“… Sie können sich kaum vorstellen, wie erfreut ich darüber war und bin, dass die
Berner Naturforschende Gesellschaft meiner so freundlich gedacht hat.”

Einstein in seinem Dankesbrief für die Verleihung der Ehrenmitgliedschaft, Princeton 1937

“… You can barely imagine how I appreciated and appreciate that the
Naturforschende Gesellschaft in Bern has thought of me so friendly.”

Einstein in his thank-you letter for the award of the honorary membership, Princeton 1937


(Society for Natural Sciences, Bern)

A short history of the Society

“The Naturforschende Gesellschaft in Bern (NGB) was founded at the time of the enlightenment as visible testimony for the growing interest in natural sciences which developed fast.”

On December 18, 1786 the seven foundation members of the “private society of scientific research friends in Bern” met for the first time in the house of Jakob Samuel Wyttenbach (1748-1830), the vicar at the Church of the Holy Ghost in Bern. The meetings of the scientifically interested persons took now place every week. From now on they conveyed and exchanged scientific knowledge. This private society developed into the Naturforschende Gesellschaft in Bern. In 1815 the Bern society was integrated into the newly founded Swiss Scientific Society (today: Swiss Academy of Sciences) as subsidiary. The members in the first years were only men with the most different occupations. Beginning in 1908 the first women were registered in the members‘ lists. In Bern the topics reached from natural history to the exact science, for example botanic, geology, geography, mathematics, physics, techniques, chemistry, meteorology, astronomy, physiology and zoology, to just name a few.

Naturforschende Gesellschaft in Bern,

One of the most famous members of the society in Bern was Albert Einstein.

Albert Einstein and the Naturforschende Gesellschaft in Bern

It was Dr. Josef Sauter (1871-1961), member of the Naturforschende Gesellschaft in Bern and colleague from the patent office, who invited the young Einstein as guest to a meeting of the Society in the autumn of 1902. This meeting took place in the hotel “Storchen” in Spitalgasse 21 in Bern. Einstein must have liked the members, the kind of the lectures and the subsequent discussions and talks, as on the session dated May 2, 1903 “Mr. Alb. Einstein, mathematician at the patent office”, as mentioned in the minutes, became a member of the Naturforschende Gesellschaft in Bern. Another entry in the minutes of this evening mentions the lecture of Dr. Paul Gruner (1869-1957) who talked about “Newer examinations concerning atmospheric electricity”. This lecture as well as the lecturer made a sustainable impression on the young and curious Einstein, who probably also participated in the subsequent discussion. Based on the minutes we can see that Einstein regularly visited the events of the society in the following time. On December 5, 1903 he himself held a lecture for the first time. He was talking in front of the members of the society about “The theory of the electromagnetic waves”. Michele Besso (1873-1955), a colleague from the patent office in Bern and one of his friends also became a member of the society on March 4, 1905. Einstein had introduced him as a guest on February 18. The young Einstein was especially impressed by the physician professor Hermann Sahli (1856-1933) who, next to Michele Besso, actively participated in the discussions. Sahli combined best scientific and philosophic thinking at its best. Many years later Einstein still was impressed “by the often wonderful remarks” which professor Sahli made during the meetings of the society.

In the “News of the Naturforschende Gesellschaft Bern, No. 1038” a reference is made to another lecture of Einstein:

1038. Sitzung vom 23. März 1907.
Abends 8 Uhr im Storchen.

Vorsitzender: Herr Ed. Fischer. Anwesend: 20 Mitglieder und Gäste.

1. Herr A. Einstein spricht “Über die Natur der Bewegungen mikroskopisch kleiner, in Flüssigkeiten suspendierter Teilchen.”
Mikroskopisch kleine, in Flüssigkeiten suspendierte leblose Teilchen (z. B. von der Größenordnung 0,001 mm Durchmesser) führen unregelmäßige Bewegungen aus, welche desto lebhafter sind, je kleiner der Teilchendurchmesser und die Viskosität der Flüssigkeit und je höher die Temperatur ist (Brown’sche Bewegung). Nach kurzer Darlegung verschiedener Erklärungsversuche wird vom Vortragenden mit Hilfe der kinetischen Theorie der Wärme auf elementarem Wege eine einfache Formel für die von den Teilchen zurückgelegten Wegstrecken abgeleitet. (Autoreferat.)
Weiteres darüber siehe: Ann. d. Physik 4. 17 1905, pag. 549. Ann. d. Physik 4. 19 1906, pag. 371.

2. Herr W. Rytz spricht über “Beiträge zur Kientaler-Pilzflora.” (Siehe die Abhandlungen dieses Bandes.)”


1038. Meeting dated March 23, 1907.
8 o’clock in the evening in the Storchen.

Chairman: Mr. Ed. Fischer. Attendees: 20 members and guests.

1. Mr. A. Einstein talks “About the nature of motions of microscopically small parts which are suspended in liquids.”
Microscopically small non-living parts which were suspended in liquids (e.g. with a diameter of 0.001 mm) move irregularly, and are all the more vivid the smaller the diameter of the parts and the viscosity of the liquid and the higher the temperature (Brownian motion). After a short explanation of different attempts to explain, the lecturer derives a simple formula for the distances the parts are traveling, i.e. with the help of the kinetic theory of heat. (auto-abstract.)
Further information see: Ann. of Physics 4. 17 1905, pag. 549.
Ann. of Physics 4. 19 1906, pag. 371.

2. Mr. W. Rytz speaks about “Contributions to the Kientaler mycology.” (See the essays of this volume.)”

After Einstein’s lecture and to his joy professor Hermann Sahli and Michele Besso again participated very actively in the subsequent discussion.

During the ceremonial act on December 9, 1936 in the auditorium of the college and on the occasion of the 150 year ceremony of the Naturforschende Gesellschaft, Albert Einstein and other personalities were appointed as honorary members. Einstein was sent the honorary deed and gave his thanks immediately after its receipt with a letter to the back then president of the society, professor of zoology Fritz Richard Baltzer (1884-1974).

Copy of Albert Einstein‘s honorary deed of the Naturforschende Gesellschaft in Bern, 1936:


Signed by Hans Adrian as secretary of the society as well as by Fritz Richard Baltzer, the President.

Copy of the thank-you letter Einstein wrote on the occasion of the award of the honorary membership:

“Princeton 4.1.37.

Herrn Prof. F. Baltzer, Bern.

Hoch geehrter Herr Kollege!

Sie können sich kaum vorstellen, wie erfreut ich darüber war und bin, dass die Berner naturforschende Gesellschaft meiner so freundlich gedacht hat. Es war sozusagen eine Botschaft aus den Tagen einer längst entschwundenen Jugend. Die gemütlichen und anregenden Abende steigen wieder auf in meinem Gedächtnis und besonders die oft wunderbaren Bemerkungen, die Prof. Sahli, der innere Mediziner zu den Vorträgen zu machen pflegte. Ich habe das Dokument gleich einrahmen lassen und als Einziges von allen Anerkennungen entsprechender Art in meinem Studierzimmer aufgehängt als Erinnerungszeichen an meine Berner Zeit und die dortigen Freunde.
Ich bitte Sie der Gesellschaft meinen herzlichen Dank zu übermitteln und ihr zu sagen, wie hoch ich die mir erwiesene Freundlichkeit schätze.
An Sie persönlich glaube ich mich auch noch gut zu erinnern. Es ist mir, als wenn ich von Ihnen einen interessanten Vortrag über die Decken – Ueberschiebungs – Theorie gehört hätte, bin aber nicht ganz sicher.

Mit freundlichem Dank und aller Hochachtung


A. Einstein.”


“Princeton January 4, 37.

Prof. F. Baltzer, Bern.

Highly estimated colleague!

You can hardly imagine how happy I was and am that the Bern Naturforschende Gesellschaft has thought of me so friendly. It was so to speak a message from the days of a long gone youth. The comfortable and exciting evenings are coming to my mind again and especially the often wonderful remarks which Prof. Sahli, the internal physician always made to the lectures. I had the document framed immediately and hung it up in my study room as the only one of all recognitions of this kind as reminder of my time in Bern and of the friends I had there.
I am asking you to convey the society my cordial thanks and to tell it how high I estimate its friendliness.
I think I can remember you personally very well. It seems to me as if I had heard a very interesting lecture of you about the nappe theory, however, I am not really sure.

With all my thanks and my esteem


A. Einstein.”

In the letter Einstein mixes up father and son in his personal recollection. It was not the current President of the society Fritz Richard Baltzer, but his father, the geologist and mineralogist Armin Richard Baltzer (1842-1913) who 1907 held the lecture “About the new theory of the folding up of the Alps (nappe theory)” which Einstein mentioned.

Einstein maintained the contacts to the Naturforschende Gesellschaft and to single members, as he still wrote letters for many years after his time in Bern. His membership in the Naturforschende Gesellschaft in Bern ended only with his death on April 18, 1955.


Hrsg. John Stachel, David C. Cassidy,
Jürgen Renn, Robert Schulmann
The Collected Papers of Albert Einstein, Volume 2Princeton 1989
Hrsg. Martin J. Klein, A. J. Kox,
Robert Schulmann
The Collected Papers of Albert Einstein, Volume 5Princeton 1993
Max FlückigerAlbert Einstein in BernBern 1974
Ann M. Hentschel, Gerd GraßhoffAlbert Einstein “Jene glücklichen Berner Jahre”Bern 2005