Much of Kew's work over the last 160 years has been on the medicinal uses of plants. Its medical history collections are correspondingly very rich. They derive from Kew's work on, for example, plant transfer, authentication of plant drugs, biochemistry, and new drugs. They also derive from Kew's role as advisor to government and commercial bodies, and from donations.
The collections begin with the re-establishment of Kew as a research institution in 1841. Contacts with the pharmaceutical industry were reinforced by the opening of the Museum of Economic Botany in 1847, which collected materia medica from trade, from research at Kew and in the colonies, and from donations, e.g. from the Great Exhibition. Kew's Library has strong holdings for 19th century pharmacognosy. Kew's Archives have major holdings on medicinal plants, including drug plants in war-time, leprosy plants, arrow poisons, camphor, and many other subjects. The Economic Botany Collection (successor to the Kew Museum) contains 80,000 artefacts and plant products; about 14,000 of its accessions have medical significance. 10,000 of these were donated by the Royal Pharmaceutical Society (RPS) in 1988.
The importance of these collections to medical history is grounded in the central role of plant-based drugs in medicine until at least the 1930s. These medicines are a vital component of any understanding of the history of the means of treatment, explanations of its success or failure, and the economics and logistics of the development of plant-derived medicines. Kew's collections have already been used by historians to examine some of these questions, in particular the British role in the discovery and transfer of medicinal plants, such as Cinchona as a source of quinine and Erythroxylum coca as a source of cocaine.
Kew's collections are of importance to medical historians because they often enable the historian to link documentation about the medical uses of a species with the taxonomically validated samples of the species that were deposited by collectors and traders in the collections at Kew as vouchers. Given the close connections of Kew and the RPS to the pharmaceutical industry, Kew's collections are highly relevant to understanding the development of the 19th century pharmaceutical industry, in particular the role of trade and of pharmacology.
Kew's role in facilitating the transfer of Cinchona cultivation in India and Java is well-documented, but the vital role of pharmacologists and Kew's botanists in elucidating the link between different Cinchona species and alkaloid content, and in developing mass market quinine products is less studied. Kew's collections have strong commercial links, particularly with Howard & Sons, the main purveyor of quinine drugs in the UK from the 1850s to 1930s. About 400 specimens derive from the collection of the eminent quininologist and pharmacist, John Eliot Howard, and virtually all the other key players in the 19th century use of quinine are well represented, e.g.: F.C. Lehman, Henry Trimen, José Pavón, Daniel Hanbury, Richard Spruce and Clements Markham. Abundant relevant textual resources at Kew exist for all of these named sources.