NICOTINE

          

Nicotine is an extremely poisonous, colorless, only liquid alkaloid that turns brown on exposure to air. The most potent ingredient of the TOBACCO plant, nicotiniana tabacum, it is found mainly in the leaves. Both nicotine and the tobacco plant are named for Jean Nicot, a French ambassador who sent tobacco from Portugal to Paris in 1560. nicotine can affect the human nervous system, causing respiratory failure and general paralysis. It may be absorbed through the skin. A typical cigarette contains 15 to 20 mg of nicotine. However, the actual amount that reaches the bloodstream and hence the brain through normal SMOKING is only about 1 mg.

* taken from GROLIER International Encyclopedia

By Grolier incorporated, Danbury, Connecticut, USA, 1991