It is a strong poisonous drug. It is the main ingredient in insecticides or bug sprays which most farmers use when growing tobacco. In its pure form, just one drop on a person's tongue would kill him/her. Nicotine is absorbed through the skin and mucosal lining of the nose and mouth or in the lungs (through inhalation). Nicotine can reach peak levels in the bloodstream and brain rapidly, depending on how it is taken. Cigarette smoking results in nicotine reaching the brain within just 10 seconds of inhalation making smoking an easy way to get someone feeling good in a short period of time. Recent research has shown how nicotine acts on the brain. Nicotine activates the circuitry part of the brain that regulates feelings of pleasure, the so-called reward pathways. Research has also shown that nicotine increases the levels of dopamine (a key brain chemical involved in mediating the desire to consume drugs) in the reward circuits.
Tar is the oily material which remains after tobacco passes through the filter. When a smoker inhales, a lot of the tar sticks to and blackens the