appreciated even by the ,american troops when the war closed4 ,the work of the ,first ,gas ,regiment with phosphorus against machine gun nests proved how valuable it is against the enemy's troops4 ,it proved also its tremendous value as a screen4 ,the ,chemical ,warfare ,service was prepared to fill a great number of artillery shell with phosphorus1 but due to the failure of our shell program to mature before the ,armistice1 phosphorus was not used by ,american artillery to any appreciable extent4 ,,smoke ,,used ,,by ,,everyone ,smoke will be used by every fighting arm of the ,service in practically every battle1 both by day and by night4 ,if you have ever tried on a target range to shoot at a target that was just beginning to be obscured by a fog1 you will recognize the difficulty of hitting anything by firing through an impenetrable smoke screen4 ,it is simply a shot in the dark4 ,future battles will witness smoke formed by smoke candles that are kept in the trenches or carried by the troops1 by smoke from bursting artillery shell and rifle grenades1 by smoke from aeroplane bombs and possibly even from what is known as the smoke knapsack4 ,the knapsack produces a very dense white smoke and very economically1 but will probably not be much used4 ,this is because1 notwithstanding its efficiency1 the knapsack cannot be projected to a distance1 that is1 the smoke screen is generated on the person carrying the knapsack4 ,on the other hand the great value of phosphorus is that it can be fired to great distances in rifle grenades or artillery shell1 and dropped from aviation bombs4 ,the smoke screen is thus established in front of the object it is desired to cut off1 whether it be a battery of artillery1 an advancing wave of infantry1 or a lookout station4 ,thus smoke1 for screening purposes alone1 will be used to a tremendous extent4 ,it will also be used in conjunction with gas4 ,,smoky ,,appearance ,,of ,,gas ,,cloud ,due to the smoky appearance of an ordinary gas cloud and to the coming use of poisonous smokes1 no one on the field of battle in the future will ever be certain that any given smoke cloud is not also a poisonous cloud until he has actually tested it4 ,and there lies an opportunity for the most intense study and for the greatest use of the proverbial ,american ingenuity that war has ever furnished4 ,in the variations that can be played with smoke containing gas1 or not containing gas1 with smoke hurled long distances by the artillery or dropped from aeroplanes1 the possibilities indeed are unlimited4 ,every officer will need to study the possibilities of smoke1 both in its use against him and in his use of it against the enemy4 ,he can probably save more casualties among his own troops by the skillful use of smoke than by any other one thing at his command4 ,on the other hand1 the unskilled use of smoke on the part of one side in a battle may lead to very great casualties in proportion to those of the enemy should the latter use his smoke skillfully4 ,this is a subject that deserves deep and constant study4 ,,protection ,,by ,,smoke ,,clouds ,smoke in the future will be the greatest protective device available to the soldier4 ,it shuts out not only the view in daylight1 but the searching of ground at night by searchlights1 by star bombs or other means for illuminating the battlefield4 ,it has already been used extensively by the ,navy and undoubtedly will be used far more extensively in the future4 ,,shell ,,markings ,modern artillery shell have distinctive colors for high explosive1 for shrapnel1 for incendiary materials1 and for gases4 ,a grayish color has been adopted as the general color of the paint on all gas shells1 bombs and cylinders4 ,in addition a system of colored bands has been adopted4 ,these bands are white to indicate poisonous non-persistent substances1 and red--persistent4 ,yellow is used to indicate smoke4 ,with any given combination of red and white and yellow bands1 the artillery-man at the front can tell1 at a glance1 whether the gas is non-persistent or whether it is persistent1 and also whether or not it contains smoke4 ,there will be secondary markings on each shell which1 to the trained ,chemical ,warfare ,service officer1 will indicate the particular gas or gases in the shell4 ,these markings however1 will be inconspicuous and no attempt will be made to give the information to the soldier or even to the average officer firing gas4 ,these secondary markings are for the purpose of enabling the ,chemical ,warfare ,service officers in charge to use certain gases for particular uses in those comparatively rare cases when sufficient gas is on hand and sufficient time available to enable such a choice to be made4 ,,chapter ,,xxiv ,,defense ,,against ,,gas 7,from the ,field ,point of ,view7 ,the best defense against any implement of war is a vigorous offense with the same implement4 ,this is a military axiom that cannot be too often1 or too greatly emphasized1 though like other axioms it cannot be applied too literally4 ,it needs a proper interpretation--the interpretation varying with time and circumstances4 ,thus in gas warfare1 a vigorous offense with gas is the best defense against gas4 ,this does not mean that the enemy's gas can be ignored4 ,indeed1 it is more important to make use of all defensive measures against gas than it is against any other form of attack4 ,gas being heavier than air1 rolls along the ground1 filling dugouts1 trenches1 woods and valleys--just the places that are safest from bullets and high explosives4 ,there it remains for hours after it has blown away in the open1 and1 since the very air itself is poisoned1 it is necessary not only that protection be general but that it be continuous during the whole time the gas is present4 ,,earliest ,,protective ,,appliances ,the earliest protection against gas was the crudest sort of a mask4 ,the first gas used was chlorine and since thousands of people in civil life were used to handling it1 many knew that certain solutions1 as hyposulfite of soda1 would readily destroy it4 ,they also knew that if the breath could be drawn through material saturated with those solutions1 the chlorine would be destroyed4 ,thus it was that the first masks were simple cotton1 or cotton waste pads1 which were dipped into hyposulfite of soda solutions and applied to the mouth and nose during a gas attack4 ,these pads were awkward1 unsanitary1 and1 due to the long intervals between gas attacks1 were frequently lost1 while the solution itself was often spilled or evaporated4 ,the net result of all this was poor protection and disgust with the so-called masks4 ,,design ,,of ,,new ,,masks ,after using these1 or similar poor excuses for a mask1 for a few weeks1 the ,british designed what was known as the ,,ph helmet4 ,in a gas attack the sack was pulled over the head and tucked under the blouse around the neck1 the gas-tight fit being obtained by buttoning the blouse over the ends of the sack4 ,this ,,ph helmet was quite successful against chlorine and1 to a much less extent1 against phosgene1 a new gas introduced during the spring of #aiaf4 ,but it was warm and stuffy in summer--the very time when gas is used to the greatest extent--while the chemicals in the cloth irritated the face and eyes1 especially when combined with some of the poisonous gases4 ,probably as a result of experience with oxygen apparatus in mine rescue work1 ,colonel ,harrison suggested making a mask of which the principal part was a box filled with chemicals and carried on the chest4 ,a flexible tube connected the box with a mouthpiece of rubber4 ,breathing was thus through the mouth and in order to insure that no air would be breathed in through the nose1 a noseclip was added4 ,this1 of course1 cared for the lungs1 but did not protect the eyes4 ,their protection was secured by making a facepiece of rubberized cloth with elastics to hold it tight against the face4 ,the efficiency of this mask depends1 then1 first upon the ability of the facepiece to keep out lachrymatory gases which affect the eyes1 and1 second1 upon a proper combination of chemicals in the box1 to purify the air drawn into the lungs through the mouthpiece4 7,details are given in ,chapter ,,xii74 ,,protection ,,against ,,smoke ,while the charcoal and soda-lime granules furnished an adequate protection against all known true gases1 they did not furnish protection against certain smokes or against minute particles of liquid gas4 ,since certain smokes1 as stannic chloride1 though not deadly1 are so highly irritating as to make life unbearable1 it early became necessary to devise means for keeping them from going through the masks4 ,this was done in the first masks by adding a sufficient thickness of cotton batting4 ,the cotton was usually placed in three layers alternating with the charcoal and granules1 as it was thought the latter would be held in place better by that means4 ,some time after stannic chloride came into use the ,germans started firing shells containing a small quantity of diphenylchloroarsine1 popularly known as 8,sneezing ,gas40 ,protection against this is discussed in ,chapter ,,xviii4 ,,choice ,,of ,,masks ,,for ,u4 ,s4 ,,troops ,when it became necessary1 with the creation of a ,chemical ,warfare ,service in ,france in ,august1 #aiag1 to decide upon a mask for ,american troops1 there were available for purchase two types--the ,british type and the ,french ,m-#b4 ,the ,french ,m-#b consisted essentially of #cb layers of cloth impregnated with various chemicals1 through which the air was breathed both in and out4 ,this mask was quite effective against ordinary field concentrations of most gases1 but was utterly inadequate to care for the high concentration of phosgene obtained in the front line from cloud gas or from projector gas attacks4 ,it was also poor against chloropicrin4 ,the ,m-#b was1 however1 very light and easy to carry and moreover was deemed sufficient to protect against concentrations of cloud gas even1 at points more than five miles distant from the front line4 ,furthermore1 it was felt desirable at first to have an auxiliary or emergency mask in addition to the principal one1 for use in case the principal mask was worn out or damaged4 ,accordingly both types of masks were adopted and the day after ,fries took charge of the ,chemical ,warfare ,service1 ,a4,e4,f41 on ,august #bb1 #aiag1 #ajj1jjj of each were purchased1 although there were then only ten or twelve thousand ,american troops in ,france requiring masks4 ,later additional masks of both kinds were purchased to tide over the ,american troops until a sufficient quantity of the ,british type masks could be manufactured in the ,united ,states4 ,the total of ,british masks purchased amounted to about #gjj1jjj4 ,however1 within a comparatively short time after ,american troops got into the front line it was realized that a second mask1 inferior in protection to the first1 was highly undesirable4 ,during a gas attack men seemed to acquire an uncontrollable desire to shift from one mask to the other4 ,this shifting in nearly every case resulted in a casualty4 ,we then came rapidly to the conclusion that one mask only should be furnished1 and that one the best that could be made1 and then to impress upon the soldier the fact that his life depended upon the care he took of his mask4 ,this proved to be an entirely sound conclusion1 as the number of men gassed through injuries to the mask was comparatively small4 ,an interesting proof of the value the soldier placed upon his mask was shown by the articles of equipment thrown away by #aj1jjj ,british stragglers in the great ,german offensive of ,march1 #aiah4 ,of the articles thus thrown away the gas mask came at the foot of the list1 with only #hjj missing4 ,the steel helmet is said to have come next with about #d1jjj missing4 ,,sizes ,,of ,,faces ,,for ,,masks ,when adopting the ,british respirator in ,august1 #aiag1 it was decided that the ,american face as well as the ,american stature was probably larger than the ,english4 ,accordingly inquiry was made in regard to the sizes of masks issued to the ,canadians as it was thought probable they required a greater proportion of the larger size masks than did the ,english4 ,when prescribing the relative quantities of each size of mask to be furnished ,americans1 the ,canadian requirements were taken as a base but with the larger sizes increased slightly over the ,canadian requirements4 ,as a matter of fact even these increases proved considerably too small1 so that the numbers in the two sizes above normal had to be finally more than doubled4 ,,objections ,,to ,,german ,,type ,,mask ,the ,american ,gas ,service felt from the beginning that a design which attached the box of chemicals to the facepiece was unsound in principle 7this design was used in the ,german mask and in the ,french ,a4 ,r4 ,s4 masks71 since it did not allow proper flexibility for increasing the size of the box to care for new gases4 ,furthermore1 the weight of the box during movement caused the facepiece to swing slightly from side to side4 ,this interfered with vision and tended to lift the facepiece away from the face and allow gas to enter4 ,that the objections of the ,american ,gas ,service to this type were correct was proved by the difficulty encountered toward the end of the war by both the ,french and the ,germans in trying to provide a suitable filter for protection against particulate clouds and the smokes1 such as stannic chloride and diphenylchloroarsine4 ,,struggle ,,between ,,mask ,,and ,,gas ,as between the mask and poisonous gases1 we have the old struggle of the battleship armor against the armor-piercing projectile4 ,while the armor-piercing projectile has always had a little the better of the game1 it is just the reverse with gases4 ,the gas mask has always been just a little better than the gases1 so that very few casualties have occurred through failure of the mask itself4 ,this margin of safety has never been any too great1 and that we have had a margin at all is due to the energy1 skill and enthusiasm of those developing and manufacturing masks in ,england1 ,france1 and particularly in the ,united ,states4 ,however1 the mask at the best is uncomfortable1 causes some loss of vigor1 and even with the very best ,american masks there is some loss in vision4 ,the wearing effect on troops results mostly from the increased resistance to breathing4 ,accordingly a tremendous amount of study and effort was made to decrease this breathing resistance4 ,in the ,english type masks this resistance was equal to the vacuum required to raise a column of water about four and one-half inches4 ,adding the sulfite paper to protect against diphenylchloroarsine increased this resistance by about one inch4 ,this put a heavy burden on the wearer of the mask whenever it was necessary for him to do any manual labor while wearing it4 ,in addition earlier masks left a good deal to be desired in the way of reducing resistance by proper sized tubes1 angles and valves through which the air was drawn4 ,this was much more easily overcome than reducing the resistance through the chemicals and charcoal and the materials for protection against diphenylchloroarsine4 ,in the latest type canister1 devised after long trials for the ,american forces1 this resistance was brought down to about two inches of water4 ,what this reduction in resistance means no one knows except one who has worn the old mask with its mouthpiece and four to six inches' resistance and has then replaced that mask for one through which he breathes naturally with only two inches' resistance4 ,,design ,,of ,,new ,,american ,,mask ,the ,american ,gas ,service felt from the beginning that the mouthpiece and noseclip must be abandoned and bent every effort toward getting a mask perfected for that purpose4 ,the ,english opposed this view fiercely for nearly a year4 ,this position on the part of the ,english was more or less natural4 ,they developed their mask in the beginning for protection against cloud gas4 ,in those days the opposing trenches were close together4 ,moreover1 front line trenches were quite strongly manned4 ,the result was that a large number of men were exposed to a very high concentration of gas1 but--and highly important--for a short period only4 ,inasmuch as the ,german feared this cloud gas even more than the ,english there was no danger of his attacking in it4 ,the ,english rules of conduct during a gas attack called for all movement to stop and for every man to stand ready until the cloud passed4 ,accordingly1 the man was breathing the easiest possible and hence did not suffer particularly from the resistance4 ,with the advent of mustard gas1 however1 the whole general scheme of protection changed4 ,mustard gas1 as is well known1 is effective in extremely low concentrations and has very great persistency4 ,in dry warm weather mustard gas1 scattered on the ground and shrubbery1 will not be fully evaporated for two to three days and accordingly will give off vapors that not only burn the lungs and eyes but the soft1 moist parts of the skin as well4 ,in cool1 damp weather the gas remains in dangerous quantity for a week and occasionally longer4 ,since this gas1 in liquid form1 evaporates too slowly for use in gas clouds1 it is used altogether in bombs and shells4 ,accordingly it could be expected to be and actually is fired at all ranges from the front line to nearly eight miles back of that line4 ,hence1 with the coming of mustard gas1 the need for protection changed from high protection for a short period to moderate protection for very long periods4 ,indeed1 mustard gas makes it necessary for men to wear masks just as long as they remain in an area infected with it4 ,there is still occasional need for high protection for short periods1 but with the increase in the efficiency of charcoal alone1 it is found that the amount of charcoal and chemicals in the canister can be very greatly reduced and still maintain sufficient protection for the high concentrations encountered in cloud gas and projector attacks4 ,,exhaustion ,,and ,,malingering ,it seems physically impossible for the ordinary man to wear the ,british mask with its mouthpiece and noseclip more than six to eight hours and vast numbers are unable to even do that4 ,how many thousands of casualties were suffered through men losing their mental balance from exhaustion and the discomfort of the mouthpiece and noseclip no one knows4 ,such men tore off the mask1 stating that they would rather die than endure the torture of wearing it longer4 ,furthermore1 the poor vision of this mask led to the habit of taking the facepiece off while still leaving the mouthpiece and noseclip in place4 ,this gave protection to the lungs1 but exposed the eyes1 and as mustard gas affects the eyes very readily this alone led to thousands of casualties4 ,there was another interesting side to this situation4 ,the malingerer who wanted to get out of the front line and was willing to take any action1 however cowardly1 to achieve that end1 deliberately removed the facepiece and thus suffered gassing of the eyes4 ,the effect of mustard gas soon became so well known that the malingerer knew gassing of the eyes never resulted in death or permanent loss of sight4 ,with the new type of ,american mask1 the protection of eyes and lungs depends solely upon the fit around the face and no such playing with the mask can be done4 ,without going into further details in regard to masks it is sufficient to state that at the end the ,americans had produced a mask thoroughly comfortable1 giving complete protection against gases and smoke clouds1 and one that was easy to manufacture on the huge scale 7fifty to seventy-five thousand per day7 which was necessary to provide masks for an army of three to four million men in the field4 ,,protection ,,in ,,war ,,is ,,relative ,,only ,napoleon is credited with saying 8,in order to make an omelet1 it is necessary to break some eggs40 ,every student of war realizes that casualties cannot be avoided in battle and yet one ,american ,staff ,officer went so far as to refuse to use gas offensively unless the ,chemical ,warfare ,service could absolutely guarantee that not a single ,american casualty could occur under any circumstances4 ,this same idea early got into the heads of the laboratory workers on masks4 ,they seemed to feel that if a single gas casualty occurred through failure of the mask1 their work would be a failure or at least they would be open to severe criticism4 ,accordingly efforts were made to perfect masks and to perfect protection regardless of the discomfort imposed upon the wearer of the mask4 ,this idea was very difficult to eradicate4 ,the laboratory worker who accustoms himself to experiment with a particular thing forgets that he develops an ability to endure discomfort1 that is not possible of attainment by the ordinary man in the time available for his training4 ,furthermore1 if the need for such training can be avoided it is of course highly desirable4 ,this applies to the mouthpiece of the ,british respirator2 to elastics that cause undue discomfort to the face2 to the noseclip and to the large boxes that cause too great resistance to breathing4 ,it may be taken as a general rule that when protection requires so much effort or becomes so much of a burden that the average man cannot or will not endure it1 it is high time to find out what the average man will stand and then provide it even if some casualties result4 ,protection in battle is always relative4 ,a man who cannot balance protection against legitimate risk has no business passing on arms1 equipment or tactics to be used in battle4 ,,training ,bitter experience taught the ,allies as well as the ,americans that no matter how efficient the gas mask and other defensive appliances1 they would not take the place of thorough and constant training4 ,one of the greatest difficulties at first was to get ,american troops to realize that a thing as invisible as gas1 with in many cases no offensive smell and producing no immediate discomfort1 could be deadly4 ,nothing but constant drill and constant reiteration of these dangers could get this fact impressed on them4 ,indeed it never was impressed sufficiently in any of the earlier divisions of ,american troops in the line to prevent their taking such chances that each division suffered heavy loss on one or more occasions from gas attacks4 ,a great deal of emphasis had been placed by the ,english upon the adjustment of the mask in the shortest possible time1 this time having been officially set at six seconds after the alarm4 ,the ,americans in adopting the mask in toto naturally had to adopt the rules for adjusting it and wearing it4 ,experience1 however1 taught them in a few months that the effort to attain too great speed was dangerous4 ,it tended to rattle the soldier and to result in poor adjustment of the mask1 both of which led to casualties4 ,accordingly in the latest instructions for defense against gas all reference to six seconds was eliminated and emphasis placed on the necessity of accurate adjustment of the mask4 ,inasmuch as any man1 practically without effort or previous drill1 can hold his breath for twenty seconds1 the need for great speed in adjusting the mask is not apparent4 ,,holding ,,the ,,breath ,the first regulations and those in general use up to near the close of hostilities1 prescribed that the soldier should hold his breath and adjust his mask4 ,it seemed impossible to overcome the natural inference that 8holding the breath0 meant first the drawing of a full breath4 ,this was obviously highly dangerous if gas were actually present before the alarm was heard1 as was often the case with projector and artillery gas shell attacks4 ,the change was then made to the phrase 8,stop ,breathing and ,stay ,stopped until the ,mask is ,carefully and ,accurately ,adjusted40 ,,psychology ,,in ,,training ,while the importance of impressing upon the soldier the danger of gas was early appreciated it was deemed necessary not to make him unduly afraid of the gas4 ,however1 as gas defense training in our ,army got a big start over gas offense training1 this became a matter of very great importance4 ,in fact1 due to a variety of causes1 training in the offensive use of gas was not available for any troops until after their arrival in ,france4 ,this resulted in officers and men looking upon the gas game1 so far as they were individually concerned1 as one of defense only4 ,accordingly after their arrival in ,france it became very difficult not only to get some of our officers to take up the offensive use of gas but even to get them to permit its use along the front they commanded4 ,notwithstanding all the care taken in training ,americans in gas defense there arose an undue fear of the gas that had to be overcome in order to get our troops to attack close enough to their own gas to make it effective4 ,this applied to the use of gas by artillery as well as to its use by gas troops4 ,however1 it should be said that in every instance where gas was once used on an ,american front all officers in the ,division1 or other unit1 affected by it were always thereafter strongly in favor of it4 ,,german ,,problems ,,in ,,gas ,,training ,the ,germans also had serious troubles of their own over the psychology of gas training4 ,as stated elsewhere they were using mustard gas nearly eleven months before the ,allies began using it4 ,during that time1 for purposes of morale1 if not sheer boastfulness1 the ,germans told their men that mustard gas could not be made by the ,allies2 that it was by far the worst thing the war had produced--and in that statement they were correct--and that they would win the war with it--in which statement they were far from correct4 ,when the ,allies began sending it back to them they had to reverse their teachings and tell their men that mustard gas was no worse than anything else1 that they need not be afraid of it and that their masks and other protective appliances gave full protection against it4 ,they thus had a problem in psychology which they never succeeded in fully solving4 ,indeed there is no question but that the growing fear of gas in the minds of the ,german is one of the reasons that prompted him to his early capitulation4 ,,gas ,,at ,,night ,in the early days it was very difficult to get officers to realize the absolute necessity of night drill in the adjustment of the mask4 ,for various reasons1 including surprise1 gas attacks were probably eighty to ninety per cent of the time carried out at night4 ,under such conditions confusion in the adjustment of the mask is inevitable without a great deal of practice before hand1 especially for duty in trenches with narrow spaces and sharp projecting corners4 ,there are numerous instances of men waking up and getting excited1 who not only gassed themselves1 but in their mad efforts to find their masks1 or to escape from the gas1 knocked others down1 disarranging their masks and causing the gassing of from one to three or four additional men4 ,the confusion inherent in any gas attack was heightened in the latter stages of the war by heavy shrapnel and high explosive bombardments that accompanied nearly all projector and cloud gas attacks for that very purpose4 ,the bombardment was continued for three or four hours to cause exhaustion and removal of the mask and to prevent the removal of the gassed patients from the gassed area4 ,,detection ,,of ,,gases ,efforts were made by the enemy and by all the ,allies throughout the war to invent a mechanical detector that would show when gas was present in dangerous quantities4 ,while scores1 perhaps hundreds1 of these were invented none proved simple1 quick1 or certain enough in action to make their adoption desirable4 ,in every case it was necessary to rely on the sense of smell4 ,thus it was that as the war wore on1 more and more attention was given to training officers and non-commissioned officers to detect various kinds of gases in dangerous quantities by the sense of smell4 ,in the ,american ,gas ,defense ,school for officers this was done wholly by using captured ,german gases4 ,this was because certain gases have quite different smells1 depending upon the impurities in the gas and also upon the solvents sometimes mixed with them4 ,thus the ,german mustard gas has a mustard smell1 while the ,allies mustard gas1 due to a slight difference in the method of manufacture1 has a very perfect garlic odor4 ,not only must officers and men who handle gas training know the smell of the various gases1 but they must know when the concentration of each is high enough to be dangerous4 ,this is not easy to learn because the strength of the various gases in dangerous concentrations varies through wide limits4 ,not only does the strength of the gases vary and the sharpness of the odors accordingly1 but the mingling of poisonous gases with other gases from high explosive and shrapnel tends to obscure these odors and make them more difficult of detection4 ,,deceptive ,,gases ,a great deal of thought was given toward the end of the war to the subject of deceptive gases which could by powerful or peculiar odors mask the dangerous gases4 ,this masking was to deceive the enemy when dangerous gases were present or to admit an attack without masks while the enemy was wearing his through thinking there was a dangerous gas when as a matter of fact none existed4 ,in gas warfare1 the ,german1 as well as the ,allies1 was exercising his ingenuity in devising new and startling methods of making gas attacks4 ,a well known trick with the ,german was to fire gases for several days1 particularly against green troops1 in concentrations so slight as to do no harm4 ,when he felt that he had lulled those troops to a sense of the ineffectiveness of his gas1 he sent over a deadly concentration4 ,in spite of the warning that this was what was happening1 he often achieved too great a success4 ,before the war closed1 however1 the ,american was beginning to out-think and out-wit the ,german in this method of warfare4 ,,mustard ,,gas ,,burns ,with the advent of mustard gas which burned the body1 a new and serious difficulty in protection arose4 ,at first it was thought mustard gas burned only when the liquid from the bursting shell actually splashed on the clothing or skin4 ,this was unfortunately soon found to be not true4 ,the gas itself rapidly penetrates clothing and burns the skin even when the concentration of the gas is very low4 ,probably the majority of burns from mustard gas arose from concentrations of gas consisting of less than one part of gas to five hundred thousand of air4 ,furthermore1 the gas is fully fifty per cent cumulative in its effects1 that is1 in extremely low concentrations over a period of hours it will produce more than fifty per cent the effect that a far higher concentration would produce in a relatively shorter time4 ,the ,allies were not long in discovering that oilcloth afforded very complete protection against mustard gas4 ,the ordinary oilcloth1 however1 was too thick1 too hot and too heavy for general use4 ,experiments soon showed that cloth thoroughly impregnated with boiled linseed oil would give protection4 ,in order to make this protection more perfect a certain amount of paraffin was added4 ,all this made the clothing air-tight1 rather stiff and always uncomfortable4 ,notwithstanding these discomforts1 hundreds of thousands of oiled suits1 and as many pairs of oiled gloves were made and issued to artillery troops1 and to troops especially charged with handling mustard gas shells1 or to those employed in destroying mustard gas in shell holes by spreading chloride of lime over them4 ,the importance of protection against mustard gas burns led to extensive researches being made with a view to finding a cloth which would be comfortable and porous and while stopping mustard gas would yet be sufficiently durable and comfortable to be issued to infantry troops as well as to artillery and other special troops4 ,this1 it is understood1 had been achieved1 just prior to the ,armistice4 ,still more desirable would be the discovery of a chemical substance which could be applied to all uniforms and ,army clothing and thus protect the regulation clothing against the penetration of mustard gas1 and thereby avoid carrying extra clothing for that special purpose4 ,,protecting ,,troops ,,by ,,moving ,,them ,,from ,,infected ,,areas ,as soon as it was fully realized that mustard gas persisted for several days it was decided to run complete reliefs of men into and out of areas that had been heavily shelled with mustard gas1 or better still1 where practicable1 to completely evacuate the area4 ,inasmuch as the gas is dangerous to friend and foe alike1 this method was comparatively safe and was used to a very considerable extent4 ,with the warfare of movement that existed over most of the active front throughout the season of #aiah1 this moving of troops out of infected areas became highly important and1 when skillfully done1 often resulted in a great saving of troops and at the same time prevented the enemy from receiving any particular tactical advantage from his mustard gas attacks4 ,there was one very excellent example of this a few miles to the northwest of ,chteau-,thierry prior to the counter-offensive of ,july #ah1 #aiah4 ,at that time the ,germans heavily shelled with mustard gas four or five small woods and two or three villages4 ,it was necessary for the men to stay in these woods during the day1 as they afforded the only protection obtainable from machine guns1 shrapnel and high explosive4 ,at the time this occurred ,american gas officers generally understood the necessity of getting troops out of a mustard gas infected area4 ,accordingly all began searching for places safe from the mustard gas4 ,in one particular instance the gas officer of a regiment discovered that a portion of the woods his men were in was free from the gas1 and the regimental commander1 promptly following his advice1 moved his troops into the free area4 ,as a result of this prompt action the regiment had only four light gas casualties1 although all told there were several hundred mustard gas casualties in this attack1 the number per thousand generally being from ten to twenty times that of the thousand men just mentioned4 ,,mixing ,,poisonous ,,gases ,on this as well as other occasions the ,germans fired some diphosgene and ,blue ,cross 7,sneezing gas71 as well as mustard gas4 ,this added to the difficulty of determining areas free from the latter4 ,in the future such mixing of poisonous gases may always be expected and1 in addition1 gases which have no value other than that of masking the poisonous ones will be fired4 ,while with practically all gases except mustard gas a man is comparatively safe while breathing a concentration very noticeable to the sense of smell1 the only safe rule with mustard gas is to consider as dangerous any concentration that can be smelled4 ,for the reason that this gas persists longer in calm areas1 woods are always to be avoided1 where practicable1 and also1 since all gases1 being heavier than air1 tend to roll into depressions and valleys1 they should be avoided4 ,there have been a number of authentic cases where batteries in hollows or valleys suffered severely from mustard gas1 while troops on nearby knolls or ridges were comparatively free1 though the difference in the amount of shelling of the two places was not noticeable4 ,of great importance with all gases is the posting of a sufficient number of sentries around men sleeping within the range of gas shell4 ,the worst projector gas attack against the ,americans was one where the projectors were landed among a group of dugouts containing men asleep without sentries4 ,the result was a very heavy casualty list1 coupled with a high death rate1 the men being gassed in their sleep before they were awakened4 ,,destruction ,,of ,,mustard ,,gas ,prior to the introduction of mustard gas all that was necessary to get rid of gas was to thoroughly ventilate the spot4 ,thus in trenches and dugouts1 fires were found to be very efficient1 simply because they produced a circulation of air4 ,in the early days1 among the ,british1 the ,ayrton fan1 a sort of canvas scoop1 was used to throw the gas out of the trenches4 ,while this was taken up in the ,american ,service1 it did not become very important1 since it was found that1 under ordinary atmospheric conditions1 natural ventilation soon carried the gas out of the trench proper1 while fires in dugouts were far more efficient than the fans4 ,likewise the ,ayrton fan smacked too much of trench warfare which had reached a condition of 8stalemate0--a condition that never appealed to the ,americans and a condition that it is hoped never will4 ,with mustard gas1 however1 conditions were entirely changed4 ,this liquid having a very high boiling point and evaporating very slowly1 remains for days in the earth and on vegetation and other material sprinkled with it4 ,this was particularly true in shell holes where the force of the explosion drove the gas into the earth around the broken edges of the hole4 ,while many substances were experimented with1 that which proved best and most practical under all conditions1 was chloride of lime4 ,this was used to sprinkle in shell holes1 on floors of dugouts and any other places where the liquid might be splashed from bursting shells4 ,it was also found very desirable to have a small box of this at the entrance to each dugout1 so that a person who had been exposed to mustard gas could thoroughly coat his shoes with it and thus kill the mustard gas that collected in the mud on the bottom and sides of his shoes4 ,,carrying ,,mustard ,,gas ,,on ,,clothing ,there are many instances where the occupants of dugouts were gassed from the gas on the shoes and clothing of men entering the dugout4 ,not only were occupants of dugouts thus gassed but a number of nurses and doctors were gassed while working in closed rooms over patients suffering from mustard gas poisoning4 ,even under the conditions of warfare existing where the ,americans were generally in action1 the quantity of chloride of lime required amounted to several hundred tons per month which had to be shipped from the ,united ,states4 ,chloride of lime was also very convenient to have at hand around shell dumps for the purpose of covering up leaky shells1 though rules for handling mustard gas shells usually prescribed that they be fired and where that was not practicable to bury them at least five feet under the surface of the ground4 ,this depth was not so much for the purpose of getting rid of the gas as it was to get the shell so deep into the ground that it would not be a danger in any cultivation that might later take place4 ,,mustard ,,gas ,,in ,,cold ,,weather ,much was learned toward the end of the war about ways of getting through or around areas infected with mustard gas4 ,for instance1 if mustard gas be fired when the weather is in the neighborhood of freezing or somewhat below1 it will remain on the ground at night with so little evaporation as not to be dangerous4 ,the same will be true during the day time if the weather is cloudy as well as cold4 ,if1 however1 the days are bright and the nights cold1 mustard gassed areas can be safely crossed by troops at night provided care is taken in brush and bushes to protect the feet and clothing from the liquid splashed on bushes4 ,if the sun comes out warm in the morning such areas may be quite dangerous for three to four hours following sun-up and indeed for the greater part of the day4 ,quite a large number of casualties were ascribed to this fact in the heavy attack on the ,british front west of ,cambrai just prior to the great ,german drive against ,amiens1 ,march #ba1 #aiah4 ,,degassing ,,units ,since mustard gas has a greatly delayed action it was found that if men who had been exposed to it could be given a thorough bath with soap and water within a half hour or even a full hour1 the mustard gas burns would be prevented or very greatly reduced in severity4 ,accordingly degassing units were developed consisting essentially of a #e ton truck with a #abjj gallon water tank1 fitted with an instantaneous heater and piping to connect it to portable shower baths4 ,another truck was kept loaded with extra suits of underclothing and uniforms4 ,these degassing units were to be provided at the rate of two per division4 ,then1 in the event of a mustard gas attack anywhere in the division1 one of these units would be rushed to that vicinity and the men brought out of the line and given a bath and change of clothing as soon as possible4 ,at the same time they were given a drink of bicarbonate of soda water and their eyes1 ears1 mouth and nasal passages washed with the same4 ,,protecting ,,food ,,from ,,mustard ,,gas ,it was very early learned that mustard gas1 or minute particles of the liquid gas settling on food1 caused the stomach to be burned if the food were eaten1 just as the eyes1 lungs and skin of the body are burned from gas in the air4 ,this made it necessary then to see that all food liable to exposure to mustard gas attacks was protected1 and tarred paper for box linings or tops was found by the ,gas ,service to furnish one of the cheapest and most available means of doing this4 ,,alarm ,,signals ,numerous1 indeed1 were the devices invented at one time or another with which to sound gas alarms4 ,the ,english early devised the ,strombos horn1 a sort of trumpet operated by compressed air contained in cylinders carried for that purpose4 ,its note is penetrating and can be heard1 under good conditions1 for three or four miles4 ,when cloud gas attacks1 which occurred only at intervals of two to four months1 were the only gas attacks to be feared1 it was easy enough to provide for alarm signals by methods as cumbersome and as technically delicate as the ,strombos horn4 ,with the advent of shell gas in general1 and mustard gas in particular1 the number of gas attacks increased enormously4 ,this made it not only impossible1 but inadvisable also1 to furnish sufficient ,strombos horns for all gas alarms1 as gas shell attacks are comparatively local4 ,in such cases1 if the ,strombos horn is used to give warning1 it causes troops who are long distances out of the area attacked to take precautions against gas with consequent interference with their work or fighting4 ,to meet these local conditions metal shell cases were first hung up and the alarm sounded on them4 ,later steel triangles were used in the same way4 ,at a still later date the large policeman's rattle1 well known in ,europe1 was adopted and following that the ,klaxon horn4 ,as the warfare of movement developed the portability of alarm apparatus became of prime importance4 ,for those reasons the ,klaxon horn and the police rattle were having a race for popularity when the ,armistice was signed4 ,a recent gas alarm invention that gives promise is a small siren-like whistle fired into the air like a bomb4 ,it is fitted with a parachute which keeps it from falling too rapidly when the bomb explodes and sets it free4 ,its tone is said to be very penetrating and to be quite effective over an ample area4 ,since future gas alarm signals must be efficient and must be portable1 the lighter and more compact they can be made the better2 hence the desirability of parachute whistles or similar small handy alarms4 ,,issuing ,,new ,,masks ,one of the problems that remained unsolved at the end of the war was how to determine when to issue new boxes1 or canisters1 for masks4 ,one of the first questions asked by the soldier is how long his mask is good in gas1 and how long when worn in drill where there is no gas4 ,this information is of course decidedly important4 ,obviously1 however1 it is impossible to tell how long a canister will last in a gas attack1 unless the concentration of gas is known--that is1 the life of the box is longer or shorter as the concentration of gas is weak or heavy4 ,a realization of this need led mask designers to work very hard1 long before the necessity for comfort in a mask was as fully realized as it was at the end of the war1 to increase the length of life of the canister4 ,to get longer life they increased the chemicals and this in turn increased the breathing resistance1 thereby adding to the discomfort of the soldier when wearing the mask4 ,finally1 however1 it was found that in the concentration of gas encountered on an average in the field1 the life of the comparatively small ,american boxes was sufficient to last from fifty to one hundred hours1 which is longer than any gas attack or at least gives time to get out of the gassed area4 ,the ,british early appreciated the necessity of knowing when boxes should be replaced4 ,they accordingly devised the scheme of furnishing with each mask a very small booklet tied to the carrying case in which the soldier could not only enter a complete statement of the time he had worn the mask but also the statement as to whether it was in gas or for drill purposes only4 ,the soldier was then taught that if he had worn the mask1 say for forty hours1 he should get a new box4 ,but the scheme didn't work4 ,in fact1 it was one of those things which foresight might have shown wouldn't work4 ,indeed1 any man who in the hell of battle can keep such a record completely1 should be at once awarded a ,distinguished ,service ,medal4 ,as gas warfare developed not only were all kinds of gas shells sent over in a bunch but they were accompanied by high explosive1 shrapnel and anything else in the way of trouble that the enemy possessed4 ,a man near the front line1 under those conditions1 had all he could do and frequently more than he could do1 to get his mask on and keep it on while doing his bit4 ,consequently he had no time1 even if he had the inclination1 to record how long he had the mask in the various gases4 ,in this connection1 after the ,armistice was signed we in the field were requested to obtain for experimental purposes #aj1jjj canisters that had been used in battle4 ,each was to be labeled with the length of time it had been worn in or out of gas1 and if in gas1 the name of each gas and the time the mask was worn in it4 ,this request is just a sample of what is asked by those who do not realize field conditions4 ,one trip to the front would have convinced the one making the request of the utter impossibility of complying with it1 for really no man knows how long he wears a mask in gas4 ,with gas as common and as difficult to detect 7when intermingled with high explosive gases and other smells of the battle field7 as it was at the end of the war1 each man wore the mask just as long as he could1 simply as a matter of precaution4 ,before hostilities ceased we were trying out a method of calling in say fifty canisters per division once a week for test in the laboratory4 ,if the tests showed the life of the canisters to be short new canisters would be issued4 ,while we did not have opportunity to try out this plan1 it gave promise of being the best that could be done4 ,with gas becoming an every day affair1 the only other alternative would seem to be to make issues of new boxes at stated intervals4 ,on the other hand there are no definite records of casualties occurring from the exhaustion of the chemicals in the box4 ,undoubtedly some did occur1 but they were very1 very few4 ,in nearly all cases the masks got injured1 or the box became rusted through before the chemicals gave out4 ,,tonnage ,,and ,,number ,,of ,,masks ,,required ,it will probably be a shock to most people to learn that with more than two million men in ,france we required nearly #aejj tons of gas material per month4 ,this tonnage was increasing1 rather than decreasing1 to cover protective suits1 gloves1 pastes1 and chloride of lime1 as well as masks4 ,the ,british type respirator was estimated to last from four to six months4 ,the active part of the war1 in which the ,americans took part1 was too short to determine whether this was correct or not4 ,the indications were1 however1 that it was about right1 considering rest periods and fighting periods4 ,with the new ,american mask1 with its much stronger and stiffer face material1 the chances are that the life will be considerably increased although the more constant use of the mask will probably offset its greater durability4 ,a longer life of mask would of course be a decided advantage as it would not only reduce tonnage1 but would reduce manufacturing and distribution as well4 ,the estimates on which we were working at the end looked forward to requiring from the ,united ,states about one-third pound per man per day for all troops in ,france1 in order to keep them supplied with gas defense material and with the gases used offensively by gas troops4 ,all gas shell1 hand grenades1 etc41 used by other than gas troops required tonnage in addition to the above4 ,,summing ,,up ,in summing up then1 it is noted that there are several important things in defense against gas4 ,first1 the mask which protects the eyes and the lungs4 ,second1 the training that teaches the man how to utilize to best advantage the means of protection at his disposal1 whether he be alone or among others4 ,third1 protective clothing that protects hands and feet and the skin in general4 ,fourth1 a knowledge of gases and their tactical use that will enable commanders1 whenever possible1 to move men out of gas infected areas4 ,fifth1 training in the offensive use of gas1 as well as in defensive methods1 to teach the man that gas has no uncanny power and that it is simply one element of war that must be reckoned with1 thus preventing stampedes when there is really no danger4 ,while these are the salient points in defense against gas1 above them and beyond them lies the vigorous offensive use of gas4 ,this involves not only the research1 development and manufacture of necessary gases in peace time1 but also the necessary training to enable our nation to hurl upon the enemy on the field of battle chemical warfare materials in quantities he cannot hope to attain4 ,,chapter ,,xxv ,,peace ,,time ,,uses ,,of ,,gas 8,peace hath her victories no less renowned than war40 ,thus runs the old proverb4 ,in ancient times war profited by peace far more than peace profited by war if indeed the latter ever actually occurred4 ,the implements developed for the chase in peace became the weapons of war4 ,this was true of ,david's sling-shot1 of the spear and of the bow4 ,even powder itself was probably intended and used for scores of years for celebrations and other peaceful events4 ,the ,world ,war reversed this story1 especially in its later phases4 ,the greater part of the war was fought with implements and machines prepared in peace either for war or for peaceful purposes4 ,such implements were the aeroplane1 submarine1 truck1 automobile and gasoline motors in general4 ,the first gas attack1 which was simply an adaptation of the peacetime use of the chemical chlorine1 inaugurated the change4 ,gas was so new and instantly recognized as so powerful that the best brains in research among all the first class powers were put to work to develop other gases and other means of projecting them upon the enemy4 ,the result was that in the short space of three and one-half years a number of substances were discovered1 or experimented with anew1 that are aiding today and will continue to aid in the future in the peaceful life of every nation4 ,chlorine is even more valuable than ever as a disinfectant and water purifier4 ,it is the greatest bleaching material in the world1 and has innumerable other uses in the laboratory4 ,chloropicrin1 cyanogen chloride and cyanogen bromide are found to be very well adapted to the killing of weevil and other similar insect destroyers of grain4 ,hydrocyanic acid gas is the greatest destroyer today of insect pests that otherwise would ruin the beautiful orange and lemon groves of ,california and the ,south4 ,illustration3 ,,fig4 #abj4 ,phosgene1 so extensively used in the war both in cloud gas and in shell1 is finding an ever increasing use in the making of brilliant dyes--pinks1 greens1 blues and violets4 ,on account of its cheapness and simplicity of manufacture1 it has great possibilities in the destruction of rodents such as rats around wharves1 warehouses and similar places that are inaccessible to any other means of reaching those pests4 ,since phosgene is highly corrosive of steel1 iron1 copper and brass1 it cannot be used successfully in places where those metals are present4 ,instead of phosgene for killing rodents and the like in storehouses and warehouses1 cyanogen bromide has been developed4 ,this is a solid and can be burned like an ordinary sulphur candle4 ,it is much safer for the purpose of fumigating rooms and buildings than is hydrocyanic acid gas when so used4 ,this is for the reason that cyanogen bromide is an excellent lachrymator in quantities too minute to cause any injury to the lungs4 ,it will thus give warning to anyone attempting to enter a place where some of the gas may still linger4 ,among tear gases1 the new chloracetophenone1 a solid1 is perhaps the greatest of all4 ,when driven off by heat it first appears as a light bluish colored cloud4 ,this cloud is instantly so irritating to the eyes that within a second anyone in the path of the cloud is temporarily blinded4 ,it causes considerable smarting and very profuse tears which even in the smallest amount continue for two to five minutes4 ,in greater quantities it would continue longer4 ,so far as can be ascertained1 it is absolutely harmless so far as any permanent injuries are concerned4 ,considering that it is instantly effective1 that minute quantities are unbearable to the eyes1 that it can be put in hand grenades or other small containers and driven off by a heating mixture which will not ignite even a pile of papers1 and that it needs no explosion to burst the grenade 7all that is used is a light cap1 set off by the action of the spring1 sufficient to ignite the burning charge71 the future will see every police department in the land outfitted with chloracetophenone or other similar grenades4 ,every sheriff's office1 every jail and every penitentiary will have a supply of them4 ,no jail breaking1 no lynching1 no rioting can succeed where these grenades are available4 ,huge crowds can be set to weeping instantly so that no man can see and no mob will continue once it is blinded with irritating tears4 ,more than that1 it is an extremely difficult gas to keep out of masks1 ordinary masks of the ,world ,war being entirely useless against it4 ,the same is true of diphenylaminechlorarsine4 ,this is not a tear gas but it is extraordinarily irritating to the lungs1 throat and nose1 where it causes pains and burning sensations1 and in higher concentrations vomiting4 ,it is hardly poisonous at all so that it is extremely difficult to get enough to cause danger to life4 ,this is mentioned because of its possible use for the protection of bank vaults1 safes1 and strong rooms generally4 ,there are many other gases that can be used for this same purpose4 ,it is presumed that gases that are not powerful enough to kill are the ones desired1 and there are half a dozen at least that can be so used4 ,if desired deadly gases can just as readily be used4 ,already a number of inventors are at work on the problem1 with some plans practically completely worked out and models made4 ,it has been suggested that one of these gases could be used by trappers in trapping wild animals4 ,hydrocyanic acid gas may be so used4 ,it acts quickly and is very rapidly dissipated4 ,an animal exposed to the fumes would die quickly and the trap be safe to approach within two minutes after it was sprung4 ,it is said that the loss from animals working their way out of traps by one means or another is nearly #bj per cent4 ,more than this1 it would meet the objections of the ,s4 ,p4 ,c4 ,a4 in that the animal would not suffer from having its limbs torn and lacerated by the trap4 ,attempts are being made to attack the locust of the ,philippines and the far west and the boll weevil of the cotton states of the ,south4 ,so far these tests have not proven more successful than other methods1 but inasmuch as the number of gases available for trial are so great and the value of success of so much importance1 this research should be continued on a large scale to definitely determine whether poisonous gas can be used to eradicate these pests--especially the boll weevil4 ,as an interesting application of war materials to peaceful uses1 we may consider the case of cellulose-acetate1 known during the war as 8aeroplane dope10 the material used to coat the linen covering aeroplane wings4 ,with a little further manipulation1 this cellulose-acetate1 or aeroplane dope1 becomes artificial silk--a silk that today is generally equal to the best natural silk--and which promises in the future to become a standard product better in every way than that from the silk worm4 ,illustration3 ,,fig4 #aba4 ,these few examples of the peacetime value of gas are worthy of thought from another standpoint4 ,being so valuable1 their use in peace will not be stopped4 ,if they are thus manufactured and used in peace1 they will always be available for use in war1 and as the experience of the ,world ,war proved1 they certainly will be so used even should anybody be foolish enough to try to abolish their use4 ,as for this latter idea1 the world might as well recognize at once that half-way measures in war simply invite disaster4 ,this chapter would not be complete without a brief statement of the necessity of a thoroughly developed chemical industry in the ,united ,states as a vital national necessity if the ,united ,states is to have real preparedness for a future struggle4 ,as will be indicated a little later1 no one branch of the chemical industry can be allowed to go out of existence without endangering some part of the scheme of preparedness4 ,let us consider first the coal tar industry4 ,coal tar is a by-product of coke ovens or the manufacture of artificial gas from coal4 ,the coal tar industry is of the utmost importance because in the coal tars are the bases of nearly all of the modern dyes1 a large percentage of the modern medicines1 most of the modern high explosives1 a large proportion of poisonous gases1 modern perfumes1 and photographic materials4 ,a consideration of these titles alone shows how vital the coal tar industry is4 ,the coal tar as it comes to us as a by-product is distilled1 giving off at different temperatures a series of compounds called crudes4 ,ten of these are of very great importance4 ,the first five are benzene1 toluene1 naphthalene1 anthracene and phenol 7carbolic acid74 ,the second group comprises xylene1 methylanthracene1 cresol1 carbazol and phenanthrene4 ,these1 when treated with other chemicals1 produce a series of compounds called intermediates1 of which there are some #cjj now known4 ,from these intermediates by different steps are produced either dyes1 high explosives1 poisonous gases1 pharmaceuticals1 perfumes or photographic materials4 ,we have all heard that ,germany controlled the dye industry of the world prior to the ,world ,war4 ,a little study of the above brief statement of what is contained in the coal tar industry along with dyes will show in a measure one of the reasons why ,germany felt that she could win a war against the world4 ,that she came so desperately close to winning that war is proof of the soundness of her view4 ,in many of the processes are needed the heavy chemicals such as chlorine1 sulfuric acid1 nitric acid1 hydrochloric acid and the like4 ,the alcohol industry is also of very great importance4 ,grain alcohol is used extensively in nearly all research problems and in very great quantities in many commercial processes such as the manufacture of artificial silk and for gasoline engines in addition to its use in compounding medicines4 ,it is of very great importance to the ,chemical ,warfare ,service in that from grain alcohol is obtained ethylene gas1 one of the three essentials in the manufacture of mustard gas4 ,while this ethylene may be obtained from many sources1 the most available source1 considering ease of transportation and keeping qualities1 is in the form of grain alcohol4 ,allied to the chemical industries just mentioned is the nitrate industry for making nitric acid from the nitrogen of the air4 ,nitrates are used in many processes of chemical manufacture and particularly in those for the production of smokeless powders4 ,the fertilizer industry is of large importance because it deals with phosphorus1 white phosphorus being not only one of the best smoke producing materials but a material that is1 as stated elsewhere1 of great use against men through its powerful burning qualities4 ,another point not mentioned above in connection with these industries is the training of chemists1 chemical engineers and the building up of plants for the manufacture of chemicals1 all of which are necessary sources of supply for wartime needs4 ,chemists are needed in the field1 in the laboratory and in manufacturing plants4 ,the greater their number1 the more efficiently can these materials be handled1 and since chemicals as such will probably cause more than #ej per cent of all casualties in future wars1 their value is almost unlimited4 ,instead of trying to ameliorate the ravages of war1 let us turn every endeavor towards abolishing all war1 remembering that the most scientific nations should be the most highly civilized1 and the ones most desirous of abolishing war4 ,if those nations will push every scientific development to the point where by the aid of their scientific achievements they can overcome any lesser scientific peoples1 the end of war should be in sight4 ,however1 we can never be certain that war is abolished until we convince at least a majority of the world that war is disastrous to the conqueror as well as to the conquered1 and that any dispute can be settled peacefully if both parties will meet on the common ground of justice and a square deal4 ,,chapter ,,xxvi ,,the ,,future ,,of ,,chemical ,,warfare ,the pioneer1 no matter what the line of endeavor1 encounters difficulties caused by his fellow-men just in proportion as the thing pioneered promises results4 ,if the promise be small1 the difficulties usually encountered are only those necessary to make the venture a success4 ,if1 however1 the results promise to be great1 and especially if the rewards to the inventor and those working with him promise to be considerable1 the difficulties thrown in the way of the venture become greater and greater4 ,indeed whenever great results are promised1 envy is engendered in those in other lines whose importance may be diminished1 or who are so short-sighted as to be always opposed to progress4 ,chemical warfare has had1 and is still having1 its full share of these difficulties4 ,from the very day when chlorine1 known to the world as a benign substance highly useful in sanitation1 water purification1 gold mining and bleaching was put into use as a poisonous gas1 chemical warfare has loomed larger and larger as a factor to be considered in all future wars4 ,chlorine was first used in the cylinders designed for shipping it4 ,these cylinders were poorly adapted for warfare1 and made methods of preparing gas attacks extremely laborious1 cumbersome and time-consuming4 ,it was not many months1 however1 until different gases began to appear in large quantities in shells and bombs1 while the close of the war1 #c years later1 saw the development of gas in solid form whereby it could be carried with the utmost safety under all conditions--a solid which could become dangerous only when the heating mixture1 that freed the gas1 was properly ignited4 ,while some of the chemicals developed for use in war prior to the ,armistice have been made known to the world1 a number of others have not4 ,more than this1 every nation of first class importance has continued to pursue more or less energetically studies into chemical warfare4 ,these studies will continue1 and we must expect that new gases1 new methods of turning them loose1 and new tactical uses will be developed4 ,already it is clearly foreseen that these gases will be used by every branch of the ,army and the ,navy4 ,while chemicals were not used by the ,air ,service in the last war1 it was even then realized that there was no material reason why they should not have been so used4 ,that they will be used in the future by the ,air ,service1 and probably on a large scale1 is certain4 ,the ,navy1 too1 will use gases1 and probably on a considerable scale4 ,thus chemical materials as such become the most universal of all weapons of war4 ,some of the poisonous gases are so powerful in minute quantities and evaporate so slowly that their liberation does not produce sufficient condensation to cause a cloud4 ,consequently1 we have gases that cannot be seen4 ,others form clouds by themselves1 such1 for instance1 as the toxic smoke candle1 where the solid is driven off by heating1 while still others cause clouds of condensed vapor4 ,this brings the discussion into the realm of ordinary smokes that have no irritating and no poisonous effects4 ,these smokes are extremely valuable where the purpose is to form a screen1 whether it be to hide the advance of troops or to cut off the view of observers4 ,these smokes are equally useful on land and on sea4 ,so great is the decrease in efficiency of the rifle or machine gun1 and of artillery even when firing at troops that cannot be seen1 that smoke for screening purposes will be used on every future field of battle4 ,when firing through a screen of smoke1 a man has certainly less than one-quarter the chance to hit his target that he would have were the target in plain view4 ,since smoke clouds may or may not be poisonous and since smoke will be used in every battle1 there is opened up an unlimited field for the exercise of ingenuity in making these smoke clouds poisonous or non-poisonous at will4 ,it also opens up an unlimited field for the well-trained chemical warfare officer who can tell in any smoke cloud whether gas be present and whether1 if present1 it is in sufficient concentration to be dangerous4 ,at the risk of repetition1 it is again stated that there is no gas that will kill or even permanently injure in any quantity that cannot be detected4 ,for every gas1 there is a certain minimum amount in each cubic foot of air that is necessary to cause any injury4 ,in nearly all gases1 this minimum amount is sufficient to be readily noticeable by a trained chemical warfare officer through the sense of smell4 ,it would be idle to attempt to enumerate the ways and means by which chemicals will be used in the future4 ,in fact1 one can hardly conceive of a situation where gas or smoke will not be employed1 for these materials may be liquids or solids that either automatically1 upon exposure to the air1 turn into gas1 or which are pulverized by high explosive1 or driven off by heat4 ,this varied character of the materials enables them to be used in every sort of artillery shell1 bomb or other container carried to the field of battle4 ,some of the gases are extremely powerful as irritants to the nose and throat in very minute quantities1 while at the same time being highly poisonous in high concentrations4 ,diphenylchloroarsine1 used extensively by the ,germans in high explosive shell1 is more poisonous than phosgene1 the most deadly gas in general use in the past war4 ,in addition1 it has the quality of causing an intolerable burning sensation in the nose1 throat1 and lungs1 in extremely minute quantities4 ,this material can be kept out of masks only by filters1 whereas true gases are taken out by charcoal and chemical granules4 ,there is still another quality which helps make chemical warfare the most powerful weapon of war4 ,gas is the only substance used in war which can be counted on to do its work as efficiently at night as in the daytime4 ,indeed1 it is often more effective at night than in the daytime1 because the man who goes to sleep without his mask on1 who is careless1 who loses his mask1 or who becomes excited in the darkness of night1 becomes a casualty1 and the past war showed that these casualties were decidedly numerous even when the troops knew almost to the minute the time the gas would arrive4 ,accordingly1 chemical warfare is an agency that must not only be reckoned with by every civilized nation in the future1 but is one which civilized nations should not hesitate to use4 ,when properly safe-guarded with masks and other safety devices1 it gives to the most scientific and most ingenious people a great advantage over the less scientific and less ingenious4 ,then why should the ,united ,states or any other highly civilized country consider giving up chemical warfare8 ,to say that its use against savages is not a fair method of fighting1 because the savages are not equipped with it1 is arrant nonsense4 ,no nation considers such things today4 ,if they had1 our ,american troops1 when fighting the ,moros in the ,philippine ,islands1 would have had to wear the breechclout and use only swords and spears4 ,notwithstanding the opposition of certain people who1 through ignorance or for other reasons1 have fought it1 chemical warfare has come to stay1 and just in proportion as the ,united ,states gives chemical warfare its proper place in its military establishment1 just in that proportion will the ,united ,states be ready to meet any or all comers in the future1 for the ,united ,states has incomparable resources in the shape of the crude materials--power1 salt1 sulfur and the like--that are necessary in the manufacture of gases4 ,if1 then1 there be developed industries for manufacturing these gases in time of war1 and if the training of the army in chemical warfare be thorough and extensive1 the ,united ,states will have more than an equal chance with any other nation or combination of nations in any future war4 ,it is just as sportsman-like to fight with chemical warfare materials as it is to fight with machine guns4 ,the enemy will know more or less accurately our chemical warfare materials and our methods1 and we will have the same information about the enemy4 ,it is thus a matching of wits just as much as in the days when the ,knights of the ,round ,table fought with swords or with spears on horseback4 ,the ,american is a pure sportsman and asks odds of no man4 ,he does ask1 though1 that he be given a square deal4 ,he is unwilling to agree not to use a powerful weapon of war when he knows that an outlaw nation would use it against him if that outlaw nation could achieve success by so doing4 ,how much better it is to say to the world that we are going to use chemical warfare to the greatest extent possible in any future struggle4 ,in announcing that we would repeat as always that we are making these preparations only for defense1 and who is there who dares question our right to do so8 ,,index ,absorbents1 ,requirements of1 #bcg ,testing1 #bei ,absorptive activity1 #bcg ,absorptive capacity1 #bch ,aeroplane1 ,smoke screen1 #cji ,american ,tissot mask1 #bbd ,ammonia canister1 #bcj ,ammonium chloride smoke1 #cbg ,animals1 ,susceptibility to mustard gas1 #agc ,anthracite coal1 ,activation of1 #bdi ,a4 ,r4 ,s4 mask1 #bjc ,arsenic derivatives1 #ahj ,arsenic trichloride1 ,manufacture1 #ahj ,arsenic trifluoride1 ,manufacture1 #ahj ,arsine1 proposed use of1 #ahj ,artillery1 ,gas1 use of1 by1 #cif ,aviation1 ,gas1 use of1 by1 #chj1 #cii ,baby ,incendiary bomb1 #cdj ,barrages1 ,gas1 use of1 in1 #cgf ,benzyl bromide1 #af1 #ada ,benzyl chloride1 #af ,berger mixture1 #bij ,black signal smokes1 #cca ,black veiling respirator1 #aie ,blue cross4 ,see ,diphenylchloroarsine ,blue pencil1 ,german1 #cdf ,bombs1 incendiary1 #ccg ,box respirator1 ,american1 #bji ,english1 #aih ,break point of canisters1 #bfb ,bromoacetone1 #af1 #ach ,german manufacture1 #adj ,bromobenzyl cyanide1 #af1 #adb ,bromomethylethyl ketone1 ,german manufacture1 #adj ,bullets1 incendiary1 #cdd ,camouflage gases1 #bc1 #daf ,canister1 life of1 ,gas concentration and1 #acb ,temperature1 effect of1 #acb ,testing1 #bfj ,carbon dioxide1 ,manufacture1 #abi ,carbonite1 #bej ,carbon monoxide1 #aij ,canister1 #aia ,manufacture1 #abh ,cavalry1 ,gas1 use of1 by1 #cgh ,cement1 ,soda-lime1 function in1 #beg ,charcoal1 #bci ,active1 #bdb ,german1 #bea ,inactive1 #bdb ,manufacture1 #bdb ,raw material1 #bci ,substitutes1 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attack10 #aj ,first gas regiment1 #ic ,flammenwerfer1 #cdi ,flaming gun1 #cdg1 #dja ,food1 protection of1 against mustard gas1 #dbb ,french artillery mask1 #bjb ,gas1 ,defense against1 #dje ,effectiveness of1 #cge1 #che ,humanity of1 #ac1 #cgj1 #chg ,offensive use of1 #che ,permanency of1 #cgh ,requirements of1 #aaf1 #cie ,gas alarms1 #dbb ,gas cloud1 height and spread1 #cid ,smoke in1 #caa1 #djc ,gas cylinder1 ,mobile1 #ag ,gas defense division1 ,c4 ,w4 ,s41 #dh ,gases1 ,detection of1 #dae ,peace uses of1 #dbg ,pharmacology1 #cec ,gas and ,flame ,regiment1 #cd ,gas mask1 ,development1 #aie ,physiological features1 #bcb ,testing1 #bei ,see also names of various masks ,gas shell1 ,markings1 #bh1 #djd ,value1 #ah1 #cif ,gassing chamber1 #ced ,gas training1 #dac ,in ,france1 #ha ,value in peace1 #cgc1 #chc ,gas warfare1 ,fundamentals1 #chh ,humanity1 #ac1 #cgj1 #chg ,german mask1 #bje ,greasene1 #bja ,green ,cross shell1 #adh ,green ,t-,stoff1 #adb ,hand grenade1 incendiary1 #cde ,hanlon 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,man test1 #bfb ,martonite1 #af1 #ach ,mask1 ,development1 #dje ,disinfection1 #bfi ,field tests1 #bgj ,issuance1 #dbc ,see also ,gas mask ,see also ,names of masks ,mechanical dispersion1 #cac ,medical division1 ,c4 ,w4 ,s41 #fh ,medical section1 ,a4 ,e4 ,f41 #aad ,methyldichloroarsine1 #aha ,moisture1 ,absorbents1 tests of1 #bei ,mustard gas4 ,see ,dichloroethyl sulfide4 ,navy1 ,canister1 #bcj ,gas1 use of1 by1 #cha ,smoke funnel1 #cje ,nelson cell1 #aag 8,nineteen nineteen0 canister1 #cbe 8,nineteen nineteen0 ,model ,american ,mask1 #bbe ,odors1 ,testing of1 #ceh ,oleum1 ,smoke material1 use as1 #bhf ,overall suit1 #bgc ,palite4 ,see ,chloromethyl chloroformate ,penetration apparatus1 ,toxic smoke1 measurement of1 #cae ,p-,helmet1 #aig ,,ph ,helmet1 #aig ,phosgene1 #ad1 #abf ,manufacture1 #abg ,properties1 #acj ,protection1 #aca ,shell filling1 #acb ,tactical use1 #acd ,phosphorus1 ,smoke material1 #bhf1 #chb ,stokes' mortar1 use in1 #cic ,see also ,smoke ,physiological action1 ,phosgene1 #ace ,mustard gas1 #afh ,toxic ,smokes1 #caf ,pressure drop apparatus1 #bff ,protective clothing1 #bgb ,protective gloves1 #bgd ,protective ointments1 #bge ,proving division1 ,c4 ,w4 ,s41 #fc ,pumice stone1 ,phosgene shell1 use in1 #acj1 #ace ,research division1 ,c4 ,w4 ,s41 #ch ,resistance1 ,canister1 test of1 #bfa ,decreased1 #daj ,respirator1 ,see ,gas mask1 ,mask ,sag paste1 #bgg ,screening smokes1 #bhe ,see also ,smoke ,screening power1 ,smoke cloud1 #bhe ,selenious acid1 ,mustard gas detector1 #aff ,shell1 ,gas1 ,filling of1 #acb ,value1 #ah1 #cif ,incendiary1 #cdd ,markings1 #bh1 #djd ,pumice stone and phosgene in1 #acj1 #ace ,smoke1 #cjc ,ships1 ,screening ,smoke1 #bii1 #cje ,shrapnel1 ,gas in connection with1 #cgi ,signal smokes1 #ccj ,tactics1 #ccc ,silicon tetrachloride1 ,smoke material1 use as1 #bij ,smoke1 ,intensity1 measurement of1 #bif ,tactical value1 #caj1 #djb ,use in offense1 #dja ,see also1 ,screening1 ,signal and ,toxic ,smokes ,smoke box1 #bii ,smoke candle1 #cja1 #cgb ,toxic1 #cah ,smoke cloud1 ,properties1 #aaf1 #bhe1 #cie ,smoke drum1 #cjd ,smoke filters1 #cbb ,felt1 #cbd ,paper1 #cbc ,testing1 #cbg ,theory1 #cbf ,smoke funnel1 #cje ,smoke grenade1 #cjb ,smoke knapsack1 #cjf ,smoke particles1 ,measurement of1 #bib ,size of1 #bia ,smoke screen1 ,purpose of1 #cji ,smoke shell1 #cjc1 #cjg ,smoke signals1 #ccc ,sneezing gas4 ,see ,diphenylchloroarsine ,soda-lime1 ,composition1 #bef ,requirements1 #bee ,sodium hydroxide1 ,soda-lime1 function in1 #beg ,sodium permanganate1 ,soda-lime1 function in1 #beg 8,solid oil01 #ccf ,spray nozzles1 #ceg ,staff troops1 ,c4 ,w4 ,s41 #ib ,standard ,box respirator1 #aih ,stokes' mortar1 #bj1 #cib ,sulfur chloride1 ,manufacture1 #aeg ,sulfuric acid smoke1 #cbh ,sulfur trioxide1 ,smoke material1 use as1 #bhi ,superpalite4 ,see ,trichloromethyl chloroformate ,tactical use1 ,chloropicrin1 #adh ,dichloroethyl sulfide1 #age1 #dag ,gases in offense1 #che ,incendiary materials1 #djb ,lachrymatory shell1 #ae ,phosgene1 #acd ,screening smokes1 #caj1 #djb ,signal smokes1 #ccc ,tactics1 ,chemical ,warfare and1 #cfc ,tanks1 ,smoke screen for1 #cji ,thermal dispersion1 #cac ,thermit1 ,uses1 #cic ,tin tetrachloride1 ,smoke material1 use as1 #bhi ,tissot mask1 #bjb ,titanium tetrachloride1 ,smoke material1 use as1 #bij ,tobacco smoke1 #cbh ,total obscuring power of smoke1 #bie ,touch method1 ,irritants1 testing of1 #cfb ,toxicity1 ,gases1 testing of1 for1 #cec ,toxic smoke1 #cac ,candle1 ,b4 ,m41 #cai ,candle1 ,dispersoid1 #cbj ,penetration1 #cad ,quantitative relationship1 #caf ,training division1 ,c4 ,w4 ,s41 #fe ,trench mortar1 #bj1 #cib ,trichloromethyl chloroformate1 #bj ,trichloronitromethane4 ,see ,chloropicrin 1 1 -,trichlorotrivinylarsine1 #ahi ,t-,stoff1 #ada ,tyndall meter1 #bii ,ultramicroscope1 ,smoke particles1 measurements of1 #bib ,vapor tests1 ,irritants1 testing of1 #cei ,versatility of absorbents1 #bch ,vincennite1 #ae1 #ahj ,vision chart1 #bga 8,vomiting gas40 ,see ,chloropicrin ,war gas4 ,see ,gases ,war1 humanity of1 #f ,wave attack1 ,disadvantages1 #af ,xylyl bromide1 #af1 #ada ,yellow cross4 ,see ,dichloroethyl sulfide ,yellow smoke1 #cca ,yperite4 ,see ,dichloroethyl sulfide