Matija Strlic, a researcher at the University College London has investigated this phenomenon. In a recent article in the The Telegraph he explains the reasons for this unnmistakble smell with a hint of vanilla that comes from an old book and its contents.
Indeed, the secret of the smell lies in the materials from which it is made of. As pages, glue and ink of the book are all composed of hundreds of volatile Organic Compounds ( VOCs ). With the passage of time, these Organic compounds break down resulting in release if new chemicals which give the peculiar smell. Books printed nowadays give different smell with time as they are not made of same components as old books. As, the type of different materials used can greatly effect the type of VOC structure and hence the type of smell.
The new chemicals released include benzaldehyde which give Almond note of smell, while vanillin, as its name suggests, gives vanilla like smell. Compounds like ethylbenzene and 2-ethylhexanol give us the sensation of floral fragrance. Similarly, the flowers pressed into the books also contribute to the smell of the book with time.
Identifying the origins of these smells can help the libraries to identify the books that are deteriorating. These books can then be protected and preserved. In a paper published by Strlic in 2009, he had identified 15 VOCs that deteriorate more rapidly than others.
It is true that this subtle fragrance that is characteristic of old books is quite mysterious. We would like to know more about the mysterious origin of these smells. And you, do these smells evoke any emotions or memories?