These words refer to substances capable of impairing health, damaging tissues or destroying life by their chemical action upon an organism or its parts. Poison is the most general of these words, being applicable to any such substance, natural or synthetic, which is deadly when swallowed, inhaled or simply brought into contact with the skin.

• Many useful drugs and medicines, when taken improperly or to excess, are poisons ; Prussic acid and carbon monoxide gas are both lethal poisons .

Toxin , though closely related in meaning, has become a specialized term for poisons developed by metabolic processes in and by animal, vegetable and bacterial organisms and capable of producing disease or serious harm.

• Tetanus is caused by toxins formed in the body by invading bacteria; Curare, a powerful arrow poison , is toxin extracted from a plant and is used in medicine as a muscle relaxant.

Venom is now generally restricted to the toxic liquid secreted by various animals, especially snakes, scorpions and some insects, and injected into their victims as an offensive or defensive weapon. Bane , from an Old English word meaning killer, has become archaic in the sense of poison , but is still found in the popular names of certain plants such as henbane , wolf’s-bane , and ratbane , once believed poisonous to these animals.

In figurative use, poison , bane and venom denote that which corrupts, harms or destroys: the poison of malicious rumours; an alcoholic who is the bane of his family’s existence; the venom of the rejected woman’s spite.