William Newnham (1790–1865) was a general medical practitioner, also qualified as an apothecary, who played a prominent role in his profession and was widely recognised for his skill. His particular medical interest lay within the fields of gynaecology and obstetrics, although he also published several papers on topics including phrenology and human magnetism. This 1830 publication contains a series of essays he had recently written for The Christian Observer. In them, Newnham argues that dreams, visions, apparitions and other apparently spiritual manifestations, whether good or bad, arise from physiological rather than supernatural causes. He provides evidence that the effects on the brain from disease, medications (including nitrous oxide and opium) and trauma, causing 'disturbance of brainular function', can produce such experiences. Anticipating criticism, he insists that the light of science benefits true religion rather than undermining it, contrasting 'real Christianity' with 'superstitious' creeds including Catholicism, Islam and Hinduism.