Pilgrimage through the History of Natural Science,
Bonn, Germany

Kaoru Harada

Kobe Shoin Women's College, Sinoharaobanoyama-cho, Nada-ku, Kobe-city, 657-0015, Japan

(Received 10 July 2001, Accepted 10 September 2001)


     In the Roman days, Bonn was a citadel of Castra Bonnensia, and later the city of Bonn was a Teritory of the Archbishop of Köln for many years. In the year 1786, the University was established, but it was closed after 10 years. In the year 1818 a new University was established again in Bonn. Since then, Bonn has been a University town. Therefore, University of Bonn is relatively new University in Germany as is the University of Berlin (established 1810). But many famous scholars have emerged from the University.The university is officially called “Rheinisch Friedrich-Wilhelm-Universität zu Bonn” by the name of the founder. However, the organization is usually called “University of Bonn (Universtät Bonn)” for convenience by the town’s name where the university is there.
     After world war II, Bonn became a temporary capital of West Germany (Deutsches Bundes Republik, DBR), and many government buildings were constructed, bringing many people to this small town. But in 1989, DBR and East Germany (Deutsche Demokratische Republik, DDR) were unified, and Berlin became the official capital of the new Germany. Government organizations and their functions in Bonn are moving slowly to Berlin, and the city of Bonn is going back to the quiet university town as it was years ago.
     This short article deals with the academic side of the city of Bonn, especially the work of scientists. In this article, I would like to show readers many photographs including portraits and plaques where the scientists were born, lived, worked, and died, monuments made of bronze or stones and various remains of the famous scientists, in particular gravestones.
     Some reader may find it strange that the author is searching and visiting graves, but visiting graveyards is an ordinary established custom in our society. Some readers may not know that the shady graveyard is a nice place to take a walk.
     I believe that it is worthwhile historically, scientifically and also philosophically to visit monuments and remains of famous scientists. The gravestone is a personal monument recording official and personal history. Visiting remains of the famous scholars gives me a satisfactory feeling. The intellectual impression is quite different from that I got by reading a textbook dealing with the same subject, because grave visiting is a personal contact with historical person. I would like to call such a visit a “pilgrimage” through the history of natural sciences. We may learn about the sciences through the pilgrimage, and also learn about history through the pilgrimage.
     In this article, famous scientists are the main target of our “pilgrimage”, however, some famous nonscientists are also included because they ware also contributors to our human history.

University of Bonn

     The most impressive public building in the town is the Electoral Residence and Hofgarten. This is a baroque Schloss, which now belongs to the University of Bonn. The large building with the black roof and yellow wall is beautiful if we look at it from the Hofgartem. At the west end of Poppelsdorf Allee there is a similarly colored Poppelsdorf Schloss. This baroque building is also used for research building of the University. Other new University buildings are distributed on the north side of Meckenheimer Allee. Backside of the Popperlsdorf Schloss is a botanical garden, which is famous for its collection of various plants. it is said that Carl Linn’e (1707-1778) stayed in this botanical garden.

Fig.1 The building of the old palaces are now used for
research and administration of the University.

Statue of A. Kekulé

     Along the Meckenheimer Allee, there stands the old chemistry building. A bronze statue of August Kekulé(1829-1896) is standing with two white stone sphinx. In the statue A. Kekulé is lecturing while holding a book in his left hand. There is a plaque in front of the basement, in which a goddess gives a benzene ring to two engineers. The goddess would be Pallas Athena. She is the virgin goddess of knowledge, battle and art. Her helmet is behind her. This picture symbolizes the discovery of the benzene structure by Kekué and the development of the coal tar industry in Germany which started at about 1860 along the river Rhein.
     The old chemistry building is now used for various branches of biological sciences. The building was constructed with the help of Kaiser Wilhelm (II). When he was a crown prince, he attended the chemistry lecture made by A. Kekulé . We now leave the research complex of University of Bonn along the Meckenheimer Allee, and cross Kelulé street on the way to Peppersdorf Cemetery.

Fig. 2a Fig. 2b
Fig.2a, 2b Kekulé's statue is standing in front of the old chemistry building along the Meckenheimer Allee.
Fig. 3 Fig. 4
Fig. 3 Two engineers are receiving "Benzene Ring" from Goddes (Pallas Athena). The relief symbolizes the prosperity of coal tar industry along the River Rhein.
Fig. 4 Road sign "Kekulé street".

Friedrich August Kekulé

     Friedrich August Kekuké (1829-1896) was born in Darmstadt as a son of high ranking officer of Hessen Darmstadt. He was a clever boy and draw picture very well. He wanted to become an architect, but he studied chemistry by the influence of Justus Liebig (1803-1873) in Giesen. After he became a chemist, he traveled to France and England and made good academic friends. After he came back to Germany, he got position at Heidelberg and became a professor of chemistry in 1856.
     Kekulé interested in valency of element probably because of the influence of his British friend Alexander William Williamson (1824-1904). Williamson was a pupil of Liebig as Kekulé was. At that time it was considered that a molecule is composed of atoms, and the studies on atomic compositions of molecule were going on. Kekulé’s interest was the atomic arrangement in a molecule. In other words his interest was the structure of molecule.
     He became a professor of chemistry at Ghent University in Belgium (1858). He presented his ideas on the valence theory. The contribution of his theory to the chemistry is that the valency of carbon atom is 4, and the atomic composition of methane is CH4. The Kekulé’s valency theory contribute to the chemical structure of organic compounds.
     There is an interesting historical fact concerning the valency of carbon atom. One Scottish young chemist Archibald Scott Cooper (1831-1892) proposed independently that the valency of carbon atom is 4. Unfortunately young man’s claim was not accepted, and he became mentally ill and he disappeared from the academic society. Later very fortunately Cooper was found and his contribution to chemistry was evaluated by both German and British chemists. The German chemist who looked for the forgotten Cooper is Richard Anschutz (1852-1937). Anschutz is the successor of Kekulé in Bonn and he published large two volumes biography of “August Kekelé (1927)” and also wrote article on the Scottish young chemist.
     One another structural problem in organic compound is the structure of benzene. Kekulé proposed cyclic benzene structure as shown below. The cyclic structure of benzene (1) is called Kekulé benzene.
     Kekulé moved to University of Bonn (1867), and stayed in the new chemical laboratory until his death. Kekulé became a nobleman in his late years, and he called himself August Kekulé von Stradonitz.
After Kekule’s death, Richard Anschutz made the following works for Kekulé.
1) preparation of his biography “Augusut Kekulé”.
2) search for A. S. Cooper.
3) establish “Kekulé Collection (Kekulé Sammlung)” in Darmstadt.
In the “Kekulé Collection”, many interesting things and goods are collected. One interesting thing is pictures drawn by 14-15 years old Kekulé.

Poppelsdorf Friedhof (Poppelsdorf Cemetery)

A. Kekulé

     We find the gravestone of A. Kekulé made of red granite and with Kekulé's beautiful bronze relief. Kekulé’s superior forehead is impressive. In the late years, Kekulé became a nobleman. He called himself August Kekulé von Stradonitz. The family crest made of bronze is on the gravestone.
Fig. 5a Fig. 5b
Fig. 5a, 5b Kekulé’s gravestone is made of red granite with bronze relief.
Fig. 6 Fig. 7 Fig. 8
Fig. 6 Marble bust of aged August Kekulé (Kekulé Collection, Darmstadt).
Fig. 7 Large biography of August Kekulé written by Richart Anschutz in two volumes(1929).
Fig. 8 Certificate August Kekulé received when he became a nobleman (Kekulé Collection, Darmstadt).

A. Strasburger

     Near the entrance of the Poppersdolf Cemetery, we find the gravestone of Alexander Strasburger (1844-1912). He is a botanist, and he traveled with Ernst Haeckel (1834-1919) for the study of genealogical study and also studied fertilization mechanism and cell division.

Fig. 9 Granvestone of Alexander Strasburger (Botanist).

Old Cemetery of Bonn (Alter Friedhof Bonn).

     Old cemetery in Bornheimer Strasse is about 400m north of Bonn station. It was established in the 18th century and was used for soldiers and foreigners. But many famous people were later buried here. They are summarized in Table (I) and the grave cites are shown in Map (I). The actual photographs of the gravestones 1)-18) which were taken by the author, are shown on the following pages.
Table 1 Famous People in Alter Friedhof Bonn

1. Rudolf J. E. Clausius, 1822-1888, Physicist.
2. Heinrich Geissler, 1814-1879, Engineer.
3. Julius Plücker, 1801-1868, Mathematician, Physicist.
4. Friedrich W. A. Argelander, 1799-1875, Astronomer.
5. K. Friedrich Mohr, 1806-1879, Chemist.
6. Johann Jakob Noeggerath, 1788-1877, Geologist.
7. Franz Hermann Troschel, 1810-1882, Zoologist.
8. Gerhard Rath, 1830-1888, Geologist, Mineralogist.
9. Ferdinand Zirkel, 1838-1912, Geologist.
10. Gustav Bischof, 1792-1870, Chemist, Geologist.
11. Hermann Schaafhausen, 1816-1893, Anatomist.
12. Robert, Schumann, 1810-1856, Musician, Composer.
    Clara Schumann, 1819-1896, Musician, Pianist.
13. Friedrich C. Dahlmann, 1785-1860, Historian, Politician .
14. August Wilhelm Schlegel, 1767-1845, Literature Critic.
15. Barthold Georg Niebuhr, 1776-1831, Historian, Politician.
16. Ernst Moritz Arndt, 1769-1860, Historian, Politician.
17. Maria Magdalena van Beethoven, 1746-1787, Mother of Beethoven.
18. Charlotte Schiller, 1766-1826, Wife of F. Schiller.
    Ernst Schiller, 1796-1841, Son of F. Schiller.

Fig. 10 West entrance of Alter Friedhof, Bonn.

R. Clausius

     Rudolf Clausius (1822-1888), is a German theoretical physicist. He formulated the 2nd law of thermodynamics, and introduced the concept of entropy, and mean free path in the kinetic theory of gas. He also proposed a new theory of electrolysis. A stone cross is on the top of the gravestone, letters on the stone are painted in gold, and the gravestone is enclosed by a low iron fence.

H. Geisler

     Heinrich Geisler (1814-1879) was originally a glassblower or glass engineer. He made various glass apparatus for scientific research and he became an expert of vacuum techniques. In 1854, he established a shop to make various apparatus for chemistry and physics in the University of Bonn. He made a mercury vacuum pump which was designed by J. Plüker and also made a vacuum tube for electric discharge (Geisler tube). He was awarded an honorary doctors degree for his contribution to physics. On the upper part of the gravestone, the letters “Dr”. are engraved separately. Letters on the gravestone are painted in red.
Fig. 11 Fig. 12
Fig. 11 Grave of Rudolf Clausius (Physicist) is surrounded by low iron fence.
Fig. 12 Glass technician H. Geisler was awarded honorary doctor≱s degree for his contributions making various glass apparatus.

J. Plüker

     Julius Plüker (1801-1868) is a mathematician and physicist. He was a professor of mathematics at the University of Bonn (1836). Plüker was known in the field of analytical geometry. He was also an experimental physicist. He was interested in the luminous effects of electric discharge through gases at low pressure (1858). He found that the glow was deflected in a strong magnetic field. Plüker’s grave is constructed with white marble, and the whole construction is like a Greek shrine, with his marble bust is sitting in the middle of the shrine.
Fig. 13aFig. 13b
Fig.13a, 13b Julius Plüker is a mathematician and experimental physicist. His grave is like a Greek shrine made of white marble.

F. W. A. Argelander

     Friedrich W. A. Argelander (1799-1875) was a professor of astronomy at the University of Bonn. When he was young, he studied law first, but he changed to the field of astronomy under the influence of Friedrich Wilhelm (1784-1846). In 1823 he became director of a new observatory at Abo in Finland. He then obtained a chair of astronomy at the University of Bonn, where he stayed for the rest of his life. He established a new observatory in Bonn with the help of his friend King Friedrich William (1840-1861, King) of Prussia. The observatory was considered a model at the time. Algelander’s contribution is the remarkable survey of the position of stars brighter than 9th magnitude in the northern sky. The catalogue he made includes 324,198 stars. The pioneering survey of the stars of the north sky advanced to further survey of southern hemisphere by the Algelander’s colleagues Eduard Schonfeld and Adalbert Kruger.
Fig.14a Fig.14b
Fig.14a, 14b Astronomer Friedrich Argelander’s grave is made of white marble with his bust.

C. F. Mohr

     C. Friedrich Mohr (1806-1879), is a chemist and pharmacist. He became lecturer (1854) and then professor of pharmacology (1867) at the University of Bonn when he was more than 60 years old. He is a pioneer of volumetric analysis. He invented various small goods convenient for chemical experiment especially for chemical analysis. The small goods invented by F. Mohr are as follows:

biuret, pinch cock, cork bowler, rubber tube, round filter paper etc.

     Mohr published numerous papers and books in the field chemistry and pharmacology. Mohr’s salt is well known in analytical chemistry. He improved volumetric analysis by making the method more reliable. He also left an interesting paper on the general view of energy. He thought that light, electricity, magnetism, and mechanical movement are equivalent (1837). The philosophical thought might be connected with the fundamental natural law of “Conservation of Energy”. Thus his thought is philosophical and scientific.
Fig. 15a Fig. 15b
Fig.15a 15b I found Karl Friedrich Mohr’s gravestone accidentally, because the word “nature” is on the front side of the stone, a marble portrait relief is on the stone.

J. J. Noeggerath

     The sitting figure of Geologist Johann Jakob Noeggerath (1788-1877) is unique and interesting.

F. F. Troschel

     The gravestone of the paleontologist F. F. Troschel (1810-1882) is made of reddish granite and the letters on the stone are gold filled.
Fig.16 Geologist J. J. Noeggerath’s grave is a sitting figure made of white marble. Fig.17 Franz Hermann Troschel is a paleontologist.

G. Rath

     Gerhard Rath is a geologist and mineralogist. He was a professor of mineralogy at Bonn. There is a round white relief portrait on his gravestone.
Fig. 18a Fig. 18b
Fig.18a, 18b Gerhard Rath is a geologist and mineralogist.

F. Zirkel

     Ferdinand Zirkel (1839-1912) is a mineralogist. He invented a new method for Rock study. He made thin sections of rocks and examined them microscopically .
Fig. 19a Fig. 19b
Fig.19a, 19b Ferdinand Zirkel is also a mineralogist and he developed a new microscopic method for study rocks.

G. Bichoff

     Gustav Bischoff (1792-1870) was a professor of geology at the University of Bonn. He planned to establish a new geology which combined physics and chemistry.

H. Schaafhausen

     Hermann Schaafhausen (1816-1893) was a physician and anatomist. He examined the excavated bone from Neanderthal, and he concluded that the bone was from an ancestral man.

Fig. 20 Fig. 21
Fig. 20 Gustav Bischoff have planned to create a new geology with solid backgrounds of chemistry and physics.
Fig. 21 Hermann Schaafhausen is an anatomist, and he examined the bones found in the “Neanderthal Cave”.

A. Beer

     A. Beer (1825-1863) was a mathematician and his gravestone is made of sandstone which is now covered with green moss. His gravestone holds his white marble relief.

F. C. Dahlmann

     Friedrich Christoph Dahlmann (1785-1860), is a German historian and politician. He was a professor at the University of Götingen. He lost his chair because of his liberalistic behavior (1837). He is one of the "Götinger Sieben". He got a position of professor of history (1843) at the University of Bonn. He was always at the far front of of the liberalistic movement. On the front side of his gravestone, there is a sturdy bronze portrait of Dahlmans.

Fig. 22 Fig. 23
Fig.22 A. Beer is a mathematician at the University of Bonn.
Fig.23 Friedrich Christoph Dallman is a historian and politician. He is one of the “Götinger Sieben”.

R. & C. Schumann

     Beautiful marble gravestones of Robert Schumann (1810-1856) and Clara Schumann (1819-1896) are in the middle of the Alter Friedhof. Robert is a well known composer and Clara is also a famous pianist. They married in 1840. Robert was mentally ill in his late years and threw himself into the river Rhein. He was rescued and hospitalized, but died without regaining consciousness. Clara’s portrait is on the 100 DM note today. Every time I visit the Schumann’s grave, I find flowers in front of the gravestone dedicated to Schumanns. A female figure sitting in the front and looking up to Robert is said to be Clara.
Fig. 24a
Fig. 24b
Fig.24a, 24b Beautiful marble gravestone of Robert and Clara Schumann is in the middle of the Cemetery. Every time I visited, I saw flowers dedicating for the musician Schumanns.

A. W. Schlegel

     August Wilhelm Schlegel (1767-1845) was a German poet and literary critic. Both he and his brother Friedrich Schlegel (1772-1829) were pioneer of the romanticism movement. He later moved to academia to study literature. He obtained the positions at the University of Jena, Berlin and Bonn. He made beautiful translations of the W. Shakespeare (1564-1616) and Dante (1265-1321) into German. He is also a founder of oriental studies.
Fig. 25a
Fig. 25b
Fig. 25a, 25b August Wilhelm Schlegel was a poet, literary critique and also a founder of oriental studies.

B. G. Niebuhr

     Barthold Georg Niebuhr (1776-1831) was a historian of ancient German history and he was also a politician. He was originally a finance commissioner of the Prussian government, but he resigned his position. He lectured in roman history at the University of Berlin and Bonn. He was the most critical historians in the modern days. His life work E#8220;Roman History, 3 vol.”was written on the basis of vast political, legal and economical backgrounds of ancient Rome.
Fig. 26a
Fig. 26b
Fig. 26a, 26b Barthold Geolg Niebuhr was critical historian of ancient German and Romans.

E. M. Arndt

     Ernst Moritz Arndt (1769-1860) was a historian, politician and poet. He was nationalistic and also an international politician in Napoleon’s time. Above all he was a patriotist and acting historian. A large tree is growing between the gravestone of Ernst and his wife Ann Maria Arndt (1786-1869) and the gravestones are inclined both outside of the grave. Stone crosses are on top of each gravestones.
Fig. 27 Ernst Moritz Arndt is a patriotic historian and also politician in the Napoleons time.

Maria Magdalena Beethoven

     There is the gravestone of Beethoven’s mother “Maria Magdalene”.

S. Schiller and E. Schiller

     Charlotte Schiller (1766-1826) is the wife, and Ernst Schiller (1796-1841) is a son of Friedrich Schiller (1759-1805). The grave was made of large black iron plate with golden letters. Friedrich Schiller’s grave is in the Goethe-Schiller mausoleum in Weimar.
Fig. 28 Fig. 29
Fig. 28 There is the gravestone of Beethoven’s mother “Maria Magdalena”.
Fig. 29 Combined grave of F. Schiller’s wife “Charlotte” and his son “Ernst” is in this cemetery.


     The house where Emil Fischer (1852-1919) was born is still in Kölner Strasse 19, Euskichen. Apparently, the house is not the original one, but a remodeled or rebuilt one. On the right side of the entrance, there is an old bronze plaque for Emil Fischer. The plaque says as follows.
“In diesem Hause wurde an 9 Oktober 1852
Emil Fischer einer der grossen Meister auf dem
Gebiete der organischen Chemie geboren”
Fig.30 Fig. 31
Fig. 30 The house where Emil Fischer (Chemist) was born in Kölner Strasse 19 Euskirchen.
Fig. 31 The plaque said “Emil Fischer was born in this house ………”, however, it seems that the house is rebuild or remodeled

     Emil Fischer Gymnasium is on the crossing point of Kölner Strasse and E. Fischerstrasse. In front on the main entrance of the high school building, there is a large plaque with Emil Fischer’s bronze portrait. The relief is similar to the Emil Fischer medal of the German Chemical Society. One gymnasium student came to me and proudly explained Emil Fisher’s plaque “Emil Fischer is the great chemist Euskirchn was born”.
Fig.32a Fig. 32b
Fig.32a, 32b In front on the main entrance of the “Emil Fischer Gymnasium”, there stands a plaque of Emil Fischer with his portrait.

     I found a memorial stone in the garden of the Gymnasium for students who died during world war II. I have seen such memorial stones several times in Germany, and they are usually found in the shade of trees. When we came back to the railway station of Euskirchan, a steam locomotive was coming in with many sightseeing passengers. Steam locomotives are always a center of attraction. It was a nice opportunity to see the antique vehicle.
Fig. 33 Fig. 34
Fig. 35 Fig.36
Fig.33 Sign of Emil Fischer Gymnasium.
Fig.34 Memorial stone (Gedenk Stein) for students died during the past world war.
Fig. 35 Road sign of “Emil Fischer Street”.
Fig.36 I have a chance to see old steam locomotive in the Euskirchen Station.

Neanderthal Man

     Neanderthal Man is an ancestral human being that lived 50-100 thousand years ago. The first bones of this kind were discovered in a calcite cave in Neanderthal near Dusseldorf in 1856. H. Schaafhausen (his grave is in the Alter Friedhof,Bonn) found several primitive characteristics in these bones. In the beginning of the 20th century, similar bones were found in the world, and the antholopological studies advanced. This type of primitive man was called Neanderthal Man. The volume of the skull is 1300-1600 ml and the height of the skull is low. By the finding of this kind of bone, these bones were classified and the route of evolution of the Neanderthal Man was studied. There is a “Neanderthal Man-Museum” in Neanderthal with many educational displays. In the Rheinisches Landesmuseum (Rhein State Museum) in Bonn, many archeological specimens are displayed. The most interesting and valuable specimen is the Neanderthal Man’s skull. This is a perfect upper skull of the old man. I took a picture with the reconstructed Neanderthal man who is a distant ancestor of mine.
Fig. 37 There is a perfect upper skull of the Neanderthal
Man in the Rhein State Museum.

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