Throughout his career the geographer, and first reader in the ‘new’ geography at the University of Oxford, Halford Mackinder (1861–1947) described his discipline as a branch of physics. This essay explores this feature of Mackinder's thought and presents the connections between him and the Royal Institution professor of natural philosophy John Tyndall (1820–1893). My reframing of Mackinder's geography demonstrates that the academic professionalization of geography owed as much to the methods and instruments of popular natural philosophy and physics as it (...) did to theories of Darwinian natural selection. In tracing the parallels between Tyndall and Mackinder, and their shared emphasis upon the technology of the magic lantern and the imagination as tools of scientific investigation and education, the article elucidates their common pedagogical practices. Mackinder's disciplinary vision was expressed in practices of visualization, and in metaphors inspired by physics, to audiences of geographers and geography teachers in the early twentieth century. Together, these features of Mackinder's geography demonstrate his role as a popularizer of science and extend the temporal and spatial resonance of Tyndall's natural philosophy. (shrink)

In 1675, Burchard de Volder (1643–1709) was the first professor to introduce the demonstration of experiment into a university physics course and built the Leiden Physics Theatre to accommodate this new pedagogy. When he requested the funds from the university to build the facility, he claimed that the performance of experiments would demonstrate the “truth and certainty” of the postulates of theoretical physics. Such a claim is interesting given de Volder’s lifelong commitment to Cartesian scientia. This chapter will examine de (...) Volder’s views on experiment and show that they are not Newtonian or inductivist, as is sometimes claimed. While de Volder thinks we need deductive reasoning from first principles to provide evidence of the certainty of the content of our physical theories, he also contends that we need experiment to provide evidence of the certainty of the existence of the particular bodies those theories discuss. This approach to experiment is based on a distinction between rational certainty and the certainty of material bodies in the actual world. While this account is deeply influenced by Descartes, it is importantly different than Descartes’ distinction between absolute and moral certainty. De Volder’s “Cartesian Empiricism” is best understood as a continuation and further development of a long tradition of teaching through observation at Leiden. (shrink)

A frequently recounted episode in early modern medicine concerns the physician Helvetius's introduction of ipecacuanha to French medical practice after curing Louis XIV's son of dysentery using this medicinal drug. To this day, the Helvetius story remains riven with contradictions, obscurity, and confusion, even down to the nature of the drug involved. This article, challenging histories of “information” as homogeneous and neutral, explores how Helvetius's reputation as a physician and pharmaceutical entrepreneur was crafted through print and correspondence. Rather than seeking (...) to establish a definitive account of “what actually happened,” it addresses the ways in which different media shaped and mediated the politics of knowledge surrounding Helvetius and his drug. Considerations of intellectual and commercial property inflected medical knowledge in different ways, producing distinct strategies of publicity. While Helvetius capitalized on courtly connections to promote himself and his drug, rivals eyed the Republic of Letters as an alternate route for establishing natural knowledge-claims. Yet the arch-newsmonger of the Republic of Letters, Leibniz, elected to preserve the connection between Helvetius and ipecacuanha in print. I argue that Leibniz's actions stemmed from a view of the public domain that downplayed discovery and emphasized disclosure of medical secrets in the public interest. (shrink)

A special interest in optics among various seventeenth-century painters living in the Dutch city of Delft has intrigued historians, including art historians, for a long time. Equally, the impressive career of the Delft microscopist Antoni van Leeuwenhoek has been studied by many historians of science. However, it has never been investigated who, at that time, had access to the mathematical and optical knowledge necessary for the impressive achievements of these Delft practitioners. We have tried to gain insight into Delft as (...) a ‘node’ of optical knowledge by following the careers of three minor local figures in early seventeenth-century Delft. We argue that through their work, products, discussions in the vernacular and exchange of skills, rather than via learned publications, these practitioners constituted a foundation on which the later scientific and artistic achievements of other Delft citizens were built. Our Delft case demonstrates that these practitioners were not simple and isolated craftsmen; rather they were crucial components in a network of scholars, savants, painters and rich virtuosi. Decades before Vermeer made his masterworks, or Van Leeuwenhoek started his famous microscopic investigations, the intellectual atmosphere and artisanal knowledge in this city centred on optical topics. (shrink)