Chemistry in war

his remark^ and conclusions, still they will be an interesting standpoint from which to view the wreckage of World Var 11-for which he, 2JF years ago,...
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Chemistry in War' FRITZ HABER

(A

lecture before

the

officers of the

"Reichs?uehrministerium"on Nooember 11, 1920)

Editor's /Vote: The many circum.rtances surrounding the occupation gf Germany and the problems before u.r i n the adminihation of its internal afairs by representatives of the United AVaialionr will make the following article of more than mere historic interest. The remarks of D r . Fritz Haber before a group of German oficers just two years ajter the close of P o r l d F a r 1 illuminate some of the habits of thought of German minds, both military and civilian. Dr. Haber speaks as a civilian who, while respecgul toward the members of the military clicque, is not bound by the narrowness of their professional outlook. I r h i l e we will not altogether agree with his remark^ and conclusions, still they will be an interesting standpoint from which which he, 2JF years ago, apparently did to view the wreckage of World Var 11-for not expect to make preparations.

T

HIS lecture will be the first of a series dealing with the relation between the circle of military officers and the members of the scientific and technical professions. Since this relation is especially important in chemical warfare, the field of chemistry receives first place. War presents itself differently, depending upon our mental outlook. For the politician i t is a continuation of politics with other means; for the general it is the art of bringing his troops to the right place a t the right time in the necessary numbers. For the technologist it is a means of destroying the enemy or driving him out of his position with technical materials, which the soldier uses. The thought of Count Schlieffen, clearly expressed in the writings of this extraordinary man, agrees with the second definition, that of troop command. In this spirit the officer corps of our army was admirably educated. The natural scientific-technical comprehension, on the other hand, was left far behind, for an illuminating reason. Schlieffen pointed i t out 11 years ago in his essay on war. In principle, there is a clear possibility of one side throwing into the scales of war a deciding weight in the form of technical development of arms. If Frederick the Great could have put into the field against his enemy of 1756 the artillery and machine guns of 1914 he could not have been conquered in seven years. But such differences in technology could not appear between crowded European peoples because of the armament race, the common effort for the utilization of technical developments for national defense. Hence, the deciding factor had to remain the command of troops and not the art and number of weapons. Naturally, all technical questions in the conduct of war took second place. Every technical deficiency brought forth rebuke; adequate preparation and

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1 Translated from H ~ s w F ,-, " ~ i i n fvortr;lge, den Jahren 1920-1923," Verlag vou Julius Springer, Berlin, 1924.

manufacture brought forth commendation, but the center of gravity of the situation did not lie there. As illuminating as this distribution of the weight was, i t nevertheless did not lead to entirely adequate preparation for war. Two essential deficiencies developed. On Schlieffen's theory it is natural that the officer should take the same view of the procurement of weapons and war apparatus that the host a t a banquet does with regard to the table utensils. Such a host decides what he has and what he needs and orders what he lacks from the store, ascertaining what the store has to offer, picking out what is best suited, and arranging for delivery. But he does not go behind the supplier, to find out if the glass factory can make the glass which must be on his table a t the proper time, nor whether the silver and steel industries can deliver what is necessary if his knives and forks are to be ready on time. This situation is natural and never leads to trouble, since everything is supervised by the business world which is organized for the purpose. But with war preparations i t is quite diierent. No one but the officer investigates, especially before the advent of war. Hence the army administration has the problem not only of ordering weapons and equipment but a t the same time of making sure that the requirements can be met by industry. In this respect, we know, there appeared a gap. The intellect of the army, trained in the command of t~oops,lacked the technical imagination to appreciate the changing conduct of war with its technical developments. Without this imagination, preparation followed historic lines. The measure of the needs, and the methods of fulfilling them, were taken from the experience of the past, in which the technical requirements were different. When reality forced a change of view, immense effort brought only one result, which remained far behind in back of a well-prepared performance of the nation. Examples, . . as far as they can be taken from chemistry, will hepart of this lecture.

But something else also appeared. For 500 years, since firearms prevailed over the shield and sword, we have been learning how to increase thefiring speed and the force and penetration of the flying steel pieces with which the enemy is fought. Finally a point was reached a t which the conduct of war was practically revolutionized. These flying pieces of steel were very effec tive in the open field but were rather easily held back by earthen walls of moderate strength. This gave the defender a fundamental technical advantage over the attacker. The human body, with its two square meters of target area, could no longer reach a defended position without damage by the steel stream from machine guns and field artillery. The defender could not be put out of commission in his earthen dugout before the attack, since the flying pieces of steel did not reach him in sufficient quantity. It would have required mature scientific imagination to foresee this situation and to resort to the help made possible by technology. This solution is gas warfare. But we did not think of its possibilities before the war, only during it. It is a second field in which chemistry has accomplished only with immense effort that which could have easily been done if the means had been planned before the war. The lack of imagination was decisive in both cases. The insight which can foresee a situation outside the professional sphere cannot be expected in everybody. It was too much to expect from the professional officer; but since it was badly needed for war preparation and since no one was in a position to appreciate this more than the officer, there was just one thing necessary: cooperation between the officer, the scientist, and the technologist, so that the power of imagination and decision of the latter two could benefit the military preparation. But this cooperation was lacking. I n our land the general, the scientist, and the technical man lived under the same roof. They greeted each other on the steps. But there was no fruitful exchange of ideas between them before the war. What was the result? When the army leaders decided a t the beginning of the war to strike in one blow with the full power of the army, and not piecemeal, the bodies of the people were trained and ready for it. But the intellectual power of the nation was not prepared, and hence the plan, which could have given us a decided advantage, was ruined. And now let me go over it in detail and discuss two phases of the situation in the field of chemistry in the war: first the difficulty of obtaining powder and explosives, and then the problems of gas warfare. Powder and explosives: These are three materials (if we refer only to the main representatives and forget about the substitutes which we finally had to use in large measure), namely, nitrocellulose, nitroglycerin, and nitrotoluol; the first two are propellants and the last an explosive material. Nitrocellulose: A compound derived from cotton and nitric acid, two raw materials which we did not have before the war from local production. Cotton does not grow in our climate; nitric acid was made only from

saltpeter, which we imported exclusively from Chile. Nitroglycerin: A compound of nitric acid and glycerin, which is contained in all animal and plant fats, which can he split by chemical means into fatty acids and glycerin. We have animal oils and fats in the country-pig fat, goose fat, mutton grease, butter, and several others. But Germany has never had enough of them, for i t is a t the height of its industrial development and its population has increased enormously. Fatty oils were the most important import. When limited to our own sources of fat our nutrition suffered, even though no food fats were withdrawn for chemical uses. When fat was used for the preparation of glycerin we starved twice as much. Let us finally discuss explosive materials. Regarding nitrotoluol, we first meet nitric acid again, whose source is in foreign lands; then toluol, the only one of these substances for which we have the raw materials, for toluol is found in small amounts in coal tar and is recovered from its low-boiling constituent by distillation. But even here we were not ready technically a t the beginning of the war, although conditions were relatively the best, since the source of the raw material was within the country. In peace times we had more toluol than we used; the result was that other uses for toluol outside the explosives industry were sought and found. It flowed into our motor fuel, which it made stable to low temperature. Consequently, in the first weeks of the war the motorized troops and the ordnance department were in strong opposition, for the ordnance department could not make sufficient explosives without toluol, which the motorized troops would not give up, since the stability of their fuel to cold was decidedly important in a fall campaign. The solution of this problem, which was the basis of the cooperation between army headquarters and the Kaiser Wilhelm Institute, of which I was the head, was not particularly difficult. The notation of Major Victor Lefehure, in his book "The Riddle of the Rhine," page 35, that experiments with chemical war materials were made in my institute in August and September, 1914, is wholly false. The experiments referred to, during which Professor Sackur met with accidental death, were made in December, 1914. Every drop of toluol suddenly became important, but the trouble was that the coal tar industry had not been organized to extract toluol completely from the lowboiling constituent of coal tar. The manufacturing process had to be changed under the pressure of war. However, toluol was always a minor difficulty. Regarding the other materials which I have named I would like to discuss cotton next. We had to have asuhstitute for cotton, which we could no longer get, if we wanted to shoot a t all. The substitute material was clearly indicated. The chemical substance of cotton was prevalent in the form of cellulose, only the physical quality was different. Although this physical difference was sufficient to introduce different manufacturing processes for the nitrocellulose, still, as in the case

of toluol, this was of minor importance compared to the cases of glycerin and nitric acid. With glycerin and nitric acid the situation was exceptionally serious. There appeared to be no possibility of a new technical method for the production of glycerin, which would free us from the necessity of splitting fat. The uncompromising alternative was to starve or to shoot. The most unexpected technical innovation of the war was the success of Dr. Connstein in controlling the fermentation of sugar with yeast so as to obtain glycerin and aldehyde instead of alcohol. The theory of this development was propounded independently and simultaneously by von Neuberg. While with glycerin there was still the possibility of helping out temporarily with fat hydrolysis until the new method was perfected, with nitric acid, on the other hand, everything was dependent upon the present supply of saltpeter in the country. If this was used up the war was ended, since we could not then make powder or explosives, or offer any substitutes. There appeared no possibility of bettering the situation with material aids or substitute materials. The Belgian saltpeter supply had so little effect upon the matter that in the fall of 1914 the absolute necessity of ending the war in the spring of 1915 was known to every expert. The peculiarity in this case lay in the large measure of the need. The necessary amount was immensely greater than that of glycerin and the problem had to he solved within half a year. Luckily the solution was known to the experts; we had a method of nitrogen synthesis with a sufficient production capacity. This was the ammonia method. The conversion of ammonia t o nitric acid on a small scale was a process known for two generations. Indeed, Wilhelm Ostwald, a t the suggestion of Mr. Duttenhofer, who had foreseen the possible dilemma many years previously, had perfected a technique for oxidizing ammonia to nitric acid, and with his advice a small technical plant was erected a t the Lothringen mine. The principal difficulty was to perfect this process in the short time from the fall of 1914 to the spring of 1915 to the point a t which it could yield sufficient quantities to meet the imperative need for munitions. It will always remain the pride of the chemical industry that it proved itself equal to this task. But the production of niter from ammonia did not alone solve the difficulty; first, because the production of ammonia in our coke ovens, although it amounted to nearly 125,000 tons per year, was not sufficient for the ever-increasing requirements of war; and then, ammonia which was used in this way could not he available for agriculture, for which it is the irreplaceable fertilizer. Hence, ammonia itself, or sources of it, had to be newly created, and for this there was only one source-the nitrogen of the air. From this need, the high-pressure synthesis of ammonia and the production of lime nitrogen during the war grew to enormous importance. They have become so large that we do not have to import from Chile any more today but can

produce in our country from the air all the fertilizer and industrial nitrogen which we need. The series of chemical changes which the war made necessary was much longer, since one product is dependent upon another. Nitrocellulose cannot be made from cellulose and nitric acid without the use of fuming sulfuric acid, which does not appear in the product but is used up in the process. Again, sulfuric acid was manufactured in Germany before the war principally from foreign sources. There were many more chemical changes and new industrial processes, but I will refrain from further examples, since I am only concerned with the general relation. I will describe only one case. As is known, we were prepared for a short war; all the difficulties were the result of its long duration. On the other hand, very early in the war great emphasis was placed upon the need for a new system of supply of raw materials for powder and explosives. If this was so necessary in August and September, 1914, that tradition was broken in using strong civilian forces in the war department, it should have been just as necessary even before the war began. The other field of endeavor in which chemistry became especially important in war, the field of chemical warfare, is burdened with misgivings from an orthodox standpoint. The disapproval which the knight had for the man with firearms is repeated by the soldier armed with steel weapons, against the man who opposes him with chemical weapons. The aversion, which arises from unfamiliarity with the weapon, is further increased by the appearance of exceptional mthlessuess and by the feeling that i t may violate the fundamentals of international law, which must even in war remain sacred in the interest of civilization. After the ravings of the foreign press, which during the war could not judge the subject impartially but only from national prejudice, the truthful verdict can only be brought to light slowly. The printed opinions of authoritative English and American sources, as well as personal interviews with responsible French officers, have convinced me that there is no particular difference of opinion among those informed of the actual facts. Chemical warfare is certainly no more horrible than flying pieces of steel; on the other hand, the percentage of mortality from gas injuries is smaller. There is little maiming, and as far as after effects are concerned, there is not enough known yet to warrant a conclusion. Under such circumstances, for obvious reasons, the prohibition of gas warfare is not easy. Proof of this is the fact that our recent enemies have not yet given up gas warfare and, according to official opinions, are not likely soon to do so. In the meantime, such a prohibition has been agreed upon a t the Washington Conference, but the treaty has not yet been ratified by all the participating powers and obviously has in no case led to the stoppage of experimental work. On the contrary, we find that in England as in America the desire to develop their own chemical industries has used

chemical warfare as a pretext. Leading personalities advocate a chemical-technical development since it promises both commercial use and a military advantage in the field of chemical warfare. This shows that the question of whether or not the Hague convention and declaration permit the use of chemical warfare agents is no longer controversial. Should i t seriously conflict with acknowledged international law the founders of the League of Nations would not hesitate a minute to outlaw it. One will have to wait and see whether a new interpretation of international law will ~ o h i b iit. t In the meantime it will be of interest to get a clear view of the military-technical properties of chemical warfare agents and of the methods of their production. All modem weapons, although they appear to have the purpose to kill the enemy, owe their success finally to the vigor with which they overpower the morale of the enemy. The battles which decide the outcomes of the wars are not won through the physical destruction of the enemy, but through psychical concussions which overcome his'powers of resistance in a deciding moment and bring up the picture of defeat. The troops, which are a sword in the hands of a leader, are made into a mob of desperate human beings by those psychical concussions. The most important element in the technique of war t o bring about this psychical shock is the artillery. But its eEects are limited, since the sensations which accompany the striking of shells on the field are always the same and hence dull the senses. A shell can be twice or four times as large and can therefore penetrate more deeply and explode more loudly; but in the end it always remains the same, and the average difference in the distance from the point of explosion is equivalent to the difference in the action of detonation and splinter. Living in underground quarters, which an expert gunner can penetrate or bury, causes a terrific strain on the nerves, but the experience of war shows that the strain can be withstood, siqce the feeling is dulled against it, as it is against anything which acts continuously and repetitiously. With chemical warfare the situation is the opposite. The most important thing about i t is the fact that its physiological reactions on the human being and the sensations which it causes change in a thousand ways. Every change of impression, made evident by the mouth and nose, womes the mind with the picture of an unknown terror and is a new strain on the moral power of resistance of the soldier a t a moment when all his mental powers are necessary for his war problem. We once tried to win by force of numbers, steadily increasing the number of shells and weight of guns, but this effort was not very successful. But here we have an effort to break enemy resistance through qualitative change of action, by utilizing gas shells. At the end of the war the gas mnnitions accounted for one quarter of the total munitions and they would still have increased if we had not reached the limit of production. War experience therefore favors the qualitatively

different gas warfare rather than the exclusive utilization of explosive munitions. The advantage of gas mnnitions is especially noticeable in a war of position, since the chemical gases penetrate every earth fortification and dugout, where the flying pieces of steel cannot find an entrance. There are two important aspects of the action of gases: one is typical of the yellow cross ammunition, the other of the blue cross ammunitiontwo types which, together with the green cross ammunition encompass our technique in this field. The particular property of the yellow cross material is that it is carried about by the clothing and shoes of people, and evaporating off in small, warm rooms produces its effects when breathed in. Since i t is scarcely detectable, such a spreading cannot easily be prevented. Relief and prevention can only be accomplished by means which are not easy to apply. Objects sprayed by yellow cross can be decontaminated by sprinkling with lime powder, and individual positions can be made tenable by the same means, but the action of this material cannot be successfully stopped. For this purpose it is necessary to use protective clothing which, together with the shoes, are taken off before entering the shelter. Not enough equipment of that sort can be made to supply "mopping-up" troops. Therefore, the objective of a large-scale bombardment with yellow cross is to make a fortified position untenable. This chemical weapon brings to an end the war of position which the development of the explosive weapon has brought about. The blue cross ammunition, on the other hand, is always used in conjunction with an explosive charge, and the explosive force is sacrificed in order to give the explosion cloud an independent fighting action. It has the important advantage that without causing severe casualties i t forces the enemy to wear gas masks. But the amount of training for soldiers necessary for the correct handling and maintenance of gas protection apparatus, and especially for the continuation of fighting ability under the mask, is unusually great. Human beings are sharply divided into those who under strict gas discipline remain calm and fulfill their battle functions, and that minority who become demoralized and give up their positions. For this reason the blue cross ammunition has become important even in a battle of movement. The effect of blue cross ammunition is short lived; those who are gassed generally recover by the next day a t the latest. It is annoying, not deadly. Under such circumstances the mental effect is much less than that produced by a material (green cross ammunition) which can cause death if inhaled. The importance of gas ammunition has been established despite its dependence upon wind and weather. All steps from the first experiment to the final manufacture took place during the war, absolutely no scientific or technical preparation preceded. The manufacture was based solely upon local raw materials. All gas warfare materials which we used were based upon (Continued on @ge 553)

CHEMISTRY IN WAR (Continued from page

coal, coal tar, alcohol, arsenic, and cooking salt-materials which are all products of our land and industry and with the exception of arsenic occur abundantly in our country. Only the capacity of the chemical factories and not the supply of raw materials sets a limit on production. It may be very inopportuue to discuss the significance of the association of officers with scientists and technologists. Nothing lies further from us than to prepare for a new war, and what else can this association mean, one might ask, but a renewal of war preparation? Did not the army become a sort of police force, as a result of the peace treaty which we signed, and why does such a force need the association with academic personnel which was important to the previous war organization? My view, on the contrary, is that strengthening and raising the morale of the officer corps is necessary for the accomplishment of the problems before i t and for the insurance of peace in the future. The mercenary army, which we now have in place of our previous army of conscription, is always in danger of becoming a tool in timesof political unrest, especially if the officer corps is not educated in the spirit of the times and if it views conditions from the standpoint of one-sided militarism as opposed to other aspects of the State. Under such conditions, problems concerned in the training of offl-

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cers are primarily ethical, but a thorough technical education is also necessary for success. The officer must fully comprehend what war demands and what the state, industry, and science can do without today, if he is to be a help rather than a hindrance to his country in times of danger. The same spiritual uplifting and development which should have been necessary for the officer corps for a small, successful war, can be just as important after what we have recently experienced. I t should be realized that the nations of the European continent cannot afford to conflict, if they want to exist next to each other without the destruction of their populations, for Europe is too poor in raw materials. From i t grows the conviction that every decade, with increased coal consumption and increased cultivation of the soil, increases our dependence upon foreign agriculture and the dangers of a new war, in which the Sea Powers might blockade our coasts. The soldier who understands war is not a danger to the state; it is the soldier who does not understand who is a danger to the country. The best and most educated officer corps is today the best guarantee of peace. The nation owes you thanks, my friends, if you tackle your problems, in spite of the lost glory, with the same thoroughness and industry as if you stood a t the head of the European conquerors.