Discovered in the early 180s and name "nicotianine".the oily essence now called nicotine is the main active ingredient of tobacco.Nicotine,however,is only a small component of cigarette smoke,wich contains more than 4700 chemical compounds,including 43 cancer-causing substances.In recent times,scientific reserch has been providing evidence that years of cigarette smoking vastly increases the risk of developing fatal medical conditions.