Periodic table centre and the transition metals, lanthanides, and actinides occupying peninsulas. Most periodic tables are two-dimensional; three-dimensional tables are known to as far back as at least 1862 (pre-dating Mendeleev's two-dimensional table of 1869). More recent examples include Courtines' Periodic Classification (1925), Wringley's Lamina System (1949), Giguère's Periodic helix (1965) and Dufour's Periodic Tree (1996). Going one further, Stowe's Physicist's Periodic Table (1989) has been described as being four-dimensional (having three spatial dimensions and one colour dimension). The various forms of periodic tables can be thought of as lying on a chemistry–physics continuum. Towards the chemistry end of the continuum can
History of the periodic table in an obscure Russian journal and then republished in a German journal, "Zeitschrift für Chemie". In it, Mendeleev stated that: Scientific benefits of Mendeleev's table Unknown to Mendeleev, a German chemist, Lothar Meyer, was also working on a periodic table. Although his work was published in 1864, and was done independently of Mendeleev, few historians regard him as an equal co-creator of the periodic table. Meyer's table only included twenty-eight elements, which were not classified by atomic weight, but by valence, and he never reached the idea of predicting new elements and correcting atomic weights. A few months after Mendeleev