Hooked!Not understood at the time, this small but relentlessly growing market had become physically dependent, hooked, on a highly addictive substance. “The casual smoking of more than two or three cigarettes during adolescence” almost invariably leads to “regular dependent smoking,” says addiction researcher Dr. Michael A. H. Russell. “Unlike the adolescent who shoots heroin once or twice a week at first, an adolescent smoker experiences some two hundred successive nicotine ‘fixes’ by the time he has finished his first pack of cigarettes.” 
Yes, inhaling was the secret. Nicotine, it seems, will penetrate and irritate mucous membranes only under alkaline conditions. Because cigarette smoke is slightly acid, it is the only tobacco smoke mild enough in mouth and throat for routine inhaling. But in the lungs the acid neutralizes, and nicotine dumps freely into the bloodstream. In just seven seconds the nicotine-rich blood arrives at the brain, so that each puff yields an almost instant nicotine reward. Youths who smoke more than one cigarette, reports a British government study, stand only a 15-percent chance to remain nonsmokers.