Airs, waters, places: perennial puzzles of health and environment.

In late eighteenthand nineteenth-century Europe, few issues stirred more public and scientific debate than those of health and environment. At the forefront of concern about science, race and medicine were questions of whether Europeans could adapt to life in tropical environments. The foregoing essays reveal a fascinating array of stories, of historically situated knowledges, each seeking audience among discordant human interests and simultaneously seeking credibility as scholarly fields of expertise. From the cauldron emerged a hybrid field of enquiry called "medical geography". And under this rubric, down the decades, several distinct and sometimes jarring voices sought academic and/or professional niches. This Epilogue shares some reflections on the variety of voices heard at the symposium and the contexts in which they made their cognitive claims. The case studies span an extensive geographical range-from colonial Indonesia to the highlands of India, from the North American Mid-West to Caribbean islands and the Northern Territories of Australia. Yet several common themes emerge. There is a preoccupation with "the Tropics" and, in some cases, a virtual identification of medical geography with tropical medicine. There is also a commonly accepted definition of a scholarly genre called "Humboldtian science"-a field of enquiry which emphasized empirical observations, fieldrather than laboratory-based experiment, large-scale generalization facilitated by innovative cartographic methods.' Central to all the essays is a fascination about the social construction of expertisemedical as well as geographical. Tensions are identified between "folk" and "scientific"