Jan Janský (; 3 April 1873 – 8 September 1921) was a Czech
serologist,
neurologist
Neurology (from , "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the brain, the ...
and
psychiatrist
A psychiatrist is a physician who specializes in psychiatry. Psychiatrists are physicians who evaluate patients to determine whether their symptoms are the result of a physical illness, a combination of physical and mental ailments or strictly ...
. He is credited with the classification of
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells.
Blood is com ...
into four
types
Type may refer to:
Science and technology Computing
* Typing, producing text via a keyboard, typewriter, etc.
* Data type, collection of values used for computations.
* File type
* TYPE (DOS command), a command to display contents of a file.
* Ty ...
(I, II, III, IV).
Life and education

Janský was born on 3 April 1873 in
SmÃchov (now part of
Prague
Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...
). He studied
medicine
Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...
at
Charles University
Charles University (CUNI; , UK; ; ), or historically as the University of Prague (), is the largest university in the Czech Republic. It is one of the List of oldest universities in continuous operation, oldest universities in the world in conti ...
in Prague. From 1899, he worked in the
Psychiatric Clinic in Prague. In 1914, he was named
professor
Professor (commonly abbreviated as Prof.) is an Academy, academic rank at university, universities and other tertiary education, post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin ...
. During
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
, Janský served two years as a doctor at the front until a heart attack disabled him. After the war he worked as a
neuropsychiatrist in a military Hospital (''Vojenská nemocnice''). He had angina pectoralis and died of
ischaemic heart disease in
Dolnà Mokropsy on 8 September 1921, at the age of 48.
Janský was also a proponent of voluntary
blood donation
A 'blood donation'' occurs when a person voluntarily has blood drawn and used for transfusions and/or made into biopharmaceutical medications by a process called fractionation (separation of whole blood components). A donation may be of wh ...
s.
Classification
Through his psychiatric research, Janský tried to find a correlation between mental diseases and
blood diseases. He found no such correlation existed and published a study, ''Hematologická studie u psychotiků'' (1907, ''Hematological study of psychotics''), in which he classified blood into four groups, I, II, III, and IV. (At the time, Janský was unaware of the work of
Karl Landsteiner, whose discovery of the A, B, and O blood types earned him the
Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine () is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, acco ...
in 1930.) At the time Janský's discovery passed almost unnoticed. In 1921 an American medical commission acknowledged Janský's classification. A similar classification was described by
William Lorenzo Moss
William Lorenzo Moss (23 August 1876 – August 12, 1957) was an American physician and professor of medicine. He developed the Moss System of blood groups in 1910 which was used to ensure safe blood transfusions before more detailed classification ...
, except the I and IV of Moss were the opposite to that of Janský's, leading to confusion in
blood transfusion
Blood transfusion is the process of transferring blood products into a person's Circulatory system, circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used ...
until the use of A, B and O became standard.
Legacy
* Frequent voluntary blood donors in the
Czech Republic
The Czech Republic, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...
and
Slovakia
Slovakia, officially the Slovak Republic, is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the west, and the Czech Republic to the northwest. Slovakia's m ...
are awarded with Janský medal (''Janského plaketa'').
*
The Secret of Blood, a 1953 Czechoslovak film about his discovery.
References
External links
Biographyon zivotopisyonline.cz
{{DEFAULTSORT:Jansky, Jan
1873 births
1921 deaths
Czech neurologists
Hematology
Serologists
Blood
Charles University alumni
Academic staff of Charles University
Czech psychiatrists
Scientists from Prague
Deaths from coronary artery disease
Psychiatrists from Austria-Hungary
Czechoslovak psychiatrists