D O C U M E N T 1 4 7 O C T O B E R 1 9 1 9 2 1 1
Seien Sie herzlichst gegrüßt von Ihrem ergebenen
Hans Thirring
Meine kleine Schwester läßt schönstens grüßen und gratuliert
bestens![8]
ALS. [23 054]. There are perforations for a loose-leaf binder at the left margin of the document.
[1]Einstein 1919d (Vol. 7, Doc. 23).
[2]Gabriele d’Annunzio (1863–1938), Italian poet, novelist, and dramatist, seized the Dalmatian
port of Fiume (the present-day Rijeka) on 11–12 September 1919 in defiance of the Treaty of Ver-
sailles and his own government. His brazen act was matched by a flamboyant rhetorical style.
[3]Einstein left for Switzerland at the end of June.
[4]Thirring 1918.
[5]Received on 23 December, it was published as Thirring 1920.
[6]Arthur M. Schoenflies, building on the work of Leonhard Sohncke (Sohncke 1879), arranged
crystal forms into thirty-two classes and 230 space figure groups (Schoenflies 1891). Schoenflies
(1853–1928) was Professor of Mathematics at the University of Frankfurt am Main; Sohncke (1842–
1897) was Professor of Physics at the University of Munich. In 1913, Sir William H. Bragg (1862–
1942) and his son William Lawrence Bragg (1890–1971) had been the first to use X-ray diffraction
systematically in the investigation of the structure of crystals. Bragg’s law correlates directly the
wavelength of the X-rays with the spacing between the planes of an atomic lattice. The Braggs had
primarily worked on table salt crystals, NaCl.
[7]Kossel developed a general theory of the chemical bond, based on Bohr’s model of the atom, by
assuming that heteropolar (ionic) compounds are built up of atoms that have released or accepted one
or more valence electrons (see Kossel 1916). Max Born and Alfred Landé used this theory to calculate
the physical properties of ionic molecules, such as their size, the way they are arranged in crystals,
and the forces that arise when these crystals are exposed to deformation (see Born and Landé 1918a,
which was presented by Einstein to the Prussian Academy on 17 October 1918; see Vol. 8, entry of
that date in Calendar).
Einstein wrote a few comments on the crystal dynamics of NaCl on the verso of the preceding doc-
ument (see its descriptive note).
[8]Gretl Thirring (1897–?).
147. From Hugo Bergmann
77, Great Russell Street, London, W. C. 1. 22. Oktober, 1919.
Verehrter Herr Professor!
Ich hoffe, Sie erinnern sich noch der Zeiten, wo wir Sie in Prag haben durften
und wo ich bei Ihnen Seminar hoeren
konnte.[1]
Ich habe Prag im Fruehjar verlas-
sen, um als leitender Sekretaer des neugeschaffenen Erziehungs Departments der
Zionistischen Organisation, bei der Organisierung des Unterrichtswesens in Palae-
stina mitzuhelfen, vor allem, um an den Vorarbeiten fuer die hebraeische Universi-
taet teilzunehmen.
Es ist die Frage, dieser Universitaet, die mich veranlasst, Ihnen nach langer Zeit
wieder einmal zu schreiben. Der schoene Gedanke soll in den allernaechsten Jah-
ren verwirklicht werden. Der Weg von der Idee zur Wirklichkeit ist kein leichter.
Es muessen die Plaene fuer einen organischen Aufbau der Universitaet geschaffen