Still, she had some very specific ideas about fragrance. She told Ernst Breaux, the perfumist, to come up with something "completely artificial."

Up until that time, fragrances were completely natural. Natural ingredients were all that were ever used to create scents, which varied widely not only by geography but also from batch to batch. In regions that grew lavender, there were lavender scents. If you were fortunate enough to have gardenias and roses, they showed up in the perfume.

Exotic ingredients like sandalwood from India were rare and extremely costly.

Coco Chanel had a different vision not only for fashion but for fragrance. Her idea was that fashion, like art, was something contrived, invented, man-made ? artificial. Just as her famous suit and pillbox hats were human inventions rather than natural, she wanted a perfume to reflect that.

Breaux did not invent aldehyde but his sample fragrances for Miss Chanel used this particular synthetic fragrance. Aldehyde is best described as a synthetic fragrance molecule. There is no equivalent in nature; it is cooked up in a lab.

According to legend (and so many are told, it's hard to sort out what really happened), Breaux made six samples, numbering them Chanel No. 1, No. 2, No. 3 and so on. Coco Chanel picked No. 5 as her fragrance. In some versions of the story, it is because she preferred that scent over the others. There is another version of the story that claimed that since Chanel would be unveiling her new line on the fifth day of the fifth month, she decided to pick the fifth sample.

Chanel No. 5 was not the first perfume to use aldehyde but it is the first major perfume to take advantage of synthetic fragrance.

Like all great perfumes, Chanel No. 5 is a mixture of many different scents. Of course, some floral notes were mixed in as well.

The best way to describe how aldehyde smells is that it adds "sparkle" to the scent. Today, many perfumes use aldehyde and some perfume experts even consider aldehyde a fragrance family or category. A very powerful "hard-core" aldehyde scent was just released in early 2007; it's called Aldehyde 44 and it's by LeLabo, carried by Barneys. An aldehyde scent you can buy more easily (online even at http://www.sephora.com) is Greed by Gendarme.

With today's general sentiment that natural is better than synthetic, some might be perplexed that the perfume world is contrarian. While some perfumistas do claim to prefer natural scents, most perfume today is synthetic. And there are some good reasons.

Synthetic molecules are much easier to control for uniform product. For instance, for scents that use a bit of lemon, what is to keep that lemony fragrance consistent over thousands of ounces? Different products picked in different places can produce wide variations in odor.

More importantly, synthetic scents help preserve the environment. There is no need to threaten the indigenous sandalwood trees of India or the musk deer with extinction because perfume lovers can get those same scents without destroying plant or animal life.

A great example of why perfume is synthetic today is musk. True musk is actually a natural substance taken from the sexual glands of a male musk deer. Sometimes other animals could be used. An animal might be killed just to extract the musk, which is mainly used to form the base notes of some fragrances. Today, it's synthetic.

Amber is sometimes listed as a perfume ingredient, but it isn't the golden fossilized resin that is sometimes used in jewelry. It's a nickname for ambergris, which is a substance that comes from sperm whales. During the whaling era, whales were slaughtered for their meat, blubber (rendered into whale oil and used for lamps), and ambergris for perfume. Today, ambergris is synthetic.

In fact, if you ever read through the various "notes" in perfume, you find a lot of things with strange names that have to be synthetic. Quest by Niel Morris has ozone notes, Coney Island from Bond No. 9 lists maragarita mix.

The original "artificial" perfume, Chanel No. 5, is still on the market. They don't keep such a thing as the perfume best-seller list but it is likely that Chanel No. 5 remained consistently popular over the past 80-some years.