FDC made in the Soviet Union, 1980. The text on the envelope reads:”Monument A.M. Butlerov”. Alexander Mikhaylovich Butlerov (1828-1886) was a Russian chemist, one of the principal creators of the theory of chemical structure (1857–1861), the first to incorporate double bonds into structural formulas, the discoverer of hexamine (1859), the discoverer of formaldehyde (1859) and the discoverer of the formose reaction (1861). He first proposed the idea of possible tetrahedral arrangement of valence bonds in carbon compounds in 1862. The crater Butlerov on the Moon is named after him.