Thanks to medical experiments performed on human subjects, we now have vaccines against smallpox, rabies, and polio. Yet the advances that saved lives too often involved the exploitation of vulnerable populations. Covering the history of human medical experimentation from the time of Hippocrates to today, this work will introduce readers to the topic through a mixture of essays and ready-reference materials. The book covers the experiments themselves; the people, companies, and government agencies that carried them out; the relevant medical and sociopolitical background; and the legislation and other protective measures that arose as a result.The encyclopedia is divided chronologically into six periods: pre-19th century, the 19th century, the pre-World War II 20th century, the World War II era, the Cold War era, and the post-Cold War period to today. Each period begins with an introductory essay and ends with a bibliography. Alphabetically arranged entries in each section cover pertinent people, experiments, and topics. The volume is enriched throughout with a wealth of primary sources, such as physicians' descriptions of their experiments. Medical experiments are not just a thing of the past, and readers will also learn about questions and debates related to contemporary efforts to advance medical science.