Illustrating microorganisms: Sir William Watson Cheyne (1852-1932) and bacteriology.

Sir William Watson Cheyne is largely known to medical history as Lord Lister's 'trusted assistant'. He spent a lifetime defending Joseph Lister's (1827-1912) antiseptic principle in the wake of scepticism and misunderstanding. However, his main contribution to Lister's work was in the embryonic field of bacteriology in the 1870s-1890s, which brought him into contact with continental researchers, particularly Robert Koch (1843-1910). In this field, Cheyne built an independent reputation as an assessor, chronicler and promoter of continental laboratory methodology. He pioneered bacteriological training in British teaching hospitals and incorporated laboratory testing into case notes as standard procedure. This paper reconsiders Cheyne's contribution to the development of bacteriology in British medicine at the end of the 19th century. It examines his motives in promoting new laboratory techniques and the methods he used to embed them in hospital procedure. It also considers how he continued to use bacteriological arguments to keep the Listerian antiseptic principle on the medical agenda well after Lister withdrew from active involvement in the field.