Book Review: The Alchemy of Air

My chemistry teacher last fall recommended reading this book, but I didn’t get around to it until just now, in the form of an audiobook while working on needle felted critters. The entire title is unwieldy but informative —  The Alchemy of Air: A Jewish Genius, a Doomed Tycoon, and the Scientific Discovery That Fed the World but Fueled the Rise of Hitler (Thomas Hager, 2008).

Nitrogen Fixation

Cannot be pried apart by plants.

The Fundamental problem is that, along with hydrogen, oxygen, and carbon, nitrogen is the fourth most common element needed for life (three percent or so). There are fairly obvious ways for plants (and therefore animals) to access the other three elements: water, carbon dioxide, and atmospheric oxygen especially. Nitrogen, on the other hand, is more difficult to find in useable form. Most nitrogen on Earth is in the form of a diatomic gas — two atoms bound closely together with a triple covalent bond. So tightly, unlike the other atmospheric gases of oxygen and carbon dioxide, it’s not available for use by plant cells. They don’t have a mechanism for splitting the atoms apart with enzymes.

Ammonia — useable by plants.

Certain bacteria are able to split apart atmospheric nitrogen and get it to bond with other elements, a process known as nitrogen fixing. These nitrogen fixing bacteria can enter into a symbiotic relationship with some plants, especially legumes, contributing useable nitrogen to the soil in exchange for sugars from the plant’s roots. Those bacteria are the primary method for natural nitrogen fixing, the only way it initially gets in the soil, along with lightning. That’s why crop rotation is important in organic farming; not all plants grow with nitrogen fixing bacteria, so it’s necessary to replenish the soil by rotating legumes, soy, or peanut crops, which have such bacteria, with cereal crops that don’t.

The other method of providing nitrogen for organic crops is through compost and dung fertilizers. By the 19th Century, densely populated regions such as China and Europe had outgrown their ability to farm enough food using only crop rotation, and were applying large amounts of natural fertilizers, saving human and animal waste and applying it as “night soil.” That let people continue to grow enough to feed themselves, but led to a lot of illnesses from fecal contamination.

The Guano Trade

Guano shoot down to the waiting ships

As the world population exceeded a billion and a half people, it became increasingly difficult to provide nitrogen to crops in sufficient quantities using only local fertilizers. People, especially in Europe, began looking elsewhere. Eventually they found a new source of fertilizer in the form of the sea bird guano off the coast of Peru, where the arid climate prevented deposits of thousands of years from washing away. There grew up a horribly brutal trade where Asian slaves toiled at mining bird feces ten hours a day in stifling heat with no rain to settle the dust. It continued until they had mined the islands down to bare rock.

Easter Island was depopulated by guano traders trying to turn them into slaves (they ended up mostly getting sick and dying instead).

Everyone was made miserable by the guano trade, but it kept going so that farmers could continue producing sufficient yields to feed Europe.


As the guano began to run out, another source of fixed nitrogen was found in the form of nitrate salts in the soil. India had especially good saltpeter (potassium nitrate), suitable for both explosives and fertilizer, and England used it to maintain it’s position as a world empire. The Peruvian desert had a similar compound, sodium nitrate, which was eventually found to also be suitable for fertilizer. It was so profitable Chile waged war with Peru over it, and eventually won, leading the substance to be called chilean saltpeter.


As the Nineteenth Century drew to a close, the scientists of Europe concluded that there weren’t enough nitrate salts in the ground to provide fertilizer for another century, and became concerned that when it ran out there would be wide-spread famine. As with most problems since the Industrial Revolution, this was seen as an opportunity for industry, and was taken up by IG Farbin, a German dye company that had just invented synthetic indigo and was looking for the next big thing.

Led by Carl Bosch, with scientific research by Fritz Haber, they became one of the first multi-national companies investing in research and development for ammonia production. Turning nitrogen and hydrogen gas into ammonia involves extremely high heat and pressures (200 atmospheres, 600 Kelvin), and no other industrial process yet used anything like it. Additionally, they had to try thousands of catalysts before hitting on the right one, which included iron and a “booster” in combination. Osmium also worked, but is much too rare. Bosch oversaw the creation of the largest, hottest, highest pressure chemical plant of his time.

Hubris and Tragedy

The second half of the book follows Haber and Bosch through a kind of classical tragedy that followed on the heels of hubris.

Haber, a militantly patriotic German Jew, oversaw the release of the first German poison gas in WWI, vats of chlorine gas, killing thousands. Having risen as one of the greatest scientists of his day, his life decayed as his wife killed herself, the allied powers branded him a war criminal, he invented the insecticide that was used to kill prisoners at concentration camps, and eventually he had to resign from his science institute and leave Germany as the Nazis rose to power.

Bosch, meanwhile, had to convert his great ammonia plants into nitric acid factories, producing the munitions that kept Germany in the war after its initial strategy of smashing through France failed, making the war much worse for everyone. Between the wars he tried to keep his industrial secrets safe and work on the next great thing for his company: synthetic fuel. Despite a struggling economy, falling ammonia sales in the wake of the poverty of the Great Depression, and spying Frenchmen, Bosch kept IG Farbin afloat and eventually built a plant that was able to produce synthetic gasoline using German coal. Just in time for the Nazis to use it to keep WWII going far past when it otherwise could have, once again using nitrate explosives and now fueling its war machine with Bosch’s synthetic gasoline. Bosch himself, who had worked with many brilliant Jewish scientists at his company, became more and more depressed, drinking and collecting scientific artifacts until eventually he died of sickness and despair, and his son committed suicide.

Industrial Fertilizers

Not what we’re going for.

So here we are, in no immediate danger of starving, but with rather too much nitrate making its way into our ecosystems via runoff while huge farms take the monoculture sledgehammer approach to its fertilizer application. In the South, that’s been creating a large “dead zone” in the Gulf of Mexico, as all the fertilizer waste gets carried down the Mississippi to the ocean.

Also not what we’re going for.

Haber-Bosch plants producing vast quantities of ammonia pulled China out of a famine that had killed tens of millions of people in 1959. As Stalin pointed out, nobody knows what to do with numbers like that. China, apparently, had been on the brink of starvation for generations, but had applied traditional organic farming techniques with great industry and care, in order to utilize every square foot of farmable land to its greatest potential. But then Mao Zedong forced them to move to the cities so there weren’t enough farmers left to apply the super labor intensive methods of traditional agriculture they had developed. Currently the problem is being dealt with through a liberal application of ammonium extracted from the air.


I enjoyed The Alchemy of Air — it was a good mix of science and history, showing the cycle of how problems produce solutions that produce other, unexpected problems. I especially liked the first third. The second third became a little tedious, focusing on Bosch’s concerns in running a huge business, the kind of leviathan that is always trying to expand and can plunge entire cities into depression if top executives make the wrong gamble, but which stagnate and eventually fall anyway if they don’t make any gambles at all. The last third was kind of grueling — everyone had become old, sick, corrupted, depressed, isolated, and complicit in the Nazi rampage.

Rating: 4.5/5 — probably as good as possible, given the material.


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