Did you realize that one-third of the nitrogen atoms in your body did not come from nature? That the food that we eat contains amino acids, that nitrogen originally came from fertilizer, and most of that fertilizer, almost all, came from chemical factories? They, in turn, extract that nitrogen from the atmosphere using a process called the Haber Process – so the fact that we and billions of other people are not starving to death is a direct result of the invention of the Haber Process.
So who was Fritz Haber? Fritz Haber was a German chemist. He was born in the kingdom of Prussia before Prussia became part of Germany. He was born to a prominent Jewish family, but attended schools that were of mixed religious backgrounds, both Jews and Catholics and Protestants. He was conscripted and served in the military – as was traditional, he served his year of military service.
In 1894, he converted to Lutheranism, and whether he did that out of personal convictions or to advance his career is not clear. But throughout his life, he identified himself as more German than Jewish. So he identified very much with Germany. And in 1909, he completed work which began with studies of the physical chemistry of gases, with the discovery of the Haber process, which I will talk about. He also developed the Born-Haber reaction cycle, which is used for understanding a variety of theoretical and practical and chemical knowledge, which led him to become, probably, the premier chemist in Germany from about 1910 to about 1930, and his laboratory, the Kaiser Wilheim Institute for Physical Chemistry, to be the greatest physical chemistry laboratory in the world.
He was instrumental in helping lure Albert Einstein to take an academic position in Germany. And he received the Nobel Prize in Chemistry in 1918 for his development of the Haber Process.
So why is nitrogen so important? Well, there’s a problem with nitrogen. 70% of the air is nitrogen. And nitrogen is essential for what? Amino acids that make up protein. That’s part of us. So the graphic I have on the right shows the natural processes for the atmosphere for the nitrogen fixing bacteria that exists in the rhizomes of some plants that take the nitrogen and turn it into compounds of nitrates and nitrates and ammonia.
But to do that is a very difficult process. It requires a lot of energy to break the double bond of nitrogens. So microbiota have to work very, very slowly. And if you want the fertilized crops, you have to have nitrogen to grow. You need to add fertilizer. And until early 1900’s, really the only source of fertilizer was nitrate oxide, essentially fossilized bird poop. And so that was the agricultural view [before Haber].
So along came Fritz Haber. Haber used the principles of entropy and energy that were first established by Chatelier in 1884 to determine that there should be a way to take hydrogen and nitrogen, and get them to combine to form ammonium, as the base process for filling fertilizer. He studied for several years and eventually discovered that the rare metal osmium should have been a good catalyst, and was able to catalyze the reaction. And in his tabletop laboratory, he was able to, drop by drop, turn air into ammonia, about 125 grams a day. That process was then taken over by Carl Bosch at the BASF, and they scaled it up enormously, so that instead of just sitting there and drip by drip, they’re able to make tons of it. And those tons were able to be turned into useful chemicals for the world and that process, the Haber process, the Haber-Bosch process, remains fundamental to the chemical world today.
In 2018, 230 million tons, metric tons, of ammonia were produced that year. That’s a lot of fertilizer. The production of fertilizer consumes about 3-5% of the world’s total natural gas output, because natural gas is used as the feedstock for the nitrogen, and to produce the heat needed for the process. This is how the world avoids starving – is from the Haber process. And there’s a picture on the right of that chemical plant in Oppau, which was the first large scale producer.
Nitrates and nitrogen are for more than just fertilizer. All the explosives that we know we use today, all the common ones at least, also use nitrogen, mostly in the form of nitrates. And the German chemists, by the time that Haber’s process had been industrialized, had methods for taking the ammonia, turning it into nitrates, and turning those nitrates into explosives like nitroglycerin, dynamite, TNT, and also very much into ammonium nitrate, which is the primary fertilizer which is still used in the world today. If you have enough ammonium nitrate in any one place and it gets dry, it can explode on its own. The most common explosive used in the world today, ANFO, is ammonium nitrate and fuel oil.
It’s also dangerous to store large amounts of it. In 1921 – remember that picture I showed you just before, of the Oppau chemical plant? It blew up, almost 101 years ago today. 4,500 metric tons detonated. It killed about 600 people in the worst industrial disaster ever in Europe. For those of you who keep track of current events, there was a ship docked in Beirut a few years ago filled with ammonium nitrate. It blew up and killed several hundred people in Beirut. It was a tremendous – this is dangerous stuff.
Haber was motivated not just by the need Germany had for fertilizer, but also the need Germany had for explosives. And Haber’s process is what kept Germany’s guns firing during World War I, and made sure that Germany – who couldn’t get the nitrates – they were embargoed by the British – couldn’t get the nitrates, could still continue to manufacture explosives. Just to give you an idea of the scale of the amount of explosives that were used during the First World War, Great Britain alone fired over 100 million artillery shells.
So who was Fritz Haber? Well, he was more than just the developer of this chemical process. He was also the father of chemical warfare. He was an enthusiastic proponent of Germany’s entry into World War I; he was one of the signatories of the Manifesto of the Ninety-Three, and he actively recruited physicists and chemists to work on the war effort. He basically rededicated the Kaiser Wilhelm Institute to war work during the time that Germany was at war.
And a key portion of that was the development of poison gas. Prior to the war, the chemists in Germany had developed hundreds upon hundreds of new chemicals for dyes and for perfumes and for industrial use. Under Haber’s direction, the chemists went back and looked to find out what was toxic, what was the most toxic, and how could it be used.
He developed the Haber equation, which was used to determine how much of a given poison gas would need to be delivered into a given area to achieve a given level of the balance. Germany was very grateful to him, the Kaiser himself promoted Haber into an Officer, which was not possible while he was serving earlier. And even after the war, Haber was still involved in the development of chemical agents, although under the cover of developing fumigants and other insecticides. And Haber’s central statement: “During peacetime,” he said, “a scientist belongs to the world, but during wartime, he belongs to his country.”
So how did we get into this situation with chemical warfare? Because it appears to be prohibited by the Hague Conventions, to which Germany was a signator. Well, the process was a slow one. The French and the Germans both had begun to use tear gas. And other chemists, notably the Nobel chemist Walther Nernst, thought that saturating the trenches with poison gas would be a way to get a quick end to the war. And so I have a quote here from Nobel Prize physicist Otto Hahn, who was accorded by Haber to do war work, and he says:
“When I objected that this was a mode of warfare violating the Hague conventions, Haber said that the French had already started, although to not too much effect, by using rifle ammunition built with gas. Besides, this was a way of saving countless lives that meant that the war could be brought to an end sooner.”
So there was this idea that chemical warfare would end the war. By the way, it turned out that after the war, Haber himself investigated the claims of the French using chemical warfare prior to Germany’s use of it. And what he determined was that what the soldiers were smelling and being asphyxiated by was the remains of the explosive that was being used in front shells. It was a low quality explosive, and they were they were smelling picric acid.
So at that point, Germany committed to chemical warfare, with Haber leading the charge. The first use was at the Second Battle of Ypres, and on the evening of the 22nd of April to May 1919, Haber was at the front with several other future Nobel Prize winners, with 6,000 canisters of chlorine gas (chlorine gas is a liquid at about 30 degrees) and specially trained combat engineers, who Haber had led the training for. And they released 168 tons of chlorine gas, which was blown by the wind into the trenches of the allies. 5,000 men died directly as a result. There were another 10,000 allies [who suffered serious casualties]. But this success was not followed up. The German high command thought this was an experiment, and they weren’t prepared for a success. Within a week, the breach in the allied lines had been sealed, and the end result had been a lot of death and a lot of agony, but no real motion in the war.
I have here a description of what it was like to suffer that first chlorine gas attack:
“…dropping with breasts heaving and agony and the slow poison of suffocation mantling their dark faces. Hundreds of them fell and died; others lay helpless, froth upon their agonized lips, and their wracked bodies powerfully sick, with tearing nausea at short intervals. They too would die later – a slow and lingering death of agony unspeakable.”
Germany continued to develop other chemical weapons – the list is very long. The most deadly of those weapons was phosgene carbonyl chloride, which was responsible for about 85,000 deaths in total during the First World War. About 100,000 of the 6 million deaths in the war were caused directly by poison gas. Perhaps the gas that caused people most pause was the use of mustard gas. This was a blistering agent which blinded people and left them with horrible blisters and left them horribly maimed, even if it didn’t kill them, and would linger on the battlefield for months after the gas had been fired. Haber rationalized the use of chemicals in the following quotation. He said:
“The disapproval that the knight had for the man with the firearm is repeated in the soldier who shoots with steel bullets towards the man who confronts him with chemical weapons. […] The gas weapons are not at all more cruel than the flying iron pieces; on the contrary, the fraction of fatal gas diseases is comparatively smaller, the mutilations are missing.”
While Haber is certainly true that men were horribly maimed and mutilated by the artillery, which was the primary killer of people during the First World War, plenty of people were maimed by gas attacks as well.
So who was Fritz Haber? After the war, he was still a German patriot. Germany had crushing war remunerations to pay, and he looked to provide his physical chemistry to extracting gold from seawater. There had been an estimate that gold was of enough quantity in seawater that it could be probably extracted and used to take pay its war debt. He spent much of the 1920’s doing that, in addition to being the head of the Kaiser Wilhelm Institute, the President of the German Chemical Society, and a variety of honorary posts.
So he led Germany’s work through the 1920s, he watched with increasing alarm the growth of the Nazi Party, even though he himself was immune from any of the formal edicts because he had served in the military at the front, and because he had converted from Judaism, nonetheless, he felt a fellow feeling for his Jewish compatriots. So in 1933, the Nazis promulgated a law, the Law for the Restoration of the Professional Civil Service, which required all civil servant servants who were of Jewish parentage to be fired from their positions unless they had actually served on the front during the war. Haber was immune, but he refused – he resigned his position and he left Germany forever. Before he resigned, he did everything he could to help find work for his Jewish employees.
He went to Basel, Switzerland and eventually went for several months to England – at the invitation of some of the generals and military men who had been his former enemies. He worked in Manchester for a while, and then was invited by Chaim Weizmann to take up the directorship of the institute in Rehovot in Mandatory Palestine that we know today as the Weizmann Institute for Science. He was on his way there, in Switzerland, when he died in 1934.
So he was a German patriot, he was the founder of fertilizer that enables us to eat our meals today, and he was also the father of chemical warfare. We’re left with the question: is science morally neutral? The Haber process could be used to make fertilizer to feed the world, or it can be used to make explosives to kill people. The poisons that Haber developed – many of them have peaceful uses today. A lot of the basis for modern insecticides came from the work that Haber was doing while he was researching poison gases. Scientists, I think, throughout the world recognized that there may be an enormous moral cost. And the question is: are we working for the betterment of humanity, or are we working for our own self-interest?
So there are a whole bunch of topics next slide that I didn’t talk about here when trying to present a brief of Haber and his very mixed legacy. And one of the people who I mentioned earlier was Chaim Weizmann. For those of you who aren’t familiar with that name, Chaim Weizmann was the first president of Israel. But before he was the first president of Israel, he was a PhD chemist. And he had determined that England was a key place that he should be. He was working ostensibly to try to discover synthetic rubber in England just prior to the war. What he discovered was something that came to be known as Bacillus Weizmannia, a bacterium that could be used to produce acetone. Acetone is a critical ingredient for cordite, which is the material used to fire artillery shells, and which the Munitions Ministry of England had a desperate need for. Lloyd George, who later became Prime Minister, was the head of the Ministry at the time, and Weizmann was one of the key figures who kept England’s guns firing during the war. So there is some evidence that the kindliness with which the British government viewed the Balfour Declaration is in part a reward to Weizmann for his work in keeping Britain’s guns firing during World War I.
A second aside, which we could talk about more, is Haber’s wife, Clara Immerwahr. She was the first female chemist in Germany. She had a variety of chemical developments, married Haber, and then he would basically have her reduced to being a wife and mother. She was a pacifist, and she argued very strongly that Haber’s work as a chemist working on war work polluted the purity of science.
After one of these arguments, just before he was to go to the front to supervise another chemical warfare attack, Clara Immerwahr Haber committed suicide under suspicious circumstances.
It’s an open question: would chemical weapons have been deployed if Haber had not embraced Walter Nernst’s initial idea? So there is still a mixed legacy. And as a final comment and sort of a lead-in, I think, into Rachel Petrov Kessler’s talk, artificial fertilizers are now a source of pollution. There are dead zones in the ocean which are dead because the fertilizer has caused microscopic plants to grow and keep the lower levels of the oceans dead. Is Haber part of that? And finally, if we do not use artificial fertilizers, then the yields of essential crops would be cut perhaps as much to one-eighth of what they are today. And I would ask as a ba’al tashchit question of whether one is wasting useful land: is it morally mandated to use fertilizers to fertilize your fields in order to feed the world?
(This post is part of Sinai and Synapses’ project Scientists in Synagogues, a grass-roots program to offer Jews opportunities to explore the most interesting and pressing questions surrounding Judaism and science. This “Shabbat Lunch and Learn” on September 3 was the first event in Temple Isaiah’s Scientists in Synagogues series, “New Wars, Old Questions: Military Technology and Jewish Teachings in the 21st Century.” Gary Heiligman, PhD is a systems engineer, software engineer, and physicist, specializing in spacecraft, missile systems, spaceborne instruments, and observatories. He received his PhD from Princeton University and works at the Johns Hopkins University Applied Physics Laboratory).