i am stumped by this riddle (as i was with the previous riddles), i keep thinking its an element, or something simple like air.
knowing the connections with the prior challenges to nicotine,
tobacco, alkaloids, etc..... in which case none of my answers are closely linked to WTA.
another guess would be flavor. (again, not a good answer as how could flavor be added up or divided?)
Dr., a clue perhaps?