This book explores the relationship between science, empire, and colonial society in the Spanish Atlantic from 1750 to 1820 as manifested in the Spanish Crown's efforts to control quina, a medicinal tree bark of the cinchona tree, which at the time could only be found in the Andean forests of South America. In 1820, cinchona bark gave rise to the antimalarial alkaloid quinine. Later in the nineteenth century, the British and the Dutch transplanted cinchona trees to Asia and used cinchona plantations to produce the quinine that would facilitate European colonization and conquest in Africa. In 1751, the Crown established a royal reserve of quina in South America, a pilot project that ultimately failed, much like the broader imperial reform of which it was a part. This book explains why, and in the process sheds new light on the politics and production of scientific knowledge, and why the eighteenth-century Spanish Empire derived so little practical benefit from science, even as the Spanish Crown became one of the biggest patrons of the sciences in Enlightenment Europe by founding new scientific institutions and supporting nearly sixty scientific expeditions.