The sense of smell is largely a chemical process. The nose is capable of detecting dangers as well as delights. Without it we would be limited to discerning only sweet, salty, bitter or sour tastes that our tongue detects.
There are between 10 and 25 million receptor cells (olfactory neurons) in the 5 square centimeters well back in our nasal cavity. In size they are 5 to 15 micrometers (5/1000 to 15/1000 of a millimeter). Their life span is measured in weeks, not years, and are replaced when they die unlike many other nerve cells in our body that are not replaced. The mucous membrane in the nasal cavity warms, moistens and cleans the air we breathe in, about 12,000 times a day! Amazing!
It is estimated that these receptor cells can detect and identify more than 10,000 scents. How these cells send such messages to the brain for decoding is still largely a mystery. Most dogs far exceed our level of detection as has recently been demonstrated by dogs detecting even the minute presence of COVID-19 virus. That is a profound wonder. You can glean more facts from books or the internet.
On a different note, some people’s character exudes a very pleasant fragrance that our nose does not identify. Sadly, others spread a stench by the way they talk or behave. Most of us are somewhere in between.
Let’s spread a little fragrance.