During the period 1880-1900, the first studies were conducted to aid in understanding the effects of electricity on the human body. Commercial electrical systems were being developed, with the first central station for incandescent lighting placed in operation in 1882. The proliferation of these new stations and their distribution systems inevitably led to accidental electrocutions. The early investigators of electrical death were primarily physicians who were troubled by the incomplete electrical knowledge of that time as they evaluated the different effects of direct and alternating currents and high and low currents. Most of the studies used animals, while postmortem examinations of electrocuted criminals provided some information, though of little practical value, concerning high-current shocks. Various theories concerning suspended animation and concerning the action of electricity on the nervous system were proposed and discarded. In 1899, Prevost and Battelli in Europe, and Cunningham working independently in the United States, showed that ventricular fibrillation was the usual mode of death for low-voltage shocks. The possibility of electrical defibrillation of the heart was clearly described by Prevost and Battelli in 1899.