National Geographic : 1987 Oct
related. For the 13 percent of readers unable to smell any two odors, these two scents were paired with overwhelm ing frequency (92 percent). This result is new; in connect ing these two specific anos mias, we may discover more about each. One clue: Both compounds seemed "musky" to many people. To measure odor identifi cation, 12 descriptions were listed for each scent. These 4. Eugenol (cloves) The principal component of clove-bud oil, eugenol also occurs in cinnamon leaf oil and has a long history of use as a spice. It was included as a repre sentative of the spicy, pungent class of smells and as a smell that would be familiar. Like scents 2, 5, and 6, eugenol was selected partly because of its easy detectability, and thus its high yield of identification responses. Familiar to cultures around the world, this "warm," aromatic scent scored highest among both sexes in identification. included one word that was considered an appropriate description, based on experi ments in the laboratory. In the survey returns the description most commonly selected by participants was, in all cases, the "correct" choice. Thus androstenone was urine/musky, banana was fruity, Galaxolide was musky, clove oil was spicy, gas odor was foul, and rose was floral. As we will see, many factors S . Mercaptans (gas) This mixture of sulfur-containing compounds includes the ingre dients used to give natural gas its obnoxious warning smell. It was included to provide an odor gener ally regarded as unpleasant. This was the only test odor designed to be both readily detectable and almost universally regarded as foul smelling. Although identification ranked high, the mercaptans proved to be less unpleasant than expected to older age groups, revealing a potential source of danger (pages 522-3). can contribute to decreased smell perception. Age takes its toll, as in some cases do condi tions such as pregnancy and tobacco smoking. Diminished perception can also result from what scientists call long-term adaptation, a process that takes place over the course of protracted exposure to an odor. A good example is the tannery worker who, after months on the job, is no longer aware of the foul smell. 9 Rose Rose is a fragrance prized through many ages and cultures. The odor in the sample was typical of many vari eties but specific to no single strain. Rose was chosen to represent flor als, a class of sweet, pleasant odors. This traditional favorite for perfumes proved its pedigree by achieving nearly unanimous detection among women and scoring almost as well among men. Perhaps the reason for this high detectability is that the scent is com posed of many individual ingredients: If your nose missed one, it recog nized another.