Prof. Sandra Widmer is the co-editor (with Veronica Lipphardt) of a new collection titled “Health and Difference: Rendering Human Variation in Colonial Engagements” (Berghahn Books, 2016). Human variation represented a central research topic for life scientists and posed challenging administrative issues for colonial bureaucrats in the first half of the 20th century. By following scientists’ and administrators’ interests in innovating styles and tools for making and circulating documents, in reshaping landscapes and environments, and in fixing distances between humans, the book advances new understandings of the materiality of colonial institutional life and governance.