In the 1870s, microscopy societies began to proliferate in the United States. Most of these societies attracted microscopists from surrounding cities, but the American Postal Microscopical Club, modelled on the British Postal Microscopical Society, used the postal system to connect microscopists scattered across the country. Club members exchanged microscope slides and notes following a chain-letter system. The main objective of the club was to teach its members how to make permanent slides. Preparation and mounting methods required technical skill, which was, as even club members had to admit, difficult to learn without personal instruction. Yet members developed ways to share craft knowledge through the post. Drawing on the private notes of a member and published reports on the slides circulated, this paper challenges the widespread assumption that the generation of craft knowledge depended on the co-location of artisans. It argues that microscopists’ knowledge of preparation methods was intertwined with their skill in building and navigating information infrastructures, and that by tracing these infrastructures we gain a better understanding of how craft knowledge travelled in the late nineteenth century.

Whilst the ‘local culture’ of experimental natural philosophy in seventeenth-century England drew on ‘resources’ supplied by the gentlemanly identity of men like Robert Boyle, this culture found much of its distinctiveness in a series of exclusions having to do with faith, gender and class. My concern in this essay is less with these exclusions, and the distinctions they enabled, than with their surreptitious returns. Following from this, as a heuristic strategy, I will try to understand how Boyle and Co. used and reacted to, repressed and cathected, that which they sought to exclude. By charting the movements of exile and return across the contested frontiers of class, gender and faith, truth and lies, authenticity and performance, we can, I believe, fruitfully complicate our understandings of both the social history of truth, and the social history of our ‘post-truth’ predicament.