SCHALLAUSBREITUNG IN TEILWEISE DISSOZIIERTEN GASEN. [Propagation of Sound in Partly Dissociated Gases.] Sitzungsberichte der Preussischen Akademie der Wissenschaften, XVIII (1920). Sitzung der physikalisch-mathematischen Klasse vom 8. April. Sonderabdruck [Offprint]).

First offprint in the original wrappers, of Einstein's paper on the subject of intermolecular forces. - Edition: In this work Einstein calculated the rate of chemical reactions in a gas by means of observations on the propagation of sound (see Mason, »Physical Acoustics«, p. 13), an important contribution to modern acoustics. - Condition: Very fine indeed. - Rarity: According to Weil early offprints of Einstein’s papers may also be qualified as original and also highly collectable editions, however they were printed in a certain, but still small print run for commercial use (mainly to sell them to fellow natural scientists): „No doubt, the first appearance in a periodical is the „original edition“, but I have to leave it open for collectors, librarians and others to decide whether these offprints in wrappers, mostly with a printed title on them (especially in the »Sitzungsberichte der Königlich Preussischen Akademie der Wissenschaften«) are also „original editions“. These offprints are printed from the same setting as the text, but often with new pagination.“ (p. 4). Additionally to offprints like the present, some copies bearing the imprint „Überreicht vom Verfasser“ [Presented by the Author]. ABPC (1973ff.) and APO (1988ff.) record only 1 copy of this edition at auction (2011). - Reference: Boni-Russ-L. 119; Collected Papers, vol. 7, 39; Schilpp-Shields 135; Weil 110.