Gulp: Adventures on the Alimentary Canal

Snakes don’t either, but they can, under certain circumstances, create an inflammable eructation of literally mythical proportions. For this story, we leave Ed DePeters in his muck boots and feed cap and turn to our snake digestion man in Alabama, Stephen Secor. First, a little background: Many plant-eating animals lack rumens, so some fermenting takes place in the cecum, an anatomical pouch at the junction of the small intestine and the colon. These same plant-eaters—horses, rabbits, koalas, to name three—tend to have a larger-than-average cecum. Pythons and boas do too, which struck Secor as odd, because they’re carnivores. Why, he wondered, would a meat-eater need a vegetation digestion unit? Secor theorized that perhaps these snakes had evolved ceca as a way to digest and take advantage of plant matter inside the stomachs of their prey.

To test his theory, Secor fed rats* to some of the pythons in his lab at the University of Alabama and hooked them up to a gas chromatograph. He tracked the hydrogen level in their exhalations as they digested whole rats over the course of four days. He did see a spike, but it appeared long before the rat arrived at the python’s cecum. Instead, Secor suspected, the hydrogen spikes were the result of the decomposing, gas-bloated rat bursting inside the python. “One thing led to another.” (Secor’s way of saying he popped a bloated rat corpse and measured the hydrogen that came off it.) Suspicion confirmed. The hydrogen level was “through the roof.” Secor had stumbled onto a biological explanation for the myth of the fire-breathing dragon. Stay with me. This is very cool.

Roll the calendar back a few millennia and picture yourself in a hairy outfit, dragging home a python you have hunted. Hunted is maybe the wrong word. The python was digesting a whole gazelle and was in no condition to fight or flee. You rounded a bend and there it was, Neanderthal turducken. Gazython. The fact that the gazelle is partially decomposed does not bother you. Early man was a scavenger as well as a hunter. He was used to stinking meat. And those decomp gases are key to our story. Which I now turn over to Secor.

“So this python is full of gas. You set it down by the campfire because you’re going to eat it. Somebody kicks it or steps on it, and all this hydrogen shoots out of its mouth.” Hydrogen, as the you and I of today know but the you and I of the Pleistocene did not know, starts to be flammable at a concentration of 4 percent. And hydrogen, as Stephen Secor showed, comes out of a decomposing animal at a concentration of about 10 percent. Secor made a flamethrowery vhooosh sound. “There’s your fire-breathing serpent. Imagine the stories that would generate. Over a couple thousand years, you’ve got yourself a legend.” He did some digging. The oldest stories of fire-breathing dragons come from Africa and south China: where the giant snakes are.




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* Flammable is a safety-conscious version of inflammable. In the 1920s, the National Fire Protection Association urged the change out of concern that people were interpreting the prefix in to mean “not”—as it does in insane. Though surely those same people must have wondered why it was necessary to warn of the presence of gas that will not burst into flame.

? “Work with your neighbors,” urges the Southeast Iowa Snouts & Tails Newsletter. “Inquire about any outdoor events in the neighborhood such as weddings, cookouts and such to avoid manure application prior to those events.” Unless your neighbors are also swine farmers, who apparently don’t mind that sort of thing. The next item in the newsletter is a Manure Injection Field Demonstration “followed by a free lunch.”

* Meaning “clotted or lumpy.” Grumous is one of many evocative words that deserve to break free from medical dictionaries and join the ranks of day-to-day vocabulary. Likewise, glabrous (“smooth and hairless”), periblepsis (“the wild look of delirium”), and maculate (“spotted”).

* Pylorus is Greek for “gatekeeper.” That’s all. As you were.

* Purchased in bulk from RodentPro.com. Life is cheap at RodentPro, as cheap as sixteen cents for an extra small pinky (a one-day-old frozen feeder mouse). Mice are also available in fuzzy (ten to fifteen days old), white peach fuzzy (“Just the right size when a pinky is too small and a fuzzy is too large”), hopper, weanling, and adult. Feeder rats and guinea pigs are sized like Tshirts: XS, S, M, L, XL, and XXL. RodentPro gift certificates are available. Because nothing says “I love you” like $100 of dead rodents delivered to the doorstep.





13

Dead Man’s Bloat

AND OTHER DIVERTING TALES FROM THE HISTORY OF FLATULENCE RESEARCH



Mary Roach's books