I found this snippet:De viribus quantitatis (Ms. Università degli Studi di Bologna, 1496–1508), a treatise on mathematics and magic. Written between 1496 and 1508 it contains the first reference to card tricks as well as guidance on how to juggle, eat fire and make coins dance. It is the first work to note that Leonardo was left-handed. De viribus quantitatis is divided into three sections: mathematical problems, puzzles and tricks, and a collection of proverbs and verses. The book has been described as the "foundation of modern magic and numerical puzzles", but it was never published and sat in the archives of the University of Bologna, seen only by a small number of scholars since the Middle Ages. The book was rediscovered after David Singmaster, a mathematician, came across a reference to it in a 19th-century manuscript. An English translation was published for the first time in 2007.[
http://books.google.com/books?id=1MIfAQ ... CE8Q6AEwBg
I found the text (handwritten, but good readable)
http://www.uriland.it/matematica/DeViri ... index.html
but better studied from this page
http://www.uriland.it/matematica/DeViri ... zione.html
in three partitions with content
... but I don't know, if this will be of big help.