Robert Willan (1757-1812) was a physician who practiced in London. Like Sydenham he was fascinated by the relation of weather to epidemics and kept strict records on when they occurred over several years. He was particularly interested in the diseases of children and carefully observed rashes and pustules as they developed in stages on the skin. The first volume of his book, On Cutaneous Diseases, was published between 1798-1808 and widely admired by the medical world. Historians generally agree that it was this book that launched the modern specialty of dermatology. The volume is notable for its' beautiful and graphic colored plates. Willan closely supervised the creation of these. In 1812 as he was preparing a second volume for publication, Willan sadly died from tuberculosis. Plate 20 shows a young child's face and arm covered in the rash characteristic of measles. It was often a severe and disfiguring disease in early modern England and could result in death as the infection spread to the tissue and bone, resulting in gangrene.