Jessop, William John Edward (1902–80), physician, was born 11 July 1902 near Mullingar, Co. Westmeath, the eldest of three sons of John Brabason Jessop, a farmer, and Mary Jane Jessop (née Anderson), daughter of William Anderson. He was educated at the Ranelagh School, Athlone, and later at Mountjoy School, Dublin. He entered TCD in 1921, obtaining a foundation scholarship, and graduated with first-class honours in experimental science (1925). Having completed an M.Sc. thesis in biochemistry (1927), he graduated MB, B.Ch., BAO the following year, with distinctions in all subjects, and proceeded MD (1935). At the age of twenty-seven (1929) Jessop was appointed professor of physiology and biochemistry in the RCSI (a post he held until 1952), and the following year became physician at the Meath Hospital (1930–80). He became widely known in physiological circles in Britain and he was chairman of the Physiological Society.
Interested in public health issues, Jessop obtained his DPH (1931) and much of his research work had implications for the health of the nation. Commissioned by the Medical Research Council of Ireland to carry out a survey of nutrition, he gathered valuable information on the incidence and cause of rickets in Dublin (1946). It was as a result of a survey of dental caries carried out by him that water supplies were first fluoridated in 1952. His interest in community health medicine led to his appointment in 1952 to the first chair of social medicine at TCD. There he continued his research, applying his biochemical approach to population surveys; he was involved in several important studies, including the Ireland–Boston study of coronary disease, the results of which were published in 1970.
At the time of his appointment the school of medicine at TCD had been severely criticised in two reports, first by the American Medical Association (1953) and subsequently by the General Medical Council (GMC) jointly with the Medical Registration Council of Ireland (1955). Owing to his successful fund-raising activities, Jessop was quickly recognised as an enterprising force in the medical school; he was appointed dean of the school of physic and dean of the school of dental sciences in TCD (1956–72), positions he held until his compulsory retirement at the age of seventy in 1972. An astute, hard-working, and energetic man, he enjoyed medical politics and faced the problems of the medical school with resolve and patience. Regarded by his peers as having a special talent for achieving the impossible, he was often to be seen running through the college from one meeting to another, ready to present equitable solutions to thorny issues. For much of his time at TCD he was also a university representative in the seanad, where he played an influential role in advocating the development of the health services and medical education in Ireland; first elected in a seanad by-election in March 1952 (when Owen Sheehy Skeffington (qv) was also a candidate), he lost his seat in 1954, but was returned at a by-election in May 1960 and at subsequent elections until he was defeated in 1973.
By the time he retired from TCD Jessop had succeeded in reviving the reputation of the medical school through better organisation, increased staff numbers and research output, and the establishment of a close relationship with St James's Hospital. In retirement he accepted a position as visiting professor of chemical pathology at the newly established faculty of health sciences at the University of Ife, at Ile-Ife in Nigeria; for the first two years he combined the responsibilities of his new position with those of president of the RCPI. He had taught many Nigerian medical students both at the RCSI and at TCD, and adapted easily to life in Nigeria, becoming well known for his personal warmth and his open-door policy. He was subsequently elected vice-dean of the faculty of health sciences at Ife and was actively involved in the development of medical education until illness forced him to retire for the second time in 1978. He was awarded an honorary D.Sc. by the university (1978) and was deeply touched by the great cheers of the students when his degree was conferred.
Jessop's skills at organising and his voracious appetite for work did not stop with his teaching appointments: he belonged to many professional organisations and became actively involved in their business, frequently holding high office. He was a member of the GMC and the Medical Registration Council of Ireland for many years, and was unique in serving on the GMC, General Dental Council, and General Veterinary Council. He was a member of the council of the Royal Zoological Society of Ireland and of the Statistical and Social Inquiry Society of Ireland. An original member of the Medical Research Council of Ireland, he was its honorary secretary and chief executive from 1952 to his retirement. His ability and contributions to medicine were acknowledged by his peers when he was elected FTCD (1958), MRIA (1965), and FRCP (1968). Elected FRCPI in 1944, he later served as president of the college (1972–3). He travelled widely and frequently, often in connection with the work of the various societies with which he was associated.
Known as ‘Jerry’ to his friends, Jessop was a warm, sociable, and hospitable man, whose sparkle, kindly wisdom, and sense of humour attracted people to him. He was a respected connoisseur of silverware and a collector of objets d'art; his other pastimes included tennis and gardening – he created beautiful gardens at his homes in Rathfarnham and Ife. A modest man, his greatest source of pride was his children. He married 10 September 1930 Kathleen (Betty) Condell, with whom he had three daughters and a son, John, who became a medical man and FRCS. Jessop died 11 June 1980 at home at Rathfarnham, Dublin.