Result as obtained by Duchinski: Russia is a name usurped by the Muscovites. They are not Slavs; they do not belong to the Indo-Germanic race at all, they are des intrus [intruders], who must be chased back across the Dnieper, etc. Panslavism in the Russian sense is a cabinet invention, etc. I wish that Duchinski were right and at all events that this view would prevail among the Slavs. On the other hand, he states that some of the peoples in Turkey, such as Bulgars, e.g., who had previously been regarded as Slavs, are non-Slav.

Letter sent to Engels in 24 June 1865.
As reported in: Karl Marx, Frederick Engels: 1864-68 (Lawrence & Wishart, 1987), p. 164