prometheansinlab

Prometheans in the Lab: Chemistry and the Making of the Modern World by Sharon Bertsch McGrayne. McGraw-Hill, $14.95, 243 pages.

The Chapel Hill News

June 15, 2003

Two Faces of Chemistry

By Phillip Manning

“Better Things for Better Living Through Chemistry” trumpeted the DuPont Company slogan from 1939 to the 1980s. And DuPont was mostly right. Chemists did make our lives better. In the 19th century, they cleaned up water supplies, eliminating the epidemics of cholera that ravaged London and other cities. Later, they invented soap, inorganic fertilizer, and nylon. But chemists’ inventions can also do harm. Chemists came up with leaded gasoline, which raised the levels of lead in the air of American towns by a hundredfold, putting millions of children at risk for brain damage and retarded growth. In her lively book “Prometheans in the Lab” (McGraw-Hill, $14.95), Sharon McGrayne explores both the good and the dark sides of chemistry by telling the stories of nine prominent chemists whose inventions remade the world.

Of the nine, no other scientist contributed more to both the beneficial and destructive uses of chemistry than Fritz Haber. Haber was a German Jew whose religion blocked the path to the university professorship he craved. He converted to Christianity in 1892 at age 24 and became a super patriotic German. Despite his hard work, obvious brilliance, and devotion to all things German, Haber was passed over for promotion at the university where he finally landed a job. He suspected his Jewish roots were holding him back. A friend of Haber’s summed up the problem: “Before 35 I was too young for a professorship, after 45 I was too old, and in-between I was a Jew.” Nevertheless, Haber toiled on, and in 1903, he began work on the biggest problem facing Europe — the prospect of a fertilizer shortage.

Europe’s population had tripled in the previous 200 years. To feed the hungry hordes, European farmers imported nitrogen-rich deposits of Peruvian guano to fertilize their fields. However, the supply of guano was dwindling. For over a century, the dream of European chemists had been to extract nitrogen from the air to make ammonia for fertilizer. But the only progress they had made was an inefficient electric-arc process that produced only small amounts of ammonia.
The problem lies in the chemistry of nitrogen. In the atmosphere, nitrogen does not exist as single atoms, but as a combination of two nitrogen atoms joined by a strong chemical bond. Haber realized he would need very high pressures and temperatures to break that bond, which would allow the nitrogen to react with hydrogen to form ammonia. He finally succeeded when he raised the temperature in his reaction vessel to 390 degrees Fahrenheit at a pressure 200 times greater than atmospheric pressure. Even so, yields were low until he discovered a metal catalyst that speeded up the reaction. Five years after he patented his process in 1908, the German company that licensed it was producing commercial quantities of ammonia. Farmers could now make “bread out of air.” It was arguably the most important invention of the 20th century. And it made Haber famous and rich.

But his world soon turned sour. In 1914, Germany invaded Belgium, starting World War I. When British ships blockaded Germany, cutting off the supply of nitrates used in explosives, Haber used his ammonia-making technology to make up the shortage. He then turned to producing poison gas. In 1915, Haber directed the release of chlorine at the western front, the first use of a weapon of mass destruction in history. The yellow-green gas drifted across Allied lines, poisoning 7,000 men and killing 350 of them. Haber never apologized for his work on chemical warfare, but it so distressed his wife that she committed suicide.

Germany’s surrender sent the patriotic Haber into a deep depression. And when he won the Nobel Prize a year later, many other winners boycotted the ceremonies as a protest against Haber, whose work had prolonged the war by years. As the Nazi’s rose to power in post-war Germany, neither Haber’s conversion to Christianity nor his patriotic work during the war could insulate him from his Jewish background. He wrote his friend Albert Einstein, “I was never in my life as Jewish as I am now.” His second wife divorced him, and his health declined.

Haber fled Germany in 1933. “Bereft of family . . . health, and home,” McGrayne writes, he moved “restlessly around Europe in a hideous danse macabre,” and died a year later. One of the poison gases he developed, the pesticide Zyklon B, was used in the gas chambers of concentration camps where millions of Jews lost their lives. But his other legacy, the process to make fertilizer out of air, is the basis for 99 percent of all inorganic fertilizer used today, and without it the world could not feed itself.

Chemists can create products for good and evil, but Fritz Haber was one of the few who did both.