A Professor of Medicine, a man well known for his earnest and oft-proclaimed Temperance views, was (yet again) lecturing the medical students on the damage that alcohol can do. To demonstrate its effect on the nervous system, he took a worm and dropped it into a glass of gin & tonic. The worm wriggled around for a few minutes before finally giving a few convulsive twitches and dying.

"And can we deduce anything from that?", asked the Professor with the triumphant air implying that only obvious conclusion could be drawn.

"Yes," came a voice from the back, "if you've got worms, drink alcohol."