2. Is there an acknowledged originator of this effect - or is it *sooooo* old that no-one knows?
I found that effect in the first magic book, in:
J.Prevost: "La premiere partie des subtiles et plaisantes inventions" (1584); in the translation in English by Sharon King: "Clever and pleasant Inventions - Part One", Hermetic Press, Inc, Seattle 1998, p.78: "To Discover in a Pleasant Manner Who is the Greatest Man of all the Company", a really wonderful plot with spectators involvement. The word is written with a bit of urine on the back of your hand, and it appears by rubbing ashes on the back of the hand.
By the way, Christoph Borer just published (Oct. 2003) his booklet (48 pages) Die Geisterschrift (The Ghosts Writing) www.passion-for-magic.ch.