Historians of science have long acknowledged that science can be defined in numerous ways. Seminal studies of the early modern period, in particular, have argued that science was (and indeed still is) not only a discipline or vocation, but a form of communication and thus can be partly viewed as a rhetorical enterprise; scientific texts, along with other printed material, public demonstrations and lectures, aimed to convince audiences of the accuracy of the theories and practices of the author or demonstrator. Surprisingly, however, historians interested in the communication of scientific ideas have paid much less attention to the rhetorical content of advertising, which was explicitly shaped to suit the aims of its producers. Certainly, medical catalogue text aimed to be informative and instructive, but it was also purposely and explicitly shaped to convince doctors to purchase products through its alignment with particular scientific theories and practices. What form then did the catalogue's, rhetorical content take?

This chapter pays particular attention to the way in which companies shaped the content of their catalogues to relate products to contemporary developments in science. Historian Mark Weather all has identified the importance of ‘science’ as a potential unifying force within the medical profession, which by the end of the nineteenth century came to mean empirically testable and measurable medical phenomena situated in either the laboratory or the clinic.