Abstract   At least since the late nineteenth century, toy chemistry sets have featured in standard scripts of the achievement of eminence in science, and they remain important in constructions of scientific identity. Using a selection of these toys manufactured in Britain and the United States, and with particular reference to the two dominant American brands, Gilbert and Chemcraft, this paper suggests that early twentieth-century chemistry sets were rooted in overlapping Victorian traditions of entertainment magic and scientific recreations. As chemistry set marketing copy gradually reoriented towards emphasising scientific modernity, citizenship, discipline and educational value, pre-twentieth-century traditions were subsumed within domestic—and specifically masculine—tropes. These developments in branding strategies point to transformations in both users’ engagement with their chemistry sets and the role of scientific toys in domestic play. The chemistry set serves here as a useful tool for measuring cultural change and lay engagement with chemistry.