Jan Jansky
Janský, Ján
Born Apr. 3, 1873, in Smichov, near Prague; died Sept. 8, 1921, in Černošice. Czech physician.
Janský graduated from the University of Prague in 1898. He became a professor at the university’s psychoneurology clinic in 1914. His studies on hemagglutination in mental patients confirmed that there are four blood groups, rather than the three groups discovered by K. Landsteiner. Janský was thus the first to describe accurately the blood group system. He published the results of his research in 1907 in Hematological Studies on Mental Patients.