Many know of the outstanding talent and creative thinking of Dmitri Mendeleev, which adorned the walls of chemistry classrooms with his portraits. However, not everyone is aware that he once had to act as a spy. For a long time, scientific discoveries played a crucial role in the defense capabilities of countries. This was also true in the 1880s, when the French invented smokeless powder and nearly mastered pyroxylin. Before this, regular gunpowder was used in armies, which created a cloud of smoke when fired, obstructing visibility and rendering further shooting pointless. Additionally, it was very sensitive to moisture.

The French made a significant breakthrough, and the Ministry of the Navy asked Mendeleev to study their discovery. Dmitri Ivanovich agreed and traveled to France, officially as part of scientific activities. There, he visited chemical laboratories and even infiltrated a factory producing smokeless powder. However, he was unable to learn the secrets of processing pyroxylin due to strict confidentiality.

Then Mendeleev resorted to cunning. Learning about a railway line leading to the factory, he bought up all the magazines and newspapers in nearby shops and studied the train schedules. Based on data about the supply of cellulose, sulfuric, and nitric acids, he was able to calculate the approximate proportions of the chemical composition of French pyroxylin. With this important information, he returned to his homeland and subsequently significantly improved French pyroxylin.