Who were Dmitri Mendeleev's friends?

The famous ones were William Ramsay, a British scientist whose team was responsible for the isolation and characterization of the 5 (lighter) noble gas elements, and Aleksandr Borodin, the Russian scientist who investigated aldehydes, and who was responsible for much of the systematization of organic chemistry that led Mendeleev to try something similar with the chemistry of the elements. (Borodin was also a noteworthy composer). There was also a connection with Marie Curie through one of her relatives.