I N T R O D U C T I O N T O V O L U M E 1 4 l x x x i i i occupied Austria, searched my apartment and took away all correspondence with Jewish-German sci- entists including Einstein’s postcards. Thus, right now, I have no letters or postcards left from Ein- stein’s hand” (Hermann Mark to Gerald Holton, 9 January 1986 [78 656]). [12]See Compton 1922. [13]See Debye 1923 and Compton 1923b. [14]Pauli 1923. [15]See Lorentz 1912, pp. 37–39. [16]See Klein, M. 1964, p. 24. [17]On the background to the rioting, the outbreak of violence, and the rumors of a right-wing putsch, see Large 2002 Niewyk 2001, p. 51 and Diehl 1977, pp. 147–150. On the wider political background to the events in Berlin, especially the ongoing German government crisis in the summer and fall of 1923, see Fulbrook 2002, pp. 26–29 Schulze 1998, pp. 254–271 and Winkler 1993, pp. 199–243. [18]The relevant passage in the document is fragmented. [19]See Einstein to H. Anschütz-Kaempfe, 17 September 1921 (Vol. 12, Doc. 237) Einstein to Max Schuler, 1 December 1921 (Vol. 12, Doc. 309) and Einstein to H. Anschütz-Kaempfe, 18 June 1922 (Vol. 13, Doc. 239). [20]See Piccard and Kessler 1925. [21]On developments in the German economy, see Feldman 1997, pp. 631–852. [22]A TDS of this biography is available (see “Albert Einstein—Beitrag für sein Lebensbild” [73 880]). An excerpt was published in Vol. 1, pp. xlviii–lxvi. [23]See Vossische Zeitung and Berliner Tageblatt, 1 February 1925, and Jewish Telegraphic Agency Daily News Bulletin, 2 February 1925. [24]See Einstein to Niels Bohr, 10 January 1923 (Vol. 13, Doc. 421), and Seelig 1960, p. 90. [25]Likewise, in Einstein 1925g (Doc. 220), Einstein writes that he “shall try to avoid controversial philosophical questions as much as possible.” [26]The same challenge can be launched against the neo-Kantian approaches of Hans Reichenbach (Reichenbach 1920) and Ernst Cassirer (Cassirer 1921) for discussion see Hentschel 1987, 1990, Ryckman 2005, and Howard 2014. [27]See Winteler-Einstein 1924 (Vol. I, p. lxii). [28]See Ben-Menahem 2001 and Ben-Menahem 2006 for more on the role of conventions in Ein- stein's views. [29]For a discussion of “Geometry and Experience” (Vol. 7, Doc. 52) in a wider historical context of debates between different traditions in geometry and their philosophical reception, see Giovanelli 2012, esp. pp. 3836–3839. [30]Bohr, Kramers, and Slater 1924a, 1924b. [31]Jordan 1924. [32]Bothe and Geiger 1925a and 1925b, respectively. [33]By the end of July, press reports on his returning to the ICIC appeared, yet these must have been erroneous (Doc. 97). [34]See Release from Württemberg Citizenship, 28 January 1896 (Vol. 1, Doc. 16) Vol. 1, the edi- torial note, “Swiss Citizenship,” pp. 239–241 Einstein to Arnold Sommerfeld, 28 January 1922 (Vol. 13, Doc. 41) Heinrich Lüders to Einstein, 15 February 1923 (Vol. 13, Doc. 431) and Einstein to Heinrich Lüders, 24 March 1923 (Vol. 13, Doc. 454). [35]See Mehra 1975, p. 125. [36]See, e.g., Planck 1906. [37]In view of the significance of Bose’s paper for Einstein’s subsequent work on the quantum the- ory of material gases, we have included Einstein’s translation of Bose’s paper together with his com- ment as Doc. 278. [38]See Ehrenfest 1911 and Ehrenfest and Kamerlingh Onnes 1915. [39]Regarding the realization of the connection between the condensation phenomenon and phase transition, see Pais 1982, p. 432, point (3). [40]The predicted behavior was first observed experimentally in 1995 in a gas of rubidium atoms cooled to 170 nano-Kelvin. A Nobel Prize was awarded in 2005.