Secrets were once considered to be, at best, marginal to the history of science and medicine. In this volume's first essay, William Eamon recalls that when he initially presented his research on these matters to historians of science in the early 1980s, it was greeted with scepticism and confusion. Over the course of the following thirty years, and especially since the publication of Eamon's groundbreaking study Science and the Secrets of Nature (1994), the study of secrets has become an established field of scholarship. Whilst many historians have taken up themes identified by Eamon, others have pursued new avenues of research. Developed out of a series of papers delivered at a symposium held in Cambridge in 2008, the essays contained in this volume further contribute to this established historiography.

Since the field is now so rich it is useful to pose the question, what do these essays taken as a whole contribute to our present knowledge? In their introduction the editors state that the volume has three key aims. First is to demonstrate that research has extended beyond ‘books of secrets’; that is, published works often penned by learned or professional men. Consequently, the range of potential sources for studying secrets has been expanded, so that it now includes manuscript sources such as household recipe books and medical case notes. This development also extends the array of potential authors who can be studied, so that it can include groups previously marginalized in the historiography, including artisans and women. Second, the volume seeks to highlight the sheer diversity of pieces of knowledge that contemporaries regarded as ‘secret’. The essays demonstrate that these included instructions for the production of foodstuffs and medicines and also technical information useful in specific trades. Finally, by introducing examples from a range of European states, the editors suggest that the collection will demonstrate regional variation in the treatment and meaning of secrets.

Composed of ten individual contributions, the collection is divided into four parts. The first of these, entitled ‘Defining secrets’, contains essays by Eamon and Pamela Smith reflecting on some of the multiple meanings of secrets in this period. The former offers fresh insights into the manner in which modern readers should engage with these materials and suggestions for future research; the latter discusses the purpose of secrets and recipes amongst artisans. The second section, ‘Secrecy and openness’, the most thematically coherent of the collection, has three chapters dealing with secrets and their disclosure in seventeenth-century England. Ayesha Mukherjee discusses the manner in which Sir Hugh Platt used both secrets and books of secrets, Michael Hunter continues to refine his portrait of Robert Boyle by tracing his changing attitudes to secrecy, and Michelle DiMeo provides a nuanced interrogation of the idea of ‘democratic Baconianism’ during the interregnum. The geographical focus widens in the third section, ‘Illicit secrets’, to encompass the Holy Roman Empire and Italy. Tara Nummedal gives an account of the interrelationship between alchemy and prophecy in the work of Anna Ziegerlin, and Tessa Storey takes us into the underbelly of Rome to describe the production and sale of medicinal and cosmetic preparations. In the final section, ‘Secrets and health’, medicine enters the scene. Monseratt Cabré considers the relationship between printed and manuscript texts in his discussion of beauty secrets in Iberia, Sandra Cavallo describes the use of recipe books in hygiene during the Renaissance, and Lisa Wynne Smith uses a French physician's case notes to extend the story of secrets into the eighteenth century.

The individual essays that make up this volume are certainly well worth reading. Many are of a very high standard, and they make important contributions to debates that would be of interest to specialists of, say, alchemy, or domestic medicine, or to those with an interest in ideals of secrecy and openness in mid-seventeenth-century England, or indeed the role played by craft knowledge during the Scientific Revolution. My main quibble is that, read as a collection, these essays do little to advance our overall understanding of secrets in science and medicine. This is partly because the volume's scope is so wide. This is an eclectic selection of essays with few directly overlapping themes. Furthermore, the main historiographical aims that the editors set out for the volume as a whole appear to me somewhat redundant. As the footnotes to the various essays attest, each of these points has already been made, often at length. Indeed, for the most part, the research presented here reflects and builds upon innovative approaches currently being used to discuss secrets and secrecy, rather than marking out new directions of inquiry. As such, this volume does provide an excellent series of snapshots of current work on secrets and secrecy broadly defined. Reading it as a whole would allow a general reader to sample some of the high-quality research being produced, but it would be unlikely to deliver any major historiographical surprises to anyone acquainted with the field.

Perhaps more than anything else, these contributions reflect how far the field has come in the years since Eamon's pioneering work. They demonstrate once more that secrets and secrecy are of vital importance to many areas of early modern science and medicine. The sheer diversity of research presented here may suggest that it is more useful to study secrets and secrecy in order to illuminate specific questions and research topics, rather than continuing to treat them as a field of study in their own right.