There are many ways of saying with the nose as protagonist: "take the nose", "stay with a palm of the nose", "go to the nose" ... We must not be surprised: after all this organ, with its wide nostrils that look like vacuum cleaner, it is beautifully evident on our faces, a sign that it must certainly perform a crucial function, that is to smell. Yet, the sense of smell is probably the most neglected among the senses, so much so that it is considered a legacy of our ancestral life when, like other animals, we sniffed the air in search of prey or to be warned in time of a danger. Thus Darwin could argue that "the sense of smell does man only very slight service" while Freud added to the dose by writing that "the decrease in olfactory stimuli seems to be the consequence of the man getting up from the ground, of the assumption of gait erect ".
Nothing could be more wrong as shown by the lively essay "The art of living smelling" (Aboca Edizioni, 2022, pp. 268, also e-book) written by Bill Hansson , scientist of smell (as he defines himself) and director of the chemical ecology department of the Max Planck Institute in Jena.
With many examples and curiosities Hansson shows us first of all how much of the world around us is regulated by the sense of smell . There are animals for which the sense of smell is essential to orient themselves in the environment and communicate. Moths, pigs and dogs are famous for their fine sense of smell. In particular, the male moth is able to follow the scent trail of the female, present in an almost homeopathic concentration, and is in fact the best sniffer in the world, with a sensitivity to odors a million times more pronounced than ours. When the salmon has to return to the same branch of the river where it was born to lay its eggs, it uses its sense of smell to find its way home. Male dogs are as good as moths and just as sensitive: for them the sense of smell is much more important than sight, in fact they "see" in the form of smells, not visual impressions. For a long time, for example, it was believed that birds did not have a sense of smell, while today we know that it is the exact opposite: vultures are able to perceive from a distance the smell of the particular molecules emitted by a dead animal, while seabirds, such as albatrosses, are able to smell a massive presence of plankton, which for them means an abundance of fish. But the sense of smell is not only typical of the animal world but also of plants , which can smell and send olfactory messages to each other or use specific smells to manipulate friends and enemies or change their emission of volatile substances when attacked.
And how is the human being nosed? Meanwhile, as Bill Hansson tells in the book, our "pepper" or "chilli" (depending on the size) is an exceptionally sophisticated organ , which is capable of distinguishing up to a billion billion odors . Thanks to the sense of smell - and we realized this dramatically with Covid which often affected the sense of smell - we have a more complex and complete understanding of the world. In fact, smells affect our food, social, emotional and sexual choices almost without us realizing it. The nose helps us to distinguish food and if we do not smell it becomes impossible to distinguish food with our eyes closed, even mustard from ketchup. With the sense of smell, the newborn recognizes his mother and we even choose , as Hansson well explains, our partner by nose. In fact, experiments have shown that our sense of smell has retained the ancestral ability to recognize those people with different immune systems and therefore more easily compatible with ours. In this way, stronger and more disease-resistant offspring can be brought into the world. The sense of smell, then, is the sense that first fails due to the onset of serious diseases such as Parkinson's disease and Alzheimer's.
But the examples of the importance of the sense of smell are endless in a book that is rich, fun, lively and which, on the nose, seems to have been made to involve us all.