Introduction

The published, public book or paper is no longer the only material of interest to historians of science and medicine. Correspondence, diaries, laboratory notebooks, clinical records and a range of other sources are now appreciated as providing valuable insights into the production, dissemination and use of scientific and medical knowledge. Several large correspondence projects testify to the place that letters occupy in contemporary historical thinking. For the Victorian era, the correspondences of Charles Darwin and Michael Faraday are the most visible examples, and those of Henry Oldenburg and Isaac Newton have illuminated the period of the early Royal Society. Victorians used letters like we use the telephone and emails: to communicate whenever they needed to. The postal service was more efficient then, with several deliveries each day, and after the railways were in full swing, often a speedier transport between cities. Consequently, individuals wrote notes and letters to communicate mundane matters, like luncheon times, greetings to the family, or the possibility of meeting. Victorians also used the postal service to talk about more serious matters, such as the books they were writing, politics, or what decisions they ought to take about substantial issues. Darwin is a particularly good example of the enabling function of a decent postal system, since he rarely left Down House and used his extensive network of correspondents as a lifeline to the wider scientific world. Thomas Henry Huxley and Michael Foster also participated in this epistolary way of life, and the correspondence reproduced here records their friendship lasting more than three decades. Despite a few obvious gaps, the surviving correspondence has a wonderful dynamic, as the two colleagues age and mature, their interests change and their relationship develops. Read straight through, the letters offer a window into the Victorian values of two major life scientists of the period.