A professor of chemistry wanted to teach his 5th grade class

 a lesson about the evils of alcohol, so he produced an
experiment that involved a glass of water,
a glass of whiskey and two worms. "Now,
class. Observe closely the worms," said
the professor putting a worm first 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 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!