Did you know many important works of ancient history and science were lost because monks bleached the pages of these important documents in order to write biblical and liturgical texts on the paper?
In the 3rd century BC, a Greek philosopher, Archimedes, discovered some of the principles of integral calculus, however, as the Roman Empire underwent Christianization, many pagan works were burned and lost (except Plato, who was beloved by the early Christians). The only remaining copy of this work by Archimedes was later bleached by monks and prayers were written on the same paper. (1)
About 2,000 years after Archimedes, integral calculus was again developed, largely by Newton and Leibnitz. Then, in 1998 scholars used modern imaging techniques (ultraviolet, infrared, X-ray, etc) to find/read the calculus, hidden underneath the prayers. This document is called the Archimedes Palimpsest.