Relationships and Family 

Jan Jansky was a Czech neurologist, psychiatrist and serologist. He was born on the 3rd of April, 1873 in the district of Smichov. He had a younger brother and a sister named Karla who married Alois Rasin, one of the founders of Czechoslovakia and former Minister of Finance, making him Jansky’s brother-in-law. On June 14th, 1899, Jansky married Hedvika Beckova with whom he had two sons – Stanislav (born in 1900) and Jan (born in 1902). They lived together in the district of Smichov and later they moved to the district of Nove Mesto. 

Biography 

In 1892, Jansky graduated from secondary school in the district of Smichov. Soon  after graduation, he started studying medicine at the Faculty of Medicine of Charles-Ferdinand University1 in Prague. He finished his studies in 1898 and started working as an assistant to Professor Karel Kuffner, the founder of Czech scientific psychiatry. Later Jansky started working as a doctor at a Czech psychiatric clinic. Apart from that, he was also working as an expert witness in psychiatry. In 1914, Jansky became Professor and the deputy head of the psychiatric clinic in Prague. 

At the beginning of World War I, Jansky went into the service as a doctor but in 1916 he was released from service due to a heart attack and went back to his home country. After World War I, he became the head of the neuro-psychiatric ward of Military Hospital in Prague. Three years later, on September 8th, 1921, Jansky died of tonsillitis at the age of 48. 

Blood Classification 

As a psychiatrist, Jansky focused on the relationship between blood agglutination and mental disorders. In 1906, after years of research, he concluded that there is no connection between blood agglutination and mental disorders. Despite that, he discovered that according to certain differences in the properties of blood cells, human blood can be divided into four groups, so due to serendipity Jansky discovered the four blood types in 1907. However, he did not name them as it is today (A, B, AB and 0); he assigned them Roman numerals (I, II, III and IV). Unfortunately, after this revolutionary discovery, Jansky no longer paid attention to blood research and focused on psychiatry and his own neurological research into the cerebrospinal fluid. 

Today, Jan Jansky is known as the founder of four blood types but it was not always the case. Karl Landsteiner, a pathologist from Vienna, worked on the same research as Jansky. In 1900 he concluded that there are three types of blood – A, B, and C. Two colleagues of his discovered the fourth blood type naming it “the exception from Landsteiner’s rule” but the first to name the blood types correctly was Jansky in 1907.