This project investigates seventeenth-century chymical collections as speculative philosophical devices. I am interested in issues of vernacularization, textual culture, and alchemical marginalia as material evidence of speculation. How were readers using and reusing texts as alchemical objects? How and why were such books and manuscripts altered by readers, translators, copiers, and publishers? What types of knowledge-making practices informed the collection and organization of chymical texts during the seventeenth century? The mid-seventeenth century was a baroque period for chymical colletions, beginning with Arthur Dee’s 'Fasciculus Chemicus' (1631) and culminating in Elias Ashmole’s 'Theatrum Chemicum Britannicum' (1652). The original goal of this genre was to curate an objective collection of the most significant alchemical texts, but by the mid-seventeenth century chymical collections had become self-referential and contained intellectual agendas perpetuated by the publisher. A material investigation of these texts shows how readers, adepts, and practitioners responded to these changes.