Harvard's "acid paper problem," as it is commonly termed among preservationists, is an inherently modern problem, affecting only books printed after the turn of the 19th century. Prior to this time, paper was made from cotton rags and books were bound with leather and glue made from animal fats.

The irony of this problem is that the oldest books actually decay slower and are consequently in better condition--assuming they have survived through the years--than the more modern books, Merrill-Oldam says.

In the 18th century, a crisis shook the paper-making industry because cotton rags became extremely scarce. In the 19th century, mills turned to making paper from wood instead.

Books are decaying rapidly today because "a tree had more to it than a cotton ball," says Merrill-Oldam. The problem is that wood contains lignin, the substance that causes newsprint even today to decay and yellow within a matter of weeks if left in the sun.

By 1900, scientists had determined the problem and began treating the wood to remove the lignin, but in the process they often reintroduced other decants and acids. In the '50s and '60s, paper was sized-smoothed out for writing--with acidic salts--another decant. It was not until the 70s that mills were reengineered to manufacture alkaline paper, which, like paper made from cotton rags, has an extremely long life.

As a consequence of all of this, literature from the 19th and much of 20th century--from the great works down to pulp fiction--was printed on rapidly decaying paper.

Preservationists have developed two techniques for conserving these problematic books.

One is a "toxic and explosive and extremely expensive" chemical treatment, which individually stabilizes the paper in each book, according to Michael McCormick, who is on the Library Committee.

The other solution is climate control, which means equipping the stacks with air conditioning and humidity control with the added benefit that the building can be sealed to keep out air pollution. The windows of Widener are often left open during the summer, which exposes the collection to air pollution and increases the books' acidity.

The importance of climate control is basic chemistry.

"The warmer and damper it gets the faster the books deteriorate. When it's hot and humid the stuff is decaying very rapidly," says James M. Reilly, director of the Image Permanence Institute.

The $28 million renovation will also involve new improved wiring and an enhanced protection system, for which the Development Office's brochure again paints a vivid need.

"Furthermore, this slow death could turn out, instead, to be a sudden one. Electrical wiring in Widener Library is antiquated, and fire protection is inadequate. Dramatic action is urgently needed," the brochure says.

The long-term solution, which Merrill-Oldam and her staff at the Preservation Center are working on, is preserving the information within the books by scanning and microfiching those that are nearly destroyed-but to do so takes years.

A climate control system will provide the preservation system with these needed years, Merrill-Oldam says.