The burgeoning nineteenth-century public-museum sector built a significant part of its natural-history specimen collections through extensive international trading. The early 2020s has seen an upsurge of scholarly interest in this largely overlooked trade. Exchange was a distinctive aspect of the natural-history trade that reveals much about the diverse practices and motives of the institutional collectors. Economic-geographic benefits included conserving the limited financial resources of museums and exploiting complementarities in the geographic distribution of specimens. Collection management, institutional reputation, social connection and international diplomacy were also part of a complex mix of value making that shaped this important international trade. We analyse the exchange practices of the three largest museums in the Australian colonies in the final three decades of the nineteenth century who exchanged Australia's ‘rare and curious’ fauna with collectors across the globe. By deploying and analysing extensive, comparative data on a particular form of natural history, zoology, and a particular kind of trade, exchange trading, among three Australian museums, this paper extends and enriches recent scholarship on the mobility of natural-history specimens and how they were traded.

How water is perceived and represented has an impact on the relationships between a given society and its water infrastructure. Historians have identified a shift in the perception of water during the nineteenth century, which was connected to the development of chemistry. From an understanding based in Hippocratic medicine and natural history that treated it as an infinite variety of substances, water eventually became understood as a simple compound consisting of oxygen and hydrogen. This resulted in the abstraction of water from its social and environmental contexts, with consequences for the way water was managed. This article aims to demonstrate that such a view gives a mistaken intellectual coherence to a fragmented and conflicted process, which involved continuities, an adaptation of old frameworks to new social priorities, and fine changes in scientific thinking and practices. This paper examines the scientific and political debates concerning water infrastructure, surveys and analyses on water quality, medical reports and political measures in nineteenth-century Italy. Ultimately, the reduction of ‘waters’ to ‘water’ in Italy was more about determining who had the authority to assess water quality in the process of creating and stabilizing new power relations between the public and the private spheres than about the abstraction of water from its social and environmental contexts.