For thousands of years, humans have used a variety of sources with which to cure their ills, cast out devils, promote their wellbeing, relieve their misery, and control their fertility. Until the beginning of the twentieth century, the agents used were all of natural origin, including many derived from plants as well as elements such as antimony, sulfur, mercury, and arsenic. The sixteenth-century alchemist and physician Paracelsus used mercury and arsenic in his treatment of syphilis, worms, and other diseases that were common at that time; his cure rates, however, remain unknown. Many drugs used today have their origins in natural products. Antimony derivatives, for example, are used in the treatment.
