Allies and Central Powers against each other, obtaining art works and funds from both, making use of their need to stimulate their respective propaganda efforts. While active as a promoter, Tzara also published his first volume of collected poetry, the 1918 Vingt-cinq poèmes ("Twenty-five Poems"). A major event took place in autumn 1918, when Francis Picabia, who was then publisher of 391 magazine and a distant Dada affiliate, visited Zürich and introduced his colleagues there to his nihilistic views on art and reason. In the United States, Picabia, Man Ray and Marcel Duchamp had earlier set up their own version of Dada. This circle, based in New York City, sought affiliation with Tzara's only in 1921, when they jokingly asked him to grant them permission to use "Dada" as their own name (to which Tzara replied: "Dada belongs to everybody"). The visit was credited by Richter with boosting the Romanian author's status, but also with making Tzara himself "switch suddenly from a position of balance between art and anti-art into the stratospheric regions of pure and joyful nothingness." The movement subsequently organized its last major Swiss show, held at the Saal zur Kaufleutern, with choreography by Susanne Perrottet, Sophie Taeuber-Arp, and with the participation of Käthe Wulff, Hans Heusser, Tzara, Hans Richter and Walter Serner. It was there that Serner read from his 1918 essay, whose very title advocated Letzte Lockerung ("Final Dissolution"): this part is believed to have caused the subsequent mêlée, during which the public attacked the performers and succeeded in interrupting, but not canceling, the show. Following the November 1918 Armistice with Germany, Dada's evolution was marked by political developments. In October 1919, Tzara, Arp and Otto Flake began publishing Der Zeltweg, a journal aimed at further popularizing Dada in a post-war world were the borders were again accessible. Richter, who admits that the magazine was "rather tame", also notes that Tzara and his colleagues were dealing with the impact of communist revolutions, in particular the October Revolution and the German revolts of 1918, which "had stirred men's minds, divided men's interests and diverted energies in the direction of political change." The same commentator, however, dismisses those accounts which, he believes, led readers to believe that Der Zeltweg was "an association of revolutionary artists." According to one account rendered by historian Robert Levy, Tzara shared company with a group of Romanian communist students, and, as such, may