Long after its alleged demise, phlogiston was still presented, discussed and defended by leading chemists. Even some of the leading proponents of the new chemistry admitted its ‘absolute existence’. We demonstrate that what was defended under the title ‘phlogiston’ was no longer a particular hypothesis about combustion and respiration. Rather, it was a set of ontological and epistemological assumptions and the empirical practices associated with them. Lavoisier's gravimetric reduction, in the eyes of the phlogistians, annihilated the autonomy of chemistry together with its peculiar concepts of chemical substance and quality, chemical process and chemical affinity. The defence of phlogiston was the defence of a distinctly chemical conception of matter and its appearances, a conception which reflected the chemist's acquaintance with details and particularities of substances, properties and processes and his skills of adducing causal relations from the interplay between their complexity and uniformity.

The reorganization of the astronomical community during the late nineteenth and early twentieth centuries, due to the rise of astrophysics, was seen by some scientists as an opportunity to join an international community of prestigious researchers. This was the case of astronomers such as Josep Comas i Solà, who publicly argued with Eugène Michel Antoniadi during the first decades of the twentieth century about the veracity of astronomical observations and theoretical conclusions on Mars and Jupiter. Their priority claims and public disputes have to be understood in a new context that provided an exceptional opportunity for amateur and professional astronomers both to play an active role in the most interesting scientific debates of these years and to gain prestige, legitimacy and power.

James Clerk Maxwell's electromagnetic theory famously unified many of the Victorian laws of physics. This essay argues that Maxwell saw a deep theological significance in the unification of physical laws. He postulated a variation on the design argument that focused on the unity of phenomena rather than Paley's emphasis on complexity. This argument of Maxwell's is shown to be connected to his particular evangelical religious views. His evangelical perspective provided encouragement for him to pursue a unified physics that supplemented his other philosophical, technical and social influences. Maxwell's version of the argument from design is also contrasted with modern ‘intelligent-design’ theory.

This paper aims to build an integrated account of the history of twentieth-century laboratories. The historical literature is fragmented, which has led to the impression that one type of laboratory has dominated, or has become more important than other types. The university laboratory has also unjustly shaped the conceptualization of other types of laboratory. This paper approaches laboratories as sites of organized knowledge production, and as entities engaged in different activities for different audiences at any point in time. Eight types of laboratory are identified, and their developments in the twentieth century are sketched. The two world wars of that century and models of innovation, building links between knowledge production in the laboratory and the impact of this knowledge outside the laboratory, are important catalysts of this history. The paper underlines that different types of laboratory have existed side by side, and continue to exist side by side.

Vanished from history is the story of the ‘Mariner's Calculator’, invented and patented at the Great Seal Patent Office, London, by Mrs Janet Taylor, in 1834. Dismissed by the Admiralty, it had no commercial future and only one instrument is known to remain in existence. The article traces the invention from its inception and provides relevant biographical details of its inventor. The authors then analyse the assessment by the Admiralty to determine if it was fair and outline the endeavour in 2004 to reassess the achievement by a reconstruction of the Mariner's Calculator from its original patent.