Thinkers Timeline

Dmitri Ivanovich Mendeleev (1834-1907) was a Russian chemist who devised the periodic table of the elements, one of the most important organising schemes in the history of science. He was born in Tobolsk, Siberia, the youngest of what may have been as many as seventeen children. His father, a teacher of philosophy and literature, went blind and then died when Dmitri was still young; his mother kept the family going by running a glass factory. When the factory burned down, she travelled more than two thousand kilometres by horse and cart to take her gifted youngest son to St Petersburg, where she eventually placed him in what became his university. He completed his studies there and went on to postgraduate research in Heidelberg and Paris before returning to teach in St Petersburg. In 1869, while preparing a chemistry textbook, he arranged the known chemical elements in order of atomic weight and noticed that their properties repeated at regular intervals. He published his first periodic table that year. The table left gaps for elements he predicted would be discovered, with detailed forecasts of their properties; when gallium, scandium, and germanium were found in the following decades and matched his predictions, the table's power became undeniable. Mendeleev was also a practical scientist who worked on Russian oil production, agriculture, metrology, and economics. He never received the Nobel Prize, despite being nominated. He died in St Petersburg in 1907.