Thank you to our colleague Robert Behra for sending us this article from The Guardian:
“Old Spines-Why We Love The Smell of Secondhand Books”.

“…lignin is a polymer that stops trees from drooping, and is chemically related to the molecule vanillin. ‘When made into paper and stored for years, it breaks down and smells good which is how divine providence has arranged for secondhand bookstores [and our rare book collections!] to smell like good-quality vanilla absolute, subliminally stoking a hunger for knowledge in all of us.'”

And thank you, divine providence!