Clairalience or "Clear Smelling" is the ability to smell a spirit. Some people claim to smell exotic perfume or flowers or cigar smoke, things like that, when a real ghost is near.
Yvonne Brown a Florida Resident who can smell when ghosts where around her. This phenomena has been reported by many who search for the lost souls of the dead in the paranormal zone. In Browns view ghosts have various odours associated with them and no to spectres or spooks smell the same.
Many famous ghosts have been known for their fragrances associated with their hauntings. Perfumes, food smells, or unnatural these odours are often encountered at the sites where they haunt. A group in California, The Ghost Hunter of Para- Haunt research recently went hunting for Marilyn Monroe's ghost. They said they encountered the smell of roses and disinfectant. Their group psychic medium Mary Simmons said that ghosts she has encountered recently are more fragrant when their more famous. In her opinion the ghosts that smell the best are the most sought after. She also told me that when hunting for the ghost of James dean she could smell a sexy manly smell of men's cologne. And when searching for the ghost of John Belushi she encountered the heavy odour of almonds and chewing gum.
Why? Simmons says she does not really know. Her explanation is that this is what the particular spirits that haunted the location wanted her to experience.
Dylan Merchant a ghost hunter from the UK tells me that the ghost of Henry VIII (28 June 1491 – 28 January 1547) King of England, smells like burning parchment paper, and wax and his wives each have distinctively different smells.
Please see : The Real Scent Of A Ghost! Also see: I Smell Dead People... I mean Ghosts!
Olfaction, the sense of smell, the ability of humans and other animals to perceive odours. As described by the Roman philosopher Lucretius (1st Century BCE), different odours are attributed to different shapes and sizes of odour molecules that stimulate the olfactory organ. The modern counterpart to that theory was the cloning of olfactory receptor proteins by Linda B. Buck and Richard Axel (who were awarded the Nobel Prize in 2004), and subsequent pairing of odour molecules to specific receptor proteins. Each odour receptor molecule recognizes only a particular molecular feature or class of odour molecules. Mammals have about a thousand genes expressing for odour reception. Of these genes, only a portion are functional odour receptors. Humans have far fewer active odour receptor genes than other mammals and primates.
Each olfactory receptor neuron expresses only one functional odour receptor. Odour receptor nerve cells function like a key-lock system: If the airborne molecules of a certain chemical can fit into the lock, the nerve cell will respond. There are, at present, a number of competing theories regarding the mechanism of odour coding and perception. According to the shape theory, each receptor detects a feature of the odour molecule. Weak-shape theory, known as odotope theory, suggests that different receptors detect only small pieces of molecules, and these minimal inputs are combined to form a larger olfactory perception (similar to the way visual perception is built up of smaller, information-poor sensations, combined and refined to create a detailed overall perception). An alternative theory, the vibration theory proposed by Luca Turin, posits that odour receptors detect the frequencies of vibrations of odour molecules in the infra-red range by electron tunnelling. However, the behavioural predictions of this theory have been called into question. As of yet, there is no theory that explains olfactory perception completely.
However, research is still being done, and institutes like the Monell Chemical Senses Centre are working to uncover the secrets of olfactory perception.