I saw this footage last night on MSNBC. The Chicago Tribune's Rick Pearson ran this story about it today:

Howard Dean has not exactly been flush with political success on the campaign trail. But that didn't stop Dean, a physician by trade, from sharing his knowledge with a Longfellow Middle School science class in LaCrosse, Wis., on Tuesday.

He told the 8th graders studying microscopic particulates that water from a freshly flushed toilet would prove to be cleaner than water from the nearby Mississippi River.

"That's disgusting," a girl shouted.

"Now let me remind you of one thing," Dean said. "Do not say that Howard Dean came to my classroom and advised us to drink water from toilets."

Dean asked the pupils the sources of their microscopic samples. One student shouted out, "dog pee."

"Which has more bacteria--dog pee or river water?" Dean asked. "I do not recommend drinking urine, but if you drink water straight from the river, you have a greater chance of getting an infection than if you drink urine. . . .

"Now, there are chemicals in urine, waste chemicals that the human body doesn't need," he continued. "But unless you have an infection, urine is cleaner."

Some pupils doubled over with laughter.