John Haygarth FRS FRSE (1740 – 10 June 1827) was an important 18th-century British physician who discovered new ways to prevent the spread of fever among patients and reduce the mortality rate of smallpox. Life Haygarth was born to William Haygarth and Magdalen Metcalfe at Garsdale, near Sedbergh, West Riding of Yorkshire, in a house where his grandparents' initials can still be seen above the door. He attended Sedbergh School and was tutored by John Dawson, a fellow Sedberghian and a surgeon and mathematician. He attended St. John's College, Cambridge from 1759 to 1766. Haygarth matriculated at the University of Edinburgh Medical School in 1762 studying medicine for three years and leaving without a degree in 1765. After a studying medicine briefly at the University of Leiden and in London, he took his MB degree from the University of Cambridge in 1766 after which he was appointed physician to Chester Infirmary in 1766. A decade later he married Sarah Vere Widdons on 23 January 1776; together they had four daughters and two sons. Haygarth's descendants now reside in Perth, Australia. Medicine Haygarth spent 30 years at Chester and became known as one of the best physicians of his time. Like William Cullen, James Currie and Thomas Percival, he was interested in a wide array of medical and social justice issues. He was particularly interested in the treatment of fever patients and the prevention of smallpox. Although he was an Anglican, Haygarth was supported by a network of Dissenting men of science and letters who helped spread his ideas. In 1774, as part of a census he administered in Chester, he asked residents about their medical history. From this information he concluded that fever patients should be separated from others and his discovery that only a tiny fraction of the population of Chester had never had smallpox led him to focus his energy on prevention. He wrote up these findings in a paper, Observations on the Population and Diseases of Chester. In 1778 Haygarth helped found the Smallpox Society of Chester; the group advocated inoculation, an unpopular position at the time, and tried to educate the populace so as to avoid casual contraction of the disease. Only four years after this effort began, Chester's smallpox mortality rate had been reduced by almost 50%. Soon other towns, such as Leeds and Liverpool, adopted the Society's methods. They were assisted by his Inquiry