Czech internist and serologist, 1873-1921. Prague; Baltimore.
Jan Jansky in 1907 classified human blood into four groups. Jan Jansky, born in 1873, graduated in the Medicine Faculty of the Carolina University of the Prague, specializing in Neurology and Psychiatry.
Dr. Jan Jansky dedicated himself to the investigations of laboratory, with the aim of clarifying a relationship between the mental upheavals and the composition of the blood. He analyzed more than three thousand samples of the blood of its patients.
The doctor wanted to find out if the serum of the psychotic patients, especially schizophrenic, differs by its coagulation characteristics from the one from the normal people. Interestingly, this was proved with more sophisticated methods almost a century later. With the coagulation of the blood, Dr. Jan Jansky established in 1907 four blood groups that nowadays we call A, B, O and AB.
With his discovery it made possible to make the transfusions without the danger that the patient died when receiving the blood of an inadequate donor. The Dr. Jansky published its discovery in the titled work "Hematologic Studies in Mental patients". In 1921 it accepted the definition of the blood groups established by the Dr. Jansky the Association of the North American doctors.