BEIJING (Reuters Life!) - Sixty-year-old Du Weisheng likes to call himself a doctor, whose time-ravaged patients are frail, often crumble at a touch and sometimes get chewed by rats.
Du preserves and restores books and scripts that are hundreds of years old at China's National Library, performing a job that is fast becoming as rare as the tomes he rescues.
Only three top universities in Beijing offer degrees in restoring ancient books and there are fewer than 150 people in China that still do this for a living.
The library is home to two million books, a third of which require fixing and some 100,000 are in very bad condition, says Du, a researcher at the rare books division. And there is only so much he and his team of 19 can do.
"We fix about 1,000 books per year and the best we can do is no more than 2,000. This means it's going to take us a very, very long time before we can finish this task," he told Reuters.
Du joined the rare book division of the National Library in 1974, leaving the military service for an office job he hoped would be less rigorous.
Since then, he has participated in restoring 161 volumes of the 600-year-old Yongle Encyclopaedia, considered one of the most valuable historical documents for Chinese history studies, as well as helping to rescue manuscripts from the oasis Silk Road city of Dunhuang written between the 5th and 11th centuries.
Du has also fixed nearly 5,000 ancient books himself, and says the way paper used to be made in China is a big factor in the erosion of ancient texts.
Apart from books that were partly destroyed by wars and improper storage, he says the switch from rice paper to bamboo paper made many books unable to weather the test of time.
According to "Chinese Paper Making Skill," a book Du's department uses as a reference, Chinese rice paper originates from the Tang Dynasty, which ruled from 618 to 907.
But during the Song Dynasty (960-1127), paper was made from trees, and fast-growing bamboo was a good way to make affordable paper that is today costing millions of dollars to fix.
Du said over a long stretch of time, paper made from bamboo gives out a chemical called oxalic acid that eats away the paper.
The solution, he says, is to make digital copies of the books to ensure they do not disappear forever, which he concedes is a very expensive process.
"There are some problems with the development of modern technology of book protection," Du said. "This is a vast investment. It is, at this stage, impossible to invest billions in the technology and equipment."
Editing by Miral Fahmy