Evils of Alcohol

A man was trying to teach his son the evils of alcohol.
He put a worm in a glass of water & another in a glass of whiskey.
The worm in the water lived while the one in the whiskey curled up & died.
"All right, son," said the Dad, "what does that show you?"
"Well Dad, it shows that if you drink alcohol you will not have worms."