The Society for the Diffusion of Useful Knowledge (SDUK) was a London-based society devoted to the production of cheap, informative publications. In 1826 its founding committee consisted of 47 members, most of whom were prominent in politics, the law, medicine, or the sciences. The committee continued to meet monthly to manage the society's affairs over the following twenty years, and committee members were often heavily involved in writing for and revising the society's many publications. Over time, there was a significant degree of turnover in committee members, with new members elected by existing ones from the society's subscribers.^[1][2]