Bencao gangmu shiyi (Supplement to Systematic Materia Medica) has been recognized as the most outstanding sequel to the sixteenth-century encyclopedia Bencao gangmu, adding over nine hundred drugs to Li Shizhen’s magnum opus. In this article, I investigate the key conditions that rendered it possible for its author, Zhao Xuemin (fl. 1753–1803), to access the textual, empirical, and material resources necessary to accomplish such a feat. I argue that despite Zhao’s efforts to frame his work in a classical light, his humble status as a sojourning private secretary in fact enabled him to derive new knowledge from both elite and lowbrow circles. Zhao and his interlocutors represent an expanding, if oft-neglected community of knowledge, who embraced literary documentation of contemporary experience as a way of transcending the accomplishments of previous authorities. Their existence signifies the beginning of a transition from a literati-dominated culture toward mass society.