For thousands of years human beings have used heat in the form of cautery to treat trauma and disease. By the late nineteenth century, as technology advanced, heat could be produced by electric current. In 1920 William T. Bovie, an eccentric inventor with a doctorate in plant physiology, developed an innovative electrosurgical unit that Harvey Cushing, the founder of modern neurosurgery introduced to clinical practice. The Bovie unit passes high frequency alternating current into the body allowing the current to cut or coagulate. After 75 years this basic device remains a fundamental tool in the practice of surgery.