The Origins of Wonder
The effect of making a handkerchief disappear from the hand and reproducing it from the pocket after each vanish is Oswald Williams's; see The Sphinx, Vol. 26 No. 10, Dec. 1947, pp. 308 & 312.
A young Peter Warlock suggested to Williams the idea of producing a lemon to give the routine a climax; see The Linking Ring, Vol. 66 No. 1, Jan. 1986, p. 77.
See also: Six-Card Repeat.