Flashback -- this is  a piece I published in Chemistry in Britain in December 2003 (just before they closed it down and relaunched as Chemistry World).  I think CiB content is no longer available online, so I'll rescue some of my favourite pieces from oblivion by posting them here ...

 

Elusive treasures

 

Michael Gross

 

If it comes to playing "six degrees of separation" with chemists, I happen to be reasonably well positioned. For example, the monumentally tragic figure of Nobel laureate Fritz Haber (1868-1934) is only three steps away, as my former PhD supervisor is a son of Haber's assistant and would-be biographer Johannes Jaenicke. I cherish this connection as it throws a somewhat unusual light on the great man.

 

The well-known parts of Haber's biography are all collossal in their impact on history and people's lives. Being a very patriotic German citizen during WW I, Haber helped to develop chemical weapons and oversaw their use at the front. Although aware of the horrendous suffering they caused, he reckoned they would bring a quick end to the war and thus reduce overall loss of lives. His young wife, Clara Immerwahr, one of the first women to gain a doctorate in chemistry, disagreed and committed suicide after failing to stop him. On the other side of the balance, one can estimate that roughly half the nitrogen feeding the world population today comes out of the Haber-Bosch process he invented. Bringing a complex biography to a tragic end, he had to flee Nazi Germany and died in Switzerland on the way to Rehovot, where Chaim Weizmann had offered him a position.

 

Haber's former assistant Johannes Jaenicke and his wife spent decades collecting materials for a biography, which due to the sheer size of the task and his failing eyesight in old age, he never finished (the recent biography by Dietrich Stoltzenberg is largely based on  Jaenicke's material). One research project that Jaenicke was involved in himself took place between the wars, and offers a little light relief in the Faustian life of Haber. In the spring of 1920, Haber surprised Jaenicke and other coworkers with the announcement that he wanted to investigate the possibility of extracting the gold content of sea water, which was estimated to be 5-10 ppb. In that case, he reckoned, extraction of significant amounts of gold should be economically feasible and might help Germany pay back the crushing debts resulting from WW I and the Versailles treaty.

 

Haber set up a group led by Johannes Jaenicke to develop this project further. During five years, up to 12 research staff and PhD students worked on the gold project under strict secrecy. While industrial sponsors including Degussa were informed, the project was kept secret from the Allied authorities. Initially, the researchers worked on improving the analytical and separation techniques. While there was only a limited number of sea water samples available, their analyses seemed to confirm that the gold content was in the ppb range. For the separation, they tested different approaches and eventually settled for binding the gold to colloidal sulphur and filter with sand also charged with sulphur.

 

By the summer of 1923, the experiments were ready to be transferred onto an actual ocean-going ship. Still under strict secrecy, a group of researchers including Haber himself boarded the passenger vessel Hansa bound for New York, officially registered as crew members. Legend has it that Haber was greatly amused to be called up as a "supernumerary accountant". While the chemists worked behind closed doors, rumours among the passengers ran wild, and upon arrival in New York, a newspaper reported: "German scientists see way to drive ships by using mysterious force." A second expedition in the autumn of the same year took Haber's team to Argentina.

 

The samples analysed during these two trips gave very different results, such that the researchers had to go back to the lab and improve their analytical methods even further, excluding both gold gains (from common chemicals, dust, or jewellery) and losses (e.g. from adsorption to equipment). Thousands of bottles were filled with sea water samples from all corners of the globe, stacked in purpose-built wooden chests, and shipped to Berlin for analysis. However, the disappointing result was that the actual gold content in most samples was two orders of magnitude lower than the early analyses had suggested, which ruled out any hope of economic retrieval. In 1927, Haber published the results and buried the project.

 

While it failed to reach the goal, however, the project did improve analytical methods, and also helped to secure the funding of Haber's research in difficult times. Even more ironically, if the project had delivered large quantities of gold, the devaluation of the precious metal might have backfired. As the Spanish found out after plundering the gold of Latin America's native population, "finding" tons of gold doesn't automatically make you rich in the long term. Nitrogen from the air was less glamourous, but ultimately more valuable.

 

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here's the cover of Stoltzenberg's biography:

 

... and here's his wife: