Smilex

Smylex(or spelled Smilex) is a mixture of the chemiclas that turned Jack Naiper into the fearsome Joker, only the difference between the vat  of chemicals that Jack fell into and Smylex is that it[Smylex] causes the victim to begin laughing uncontroabley eventually followed by death,( witha permanent "grin" like the Jokers) while the chemicals just bleached his skil chalk white, dyed his hair green and turned his lips ruby red. The Joker has been seen to use Smylex 4 times in Batman(1989). Once when he killed Becky, a news repoter, you can see it used on the two modles, and when he gassed the crowd at Gotham City's 200th anneversery festivle. The Joker put his Smylex into beuty products, like hairspray or lipstick, this became known after the Joker aired a commercial for Smylex after killing a news reporter and says, "heres the gag! You probably bought the already!", indicatin that he has put them in Gotham's beuty products