The Basic Nature Of How Perfume Works.
To apply the loosest definition, perfume is any substance that you wear and that smells. There are no requirements for it to smell good. Clearly, your experience of a perfume comes not only from the stuff in the bottle but also from the stuff in your head.
Our reaction to smell is primal in nature. Our sense of smell goes thru less higher brain processing than our other senses do. Because of this, smell can evoke an immediate emotional response.
The Composition of Perfume Smell
Most perfumes are engineered to have three part smell: the top note, the heart note, the base note. Top notes are composed of the lightest molecules. Therefore they evaporate first, followed by heart notes and base notes.
Top Notes
Appears within 15 minutes of applying. Designers often put weird or spicy smells in this phase so that they interest you, but don't hang around long enough to offend.
Heart Notes
Appear after 3 to 4 hours. They are probably what you remember about the perfume; if it's a floral perfume, flowery smells go here.
Base Notes
Appear 4 to 5 hours after application. Base notes are often used as a fixative to hold and boost the strength of the lighter top and middle notes. Musky, watery, mossy and woody scents often go into the base.