This book is the first transcription and extensive commentary on a fascinating but almost entirely overlooked manuscript compilation of medical recipes and letters, which is held in the University of Nottingham. Collected by the Marquess and Marchioness of Newcastle, William and Margaret Cavendish, during the 1640s and 1650s, this manuscript features letters of advice, recipes, and sundry philosophical and medical reflections by some of the most formidable and influential physicians, philosophers, and courtly scholars of the early seventeenth century. These include "Europe's physician" Theodore de Mayerne, the adventurer and courtier Kenelm Digby, and the natural philosopher, poet, and playwright Margaret Cavendish. While the transcription and accompanying annotations will allow a diverse array of readers to appreciate the manuscript for the first time, the introduction situates the Cavendishes' recipe collecting habits, medical preoccupations, natural philosophical views, and politics within their social, cultural, and philosophical contexts, and draws out some of the most significant implications of this important document.