John Berry Haycraft was a professor in physiology

Physiology

Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

 and carried out important medical research.

Haycraft was born in London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 in 1875 and received his medical education in Edinburgh

Edinburgh

Edinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...

. He worked for a time in Ludwig

Ludwig

Ludwig may refer to:* Ludwig , a German name* Ludwig , a German surname* Ludwig , a 1972 film by Luchino Visconti about Ludwig II of Bavaria* Ludwig , a 1977 animated children's series...

's laboratory in Leipzig

Leipzig

Leipzig Leipzig has always been a trade city, situated during the time of the Holy Roman Empire at the intersection of the Via Regia and Via Imperii, two important trade routes. At one time, Leipzig was one of the major European centres of learning and culture in fields such as music and publishing...

.

In 1881 he was appointed chair of physiology at Masons College

Mason Science College

Mason Science College was founded by Josiah Mason in 1875, the buildings of which were opened in Edmund Street, Birmingham, England on 1 October 1880 by Thomas Henry Huxley...

, Birmingham

Birmingham

Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...

. He taught in Birmingham and attracted many students to the city. During his years in Birmingham and Edinburgh, Haycraft had been actively engaged in research and published papers on the coagulation

Coagulation

Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis, the cessation of blood loss from a damaged vessel, wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel...

 of blood

Blood

Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 and in 1884, he discovered that the leech

Leech

Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like other oligochaetes such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from other oligochaetes in significant ways...

 secreted a powerful anticoagulant

Anticoagulant

An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...

, which he named hirudin

Hirudin

Hirudin is a naturally occurring peptide in the salivary glands of medicinal leeches that has a blood anticoagulant property...

, although it was not isolated until the 1950s, nor its structure fully determined until 1976.

Haycraft returned to London 1892 and was appointed a research scholar of the British Medical Association

British Medical Association

The British Medical Association is the professional association and registered trade union for doctors in the United Kingdom. The association does not regulate or certify doctors, a responsibility which lies with the General Medical Council. The association’s headquarters are located in BMA House,...

.

In 1893 he was appointed chair of physiology at University College

University College

University College can refer to several institutions:- Canada :* University College, University of Toronto* University College of the North, The Pas, Manitoba* Booth University College, Winnipeg, Manitoba...

, Cardiff

Cardiff

Cardiff is the capital, largest city and most populous county of Wales and the 10th largest city in the United Kingdom. The city is Wales' chief commercial centre, the base for most national cultural and sporting institutions, the Welsh national media, and the seat of the National Assembly for...

where he worked until retirement in 1920. Haycraft died three years later.