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See Inside January 2007

Sweet and Soiled Science

Limbs and hands from the northeast to the southwest
Steve Mirsky



FRANK VERONSKY
What makes the sap run? Because he or she wants to serve in Congress. Well, that's the first answer that springs to mind this autumn day just after the November elections, and we'll get back to that subject later. But a better answer deals with a better interpretation of the question--regarding maple syrup. That subject was also on my mind, I having recently returned from a trip to the Proctor Maple Research Center in Underhill Center, Vt., while attending the annual meeting of the Society of Environmental Journalists in Burlington.

Turns out that what makes that sap run is devilishly complex. It's so complicated, in fact, that the only way I may ever really understand it is to have the scientists who research this question write a feature article for Scientific American so I can read it.

The key point, though, is that sugar maple trees have the unusual property of producing positive internal pressure after freezing and thawing. That internal pressure can tap, I mean top, that of a car tire, reaching about 40 pounds per square inch. In order to top, I mean tap, the tree, makers of maple syrup rely on the tree tap, I mean top--the branches are really where the action takes place that ultimately brings you your favorite pancake tapping. I mean topping.

Most trees have fibers filled with water, but sugar maples have air-filled fibers. "So," explains top tap (works either way) researcher Timothy Wilmot, "instead of getting the conditions you'd expect--where freezing would cause an expansion and something would come out of the tap hole when it froze--because of the physiology of the maple wood, water is actually sucked up during the freezing period. And during the thawing period, it's pushed out."

Because making the sap run--we're still talking maple trees here--requires a series of freezes and thaws, the entire industry is dependent on temperatures oscillating between a narrow range just below and just above freezing. A growing fear in the northeastern U.S. is that sustained warming will push both that temperature range and the sugar maple range north of the freezing point and border, respectively. Indeed, the sugaring season is getting shorter in Vermont but not in Canada. Yet.

By the way, I took a break in the middle of writing this story to have pancakes and Vermont maple syrup. While eating, I read a short item in the publication Funny Times that concerned a visit to a grade school by a firefighter. He showed the students a smoke alarm and asked if they could identify it. One kid responded, "That's how Mommy knows supper is ready." Just minutes earlier I had shut off a smoke alarm to prevent the hearing damage that ordinarily accompanies my pancake cooking.

Speaking of smoke-filled rooms, back to the election. The week before the voting, a story circulated about the practice among many politicians of using liberal--even among conservatives--dollops of those syrupy hand sanitizers when they're meeting and greeting hundreds of strangers. Seemed like a good and innocuous idea, and one of the few on which George W. Bush and Al Gore publicly agree.

But New Mexico governor Bill Richardson said he found it "condescending to the voters," according to the New York Times. "I'm not afraid to get my hands dirty," Richardson said. Two stats: Richardson holds the world record for most hands shaken--13,392 in eight hours at his state fair and at the University of New Mexico in 2002; a 2005 American Society for Microbiology study of more than 6,000 subjects found that 18 percent did not wash their hands after using a public restroom. So, unless New Mexicans are unusually clean or the venues had no facilities, Richardson probably shook hands with about 2,400 could-be contaminated constituents. And he may have passed along their microbes to the washed masses. Syrupticiously.

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