A Cautionary Tale of Technological Medical Progress and the Consequences of Human Experimentation. Radiation Evangelists explores X-ray and radium therapy in the United States and Great Britain during a crucial period of its development, from 1896 to 1925. It focuses on the pioneering work of early advocates in the field, the "radiation evangelists" who, motivated by their faith in a new technology, trust in new energy sources, and hope for future breakthroughs, turned a blind eye to the dangers of radiation exposure. Although ionising radiation effectively treated diseases like skin infections and cancers, radiation therapists - who did not need a medical education to develop or administer procedures or sell tonics containing radium - operated in a space of uncertainty about exactly how radiation worked or would affect human bodies. And yet radium, once a specialised medical treatment, would eventually become a consumer health product associated with the antibacterial properties of sunlight. This book raises important questions about medical experimentation and the so-called Golden Rule of medical ethics, issues of safety and professional identity, and the temptation of a powerful therapeutic tool that also posed significant risks in its formative years. In this cautionary tale of technological medical progress, Jeffrey Womack reveals how practitioners and their patients accepted uncertainty as a condition of their therapy in an attempt to alleviate human suffering.