Tikalon Blog by Dev Gualtieri

The Scent of Books

May 22, 2017

The human sense of smell is not as acute as it is in many animals, but it does serve some useful purposes. We're able to distinguish between good food and food that's spoiled or not that nutritious. Animals use smell as an aid in finding a mate through detection of the complex chemical vapors called pheromones they emit to signal their presence.

Since human pheromone emission is much more subtle, we augment our aura with perfume and cologne. These seem to work well, since most men will admit that the scent of a certain perfume will bring back memories of a girlfriend. The senses of taste and smell are intimately linked, since olfaction is an important supplement to the tongue's primitive taste receptors.

The prime example of taste evoking memory is contained in Marcel Proust's novel, "À la recherche du temps perdu," a title that's commonly translated as "Remembrance of Things Past." This is a considerable work that's three thousand pages long and contained in seven volumes. It's understandable that Proust had a hard time finding a publisher for this work, and he self-published the first volume.

There's a scene in Proust's novel known as the "episode of the madeleine" in which the taste of a cake triggers a childhood memory. The scent of pierogi brings to my mind memories of my maternal grandmother, but I haven't yet started writing my seven volumes.

A plate of potato pierogi, just like babcia used to make.

(Modified Wikimedia Commons image by Kagor.)

Virtual reality is making inroads into entertainment, but an early leap into virtual reality was provided by Smell-O-Vision. This technology, patented by Hans Laube in 1959,[1] synchronized odors with scenes in a film. Alas, the technology was ahead of its time, so it was ridiculed in the media, being named as one of the "Top 100 Worst Ideas of All Time," along with New Coke, spray cheese, and the programming decision that led to the Y2K bug.


Smell-O-Vision was based on odor-containing cells selected by a simple reel-to-reel transport system. Today, it would be very easy to make a personal odor delivery system for virtual reality systems using thick film technology with resistive heating elements. (Portion of fig. 1 from US Patent No. 2,905,049, "Motion pictures with synchronized odor emission," by Hans Laube, September 22, 1959.[1])

One odor I haven't experienced in quite a while is the smell of books in a library. I haven't been inside a library in years, since all my reading materials are obtained from online shopping, or through the Internet. If I ever again venture into a library, I'm sure the smell will be that of carpets and computers, not the smell of old books, and those smells would not evoke childhood memories.

A recent study by Cecilia Bembibre and Matija Strlič at the University College London Institute for Sustainable Heritage has quantified the nature of "book smell."[3-4] Their results are published in an open access article in the journal, Heritage Science.[3] The study authors point out that odors are important in our lives, but we have little knowledge of the smells of the past. They argue that smells are part of our cultural heritage, so they should be identified and conserved.[3]

As a start, they did a study in which they collected library visitor impressions of book odor.[3] chemical analysis was also undertaken of the volatile organic compounds emitted from historic books.[3] Says study coauthor, Cecilia Bembibre, "The role of smells in how we perceive heritage has not been systematically explored until now."[4]

In a first study, visitors to St Paul's Cathedral's Dean and Chapter library, London, were asked to characterize its smell.[4] All visitors described the library's aroma as woody, followed by smoky (86%), earthy (71%) and vanilla (41%). More than 70% of the visitors described the smell as pleasant.[4]

Old books are "woody," followed by "smoky," and "earthy."

A graphical exposition of how study participants perceived the smell of old books.

(Portion of fig. 3 of ref. 3, licensed under the Creative Commons Attribution 4.0 International License.[3])

In another experiment, visitors to the Birmingham Museum and Art Gallery were presented with the smell of an unlabeled 1928 book obtained from a second-hand bookshop in London. The words used to describe the smell were collected, and terms related to chocolate were used most often used, followed by coffee, old, wood and burnt (see figure).[4] Other terms included fish, body odor, rotten socks and mothballs.[4]

Word cloud of terms used to describe an old book. (Portion of fig. 2 of ref. 3, licensed under the Creative Commons Attribution 4.0 International License.[3] Click for larger version.)

The researchers did a chemical analysis of volatile organic compounds sampled from books in the Dean and Chapter library. They were able to catalog the major chemicals present in "book smell," as listed in the following table. These were obtained using a technique called solid phase microextraction and gas chromatography-mass spectrometry (SPME–GC–MS}.[4]

	Compound	Aroma descriptor
	Acetic acid	Sour
	Propanoic acid	Pungent, rancid, soy
	2,4-Dimethylheptane	Gasoline-like
	Toluene	Paint
	Hexanal	Grass, tallow, fat
	Nonane	Alkane
	Furfural	Bread, almond, sweet
	Heptanal	Fat, citrus, rancid
	Undecane	Alkane
	Dodecane	Alkane
	Benzaldehyde	Almond, burnt sugar
	d-Limonene	Lemon, orange
	Nonanal	Fat, citrus, green
	Undecanal	Oil, pungent, sweet
	Icosane	Alkane

The authors suggest that the method could be used as a diagnostic tool to assess the condition of an object through its olfactory profile.[4] Odors can be used to enhance visitor experience in museums by understanding what the past smelled like.[4]

The Scent of Books

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