Most people know the familiar scent of an old book, whether it be at the library or a cosy corner of the book shelf at home. It's somewhat a old, homely smell that's reminiscent of a mixture of almond, vanilla, and grass.
But why do old books smell like that?
Scientists at the University College in London investigated and found that it was due to organic compounds in the pages that break down over time and release chemicals. As readers sift through the pages of an old book, hundreds of volatile organic compounds (VOCs) are released into the air, causing the unmissable old book smell.
Some of the paper in the books analysed by the scientists contained rosin (or pine tar) and wood fibre. These are among the fastest types of paper to degrade.
The scientists say that the techniques use could be used to detect degradation and better protect old books in museums and libraries.