It is shown that Schröder's discussion of the logic of relatives coined by Peirce led to a deep change in his conception of the role of logic in founding mathematics. His algebra and logic of relatives became the pasigraphic key for the creation of a scientific universal language, which he had already demanded programmatically in his early semiotic writings, and which should also become the instrument to set up ал "absolute algebra", a general theory of connexion. Therefore Schröder's logical writings in the years between 1895 and 1901 do not chiefly deal with the application of mathematical methods to the analysis of logic, but, rather in accordance with the basic logistic thesis, with the description and analysis of mathematics by the means of logic. Schröder's turn to logicism is documented with published and up to now unpublished testimonies. The relevant parts of Schröder's correspondence with Paul Carus and Felix Klein are edited in the appendices.

A description is given of the holdings of the Bertrand Russell Archives relating specifically to Schröder. These include Russell's copy of various works of Schröder, as well as Russell's none too numerous or detailed notes on these materials. There is no Russell-Schröder correspondence, although Schröder figures in Russell's correspondence with others, primarily with Р. E. В. Jourdain and with Louis Couturat.

Russell's appraisal of Schröder's work was largely negative, and there is relatively little in the Russell Archives that relates to Schröder. What material there is, however, reenforces the conclusion drawn from published pronouncements in The principles of mathematics and elsewhere that Russell had little regard for Schröder's work in particular or for the entire algebraic tradition in general.