Cotton candy spun off from the British actor/author's fancy that actors are more superstitious than other journeymen. There's an interminable sampling of f'instances: rituals (the Lunts would not pass anyone, on stairs before the curtain), talismans, general taboos and good luck traditions. For luck, the cast of a new musical touch the ""Gypsy Robe"" (a garment passed on from a previous show ""gyps"" -- chorus member -- to another); one never speaks the last line of a play before the first performance; one shouldn't wear green; and there's that mysterious matter of the age-old curse on Macbeth. Huggett has delivered a highly unlikely but entertaining history of the curse. It seems that productions through the centuries have left a wake of dead and wounded actors, including Charlton Heston, whose tights were accidentally washed in kerosene. With pleasant photographs of mainly fallen idols, a petty piece signifying nothing -- but harmless.