Burton Cleetus and Anne Gerritsen (eds.), <i>Histories of Health and Materiality in the Indian Ocean World</i> London: Bloomsbury, 2023. Pp. 320. ISBN 978-1-350-19588-2. £86.00 (hardback).

How do medical concepts travel?What about medications, to say nothing of the abstract intellectual parameters of medical practice?Is it possible to separate pharmaceuticals entirely from their place of origin or from the practitioners who know how to administer them?This wide-ranging volume provides a dozen contrasting examples of how medical objects are constituted, valued and transmitted within and beyond the Indian Ocean world.Originating at a Wellcome Trust-supported workshop on Health, Medicine and Trade across Cultures, the case studies span more than four centuries.Editors Burton Cleetus and Anne Gerritsen offer material-culture studies as a unifying framework.In their view, 'therapeutic objects' merit analysis because they are 'subjected to multiple layers of negotiations brought about both by colonial dominance as well as nationalist upsurge ' (p.11).Although there may be no way to completely isolate objects, concepts or practices from their original cultural context, Cleetus and Gerritsen argue that this very fact makes them invaluable tools for 'highlighting important historical changes in context' (p.17).Roughly half of the chapters focus on specific objects, and these deep dives are tantalizing.The authors move beyond spices and textiles to explore commodities that have received less scholarly attention, some native to India and others imported.For instance, Amrita Chattopadhyay unpacks the culturally specific ways in which perfumes were used within India, and how class, caste and gender shaped their meanings.Greeshma Justin John explores how soap was constituted in Keralam.This seemingly simple product raises questions not only of modernity and gender, but also of religion and politics.John outlines the popularity of vegetable-based soap compared to other brands that included tallow, traces the evolution of its therapeutic and swadeshi (anti-colonial, self-sufficiency) associations and highlights the radical liberation that soap offered low-caste Dalits (p.161).Specialized medical objects often have layered meanings.Anne Gerritsen suggests that we should 'approach rhubarb less as a commodity and more as a concept' (p.65).This allows her to highlight competing understandings of the plant's roots, stems and extract in Chinese, Indian and Western contexts, ultimately concluding that the 'stories told about its remote origins and its complex itineraries were key to its appeal' (p.80).David Arnold presents brief portraits of an intriguing trio of poisons.He argues that nux vomica, arsenic and kerosene are all examples of a 'pharmakon', a substance that could both poison and cure (p.127).Like rhubarb, the meanings of these border-crossing ingredients changed as they travelled across the oceans and entered into new social contexts.The chapter by Suparna Sengupta demonstrates that ideas moved around the Indian Ocean just as objects did.In her