Spencer Timothy Hall (1812–1885) was a writer and practitioner of mesmerism. He grew up in rural Nottinghamshire, apprenticed himself to a printer, and in 1836 he started his own printing business. He later became co-editor of the Sheffield newspaper The Iris, and published several books describing the countryside. After watching a demonstration of mesmerism in 1841 Hall became a practitioner himself, demonstrating mesmerism throughout Britain and offering treatment. His most famous patient was Harriet Martineau, who became an enthusiastic supporter of the technique. This book, first published in 1845, describes Hall's first encounter with mesmerism and explains his decision to become a mesmerist. He discusses thirty-four cases in which mesmerism apparently cured medical problems and describes the treatment he gave to Harriet Martineau. This fascinating book provides valuable insights into both the practice and theory of mesmerism in the early Victorian period.