D O C U M E N T S 1 8 , 1 9 J U LY 1 9 2 7 6 7 ALS. [6 061]. [1] Barthel (1904–1980) was a doctoral student in chemistry at the University of Strasbourg. [2] Einstein 1912b and 1912f (Vol. 6, Docs. 2 and 5). [3]  is the radiation energy density. [4] A subscript 0 is missing (see the equation below). [5] Molecules of type 1 are dissociated in molecules of types 2 and 3 are the corres- ponding numbers of moles in the volume V. (and A below) are constants. [6] Eq. (4b) in Vol. 6, Doc. 2) has  where Barthel has . N is Avogadro’s constant, and  is the quantum of energy. See Einstein’s eq. (4afor the meaning of . 18. Elsa Einstein to Reichsbund Jüdischer Frontsoldaten[1] [Berlin, after 6 July 1927][2] Das Protektorat kann mein Mann nicht mitübernehmen trotz der Sympathie für die geplante Veranstaltung, da er mit den allgemeinen Tendenzen Ihres Vereins nicht übereinstimmt.[3] ADftL. [44 040]. Written at the bottom of Abs. 54 in Einstein’s hand. [1] The Reichsbund was established in 1920 by the retired army captain Leo Löwenstein “for the purpose of defending Jews from their detractors” and to contribute to the welfare of the former com- batants. Its forerunner, the Vaterländischer Bund jüdischer Frontsoldaten, had been founded in early 1919 as a reaction to the “Jewish census” (“Judenzählung”), held by the Prussian War Ministry in October 1916, which counted the number of Jews in the German army in response to accusations of underrepresentation of Jewish soldiers participating in the war (see Dunker 1977, pp. 186–187 Niewyk 2001, pp. 89–90 and Benz 2012, p. 515). [2] Dated by the fact that it is a draft for a reply to Abs. 54. [3] The Reichsbund had asked Einstein to take on co-patronage of a charity event for unemployed Jewish veterans, widows, and orphans (see Abs. 54). Einstein would have opposed the Reichsbund’s fervent German nationalism and its advocacy of an active campaign against anti-Semitism. For his views on combating anti-Semitism, see Einstein to Central Association of German Citizens of the Jewish Faith, 5 April 1920 (Vol. 9, Doc. 368). 19. To Elsa Einstein [Zurich, 9 July 1927] Liebe Else! Bin soeben glücklich in Zürich angekommen, von Tete[1] erwartet. Konnte kaum über die Grenze, da ich keinen Pass bei mir hatte. Musste 10 fr. deponieren. n 1 n 2 n 3   A  1  + ------------