The routine is described by Professor Hoffmann in Modern Magic in the section on Tricks with Handkerchiefs. In essence, the performer produces sweets from a borrowed handkerchief. This particular trick was found in an envelope postmarked 1955.
Hoffmann (Angelo Lewis) wrote a great deal, and a great deal has been written about him over the years. This short, illustrated article by Brian Lead contains interesting information about Professor Hoffmann, his output of books and how he was regarded by the world of magic.