McWilliam included a history of yellow fever, pathology, description of symptoms, sequences, causes, treatment. He also described the state of medicine among the Africans. He specifically described the ventilation of the ships, which was carried out on the plan adopted by David Boswell Reid for the houses of parliament, and an abstract of meteorological observations, and a brief account of the geology of the Niger, condensed from the notes of William Stanger. Digital facsimile from the Internet Archive at this link.