The first edition of Conring's study on the circulation of blood, the first German writer to defend William Harvey's theory. Conring's Aristotelianism and his criticisim of hermetic medicine led him to seek natural causes of anatomical phenomena. Included are three other works: 'Anatome fermentatione Platonicae' by Anton Gunther Billich (1598-1640; a response to this work by Conring entitled: 'De fermentatione exercitationes' by Conring; and the medical letters of Daniel Sennert (1572-1637). The two works on 'Fermentation' are a discussion on a subject of lively discussion during the mid-17th century. 'Fermentation' here means the process of the digestive system and the creation of blood. Carmen Schmechel states in her abstract on Descartes and Fermentation that: "Starting around the mid-seventeenth century, ‘fermentation’ undergoes a major change: from a phenomenon understood in either traditional Galenic or alchymical terms, into a more decidedly corpuscular phenomenon that better suited an emerging mechanistic framework in natural philosophy" (BJHS, March 2024). Despite the importance of this book, it is rare in the marketplace. 8vo (15 x 10cm), [xiv], 626pp. Occasional browning and/or foxing, some worming to inner margin at title-page, front endpaper, upper spine, and front cover. Bound in contemporary vellum, spine soiled.