In the last thirty-five years, images in the sciences have seen their share of attention by historians, philosophers and sociologists of science, medicine and technology, but also by art historians and scholars of media, literature, communication and visual studies. The sheer variety of disciplinary approaches has made for an enormously rich literature. With so many studies and approaches to a subject, already with so many different facets, one risks getting lost in disorienting diversity or remaining content with narrowing islands of interest. And it does not help, moreover, that much of this important literature comprises micro-studies that tend not to go beyond a certain level of generalization. Given this state of affairs, we must heartily welcome Klaus Hentschel's Visual Cultures in Science and Technology, a timely but colossal endeavour to take stock of the literature on visual cultures of science.

Hentschel is one of the leading historians of physics of his generation, who, among other things, has not only produced a number of original studies on visual representations in the sciences but also developed the Database of Scientific Illustrators, 1450–1950, an invaluable online aid containing information on (as I write) almost 11,200 scientific illustrators. In his latest book, Visual Cultures in Science and Technology, Hentschel synthesizes the existing literature on scientific images, in order to act as a comparative history that operates at the ‘meta-level’ (p. 1), actively in search of ‘deeper historical patterns’ (p. 4). To be sure, the literature upon which the book's synthesis and generalizations rest is by no means meagre: it includes over two thousand works, all included in a valuable bibliography (which opens with helpful advice and recommendations on how to broach the vast secondary literature). Hentschel directly engages with historical and sociological research into the sciences, mathematics, engineering, technology, medicine and even art. What is more is that Hentschel takes seriously all sorts of media and instruments, practices and materials connected to the visual cultures of science. In fact, one of the extraordinary accomplishments is Hentschel's ability to remain sensitive to the fine differences in all of this, whilst engaged in a generalizing and comparative project. It should also be said that Hentschel is not afraid to confront head-on issues surrounding generalization.

With 126 black-and-white figures in the text, and sixteen colour plates, Visual Cultures in Science and Technology is well illustrated. Considering its range, furthermore, the book will be attractive to both specialists and students alike, as a major resource both inside and outside the classroom. But the work also contains a sustained perspective and argument, one that is developed using over a hundred case studies, which are derived from secondary sources. The overarching driver is the notion of visual cultures, whose robust characterization is the primary concern of the author's focused generalizations. The main outcome of his meta-level, comparative analysis of cases, in other words, is to provide readers with a fuller understanding of what constitutes visual cultures in the sciences. Hentschel argues that visual cultures are made up of a web of ‘visual or scopic domains’ that themselves depend on practices, materials, instruments and techniques that shape ‘modes of visuality’ of whole groups of practitioners in particular historical periods – some periods being more prone to visual cultures than others. As such, there are cultural, social and institutional, as well as aesthetic, biographical and psychological, levels at work throughout the book. It is with this in mind that we are to understand one of the outcomes of this study, namely visual cultures are made up of at least nine overlapping layers which include such things as the skills attained in pattern recognition by practitioners, their mastery of visual thinking, practical training, aesthetic pleasure and a fusion of labour and pleasure on the part of practitioners. It is based on these layered aspects of visual cultures in the sciences that Hentschel structures the presentation of the case studies and thus the chapters of the book.

Visual Cultures has fourteen chapters. Given the limited amount of space, there is no way I can do justice to all that is contained in these dense chapters. It must suffice to merely summarize each chapter. The long introduction clarifies concepts such as ‘visual cultures’ and ‘visual domains’; it also grapples with the different forms that the distinctions between the visual and textual have taken in history and their relevance; it goes on to provide a list of ‘deep insights from early visual studies’ (pp. 70–72), and provocatively concludes with some of the ‘wrong turns’ taken in the visual studies literature. Chapter 2 continues to further clarify the notion of visual cultures especially in relation to visual studies, but it also lays down the import of the nine layers for visual cultures in science, already mentioned above. Chapter 3 is important for encapsulating the essentials of the book's main thrust into a bite-sized form. Chapter 4 details a fascinating prosopography, based on a number of ‘pioneers’ of different visual science cultures. By employing a number of cases such as perspective drawings, indicator diagrams and MRI, CT and PET scanners in medicine, Chapter 5 details the fundamental idea that visual cultures thrive off the transfer of visual techniques from one visual domain (and period) to another. The next two chapters shift focus to specific challenges and insights, such as making more visible the significance of image technicians and supporting illustrators (in Chapter 6), and (in Chapter 7) the insight that images do not come alone (it is here that scientific films and cinema are discussed). The next three chapters resume the focus on the layers of visual cultures, and thus include a study of practical training in visual skills that uses slides, posters, X-ray atlases, etc. as cases in Chapter 8; the mastery of pattern recognition in Chapter 9 (which includes electron microscopy, CT scans, Chladni figures and the Martian ‘canal’ controversy as case studies); and visual thinking in Chapter 10. The next chapter marks a break, where the author deals with the important problem of colour in scientific images. We resume the focus on the layers in Chapter 12, turning to aesthetics and beauty, which, Hentschel argues, act as the ‘glue’ that internally holds visual cultures together. For good measure, Chapter 13 deals with a number of visual cases revolving around challenges posed to visual perception. And Chapter 14 provides the reader with a succinct conclusion.

Apart from a number of typos, which will hopefully be corrected for the second edition, this reader found that a few of the chapters could have been integrated better. Despite these minor points, Hentschel's achievement is impressive. The huge number of secondary sources is handled judiciously, and is marshalled in ways that remain focused and informative. At the same time, Hentschel does not shy away from adding his own two cents, making for a lively and insightful read throughout. He has written a work that operates both as a major resource, friendly to those who want to merely dip in and out, and as a major scholarly contribution with a sustained argument about what constitutes visual cultures in science. Indeed, Hentschel must be congratulated on a fine contribution, one that actually gives much-needed shape to the field of visual cultures and the sciences.