Academician Vladimir Vernadsky:  the years of hardship (February 1917 — February 1921)

ominent natural scientists of the first half of the 20th century. As a researcher and thinker, organizer of scientific teams and public figure, essay writer and historian of science, he made a great contribution to the development of geochemistry, mineralogy, and crystallography, created such new scientific fields as biogeochemistry and radiogeology, was the first to study the role of animate matter in geological processes, and filled the notions of biosphere and noosphere with new scientific content. The essay is dedicated to the difficult period in the scientist’s life when he was forced to live first in Ukraine (in Poltava and Kiev) and later in the Crimea (in Simferopol).