Sir Kenelm Digby (1603-1665) was an English courtier and diplomat. He was also a highly reputed natural philosopher, and known as a leading Roman Catholic intellectual and Blackloist. For his versatility, Anthony a Wood called him the "magazine of all arts". He published a work of apologetics in 1638, A Conference With a Lady About Choice of a Religion. In 1644 he published together two major philosophical treatises, The Nature of Bodies and On the Immortality of Reasonable Souls. The latter was translated into Latin in 1661 by John Leyburn. These Two Treatises were his major natural-philosophical works, and showed a combination of Aristotelianism and atomism. He was a founding member of the Royal Society and a member of its governing council from 1662 to 1663. His Discourse Concerning the Vegetation of Plants (1661) proved controversial among the Royal Society's members. He is credited with being the first person to note the importance of "vital air", or oxygen, to the sustenance of plants. He is known for the publication of a cookbook, The Closet of Sir Kenelme Digby Knight Opened, but it was actually published by a close servant, from his notes, in 1669, several years after his death. It is currently considered an excellent source of period recipes, particularly for beverages such as mead.