A purportedly hermaphrodite monkey which was offered to Grand Duke Ferdinando III of Tuscany in 1791 was sent to the Royal Museum of Physics and Natural History for an evaluation. In their investigation, the museum's naturalists encountered a fundamental classificatory problem which made it impossible to decide whether the animal was monstrous or normal – a ‘taxonomist's regress’ which constitutes a special case of finitism as analysed in the Edinburgh school's readings of Wittgenstein. The communication between museum and court shows that in resolving this ambiguity, museum naturalist Giovanni Fabbroni demarcated experts from laypeople and defined state interest by distinguishing between the grand duke's private interests and those of the state. This case thus highlights the role of late Enlightenment absolutism for the creation of modern practices and concepts of expertise in the service of the state.

After a brief account of the uncertainty of medicine in early modern thought, this paper focuses on two supple, sophisticated accounts of medicine by ‘non-medical’ writers – Michel de Montaigne's views of medical theory and medical practice and Francis Bacon's proposals for renovating both – in which the claims of individual sufferers are set against the normativity of medicine as a whole. From around 1500 to around 1680, in the common ensemble of both learned and popular invective, medicine was disparaged as poor philosophy and worse practice, even as the ‘lowest of professions’. In remarkably broad, elegant interventions, Montaigne argues that medicine is based on ‘examples and experience’ (and ‘so is my opinion’, he adds), impugning its universalizing claims with the tractable experience of his own embodiment, with his own historia and consilium, while Francis Bacon enlists dietetics, Hippocratic case-taking and medical history in his broad programme for the reform of medicine. He more or less accepts Montaigne's argument for particularity in medical theory and practice, but presses the particular into service in his reformist programme. Like many sixteenth- and early seventeenth-century scholars and physicians frustrated with Galenic methods and models, both turn to Hippocratic practice and to hygiene and dietetics as salves for an ailing discipline. Finally, I argue that both writers enquire into viable means for inflecting learned medicine with particular experience, and both settle on rhetorical tools – analogy and exemplarity – as the means by which universalized medical models might be particularized or reformed.

William Hamilton's celebrated letters, articles and publications embodied his experiences as a direct observer of nature. This paper tracks their different courses through preparation, production, distribution and consumption to expose the networks through which Hamilton's knowledge was made and moved. It makes a detailed study of the changes incurred when his experiences were translated between written, oral, painted and printed formats. Sensitive to contemporary notions of curiosity, it then links these changes to the distinct audiences that each embodiment found. The paper frames each piece as an opportunity for beholders to become virtual witnesses in order to describe people's diverse encounters with Hamilton's work. This model is developed to highlight the agency and diversity of readers and the importance of physical format for the movement of witnessing tools. The exploration of Campi Phlegraei demonstrates how this method of communications study can be a valuable approach to the history of science.

One of the most fascinating experiences gained by the meteorological observers of the Correspondentie Sociëteit concerned the practical use of new instruments. In the period after 1775 renewed interest in meteorology had stimulated the development of various new meteorological instruments. These instruments seemed at first to be a welcome addition or improvement in quantitative meteorology. How did the Correspondentie Sociëteit cope with these new developments? What factors determined whether or not the instruments were accepted as a useful addition to instruments already available? Four examples will be used to illustrate how this issue was tackled.