Many people wear perfume to enhance their natural scent. They may also use it to create a specific smell that they associate with an event or memory. Perfume is often made with a combination of different essential oils or extracts, along with solvents and other chemicals. These ingredients are diluted in alcohol or other solvents such as denatured alcohol, which helps the scent last longer.
Perfume can be categorized as floral, oriental, woody, fruity or fresh. A perfume that is predominantly floral would contain a mix of flowers, herbs and spices such as rose, jasmine or lavender. A fragrance that is predominantly oriental would contain more exotic scents from spices and herbs such as frankincense, myrrh or patchouli. The fresh category of perfume is the youngest and has a clean, aquatic or ocean-like smell that is usually created with synthetic substances such as calone, which was discovered in 1966.
People have used fragrances for thousands of years to mask body odor and to enhance their mood. During this time, various civilizations experimented with the extraction of aromatic oils. One of the earliest methods used was enfleurage, which involves placing a flower or other natural substance in an oil base to extract the scent. The technique was popular in the 17th century, when France and Italy became major centers of the perfume industry. The 9th-century Persian chemist Ibn Sina invented the distillation process, which allowed for a greater variety of essential oils to be extracted from natural sources such as flowers and spices.
Other natural materials such as animal secretions, mosses, tree resins and coal tars are also used in perfumes to add texture or to support the scent. These natural products act as fixatives, which prevent the more volatile perfume ingredients from evaporating too quickly. Some of the most common animal secretions that are used as fixatives include ambergris from sperm whales, castor oil (also known as castoreum) from beavers, musk from musk deer and civet from a civet cat.
The final product is a complex blend of ingredients that includes several hundred chemicals. The most important elements are the top notes, which are the light, volatile odors that are noticed immediately after application; the middle or heart notes, which provide full character and body; and the base note, which is the long-lasting aroma that is reminiscent of the person who wears the perfume. To achieve a balanced, harmonious scent accord, the ingredients are mixed carefully with the knowledge of how each odor will be affected by the evaporation process. Perfumes are often described in a musical metaphor, with the initial impression provided by the top notes leading into the middle and then the base. In addition to the perfume ingredients themselves, blending agents are used to smooth out transitions between the different “layers” of the scent. These blending agents can be as simple as an oil or alcohol, and they can also be a primary scent ingredient such as linalool or hydroxycitronellal.