"Mendeleev's chemistry textbook, his main work, was first published in Russia in 1868-1871 under the title Osnovy khimii. Mendeleev's work on his textbook led him to the discovery of the periodic law, by which the elements are arranged by atomic weight in groups with related chemical and physical properties. Despite the work's importance, it did not appear in a Western European language until two decades after its first publication, when it was translated into both English and German. Both translations were based on the fifth Russian edition." (Norman 1493)