3 6 4 D O C U M E N T 2 2 0 J U N E 1 9 2 8 Published in Preußische Akademie der Wissenschaften (Berlin). Physikalisch-mathematische Klasse. Sitzungsberichte (1928): 224–227. A manuscript ([4 025]) is also available. [1] Submitted by Max Planck (see Abs. 593). [2] See Einstein 1928n (Doc. 216). [3] In the manuscript, “daher nicht unwahrscheinlich.” [4] In the manuscript, “verdrängen und ersetzen.” [5] The three terms on the right-hand side of (1a) should be multiplied instead of separated by com- mas, as in the draft. [6] The footnote is not in the draft it must have been added in the proofs. For discussion of this inde- terminacy, see Einstein’s correspondence with Chaim Herman Müntz, especially Docs. 245 and 258. [7] Equations (5) give rise to corresponding identities for equations (7), and thus to the identities that Einstein writes down explicitly at the top of page 227. [8] Einstein also takes quantities like to be of second order (see Doc. 251). [9] For discussion of this alternative Lagrangian in comparison to the one chosen at the beginning of this document, see Einstein’s correspondence with Müntz, especially Docs. 245, 247, 250, and 256. 220. To the Association of Free Socialist Youth[1] [Berlin,] 14. Juni 1928 Nach meiner Ansicht ist es vom Standpunkt der internationalen politischen Be- ziehungen von erheblicher Bedeutung, dass Ihre Vereinigung bei dem Kongress in Warschau vertreten ist.[2] Es ist deshalb nach meiner Ueberzeugung sehr zu wün- schen, dass Sie durch Zuwendung der nötigen Mittel in den Stand gesetzt werden, sich dort vertreten zu lassen.— Mit ausgezeichneter Hochachtung TLC. [45 714]. Addressed “Bund freier sozialistischer Jugend Zehlendorf-M. verl. Riemeister- str.122.” Enclosed in Abs. 598. [1] The Bund freier sozialistischer Jugend was founded in 1926 as a left-wing socialist youth orga- nization through the amalgamation of proletarian and bourgeois youth movement associations. Ideo- logically, it was pacifist in nature and aimed to be independent of both the SPD and the KPD (see Stambolis 2013, p. 47 Holler 2014, pp. 180–181 and Reulecke 2014, p. 149). [2] For the Bund’s appeal for help in participating in the Warsaw conference, see Abs. 591. k  a k  x -----------