RESUMO
The article investigates how knowledge of medicinal plants and related treatment practices are assimilated and transformed. Taking as its focus the use of chaulmoogra oil to treat leprosy, it examines how information on this plant was incorporated and transformed into scientifically validated knowledge when 'Brazilian chaulmoogra' came onto the scene. Pointing to the addition of chaulmoogra byproducts to the Instituto Oswaldo Cruz's production agenda in the 1920s, the study establishes links between productive processes and relates these to the period's scientific context. From the late nineteenth century until the 1940s, chaulmoogra oil was the great hope in efforts to cure leprosy. During this period, chaulmoogric treatment earned a place as scientific knowledge thanks to research studies conducted in laboratories throughout the Western world.