Just after noon on 22 July 1880, James Greenwood, a forty-nine-year-old woolsorter based in a factory around five miles west of Bradford, left his work early after complaining of a slight cold and ‘aching pains in his bones’. Greenwood went to bed when he returned home, but by the next morning his condition had worsened substantially. His anxious wife sent for a local medical practitioner, Dr Jackson, but by the time Jackson arrived to examine his patient at around ten o'clock in the morning, Greenwood was ‘in a state of collapse’. Shortly afterwards, and fewer than twenty-four hours after leaving his work, James Greenwood was pronounced dead, leaving behind his wife and seven children. Following his death, two other local doctors – John Henry Bell and John Spear – conducted a post-mortem examination of the body and declared that the cause of death was woolsorters' disease. Spear took samples of blood and sent them to William Smith Greenfield of the Brown Animal Sanatory Institution in London for microscopic analysis.