This paper examines the rise and fall of the British popular microscopy movement during the decades surrounding the turn of the twentieth century. It highlights that what is currently understood as microscopy was actually two inter-related but distinct communities and argues that the recognized collapse of microscopical societies in the closing decades of the nineteenth century was the result of amateur specialization. It finds the roots of popular microscopy in the Working Men's College movement and highlights how microscopy adopted its Christian Socialist pedagogy of equality and fraternity, resulting in a radical scientific movement that both prized and encouraged publication by its amateur adherents, who often occupied the middle and working classes. It studies the taxonomic boundaries of this popular microscopy, particularly focusing on its relationship with the study of cryptogams or 'lower plants'. It explores how its success combined with its radical approach to publication and self-sufficiency created the conditions for its collapse, as devotees established a range of successor communities that had tighter taxonomic bounds. Finally, it shows how the philosophy and practices of popular microscopy continued in these successor communities, focusing on the British expression of mycology, the study of fungi.
While the link between navigation and astronomy is quite evident and its history has been extensively explored, the prognosticatory element included in astronomical knowledge has been almost completely left out. In the early modern world, the science of the stars also included prognostication known today as astrology. Together with astronomical learning, navigation also included astrology as a means to predict the success of a journey. This connection, however, has never been adequately researched. This paper makes the first broad study of the tradition of astrology in navigation as well as its role in early modern globalization. It shows how astrological doctrine had its own tools for nautical prognostication. These could be used when dealing with the uncertainty of reaching the desired destination, to inquire about the condition of a loved one, or an important cargo. It was widely used, both in time and geographical context, by navigators and cosmographers for weather forecasting and elections for the start of a successful voyage.
As well as the mathematically-supported celestial mechanics that Newton developed in his Principia, Newton also proposed a more speculative natural philosophy of interparticulate forces of attraction and repulsion. Although this speculative philosophy was not made public before the 'Queries' which Newton appended to the Opticks, it originated far earlier in Newton's career. This article makes the case that Newton's short, unfinished manuscript, entitled 'De Aere et Aethere', should be seen as an important landmark in Newton's intellectual development, being the first work in which Newton assumed there are repulsive forces operating at a distance between the particles of bodies. The article offers an account of how Newton came to write 'De Aere et Aethere' and why. It also outlines its relationship to the 'Conclusio', with which Newton briefly intended to finish the Principia, and to the 'Queries' in the Opticks. The date of the manuscript is disputed, and the article also aims to settle this dispute. Claims that the 'De Aere et Aethere' must have been written before the 'Hypothesis... of Light' of 1675 are dismissed, and it is suggested, following R. S. Westfall, that it was written after a well-known letter Newton wrote to Boyle early in 1679.