How do bogs keep things fresh?

Answers to your questions about the news.
July 28 2006 6:50 PM

Bless This Boggy Book

How do bogs keep things fresh?

Download the MP3 audio version of this story here, or sign up for The Explainer's free daily podcast on iTunes.

A construction worker discovered an ancient book of psalms while excavating an Irish bog last Thursday. Ireland's National Museum has called it "a miracle find" and labeled the 1,200-year-old tome the "Irish equivalent to the Dead Sea Scrolls." How could the book have survived for so many years in a bog?

European peat bogs happen to be excellent at preserving organic matter. Bits of animal skin—like the vellum pages upon which the ancient psalter was written—can last for hundreds or thousands of years when they get trapped under the surface of peat at the top of a bog. That's because they're exposed to an acidic environment with lots of sphagnum moss and very little oxygen. These factors make life very hard for the microbes that would otherwise cause rotting and decomposition.

Daniel Engber Daniel Engber

Daniel Engber is a columnist for Slate

Advertisement

The sphagnum moss produces an antibiotic substance called sphagnan that staves off rot in several ways. First, it binds with proteins on the surface of microorganisms in a way that immobilizes them and removes them from the water. Second, its highly reactive carbonyl groups can alter the chemicals and nutrients that would be necessary for the decomposition of a piece of organic matter. Third, the sphagnum moss causes the organic matter to undergo certain chemical changes that make it more impervious to rot—in much the same way that animal skins can be preserved as leather.

The peculiar properties of these bogs have made them invaluable archaeological repositories. More than 1,000 specimens of well-preserved human remains have been found under beds of peat moss. These "bog bodies" can retain their key features for thousands of years. In many cases the chemicals in the bog break down the skeleton and leave only the soft tissue. The tanning reactions from the sphagnum moss give the skin on these remains their characteristic dark-brown color.

Among the bog bodies, the most famous is the Tollund Man of Denmark. * He died in about 350 B.C., but you can still see the stubble on his chin, and the rope that killed him remains tied around his neck. The Lindow Man, who was found in England in 1984, still has a beard and a mustache. Researchers say his killers struck him on the head, cut his throat, and strangled him before tossing him into the bog.

Got a question about today's news? Ask the Explainer.

* Correction, July 31, 2006: This piece mistakenly identified Tollund Man as being from Norway. The body was found in Denmark. (Return  to the corrected sentence.)

TODAY IN SLATE

Politics

The Right to Run

If you can vote, you should be able to run for public office—any office.

Move Aside, Oxford Comma, the New Battle Is Over Single or Double Quotes

Renée Zellweger’s New Face Is Too Real

Sleater-Kinney Was Once America’s Best Rock Band

Can it be again?

Ben Bradlee’s Fascinating Relationship With JFK

Culturebox

The Simpsons World App Is Finally Here

I feel like a kid in some kind of store.

Technology

Driving in Circles

The autonomous Google car may never actually happen.

My Father Invented Social Networking at a Girls’ Reform School in the 1930s

How Punctual Are Germans?

  News & Politics
The World
Oct. 22 2014 11:57 AM Why Wasn't the WHO Ready for Ebola?
  Business
Moneybox
Oct. 21 2014 5:57 PM Soda and Fries Have Lost Their Charm for Both Consumers and Investors
  Life
The Vault
Oct. 22 2014 11:36 AM Casting the Role of Scarlett O'Hara Was Really, Really Frustrating
  Double X
The XX Factor
Oct. 22 2014 10:00 AM On the Internet, Men Are Called Names. Women Are Stalked and Sexually Harassed.
  Slate Plus
Working
Oct. 22 2014 6:00 AM Why It’s OK to Ask People What They Do David Plotz talks to two junior staffers about the lessons of Working.
  Arts
Behold
Oct. 22 2014 11:04 AM Do All U.S. Presidents Look the Same? What About Japan’s Prime Ministers?
  Technology
Technology
Oct. 22 2014 10:29 AM Apple TV Could Still Work Here’s how Apple can fix its living-room product.
  Health & Science
Science
Oct. 22 2014 11:30 AM Where Does Ebola Hide? My nerve-wracking research with shrieking bats.
  Sports
Sports Nut
Oct. 20 2014 5:09 PM Keepaway, on Three. Ready—Break! On his record-breaking touchdown pass, Peyton Manning couldn’t even leave the celebration to chance.