A composer would write his pieces with a pencil, while a chemist covered these inscriptions with gelatin and egg albumen to make them more durable. The chemist was on friendly terms with Mendeleyev and Butlerov, while the composer was a member of the Mighty Group. These were not two different persons, but constituted one and the same man – the best chemist among composers and best composer among chemists. Taking color from Lermontov, we may call this date the Day of Borodin. Chemist and composer Alexander Borodin featured Leonardo’s complex. This psychological term means that he tried to express himself in different professions. His teacher, professor Zinin reproached Borodin for trying to kill two birds with one stone. Having heard his wonderful music, however, the professor gave the green light to hunting two birds at once. The hunt was difficult: Alexander Borodin, busy with research and pedagogical activities, would compose music in the rare time of rest or illness. He would even complain about his music mates wishing falling ill to him instead of health. The academician and head of chemistry department at the Medical Surgery Academy of Saint Petersburg was a self-rigorous man. That is why his musical heritage was not as great as it could have been. He had been writing the main music piece of his life – opera Prince Igor – for 18 years and failed to finish it. It was finished by Rimsky-Korsakov and Glazunov. On the other hand, his contribution to chemistry is substantial enough. Moreover, it would have been even greater, if the government had taken care of scientific development and allocated more money for research.