Arrow poisons are used to poison arrow heads or darts for the purposes of hunting and warfare. They have been used by indigenous peoples worldwide and are still in use in areas of South America, Africa and Asia. Notable examples are the poisons secreted from the skin of the poison dart frog, and curare (or 'ampi'), a general term for a range of plant-derived arrow poisons used by the indigenous peoples of South America. Poisoned arrows have featured in mythology, notably the Greek story of Heracles slaying the centaur Nessus using arrows poisoned with the blood of the Lernaean Hydra. The Greek hero Odysseus poisons his arrows with hellebore in Homer's Odyssey. Poisoned arrows also figure in Homer's epic about the Trojan War, the Iliad, in which both Achaeans and Trojans used toxic arrows and spears. Poisoned arrows are referred to in the Book of Job in the Bible, descriptive of the sufferings experienced by the just man, Job. The modern terms "toxic" and "toxin" derive from the ancient Greek word for "bow", , from Old Persian *taxa-, "an arrow". Poisoned arrows were used by real people in the ancient world, including the Gauls, ancient Romans, and the nomadic Scythians and Soanes. Ancient Greek and Roman historians describe recipes for poisoning projectiles and historical battles in which poison arrows were used. Alexander the Great encountered poisoned projectiles during his conquest of India (probably dipped in the venom of Russell's viper) and the army of the Roman general Lucullus suffered grievous poison wounds from arrows shot by nomads during the Third Mithridatic War (1st century BC). In the Kingdom of Kush, arrows were often poison-tipped. There is some indication that poisoned arrows were used in battle against the Romans from 27 BC to 22 BC. The use of poisoned arrows in hunting and warfare by some Native Americans has also been documented. Over the ages, Chinese warfare has included projectiles poisoned with various toxic substances. Varieties Arrow poisons around the world are created from many sources: Plant-based poisons Curare is a generic term for arrow poisons that contain tubocurarine, curarine, quinine, protocurarine and related alkaloids. Most frequently it is derived from the bark of Strychnos toxifera, S. guianensis (family Loganiaceae), Chondrodendron tomentosum or Sciadotenia toxifera (family Menispermaceae). Curare is a competitive antagonist that blocks nicotinic acetylcholine receptors on the post synaptic membrane of the neuromuscular junction. It is a muscle relaxant