According to the author, alchemy was the belief that "all the metals (and, indeed, all forms of matter) are one in origin, and are produced by an evolutionary process. The Soul of them all is one and the same; it is only the Soul that is permanent..." Redgrove offers a detailed account of alchemy's controversial history, treating both the theoretical and physical approaches to the field. Alchemy: Ancient and Modern has long been viewed as a significant introductory text to the subject. Herbert Stanley Redgrove (1887-1943) wrote several texts on similar topics, including A Mathematical Theory of Spirit, Bygone Beliefs and Purpose and Transcendentalism. He was a chemist and a founder of the Alchemical Society in London. This edition is dedicated to Adam Kendall, in his distinctive way an authority on the mysteries of the past.