The practices of ancient Hindu, or Vedantic, medicine (1500-1000 bc) are described in the works of two later physicians, Charaka (lived about 2nd century ad) and Susruta (lived about 4th century ad). Susruta gave recognizable descriptions of malaria, tuberculosis, and diabetes. He also wrote about Indian hemp, or Cannabis, and henbane for inducing anesthesia, and included specific antidotes and highly skilled treatments for bites of venomous snakes. An ancient Hindu drug derived from the root of the Indian plant Rauwolfia serpentina was the source of the first modern tranquilizer. In the field of surgery, the Hindus are acknowledged to have attained the highest skill in all antiquity. They were probably the first to perform successful skin grafting and plasti.