William Hewson

William Hewson was born on November. 14, 1739 in Hexham, Northumberland, England. The son of a respected local surgeon also named William Hewson. As was the custom in those days he did not attend medical school, so after attending Hexham Grammar School, he was apprenticed to his father, and was also a pupil of Richard Lambert of Newcastle. In 1759 he went to London, where he lodged with John Hunter. While attending lectures on anatomy given by Hunter's older brother William, he studied at Guy's and St. Thomas hospitals. When in 1760 William Hunter went abroad with the army, Hewson continued the lectures for the other pupils.

Recognizing his extraordinary ability, when William Hunter returned he offered to take Hewson on as a partner teaching anatomy, if Hewson would go to Edinborough and study for a year, which Hewson did. He returned to London in the winter of 1762 and began lectureing with Hunter which provided him a steady income. The Hunter brothers both studied and taught anatomy, but in addition to studying human anatomy they also studied the anatomy of fishes, birds and animals, as did Hewson when he came under their influence. Hewson became interested in blood, lymph and lymphatic organs such as the thymus which which he was one of the first to study microscopically. In 1770 Hewson married Mary Stevenson, with whose mother Benjamin Franklin lodged with when he came to London in 1757. Franklin stayed in London until 1775 and became good friends with Mary, whom he called "Polly". Hewson dedicated one of the books that he wrote to Benjamin Franklin.

Hewson was the first to show that the lymphatic system was not part of the circulation and that nodes are stopping points along the lymphatic vessels. He also demonstrated that all parts of the body drain into the lymphatic system and not just the small intestine, by using a dye which he showed ran throughout the body of an animal test subject. The lymphatic system is part of the immune system through which fluid and white blood cells are transported to the heart, and because all parts of the body drain into the lymphatic system it serves as as place where foreign particles can be detected by white blood cells.

Hewson also investigated blood coagulation. He was the first to identify that fibrinogen, the protein that causes blood to coagulate, is found in the plasma. Before it was believed that the protein was a constituent of red blood cells. He believed that it was contact with air that caused blood to coagulate, but this was later disproved by John Hunter who showed that blood could coagulate in a vacuum. It was due to the observations of Hewson that later scientists were able to discover all of the factors of the coagulation cascade, a series of proteins that activate fibrinogen and cause blood to coagulate.

In late April of 1774 Hewson accidentally wounded himself while dissecting a corpse. Septicemia followed and he died on May, 1, 1774 at the age of 34, and was buried at St. Martins in the Fields.

References:

Dameshek, William; "Editorial: William Hewson, Thymicologist; Father of Hematology"; Blood(1963)21:513-516

Doyle, Derek;"William Hewson(1739-1774): The Father of Haematology"; British Journal of Heamatology(2006)133:375-381

Stephen, Leslie and Lee, Sidney;"Hewson, William" in The Dictionary of National Biography Vol. 26; Smith, Elder and Co.; 1891