unexpected insights. In contrast, in the first and final seminars the witnesses were small groups of participants who had worked closely together, and produced more cohesive, but predictable analyses. The first transcript of the volume is on 'Making the human body transparent: the impact of nuclear magnetic resonance imaging'. This is a fascinating at times technically obfuscating account of the difficulties of developing, evaluating and implementing complex medical technology in an era when other options seemed to offer more promising ways forward than MRI. The second seminar focused on the structural and personal reasons for engaging in research in general practice. These confirmed a well-known picture in that research was largely organized by personal curiosity about epidemiological subjects. It remained the concern of an enthusiastic minority because of the inadequate time available after clinical practice; the lack of research training for general practitioners; and the under-funding of later departments of general practice which therefore curtailed their research capacity. In the third seminar on the use of psychiatric drugs there were perceptive analyses of the serendipitous discovery of the miracle-working drugs of the late 1940s and 1950s in an era before the conventional clinical trial; their use on patients without the constraints of later regulatory machinery; and the dramatic transformation of the asylum. In addition, it was interesting to learn about an earlier Calvinistic reluctance by pharmaceutical companies to develop certain drugs for sexual dysfunction, despite good evidence of their effectiveness. The final witness seminar on the MRC Common Cold Unit revealed that good science in those halcyon early days of the MRC was a matter of trusting gifted individuals to get on with their research. It also revealed the difference between formal structures and actual practice. The seminar was helpful, like all enlightening historical meetings, in distinguishing myth from fact, and doing so in unexpected ways. The "myth" that some impecunious people had a cheap honeymoon at the Unit was exposed as fact, whilst the common perception that it was a unit researching the common cold was revealed as a gross oversimplification of its much more varied work in virology. Given the variety of subject matter in a volume such as this one, where few readers are likely to be equally interested in such disparate themes, a recent decision to publish single witness seminars is to be welcomed.