Letters received from Eduard Bernstein 1887-1911, Gustave Brocher and Victorine Brocher-Rouchy 1881-1904, Général G. Cluseret 1873-1876, 1880, Ferdinand Domela Nieuwenhuis 1899-1914, Pierre Fluse 1874-1904, James Guillaume 1873 and n.d., Johann Most 1884-1886, Emilie and Julius Motteler 1894-1914, Maurice Pelloutier 1900-1903, Paul Robin 1899-1908, Georges Sorel 1902-1910, Max Trautner 1888 and others; manuscripts of the preface to his translation of Louis Büchner's Force et matière , of `The international police spies', of a critical review of Josef Peukert's memoirs, etc.; records on the trial in Leipzig against Josef Breuder, Dave and others, accused of high treason 1880-1881; file concerning the arrest in Germany of Johann (John) Neve, administrator of Freiheit London, 1885-1888; file on the controversy between the group Most/Dave and Peukert/Charles Theodor Reuss, started within the Communistischer Arbeiter Bildungs Verein (CABV) in London 1886-1887; some membership cards, notes, press clippings and copies of periodicals relevant to the archive.