Does wisdom perhaps appear on the earth as a raven which is inspired by the smell of carrion?

FRIEDRICH NIETZSCHE (1844-1900)

Odour

Resetting Your Sense of Smell


If you, or your house, smell bad you quickly become acclimatised to the smell and cease to notice it. The way to overcome this and effectively re-boot your nose is to increase the blood flow to it. This can be done by cardio exercise, so the way to check whether your house smells objectionable is to run up and down stairs several times (so, even if your house doesn’t smell, you will).

Submarine crews report that they become so accustomed to the ambient odour of unwashed socks inside the sub that the fresh air they breathe when they first surface makes them gag.

Body Odour


All of us have our own smell-print, as unique as a fingerprint. You can’t change this ‘core odour’ with perfume or diet – though you could cover it up – because it’s a product of your genes. Investigators can swab crime scenes to capture the criminal’s scent in the hope of finding a match later.

When we get ill we smell worse, but certain illnesses have specific scents. Diabetes sufferers are often reported to smell like slightly rotten apples; typhoid fever smells like baked bread, yellow fever smells like a butcher’s shop and the glandular disease, scrofula, smells like stale beer.

In an experiment, female subjects wore underarm pads while watching films. The pads were then given to other women, who were able to tell which of them had been worn by women who watched scary films. Men did not have this ability.

Up to 95% of East Asians don’t have the gene for smelly armpits, 98% of Europeans do.

STEVE MARTIN

I cannot smell mothballs because it is so difficult to get their little legs apart.

How Do You Smell?


In a study of 13 mammal species, elephants were found to have way more genes associated with smell than any other, nearly twice as many as rats, twice as many as dogs and 5 times as many as humans. The number of olfactory receptor genes ranged from 296 in orangutans to 1,948 in African elephants. Humans only have 396. Surprisingly cows do pretty well with 1186.
 
Although the researchers didn’t test the function of each gene, it’s well known that elephants have a very good sense of smell.

African elephants’ sense of smell is so good they can smell the difference between two tribes living in Kenya: the Maasai, whose young men prove their virility by spearing elephants and the Kamba, farmers who usually leave elephants alone. They show more fear when they detect the scent of clothes previously worn by Maasai than by Kamba men.

WILLIAM CONGREVE (1670-1729)

You are all camphire and frankincense, all chastity and odour.

A Trillion Scents


Everyone thought the human nose could smell 10,000 different smells until new research in 2014 found it's actually more like a trillion. The idea of 10,000 scents has been around since the 1920s and was a theoretical estimate that wasn't based on any hard facts or data.
 
The researchers who came up with the new figure had a hunch it wasn't right as we have over 400 different smell receptors which work together. The three light receptors in our eyes let us see around 10 million colours so the 10,000 figure seemed low.
 
Scents are made up of combined molecules, e.g the smell of a rose is 275 different molecules. The researchers made new combinations of 128 molecules to test if participants could recognise them. Each person was given three samples, two that were identical and one that was different then asked to identify the odd one out. They found that the samples could be 51% the same and people would still be able to tell them apart. This means that with the 128 molecules used in the experiment people could identify between over a trillion different smells. The real number is probably higher as there are a lot more molecules out there in the world.

Some people get ‘asparagus wee’ after eating it, others don’t. Some people do but they think they don’t because they can’t smell it.

A Californian company has developed a perfume that makes cows smell like people, so mosquitoes bite them instead of us.

The maned wolf's pee smells like cannabis.

Rats and moles have independently acting nostrils and can smell in stereo.

Dog nostril research shows that dogs investigate noxious smells with their right nostril and switch to the left for good smells.

Each of your nostrils smells the world slightly differently from how the other one smells it.

Foot odour apparently comes in four main varieties: sweaty, cheesy, vinegary, and cabbagey.

'Graveolent' means rank-smelling or fetid.

A tapir smells like a crate of lettuce.

Smellyness


In 2005 it was shown by a group of researchers at Oxford University that the brain can be tricked into believing an odour is pleasant just by giving it a more appealing name.

Presented with a sample of a cheddar cheese odour, test subjects found that they preferred the smell if the sample was labelled as 'Cheddar cheese' to when it was labelled as 'body odour'.

Cows can detect odours from a distance of six miles away.

Don't Touch


Some plants deliberately produce a putrid smell when you fiddle with their roots. Until recently it was assumed that these odours are released passively as a result of tissue damage, but Rabi Musah of the University at Albany in New York has discovered that plants of the mimosa genus actively release a nasty smell when they sense the touch of a potential threat. Even a seedling just a few centimetres high can fill a room with a disgusting smell, and the roots seem to be able to distinguish between different kinds of touch. A single touch with a finger is always enough to trigger the stench but the roots never respond to a glass or a metal object. Nor do they usually react to a single touch from soil. Just how the plant senses these distinctions is unknown.

Journalist Cyrus Redding (1785-1870) claimed that, as a boy in Devon, he could tell if a letter came from London just by smelling it.