Recently the second volume of Józef Kowalewski (or Joseph Etienne Kowalewski, or Osip Mikhailovich Kovalevskiy)’s Mongolian-Russian-French Dictionary along with the author’s personal editorial notes was discovered in the St. Petersburg University Library. According to a small note attached to the inner side of the volume’s front cover it was presented to the library by Prof. Władysław Kotwicz in 1923. The 950 pages of the volume contain thousands of the author’s editorial notes that can be divided into two major groups – corrections and additions. Both types of editorial work were done by the author on all levels of the dictionary’s entries, running from corrections of inaccurate transcription of Mongolian words and their equivalents in various languages to new lexical material and extensive commentaries in European languages on Buddhist terms and personal names. J. Kowalewski’s editorial notes are of great value both for historians of academia and scholars of the Mongolian language and culture.