(b. Hexham, Northumberland, England, 14 November 1739; d. London, England, 1 May 1774)
Hewson, son of a country surgeon, was trained in medicine at Newcastle-on-Tyne and went in 1759 to William Hunter’s anatomy school in London, where he also attended St. Thomas’s and Guy’s hospitals. After a winter’s course at Edinburgh in 1761–1762, he became assistant and partner in Hunter’s school. In 1767 he published the first practical account of paracentesis of the thorax in cases of emphysema, later admitting that this operation had been proposed by others.
During 1768–1769 Hewson read three papers to the Royal Society on his exploration of the lymphatic system in the lower vertebrates, which led to a priority dispute with Alexander Monro II; John Hunter also claimed to have preceded him. Hewson had in fact made a more complete demonstration of his subject than any of his predecessors through the previous century. He was elected a fellow of the Royal Society on 8 March 1770 and was awarded the Copley Medal in November. He continued as Hunter’s resident assistant until his marriage to Mary Stevenson on 10 July 1770. Hunter proposed in 1771 to dissolve the partnership because Hewson no longer lived in the school, while Hewson claimed personal ownership of preparations that he had made while teaching there. Benjamin Franklin effected their reconciliation, but Hewson set up his own school in Craven Street in September 1772.
Hewson had reported his microscopical research on blood to the Royal Society during 1770. By well-planned experiments and precise thermometry he ascertained the role of fibrinogen and gave the first valid account of coagulation. Microscopy was little practiced because the compound microscopes of the time produced distortions and current methods of preparing tissue for examination were inadequate. Hewson relied on a single lens and devised a satisfactory means of mounting “wet” specimens. He was the first to observe the lymphocytes in the thymus and spleen and concluded that their production was the function of these glands. He republished his papers on the blood in 1771, adding a long appendix on his dispute with Monro about the lymphatics. He reported his observations on the red corpuscles in 1773, showing that they were discoid—not spherical, as was believed—but mistaking the dark center of the disk for a nucleus. He was also the first to describe clearly the three parts of the blood, components already known to contemporary anatomists.
Early in 1774 Hewson republished his papers on the lymphatics. After his death, from the effects of a dissection wound, his school and researches were continued by Magnus Falconar, who married Hewson’s sister Dorothy on 7 September 1774. Falconar repeated Hewson’s experiments on the spleen and thymus and in 1777 published his corroboration with a reprint of Hewson’s paper on the red corpuscles. He died of phthisis on 24 March 1778, aged twenty-three; his and Hewson’s joint museum was sold that October.
I. Original Works. Hewson’s MSS are held in the archives of the Royal Society of London. His articles and books are listed in his Works (1846), pp. xix-l; and the books alone in K. F. Russell, British Anatomy 1525–1800 a Bibliography (Melbourne, 1963), pp. 127–129. They include “The Operation of Paracentesis Thoracis,” in Medical Observations and Inquiries, 3 (1767), 372–396; “The Lymphatic System in Birds,... in Amphibious Animals,... in Fish,” in Philosophical Transactions of the Royal Society, 58 (1768), 217–226, and 59 (1769), 198–203, 204–215; “Experiments on the Blood”; “On the Degree of Heat Which Coagulates the Lymph”; “Further Remarks on the Properties of Coagulable Lymph,” ibid.,60 (1770), 368–383, 384–397, and 398–413, respectively; An Experimental Inquiry Into the Properties of the Blood, and an Appendix Relating to the Discovery of the Lymphatic System (London, 1771); “On the Figure and Composition of the Red Globules,” in Philosophical Transactions of the Royal Society, 63 (1773), 303–323; Experimental Inquiries; Part 2... the Lymphatic System (London, 1774); “A Letter to Dr Haygarth” in Medical and Philosophical Commentaries (Edinburgh), 3 (1775), 87–93, on the thymus and spleen, 1773; and Experimental Inquiries: Part 3... the Red Particles of the Blood,... the Structure and Offices of the Lymphatic Glands, the Thymus Gland and the Spleen, Magnus Falconar, ed. (London, 1777).
His works were brought together as Opera omnia..., J. T. van de Wynpersse, ed. Leiden, 1795); and The Works of William Hewson, edited, with intro. and notes by George Gulliver (London, 1846).
A portrait by Vandergucht was engraved in 1780 and is reproduced in the Works (1846).
II. Secondary Literature. Hewson’s MS sources are in the archives of the American philosophical Society, the British Museum (Natural History), the College of Physicians of Philadelphia, and the Royal College of Surgeons of England. For information on Hewson, see the following sources, listed chronologically: Museum Falconarianum, a Catalogue of the Anatomical Preparations of the Late Magnus Falconar and William Hewson...Sold by Auction (London, 1778); S. F. Simmons, Account of William Hunter (London, 1783), with a brief memoir of Hewson by his widow (pp. 38–39); J. C. Lettsom, “Memoirs of the Late William Hewson,” in Transaction of the Medical Society of London, 1 , pt. 1 (1810), 51–63; “Correspondance,“in T. J. Pettigrew, Memoir of J. C. Lettsom, I (London, 1817), 136–147, a memoir of Hewson by his widow; G. Gulliver, “On the life and Writings of Hewson,” in The Works of William Hewson, pp. xiii-xlviii; J. F. Payne, “Hewson, Willim,” in Dictionary of National Biography, new eds., IX, 763–764; L. G. Stevenson, “William Hewson, the Hunters, and Benjamin Franklin,” in Journal of the History of Medicine, 8 (1953), 24–328, documents on the quarrel of 1771–1772; M. C. Verso, “A note on the Observations of Hewson and Falconar on the Morphology of Red Blood Cells, with an Accont of Their Theory of Blood Formation,” in Medical Journal of Australia, 2 (1957), 431–432; J. Dobson, “John Hunter’s Microscope Slides,” in Annals of the Royal College of Surgeons of England, 28 (1961), 175–188, slides acquired from Hewson’s sale, with a discussion of Hewson’s microscopy; and W. Dameshek, “William Hewson: Thymicologist, Father of Hematology,” in Blood, 21 (1963), 513–516.