 Volcanic ash preserved some of the Roman library of the Villa of the Papyri in Herculaneum.Ironically, the manuscripts that were being most carefully preserved in the libraries of antiquity are virtually all lost.Papyrus has a life of at most a century or two in relatively moist Italian or Greek conditions; only those works copied onto parchment, usually after the general conversion to Christianity, have survived, and by no means all of those.