The Commission concluded in 1876 that the mediumistic phenomena it examined were produced either by unconscious muscular movement or by conscious deception, and that, in the words of its report, Spiritualist doctrine was superstition. Mendeleev set out the case in detail in his own subsequent publication, Materials for a Judgement about Spiritualism, treating the episode as a model of how established science should respond to a popular supernatural claim: not by refusing to look, but by looking under carefully controlled conditions and publishing the result.
The verdict did not end Spiritualism's popularity in Russia, and Mendeleev's colleagues Butlerov and Vagner, both members of the Commission itself, remained unconvinced by its conclusions, a genuine and documented scientific disagreement rather than a settled consensus even within the investigating body. The episode places Mendeleev, alongside later twentieth century figures such as Paul Kurtz and James Randi, within a specific historical lineage of scientists who treated paranormal claims as directly testable propositions rather than matters of taste, and who used their own institutional standing to organize a formal test.
Mendeleev framed the episode as a matter of scientific responsibility: a science confident enough to organize matter into a periodic law owed the public a rigorous, open test of a popular claim rather than private dismissal from the sidelines.