‘The Russian genius: Mendeleev’ covers the life and work of Dmitri Mendeleev, who not only discovered the periodic system, but also recognized that it pointed to the periodic law. Mendeleev was rejected by Moscow University on race grounds, so studied at St Petersburg before moving to Germany. Mendeleev differed from rival chemists in that he rejected the notion of the unity of matter, Prout’s hypothesis, and the notion of triads. In a single day in 1869, he sketched out an entire periodic table. This table made many accurate predictions, but also made some mistakes. Inert gases, when first isolated in 1894, struggled to fit into Mendeleev’s periodic table, but in 1900 they were successfully accommodated.