Green Clover and Dynamite

Exhibition project with the Carl-Bosch-Museum, Heidelberg

Nitrogen surrounds us: 78 percent of the air that we breathe is pure nitrogen. But this kind of nitrogen is almost useless for life. Living organisms do not need pure nitrogen, but nitrogen in a biologically available form. The latter form of nitrogen is essential for living organisms – no higher life is possible without amino acids, without proteins, without DNA. Almost all biologically highly active substances contain nitrogen atoms at central places. Yet chemically ligated nitrogen, in contrast to the abundance of pure nitrogen, is scarce on Earth. Only lightnings procure supplies now every once in a while and some living organisms: It was a significant step for the evolution of life on planet Earth when some kinds of bacteria managed to make atmospheric nitrogen biologically available by using the enzyme nitrogenase. All higher life could only develop due to this unique invention.

But not only for the evolution of life, but also for human history, particular nitrogen compounds are of high importance. Saltpeter and ammonia, two quite simple nitrogen compounds, are counted among those handful of substances, which have shaped human history and still do. For saltpeter is indispensable for the production of dynamite. Without it, no kingdom, no large republic could survive for a long period of time. Without saltpeter there would be no gun powder, no munition, no nitroglycerin. Until the 19. century saltpeter was obtained biologically, with the help of those above mentioned microorganisms and from dung, excrement or corpses. The repositories of saltpeter in India (Birhan) and later in Chile were quickly depleted, and besides, were controlled by the British and the Dutch. That is why German industry attempted with highest pressure (in every respect!) to develop an industrial  process, with which saltpeter could be obtained from the air. The attempt was successful: The Haber-Bosch process, which initially was brought into production in September 1913, allowed the synthesis of saltpeter from atmospheric nitrogen, fossil oil and natural gas – at high pressure. Beside those bacteria, which were “monopolizing” the nitrogen compound until then, the industrially fixated nitrogen replaced it increasingly. Today the industrialized agriculture without the “saltpeter from the air” produced by the Haber-Bosch processes would be impossible and would collapse.

The exhibition, which is currently shown in the Museum of Natural History in Augsburg, tells the story of nitrogen and goes on from there to ask about the history and future of human history on planet Earth. It is a story that leads around the globe and in far-away, exotic countries such as India, China and Chile and finally ends in the Rhine-Main-Neckar triangle. It contrasts old, partly archaic discoveries with the latest technology: We tell a story that guides us through time. In doing so we proceed chronologically. Firstly, the earliest uses of saltpeter by alchemists is shown, afterwards we pass into the part about gun powder. Actually, while searching for the philosopher’s stone, alchemists first discovered gun powder. From that point on saltpeter was mainly used for the production of gun powder. Another way of using materials that contain saltpeter is the fertilization of land. In 1830, Justus von Liebig proved in his field of agricultural chemistry that nitrogen, besides phosphor and other substances, is indispensable for the nutrition of plants. From this point on, saltpeter was used not only as fertilizer for the fields that should feed a growing world population, but also for munition. Thus, this substance henceforth brought bread and death! And those countries and regions that contained significant saltpeter deposits became even more important. With the groundbreaking development of the Haber-Bosch process suddenly the cards on the saltpeter market were shuffled in a new way. From now on, every country that possessed the facilities and fossil fuels could produce as much saltpeter as seemed necessary for warfare and fertilization. While the strategic significance of saltpeter slowly decreased in the 20. century because of the development of new weapons, its significance as fertilizer gained more and more importance. With the help of saltpeter it became possible to cultivate even those areas where cultivation didn’t seem lucrative before, such as meager meadows, stony areas, and fens. The seemingly harmless fertilizer cannot be underestimated in its impact on the landscape.

On the other hand it becomes more and more clear today that there is enough fertilizer available to feed the growing population but there are not enough fields for cultivation.

Starting from the chemical element nitrogen and its compounds, the exhibition aims at looking at natural and political coherences from a different angle. Our modern world is presented from a supposedly marginal point of view in a new way. Central questions, such as the global population boom, but also the loss of species will be explained. The inventions or inventors are not supposed to be celebrated or demonized, but instead, the visitor receives information about arguments for and against different developments and can form an opinion by himself. This exhibition is about providing fascinating information and a coherent story as well as about generating enthusiasm for sciences, especially chemistry and biochemistry, by showing interactive exhibits that appeal to all senses and should promote scientific and technical education.

Start of project: April 2012

Project board:
Jan Dübbers, Bianca Flock, Sabine König, Gerda Tschira (Carl Bosch Museum Heidelberg);
Dr. Claudia Schmidt, Dr. Jens Soentgen (University of Augsburg);
Knut Völzke (Leise Design).

Funded by the High Tech Offensive Zukunft Bayern and the Klaus Tschira Stiftung.


For further information:



Dr. Jens Soentgen
Wissenschaftszentrum Umwelt
Universität Augsburg
Universitätsstraße 1a
D-86159 Augsburg