The prophecy was made in the fall of 1898, in a music hall in Bristol, England, by a thin man with a graying, neatly trimmed beard and a mustache waxed to alarmingly long, needlelike points. His audience, the cream of British science, thousands of formally dressed men and bejeweled women, were seated in a low-rent venue, what Americans would have called a vaudeville palace--a last-minute substitute for an academic auditorium that had burned down--but they dutifully filed in and filled every seat from the orchestra pit to the highest balcony. The hall was uncomfortably hot, especially in the upper seats. Exquisitely gowned women began opening their fans. Evening-coated men began murmuring to their neighbors that it looked as if it were going to be a long evening.
The speaker was Sir William Crookes, 1898's incoming president of the British Academy of Sciences. Impeccably dressed, erect and resolute, he looked every inch the triumphant, newly knighted physicist he was: inventor of the Crookes Tube (a predecessor of the cathode ray tubes used later for televisions and computers), recent discoverer of an interesting new addition to the periodic table that he had named thallium, fearless explorer of science, even out to its furthest edges--Crookes was an active researcher in the area of seances and the question of life after death.
Inaugural speeches were often deadly dull. The incoming presidents of scientific associations almost always droned long lists of achievements made during the past year, with nods to numerous individual researchers, sprinkled with homilies about the importance of science for the British Empire. Crookes, however, had decided to shake things up. He adjusted his oval glasses, glanced at his notes, looked up, and got right to the point. "England and all civilized nations," he said, "stand in deadly peril."
The fans in the balcony stopped fluttering. Crookes's voice was clear but he spoke softly. The hall went silent, the audience straining to hear as the speaker continued. If nothing was done soon, he explained, great numbers of people, especially in the world's most advanced nations, were soon going to begin starving to death. This was a conclusion that he was forced to accept, he said, after considering two simple facts: "As mouths multiply," he said, "food sources dwindle." The number of mouths had been increasing for some time thanks to advances in sanitation and medical care, from the installation of improved water systems to the introduction of antiseptics. These were great triumphs for humanity. But they carried with them a threat. While population increased, land was limited; there were only so many farmable acres on earth. When every one of those acres was under the plow and farmed as well as it could be, the population would keep going up, the farmed and refarmed soil would slowly lose its fertility, and mass starvation would, of necessity, ensue. His research led him to estimate, he said, that humans would begin dying of hunger in large numbers some time around the 1930s.
There was only one way to stop it, he said. And then he told them what it was.
Every agricultural society in every age has had its own methods, rites, and prayers for ensuring rich crops. Homer sang of farmers gathering heaps of mule and cow dung. The Romans worshipped a god of manure, Stercutius. Rome made an early science of agriculture, ranking various animal excrements (including human), composts, blood, and ashes according to their fertilizing power. Pigeon dung, they found, was the best overall for growing crops, and cattle dung was clearly better than horse manure. Fresh human urine was best for young plants, aged urine for fruit trees.
Both the Romans and the ancient Chinese also understood that there was another key to a healthy farm: crop rotation. No one knew why or how it worked, but never planting the same crop twice consecutively in the same land, instead alternating it with certain crops like peas and clovers, managed to replenish the fertility of fields. Every few years the Chinese made sure to rotate in a crop of soybeans; chickpeas were the crop of choice in the Middle East, lentils in India, and mung beans in Southeast Asia; and Europeans used peas or beans or clover. "Oats, peas, beans, and barley grow" was more than a children's rhyme. It was a timetable for successful farming.
Healthy farms had compost pits, plenty of domestic animals for manure, and a system of crop rotation. But it was never enough. It took scores of tons of manure per acre to grow great crops. Manure gathering and handling grew into a small industry, employing thousands of workers who scoured the countryside for cow and pig excrement, cleared city streets of horse manure, and then sold it by the stinking ton to farmers and gardeners. There was never enough. A heavy application of manure helped for a season or two, but then the fertility of the soil declined and more was needed. In the most intensively cultivated land in Europe--the Marais district of Paris--owners of small city-garden plots applied dung at rates as high as hundreds of tons per acre, and every year they had to repeat the process. By 1700 or so, hungry Europeans were experimenting with other soil additives in an attempt to increase their yields, trying sea salt, powdered limestone, burned bones, rotting fish, anything that might keep their soils producing.
But the world's best farmers were not in Europe. In the wet, warm farmlands of southeastern China, farmers a millennium ago were already expert in using every possible kind of fertilizer, hoarding their human waste and adding it to the output from their domestic animals, composting vegetable scraps and leaves, and tossing in seed cakes to enrich their fields. It was all applied to the most ingenious farm system imaginable: a complex of dike-and-pond fields in which they grew not only rice, mulberries, sugarcane, and fruits but also carp. The fish waste helped fertilize the crops. The dung of the water buffaloes used to work the fields helped fertilize the crops. So did the waste of the ducks that swam in the ponds. They grew a native water fern in the paddies that acted like a crop of soybeans, adding fertility to the soil. The tropical climate allowed multiple harvests per year. This was the highest-yield traditional agricultural system ever devised. Using it, the Chinese could feed as many as ten people with the output from each acre of farmland, a yield of food five to ten times higher than the European average of the 1800s. "The Chinese are the most admirable gardeners," an appreciative European scientist wrote in 1840. "The agriculture of their country is the most perfect in the world."
It was not enough. During the nineteenth century, millions of people left the farm and flocked to cities during the Industrial Revolution. As the cities grew and the population of the earth rose faster and faster, it became clear that feeding ten people per acre, the pinnacle of traditional agriculture, was nowhere near good enough. The crisis Crookes predicted would have happened fifty years before his speech, but for the opening of vast new farming territories, from the Great Plains of the United States and the steppes of Russia to the vast landscapes of Australia. When their land played out, farmers simply moved west or south or east to the next expanse of virgin soil.
Now, however, Crookes warned, the earth held no more Great Plains. The globe had been explored, mapped, and the best agricultural areas settled and plowed. From this point on, farmers would have to make do with the land they had, refarming the same acres year after year. This brought Crookes to the critical issue: When land was farmed repeatedly, no matter how carefully crops were rotated, no matter how scrupulously every bit of animal dung was applied, the soil slowly lost its original fertility.
His analysis focused on wheat, the staple of Europeans and North Americans, the staff of life for Caucasians. Any drop in wheat production threatened, as he put it, "racial starvation." His conclusion, based on what he called stubborn facts, seemed incontrovertible: In a few decades, the populations of the great wheat-eating peoples--including the Caucasians of the British Empire, northern Europe, and the United States--would outstrip their grain of choice, and thousands of people, then hundreds of thousands, then millions, would begin to die.
The best traditional farming techniques in the world were not enough to avert the coming crisis. England itself was using the most advanced farming techniques, the best possible mix of crop rotation, animal manuring, and composting, and the English, he said, would be starving now if they did not import tons of grain from other nations. What would happen when those other nations, in order to feed their own growing populations, stopped exporting?
There was only one answer, Crookes said: the creation of vast amounts of fertilizer, new fertilizer by the thousands of tons. As there was not enough natural fertilizer in the world to meet the needs of the coming twentieth century, some way would have to be found to make more, to make it synthetically, to make it in factories. Finding new ways to make fertilizer, discovering and making what he called chemical manures, Crookes told his audience, was the great challenge of their time.
"It is through the laboratory," he said, "that starvation may ultimately be turned into plenty." He then pinpointed the kind of scientist who would save humanity. "It is the chemist," he said, "who must come to the rescue. . . . Before we are in the grip of actual dearth the chemist will step in and postpone the day of famine to so distant a period that we and our sons and grandsons may legitimately live without undue solicitude for the future."
Empty a bag of store-bought fertilizer and what pours out is usually a mix of three elements, N, P, and K--nitrogen, phosphorus, and potassium--the three most essential nutrients for plants. None of today's major crops can survive without them. All of them can be found, in varying but generally low amounts, in manures and composts. It is because of these nutrients that compost and dung were the farmers' best friends.
For most crops, the most important of the three is nitrogen. Atoms of nitrogen are stitched into every protein and every bit of DNA and RNA in every cell of every plant (and every animal). Without nitrogen, life is not possible. This single element is so important that its availability represents a limiting factor for most plant ecosystems, which means that the availability of nitrogen pretty much determines how much will grow. Low nitrogen equals low yields. High nitrogen equals big crops. It seems just about that simple.
But it's not. Plants need nitrogen, but they are picky about the kind of nitrogen they use. Almost 80 percent of the air around us is nitrogen, for instance--we are swimming in an ocean of it--but it is locked up, unavailable to plants and animals. They have no mechanism for absorbing and metabolizing atmospheric nitrogen.
Plants use fixed nitrogen, nitrogen in a chemical form different from how it exists in the air, usually a solid or liquid form. Manure is a source of fixed nitrogen, and so is compost--which is why they make good fertilizers. Uncultivated, virgin soils have fixed nitrogen stored in them; this is why pioneers' first few crops in a new land are generally the best they'll ever see. As the crops use up the fixed nitrogen, the amount in the soil drops, and so does fertility. Crops become sparser, plants punier, and yields lower.
"Wheat preeminently demands nitrogen," Crookes told his audience. But centuries of wheat farming had depleted the soil's stock of fixed nitrogen, and farmers were unable to adequately replace it. Using current farming practices, he warned, "We are drawing on the earth's capital, and our drafts will not be honored perpetually."
Crookes knew that his remarks might come as something of a surprise to his audience. Most Englishmen believed that there was in fact no fertilizer shortage at all. Fertilizer was available in plenty; it came in canvas bags, delivered by the tens of tons from South America, shiploads of fertilizer unloaded at docks in all English ports. British farmers had been swearing by it for decades. First, in the 1840s, there had been mountains of South American bird guano, which many European farmers were convinced was the best fertilizer in the world, then later Chilean nitrate, a very clean, white fertilizer, mined somehow from the desert wastes somewhere near the Andes. It was magical stuff, the nitrate, excellent fertilizer, granular, easy to apply, raised yields enormously. Dizzying fortunes had been made trading nitrate stocks in London. South America was full of fertilizer, was it not?
Crookes carefully explained that indeed there was an end to the South American supply, and it was coming soon. Wheat growers had become increasingly dependent on the Chilean product, spreading it on their fields by the hundreds of thousands of tons per year. Such use simply could not be sustained. He ran through more numbers, showing that if current trends continued, the Chilean nitrate fields would be exhausted within decades, perhaps by the 1920s, certainly by 1940. When that happened, the game was up. With no more big sources of fertilizer, yields would plummet and people would starve--unless scientists could come up with an answer.
He ended by calling his fellow researchers to action. The only answer, he said, was to find a way to make synthetic fertilizers--fixed nitrogen--refining it from the earth's greatest reservoir of nitrogen: the atmosphere. Other scientific discoveries might make life easier, might help build wealth, might add luxury or convenience to the lives of the wheat-eating peoples, but the necessary discovery, the vital discovery--the discovery of a way to fix atmospheric nitrogen--was a matter of life and death. "Unless we can class it among the certainties to come," he said, "the great Caucasian race will cease to be foremost in the world, and will be squeezed out of existence by races to which wheaten bread is not the staff of life."
Crookes's racism was as naked as it was common. In 1898 most Englishmen took it for granted that they represented the pinnacle of civilization. His audience was English and he spoke to their native prejudice, using their chauvinism as another way to drive home his point. In fact, the same "stubborn facts" applied to other races as well. The entire population of the world, whether it ate wheat, rice, corn, or millet, needed fixed nitrogen. Whoever found a way to create it out of the air would not only save humanity but would likely become very, very rich.
"A brilliant success," Crookes wrote a friend a few days after his speech. "I am overwhelmed with compliments, several old stagers saying it was the best address that they had ever heard." He did not mention that a fair portion of those in the upper balcony exited about halfway through his eighty-minute talk, fleeing the stifling heat. Those who stayed, however, including some reporters, were impressed. Word of mouth turned his presentation into a sensation. News of the impending doom of the Caucasian race rippled out from Bristol through England, then to newspapers around the world. His words were read not only by scientists but economists, politicians, intellectuals, and businessmen. Some experts chimed in supportively; others were critical. It was very much like today's global-warming debate. The publicity all helped boost Crookes's presentation into the ranks of the most influential public addresses of the day. He received so much attention for it that he later expanded his remarks into a popular book.
Just as with global warming, the issue became a matter of controversy between those who accepted Crookes's figures and those who believed that his "crisis" was overdramatized. A few critics challenged his numbers, especially his estimates of the amount of nitrates left in Chile. They said that the South American desert was not about to run dry, that it was practically an endless sea of fertilizer.
Excerpted from The Alchemy of Air by Thomas Hager, Author of The Demon Under the Microscope. Copyright © 2008 by Thomas Hager. Excerpted by permission of Broadway, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.