Abstract

When he died in 1598, Joachim Camerarius the younger, botanist, humanist and municipal physician to the imperial city of Nuremberg, left behind him more than 3000 letters sent by 190 physicians from Antwerp to Rome, and as far east as Constantinople. As evidence of a social network, Camerarius’ letters describe a densely populated circle of learned, practicing physicians, with strong interests in botany and, more specifically, in the pharmaceutical dimensions of herbal knowledge. Correspondence was a form of exchange; as well as letters, Camerarius received plants, books, drawings and remedies. It was also a form of collaboration, in that the physicians who sent letters to Camerarius, used this network to offer information, consult on cases, and to discuss and share identification of local and rare plants. In early modern medical discourse, correspondence became a scientific technique – a means of slowly testing evidence, and achieving through corroborative reporting, a consensus that legitimated it.

Focusing specifically on letters between Camerarius, the renowned botanist Carolus Clusius (1526-1606), and their Bohemian circle of acquaintances, my paper examines shared attempts to identify the anemone, a species to which both Clusius and Camerarius devoted long chapters in their published volumes. Comparing the incremental, communal process of identification in their letters, to the authors’ published results, my paper shows that observation was a dynamic practice. For botany, and I argue for medicine more generally, consensus became the professional prerequisite for both knowledge held and decisions made. As an element of the growing professionalization of practical medicine, this epistemological shift had ramifications for the social organization of medicine as well. Having looked at the place of consensus in theory, my paper traces the development of the ‘second opinion’, in what Camerarius himself termed Nuremberg’s ‘medical reformation’.