"This talk offers an overview of my forthcoming book by the same title, which seeks to make four interlocking arguments. First, that it was in medicine, rather than science, that we see the ‘main game’ for the development of naturalistic understandings of race in the nineteenth century; second, that a key focus for this development was to be found in medical statistics: the roots for much of our thinking about scientific uses of race today lie in the racialized statistics of the era of high imperialism; third, that the history of race must be written in an imperial and not merely a national register, a point that also requires us to see the history of slavery and its abolition as having effects well beyond the areas of its immediate application; and fourth, that the medicine of empire ‘struck back’ after the end of the Napoleonic Wars, so that understandings of diseases that would never reach British shores nonetheless shaped even the most parochial of metropolitan medicine. Along the way, I offer some thoughts on the relationships between the arguments of this book and my last, Difference and Disease: Medicine, Race, and the Eighteenth-Century British Empire."