6 6 D O C U M E N T 3 7 J A N U A R Y 1 9 2 1
Bitte gelegentliche Retournierung.
An Becks Briefadresse sehen Sie die von uns besprochene häufige Verwechs-
lung Ehrenfest Ehrenhaft.
TLS. [10 371]. Written on letterhead “Professor Dr. F. Ehrenhaft K. K. Universität Wien Physikali-
sches Institut.” The last two paragraphs and smaller emendations are in Ehrenhaft’s hand.
[1]Olga Ehrenhaft-Steindler; Elsa Einstein.
[2]Where Einstein had recently given a lecture to the Allgemeine Studenten-Vertretung at the Tech-
nical University of Dresden (see Doc. 24).
[3]Eugen Lederer (1884–1947), director general of Westinghouse, was also president of the
Chemisch-physikalische Gesellschaft in Vienna.
[4]During his visit in Vienna, he stayed with the Ehrenhafts (see Doc. 24).
[5]Probably Ludo Moritz Hartmann (1865–1924), Professor of History at the University of Vienna,
Austrian envoy in Berlin, who had been involved in Ehrenhaft’s candidacy for a chair in physics at
the University of Vienna (see Einstein to Ludo Moritz Hartmann, 2 April 1920 [Vol. 9, Doc. 365]).
[6]Rudolf Wegscheider (1859–1935) was Professor of Chemistry at the University of Vienna and
president of the Verein Österreichischer Chemiker.
[7]The Arbeiter-Zeitung was the organ of the Austrian Social Democratic Party. Friedrich Adler
(1879–1960) was secretary of the party.
[8]Possibly Gustav Jäger (1865–1938), Professor of Physics at the University of Vienna.
[9]Carl Beck (1864–1952) was Professor of Surgery at the University of Illinois, and co-founder of
the St. Anthony’s and North Chicago Hospitals. For his letter, see Carl Beck to Einstein, 28 December
1920 (Vol. 10, Doc. 248).
[10]Steindler (1878–1959).
[11]Apparently Einstein proposed that Ehrenhaft use a new substance, a selenium modification, in
further experiments. Earlier (see Ehrenhaft 1920), Ehrenhaft had evaporated selenium powder in a
radon atmosphere. The decay products, radium A to radium D, precipitated on the selenium droplets.
When placed in an electric field that initially kept the condensed particles afloat, the change in their
charge due to the emission of -particles from their radioactive coating put the particles in motion.
To keep them afloat, a compensation by the field intensity was needed, and this field change was used
to calculate the change in the particles’ charge.
37. To Max Born[1]
[Berlin,] 31. I. 21
Lieber Born!
Ich schreibe Ihnen heute hauptsächlich aus dem Grunde, weil ich das Kampfbeil
feierlich eingraben möchte. Ich habe mich nämlich mit Ihrer Frau der meinigen zu-
liebe gekabbelt, hauptsächlich eines übersalzenen Briefes wegen, den sie ihr ge-
schrieben
hatte.[2]
Nun ist aber wieder Gras darüber gewachsen, und es ist nicht
gut, wenn solche Kerle wie wir wegen solcher Bagatellen den Kontakt verlieren.
Das unglückliche Opus von Moszkowski ist erschienen ohne dass die Erde erzit-
terte (bisher) und ohne dass ich darin gelesen
hätte.[3]
Für Bogaslawski weiss ich