Jan Jánský–a prominent Czech physician

Throughout history, blood has been a bit of a mystery to people. They knew it was impossible to live without it, but they didn't know why. At the same time, they knew nothing at all about its composition or even about the modern-day blood types. Most of the discoveries concerning this life-giving fluid have only happened thanks to the invention of quality microscopes and medical procedures in the last 150 years. In connection with blood, Jan Jánský, a native of Prague and a physician, comes on the scene, confirming though experimentation the existence of 4 different basic blood types. And this year, on April 3rd, we commemorate 150 years since his birth.

Jánský in a nutshell

Jan was born on 3 April 1873 in the Prague district of Smíchov, then a village on the outskirts of Prague. He studied medicine at the University of Prague and after graduating, decided to pursue a career as a psychiatrist. Around 1900, his sons were born. Since the First World War, during which he served as a military doctor, he developed heart problems that resulted in the then incurable angina pectoris. He died in Central Bohemia not far from Prague at a relatively young age of 48 on 8 September 1921. But how did a psychiatrist get into blood type research? It's an incredible story.

Medical practice and research

As a psychiatrist working in Prague, he dealt, among other things, with the relationship between blood clotting and mental disorders. It was fashionable at the time for mental disorders to be seen as being triggered by various blood disorders. After several years of research, he concluded that there was no connection between blood clotting and human mental illness. Based on these findings, he wrote a scientific treatise and in November 1906 gave a lecture on this topic. In a sample of 3,160 mentally ill patients he examined, he demonstrated that human blood can be divided into 4 basic types according to specific differences in the properties of red blood cells. In 1907, his work was published, with the four basic blood types he described being somewhat of a by-product of this originally divergent research! However, he did not go on to do further research on blood and focused solely on psychiatry and neurological disorders. He intensively researched the nature and significance of cerebrospinal fluid.

Who discovered blood types?

Encyclopaedias generally note that blood types were discovered by the Austrian physician Karl Landsteiner, who received the Nobel Prize in 1930 for his life's work. It is true that the basic division of blood into groups was described by Landsteiner in 1901. But at that time, he described only 3 groups. The fourth was described by other doctors a few years later. In 1907, Janský came to the same conclusions, independently of them, also proving the existence of the fourth group, and was therefore the first to correctly classify the four blood types as we know them today. These doctors did not know of each other at all. And lastly, the American physician W. L. Moss researched the blood types independently of his European colleagues. He heard about Jánský only after his discoveries and before their publication in 1910. He humbly acknowledged that he was not the first, and that he gave precedence to Jánský. It can be said here that blood types have more than one discoverer and it is by mere chance that the discoveries were published in the local medical journals only a few years apart. However, Jánský, being a specialist in psychiatry, did not further address of build on his research. Unlike the Austrian physician K. Landsteiner, who dedicated his life to blood research, and who is currently listed as the main discoverer.