* Photo: Thomas Hannich * Tobacco

Thanks to nicotine, this plant may be mildly hallucinogenic. It can be chewed, brewed, smoked, or, as some South American shamans prefer, enjoyed as an enema.

Paper

Tobacco firms are very secretive about their products' myriad ingredients, but we do know that about 10 percent of any given smoke is simply cellulose and a thin strip of adhesive.

Ammonium Hydroxide

Essentially ammonia in water. There is some evidence that ammonia reacts with tobacco to free the nicotine, making it more accessible to the bloodstream (manufacturers dispute this). Of course, the Material Safety Data Sheet warns that inhaling ammonia vapors, whatever the source, may damage the upper respiratory tract.

Castoreum

Commonly found in the secretions of a beaver's castor glands (located near the animal's genitals), this substance when processed gives your cigarette a sweet odor and smoky flavor. In 1991, Phillip Morris used just 8 pounds of the pungent stuff to make 400 billion cigarettes — proving that a little genital secretion goes a long way.

2-Acetyl-3-Ethylpyrazine

According to tobacco-industry documents, this pyrazine (an aromatic ringed compound) provides an "earthy depth of flavor." Funny, when the same compound is used in food preparation, it's described as tasting like potatoes.

Copaiba Oil

One way that Brazil intends to make itself hydrocarbon-independent is with the oleoresin of the copaiba tree, which is so flammable it can practically fuel a diesel engine without any refining at all. Why is it in cigarettes? One possibility is that ammonium hydroxide decreases combustibility, so manufacturers have to counteract it with a nontoxic accelerant. Perhaps, but copaiba oil is also used as a folk remedy for prostate tumors (and gonorrhea).

Phenyl Methyl Ketone (Acetophenone)

C 6 H 5 COCH 3 is a major component of tear gas, which should come as no surprise to anyone who's hung out in a smoke-filled bar. Here it may act as a low-level narcotic.

Gamma-Heptalactone

This compound is a mild inhibitor of the CYP 2 A 6 enzyme, which helps break down substances — including nicotine — in the bloodstream. By slowing this process, heptalactone may help keep the precious nicotine in your body longer.

Sugar

Burning sugar releases acetaldehyde (as does fermenting alcohol), which at least one study says has a narcotic effect. It's also a positive reinforcer when combined with nicotine — each amplifies the other's effect on your brain (and the likelihood you'll want to keep smoking).

Levulinic Acid

This crystalline substance desensitizes the upper respiratory tract, creating a perception of smoothness or mildness. It's also another way of juicing tobacco's high — levulinic acid enhances the binding of nicotine to the appropriate receptors in the brain, giving you more bang with each puff.

L-Arginine

Smoking tobacco causes monocytes (specialized white blood cells) to stick to the endothelial cells on the inner walls of arteries and veins. This buildup, like all circulatory blockages, can lead to heart attack and stroke. Arginine, a common amino acid, may reverse some of this accumulation when taken orally. So, in a sense, maybe cigarettes aren't so bad after all.

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