Justus Friedrich Karl Hecker was a German physician and medical writer, whose works appear in medical encyclopaedias and journals of the time. He particularly studied disease in relation to human history, including plague, smallpox, infant mortality, dancing mania and the sweating sickness, and is often said to have founded the study of the history of disease. The account of "The Black Death" here translated by Dr. Babington was Hecker's first important work of this kind. It was published in 1832, and was followed in the same year by his account of "The Dancing Mania." The books here given are the two that first gave Hecker a wide reputation.