The benefits of a little bit of poison. Snakes
Snakebite can be a killer. Ask any student the morning after a session on the lager and cider mix.
The other kind is pretty lethal, too. Snakebites can be haemotoxic - poisoning the blood - or neurotoxic - interfering with the body's nerve-muscle communications, sending their victims into spasm or paralysis, and sometimes to their deaths. But venom also has its beneficial side.
We often build up resistance by exposure to small amounts of the very thing that could otherwise be hazardous to health. By alerting the immune system to the chemical shape and structure of an invader, our bodies get ready to repel it.
But Dr Constantine Hering, a 19th-century pioneer of homeopathy, overdid it during his research on snake venom. He had heard that the South American bushmaster snake might have medicinal properties and travelled to the Amazon to investigate. But while handling the noxious substance, some found its way into his own bloodstream and he fell into a long, delirious coma.
He survived, but developed an aversion to tight clothing and became obsessively jealous. The bushmaster's venom, lachesis, is now used in a diluted state to treat people who suffer from the same things. It is also given as a treatment for the menopause.
Other parts of the snake also have their uses. Snakes' skins have been used to treat head and backaches, their fat to cure baldness and their gall bladders to relieve the pain of childbirth. Venom from the arrowhead viper can help reduce blood pressure, and cobra venom has been used as a pain reliever.
But the most common curative use of snakebite is as an antidote to I snakebite. First, the venom is "milked" from the reptile's fangs. Then it is injected in increasing doses into horses or sheep, until they build up an immunity. Finally, the serum containing the antibodies is separated from the animal's blood. All you have to do for it to work is remember the snake that bit you.