Odd Sweet Smell you like.

WHY DO YOU LIKE THAT SMELL?

Some things just put us in a trance when

we smell them like old books can smell

like that smell. What is it? I love it

when it comes down to it, they are just a

bunch of paper, so we're going to explore

the chemicals that make up our favorite

and least favorite smells in this

scishow compilation to understand why

for example, books smell way more

satisfying than a stack of paper there

are all sorts of chemicals involved in

binding waterproofing and other

processes that put books on the top

shelf of smells.

Walk into an old library or secondhand

bookstore, you'll be surrounded by that

comforting old book smell, you know, the

some people describe it as a little

musty with hints of vanilla or coffee or

even newly cut grass, or maybe you prefer

the smell of new books, which can seem

crisp and fresh, but what causes books to

have such a distinctive smell. Sense of it

comes down to a handful of chemicals

compounds found in the paper ink and

bindings of the book, see, the paper is made

up of wood pulp, so it has a lot of

organic compounds, which are just

chemicals that contain carbon

specifically, the article has a lot of the

polymer cellulose, which is a long-chain

of the molecule glucose that's bound

together with the help of lignin, another

complex organic polymer found in plant

cells, and over time, these chemical

compounds react to things like light,

heat and moisture in their surroundings

and start breaking down in the process

they release volatile organic compounds

or VOCs, which easily vaporize and enter

the surrounding air. There are different

kinds of these VOCs and which ones are

released depends on how the manufacturer

made the paper and bound the book. If you

detect a hint of almond, you're probably

smelling benzaldehyde, a ring of carbons

connected to another carbon that's

double bond into an oxygen it's

naturally found in almonds, which

explains the scent of a vanilla-like

fragrance is thanks to vanillin the main

compound that gives vanilla its smell

and flavor if you smell something sweet

it's likely because of ethyl Benzene, a

ring of carbons connected to a short

carbon chain that's often used to

manufacture plastic, it's also in things

like inks and paints if you're detecting

a light floral Aroma, you're probably

smelling too ethyl hexanol, a kind of

alcohol that's often used in solvents

but also in flavors and scents of new books

release different types of VOCs because

modern manufacturing processes use

different types of chemicals, like

hydrogen peroxide to bleach the paper

and alkyl ketene dimers to make paper a

little water-resistant scientists and

historians can use these volatile

organic compounds to learn more about

the age and condition of older books or

to reveal parts of their history, like

whether they've been exposed to smoke or

had water damage, and learning more about

old book smells can help historians

determine which ones are degrading and

need to be better preserved and

protected, so it turns out we can know a

a lot from the smells in books, not just

the words in them

there's nothing like curling up with a

Good Book on a Rainy Day combines the

perfect book smell with a calming

scent of the rain and you are in for a

good time, but water very clearly doesn't

smell like anything so that you might be

enjoying the soothing smell of rocks, no

plants or ozone? Well, that's what Michael

explain that one, too

lots of people love the smell of rain

it's an aroma we associate with

freshness and cleanness and wetness, but

water doesn't smell like anything

so, what exactly is that wet Aroma? Well

it turns out that even though rain often

smells clean to us, and much of its scent

comes from dirt and rocks, the

the smell of rain has its own scientific

name petriker from the Greek word for

rock Petra and or the blood-like

substance that was said to flow through

the veins of the Gods but the source of

the smell isn't rocks itself; it

mostly comes from Plants, especially

during extended dry periods, some plants

release oils that are rich in fatty

acids, some of which you might recognize

as food ingredients like palmitic and

stearic acids Plants release these acids

when water is scarce because they block

other seeds in the ground from sprouting

which reduces competition for water and

over time, these oils build up on the soil

and rocks, and when rain falls, it kicks

them up into the air and cause them to

release fragrant volatile compounds that

to us smell fresh vegetal and altogether

pleasant, but that's only one component

of rain smell, petracur also contains a

chemical that's released by soil

bacteria called geosmin or Earth smell

and as the compound that gives the ground the

smell that we think of as earthy German

is a savory kind of alcohol

it's what gives some vegetables and

wines their loamy, dirty flavor, certain

soil bacteria release geosmin when they

die or when they go dormant, especially

in hot, dry conditions and when rain

finally comes along, it disperses the

chemical into the air in the form of a

fine Mist, so a lot of what you detect

when you smell the rain, you are actually

compounds that are living things have

produced to get through dry spells this

would explain why the smell is

particularly strong if it hasn't rained

in a while, but there's one more source

of rain scent that you can smell even

before it rains, ozone is just a

molecule of oxygen, but it has such a

distinctive Aroma that its name also

comes from the Greek word ozone to smell

ozone or O3 is produced when lightning

ionizes a molecule of oxygen or O2 in

the air separating the atoms when they

recombine some of them to form groups of

three creating ozone, which has a sharp

bracing scent that gives Petrichor its

invigorating quality, so the next time it

rains where you are, take a moment to

stop

smell the chemistry