Without some sort of preservation method, coffee becomes stale.

"I'd really like to buy the details of that preservation method," Marshall said.

Some accounts indicate that this preservation method was being used long before Prohibition.

This preservation method does not raise the pavement surface elevation.

The unusual preservation method is being considered because the tomb's current situation makes it impossible to prevent further damage and stop the spread of mold.

Mr. Billington said the library is looking into a number of preservation methods.

Drying food is the world's oldest known preservation method, and dried fish has a storage life of several years.

But environmental groups and planners said the tax would complement other preservation methods.

These preservation methods ensured the meats would have longer shelf-lives.

A preservation method using both pressure and another treatment (such as heat) to kill spores has not yet been reliably achieved.