FDC made in the Soviet Union, 1961. The text on the envelope reads:”To the 100th anniversary of the birth of Nikolay Zelinsky”.
Nikolay Dimitrievich Zelinsky (1861-1953) was a Russian and Soviet chemist, an academician of the Academy of Sciences of the USSR.
Zelinsky studied at the University of Odessa and at the universities of Leipzig and Göttingen in Germany. Zelinsky was one of the founders of theory on organic catalysis. He was the inventor of the first effective filtering activated charcoal gas mask in the world (1915).