A professor of chemistry wanted to teach his fifth grade class a lesson about the evils of liquor, so he produced an experiment that involved a glass of water, a glass of whiskey, and two worms.

"Now, class. Observe the worms closely," said the professor as he put the first worm into the water. The worm in the water writhed about, happy as a worm in water could be.

The second worm, he put into the whiskey. It writhed painfully, and it quickly sank to the bottom, dead as a doornail. "Now, what lesson can we derive from this experiment?" the professor asked.

Little Johnny, who naturally sits in back, raised his hand and wisely, responded, "Drink whiskey and you won't get worms!"