Medicine as a “tool of empire” aided European conquest of tropical regions by blunting the impact of infectious disease on soldiers and settlers.1 Yet the persistently high rates of European morbidity and mortality in overseas colonies prompted intense debate as to whether the natives of a temperate climate could truly prosper in tropical lands, and vice versa. The fields of tropical medicine and tropical hygiene developed in the late nineteenth century to examine what were seen as environmental barriers to European settlement, to study both the particular pathogens of the colonies and to develop practical measures to promote acclimatization.2 More broadly, “acclimatization studies” united scientists from many different disciplines – including geographers, medical scientists, anthropologists, agricultural specialists, zoologists, and biologists – in the pragmatic aim of settling, administering, and making profitable Europe’s colonial outposts.3

Environmental challenges to European settlement threatened to undermine unquestioned faith in European superiority, shored up in this period by faith in the possibilities of science.