Human scents are familiar but difficult to describe

What do you think when one day you feel the smell of old people or the smell of rival love?

Have you ever wondered how many scents exist around us? It would be a huge number because there are many smells that you never noticed or heard of. The following article will give you some smells that you will be surprised to hear about them.

Here are the scents that exist around us:

From scent on human body

1. The smell of potential enemy

When it comes to testosterone, men think immediately. But in fact, this hormone also exists in the female body, even helping women have a special 'superpower' : recognizing their potential enemy.

American scientists have done research on this topic. Jon Maner, a University of Florida psychologist and his colleague James McNulty conducted an experiment on women aged 18-21. In it, the people tested will be divided into 2 groups.

The first group must wear the prescribed t-shirts at the two stages of the menstrual cycle (a time of pregnancy, the most difficult time to get pregnant), without the use of shampoo, perfume, Aromatic soap. The second group will be assigned to smell on those shirts without knowing about the women in the other group.

The results showed that T-shirts worn during pregnancy had a characteristic scent, stimulating testosterone production in women who smelled those shirts; while T-shirts in the period of less likely to become pregnant give the opposite result.

Testosterone - the key to helping the weak recognize adulterous husbands

With this characteristic, when the man 'craving phở', the scent of the lover will remain on their bodies. And you can use your nose to find out what your rival is.

2. The smell of the elderly

Science has shown that there is a very characteristic smell in the elderly.

Specifically, Japanese scientists had an experiment on 22 volunteers from the age of 26 - 75. They took these volunteers' worn shirts, then analyzed them and compared them. compare.

In the coats of the elderly, a large number of 2-nonenal compounds were discovered. The amount of this compound in the elderly is three times higher than that of the middle-aged people, and many times more than the young people.

Many assumptions are made around the formation of 2-nonenal, but the most agreed opinion is from the breakdown of fatty acid chains.

Scientists describe the smell of this compound very uncomfortable, like being mixed between the smell of the throne of plants and the smell of grease. Perhaps it is because of the familiarity with this uneasy scent that the elderly do not really feel uncomfortable with the body odor from young people or middle-aged people.

. to natural scents

3. The smell of rain

When the showers came, everyone could smell a refreshing and pleasant scent. However, when tasting the taste of the rain with the tongue, it was clear that the rain did not smell anything. So where is the cause? Is it because the nose of the human has a problem?

The truth is not so. In fact, rain does not taste but they appear to entail the presence of a scent in the air. According to scientists, the scent you smell is actually an essential oil that plants produce when the weather is too hot and dry.

In 1964, two experts, Isabel Joy Bear and RG Thomas from Australia, began a research project called 'The Odor of the Rain'. They discovered that in the days when the weather conditions were too hot, most plants would produce a compound called geosmin.

The closer you are to places with lots of trees or lawns you will see a clear 'smell of rain'.

Spores of actinomycetes, a fibrous bacterium, will carry geosmin molecules dispersed in the air or absorbed into the soil. Rain will cause these spores to burst and the scent of geosmin will spread everywhere. That is also the reason why the closer to the tree or grassy areas you will see a clear "smell of rain".

Although the concentration of geosmin in the air is very small, it is very sensitive to the human nose. Just one amount of geosmin, approximately 5 parts per 1,000 billion, is our sense of smell.

4. The smell of old books and newspapers

Every time you set foot in large libraries, you can immediately smell a very strange smell. The special thing is that you can only smell this smell when you get close to the old bookshelf.

Scientists have studied and found that the same books and old newspapers that were the "culprits" created this strange scent.

Specifically, each book is composed of different types of organic compounds. As time went on, the above organic substances encountered many external impacts such as light, air humidity . Since then the chemical reactions occurred, creating new organic substances that are volatile and do for books that smell 'strange'.

Common organic substances produced after that process are acetic acid (CH ₃ COOH), benzaldehyde (C ₆ H ₅ CHO) - a almond aromatic ring compound.

In addition, the old paper books also produced some other compounds such as butanol (C ₄ H ₉ OH), furfural (also with almond smell) or octanal (C ₈ H ₁₆ O).